# Almi's Logitech Z-5500 Mod (High-End upgrade for the speaker system)



## ramachandra

Logitech Z-5500 Digital 5.1 Speaker System Modding




This great speaker system brought many happy hours for its owners since its appearance and it’s still very popular. A nice combination of decent sound quality with an affordable price tag. After years of active friendship we may fell the need for something more advanced, when we realise almost noting left to gain using the latest sound cards with the system. Good to know that our beloved one has a second chance to remain as a companion in the coming years.

Probably many people tried to use higher quality wires for the speakers or even change them to something better to improve the sound. From the audiophile point of view, there is much more to be done in the inside of the system than you would think at first. One reason is the age of the design the other is the cost effective, low-end components. I’m sure there are many who is not familiar what can be done in the inside, so I started this thread for those. There is no new discovery here, and I have nothing to offer for experts or rocket scientists.  




 

Thanks to my relatives I had the opportunity to examine the systems (because I do not have one) and figure out how to improve its sound quality beyond the original. On the end of the modding they have concluded the effort well worth it. Of course the design holds many limits and opportunities, and I tried to focus on what is supposed to be a good investment. With some skill of soldering and some know-how you can upgrade your favourite to a much better one and enjoy  the great taste of modding. I try to provide all the details and share what I’ve learned to make it easy for anybody who get the inspiration to try it.
Please remember, modifications most certainly void the warranty and aren’t risk free, mistakes are part of human nature. If you want to be very sure nothing goes wrong during the upgrade, it’s wise to let an expert to do the job for you.  

First things first. If you are using your speaker system connected to the integrated sound card by analog or digital connection, I suggest leaving this upgrade for later. As we experienced the dedicated higher quality cards are noticeably handle both tasks better.   
From the Analog VS Digital input comparison the analog is the winner with the Z-5500. This is getting more interesting if you are familiar with the fact, the analog signal first digitalized in the control pod, than converted back to analog after processing.

*You may need:* 
glue gun
Phillips screwdrivers
magnifying glass
stain remover or alcohol and cotton buds (to clean off soldering paste)
small size players
2A slow-blow fuses (just in case)
thermal paste (nothing exotic)
few female screw 3M or bolt cutter
solder (good quality suitable for smd)  
tweezers (to hold a chip comfortably)  
soldering paste or flux (essential for soldering chips)  
soldering iron (for the OpAmps up to 30W, and a little more for desoldering coming  handy)  
or  
temperature controlled soldering station  
steel scrubber (new from the kitchen to the soldering tip keep clean)
wire (between the caps and PCB)

_Capacitors for the amplifier and preamplifier panel:  _
12 pcs 220nF 63V or 100V MKT film capacitors Wima, Philips, ERO, etc. (optional)  
7 pcs 220nF 63V or 100V axial film capacitors (polystyrene, MKP films or Sovjet K73-16) 
2 pcs 1uF 63V MKT film  (optional)
13 pcs 22uF 50V Elna Silmic II (or Silmic, Cerafine, Tonerex or Nichicon: KZ, FG)
1 x 10uF 50V (same)
12pcs 47UF 50V (same but only 6 pcs for the third Mod)
_ 
Control panel:
analog input_
6 pcs 47uF 25V Elna Silmic II (or Silmic, Cerafine, Tonerex or Nichicon FG)
6 pcs 10uF 16V Elna Silmic II or Tonerex 10uf 50V (not much space available)
_analog output_
6 pcs 47uF 25V Elna Silmic II(or Silmic, Cerafine, Tonerex or Nichicon FG)
6 pcs 22uF 16V (same)
_volume controll_
2 pcs 10uF 16V (same)
1 pcs 47uF 16V Sanyo Os-Con (or the others abowe)

_Main filter capacitors:  _
2 pcs 50V 10000uF Elna: Denon, Elna for Audio or Nichicon: KG, KW, FW
1 pcs 4700uF Elna: Kenwood 75V or  Nichicon: KG, KW, FW  
(The advantage of the nichicon KW and FW is the small size)

_Operational Amplifiers:  _
11 pcs OPA1602AID or OPA1612AID (5pcs the minimum recommended, but if you working on the third Mod buy only 2 pcs, plus 5pcs 0.47uF 63V axial film capacitors)

A practical source of the components is eBay. The predictable cost is starting from 70€ for a full mod, and the surplus quantities you have to buy from components, are not part of my estimation.





*Operational amplifiers (OpAmp):  *
The entire speaker system has 11 pieces. There are 6 in the control panel, and the remaining five what I recommend as priority to replace in the box of the subwoofer.  The replacement of OpAmps usually means the main cure for the poor sound for many sound systems.  Other than soldering, this is a relatively simple task because there is easy access to them. Perhaps the simplest way to remove the stock OpAmps is to cut across the pins one after another than clean of what is left on the PCB with a soldering iron. Cutting multiple pins in the same time is an unnecessary risk to take and easy to end up pulling off the pads from the board, than you have a problem to solve.





_The way I like to do desoldering is:_
- add plenty soldering paste over the chip
- solder the pins together both sides  
- heat the sides quick (480°C or 896°F) meanwhile pushing a small screwdriver under it gently, almost no pressure applied
- lift one side a bit than the other until the original soldering isn’t not holding any more
- switch to the tweezers and lift off the chip
- cleaning off all the solder
- cleaning  off all the soldering paste using spirit and cotton buds
Done!

_The soldering: _ 
- use plenty of fresh soldering paste on the board
- stick the chip to the paste and recheck alignment
- hold it with the tweezers and solder one pin in a corner
- make a bit of correction if the chip is moved, than solder another pin on the opposite side
- add more paste over the pins if necessary
- solder the pins one after another
- clean of the paste
- check connections using magnifying glass, or better with the diode tester (one pin directly near the chip body, meanwhile using the other to find connection on the nearably SMD components.)
Done!

I really love Texas Instruments Operational Amplifiers in general. The stock R4580I clearly not belong to that group, because the less you have from them, the better the sound you get, so it’s better to get rid of the crap. My recommendation is the OPA1602AID, it proved itself in many sound equipment I have modified in the past, and have a detailed clean-rich sound without regret and is up to high expectations. My priority is sense perception only, not to achieve impressive readings by test equipment or go blindly after datasheets. So I see no problems to use or recommend to anybody, and sleep well at night. The sound of the Z-5500 simply becoming much closer to that what I can hear directly from a soundcard by a good headphone.
God knows how many OpAmps are exist today and so many more to chose from according to your taste or need, and the following links provide information where to start. The printed stripe on the PCB mark the top of the OpAmps. If you chose different chips a small dot or half circle serve the same purpose for alignment.
http://www.head-fi.org/t/397691/audio-gd-discrete-op-amps-reviewed-opa-earth-opa-moon-opa-sun-v-2
http://www.diyaudio.com/forums/chip-amps/154106-best-sounding-audio-integrated-opamps.html
http://www.head-fi.org/t/432749/the-opamp-thread/3840





*Electrolytic capacitors:*
They play a very important role in sound quality, it’s amazing how the sound changes by different brands and types. The stock Su’scon caps (Tbor in a newer versions) made for general purposes, not for audio and as a brand, they already have a poor reputation. In this situation we are not to worry about durability, much more concerned about how it performs in audio. Alternatives are many and I suggest to go for the High-End audio grade capacitors to achieve the most impressive result. Otherwise what is the benefit to change them?

From the bigger PSU caps price comparison gives an idea. Common but not a rule in the audio world, the bigger size caps are superior.
When choosing capacitors it’s important not to go under the original voltage rating. Using higher is better because the lower ESR and durability. Unfortunately they cost more and take up more space and the benefit is arguable. Many audio grade capacitors are almost twice as big as a standard! Sometimes it’s more practical to buy (like I did) higher voltage capacitors, instead of hunting for different voltages and pay the extra for shipping after the many purchases.  

These pages contains descriptions about audio grade electrolytic capacitors:  
http://tech.juaneda.com/en/articles/electrolyticcapacitors.html 
http://www.head-fi.org/t/528380/electrolytic-capacitors-used-in-audio-dc-blocking-comparison-tread 


*PreAmp panel: * 
As we can see, it contains ceramic capacitors and they are not great for audio in general. Maybe they are impressive in some ways, but for those who spent time to examine how they are behave in audio circuits are avoid them.  
http://www.reliablecapacitors.com/pickcap.htm 





I guess Logitech also had the same feeling and moved towards the C0G/NP0 ceramic  in a later version, those aren’t as bad for audio.  
Polystyrene is one of the best and maybe a hard to get alternative, loved by the fans of tube amplifiers.  
http://www.radio-electronics.com/info/data/capacitor/polystyrene-film-capacitor.php
Wima MKP, MKS capacitors have a good reputation for audio and are relative easy to find.   
This is not a 1000€ system, so there’s no point to go mad and buy fancy, expensive film capacitors for this position.  

*Speakers:*
A vital part.  Perhaps the best upgrade you can do with the original satelites to use cotton wool to fill up the boxes, but not too thigtly.
Here you can find a good comparison on how the original satelites perform agains more expensive speakers:  


*Speaker wires: * 
I haven’t paid much attention for wires for a long time, until I got my experience with a short jack extension lead, and got me surprised how bad the sound turned out to be. My first thought was, there’s problem with the contact than I realised it’s not at all.
 I don’t think you will be further away with some cheap wire from the supermarket, or worth every penny to spend on someting expensive. There are people who swear solid core wires are a step forward over stranded wires and perhaps you can try out coax or other copper cable if you have any arround. Thick core is preferable.
Maybe you will find this intresting about cables:
http://www.audioholics.com/education/cables/cable-distortion-and-dielectric-biasing-debunked 


The first Mod

No matter how much I prepared , I had to rely on the local tools for the first project and it certainly made things slow for me, still proven to be enough to have the standard equipment to complete the whole process.  





This system had already seen modification, since the owner started to use five of the JBL SCS178 Home Cinema speakers years ago, and they became more beneficial after the upgrade. Certainly one of the main disadvantages of the many.1 sound systems are the lot of small speakers without the ability to cover the full sound spectrum.
With some solid copper wire left from the rewiring job in the apartment, I had an idea to use it to replace the originals.  

The OpAmps are the easiest and logical targets for the start, and do not require to take out the whole PCB of the amplifier part like the recapping. Doing the job step by step is the recommended way, even if it bores you a bit to do it so many times. At least when you have a problem, you have an idea where to look during the upgrade. One or two spare OpAmp is good to have just in case if one of them is faulty and you don’t want to wait days to get another.





Here the original soldering isn’t giving a headache, the complications are the wires and the great amount of glue over the parts on the PCB. It also covers small SMD components or the wires of the ferrite beads. So just be extremely careful with cutting tools! Instead try to mechanically remove them first where it’s easy, than in the critical areas use a hair dryer to melt the stuff, or (what I don’t like) the with the soldering iron.  Then you will really start to love the steel scrubber!  

The new caps take up more space and have more weight too, so don’t forget that this is a Subwoofer, constant vibrations are expected, and the long length of capacitor legs are not a good idea. When your tests are done I suggest to use glue gun to stabilise them.  









On the bottom of the amplifier PCB there is one NP (not polarised) 100uF 10V capacitor. Because the polarity is marked on the panel, I decided to give it a try with a polarised, same valued cap. I had to change it back because it resulted in some constant noise from the SUB.    

For the filter capacitors of the amplifier board I have decided to use a combination of more different value caps in parallel instead of only two. It is not necessarily a well paid out investment, and is a small benefit mostly for the bass.  
In general, recommended to use the same type of capacitors, or increasingly better quality towards to the smaller values to avoid generating noises. There are too many suggested ratios, and I simply don’t know what provides the best results.





The sizes of my new Elna DENONs are almost double of the old residents, so the simple replacement fell out of the choices. On the photo, with the help of a prototyping matrix board I’ve improved the stability of the capacitors, and used the glue gun to fix it to the bottom of the box, plus the two big caps got a self adhesive hooks and loops tapes on the back to be sure. If necessary the ends of the wires can get some glue to avoid breaking from vibration in the future. I bet someone thinks using wires as I did isn’ the best or even outrageous, but I rather have them this way instead keeping the original c(r)aps. In the next mod I came up with a better solution.  

When I reached the control panel I didn’t have enough capacitors left to upgrade the analog part. My original idea was to build a new, simplified control panel, because I love minimalistic design on the signal path, so I didn’t pay much attention for the circuits of the control panel in the beginning. Then the plan took other direction, and I have changed 3 OpAmps on the analog input, and unfortunately the end of my holiday trip stopped me to experiment further this time.  





I’m sure many people have noticed the heat generated by the chips in the control panel. I saw a smoky one somewhere on the Internet, so to use a few heat sinks (made for RAM) over the bigger chips are not doing any harm. Just because they tolerate heat well not necessarily mean they love it too in the long term, especially in the summer in some countries.

I had a mixed feeling to change the main capacitor of the control panel, because it have both analog and digital circuits, and the controlling electronics not always love lower ESR caps. The sound system doesn’t remember some of the settings after a complete power off. This is not entirely new according to the owner, so I can’t be entirely sure it is related. He developed quick addiction to the new sound of the Z-5500 and not supported my idea to return to the old capacitor. Days later, after the proper burn-in period he reported this little complication have vanished again.   





*Examining the effect of the upgrade step by step: * 
it isn’t require special predictions what to expect from an upgrade like this, if you have done something similar.  This sound system isn’ mine and the owner knows its sound very much, so it was the appropriate choice to use his help to determine what is changed.  

First, the new speaker wires and the polystyrene capacitors resulted in more details in the high range.  

New OpAmps for the speakers in the subwoofer box gives you more resolution and clarity, the guitars becoming alive.  Now the new dimension for the further upgrade is open.

By the change of the two OpAmps belonging to the SUB, the days of the “big vibrator” is over, the bass is fast and accurate, integrated in the rest of the sound, not standing out.  

After the change of the capacitors on the amplifier panel the dynamic, alive sound appeared, the low range sounds improved, the feeling of soundstages is impressive.  

The main filter capacitors give some more energy and refinement for the sound, now the bass hits perfectly.  

Finally, the change the three OpAmps belong to the analog inputs resulted in some more small improvement in every level.

I have to say that the sound became much closer to that what you can expect from a good quality speaker system. The guitar sound as a guitar, cymbal clashes not crushes, the drums don’t just shake the glass out of the window and so on.  


The second Mod

I spent only the third of the time thanks to the gained experience and well equipped home environment.  Here I chose mostly Nichicon KZ, KG capacitors, because this system have the original speakers, and as I remember people are complained about the poor midrange and that is exactly one of the beautiful strenght of the Nichicon capacitors. The other reason was to have fun with a different sound. Either way if you chose from the High-End audio grade capacitors, - even mixing types, it’s one of the brands you can’t go wrong with, especially without previous experience of their sound signature - you will love them for sure.
Here I have changed the capacitors too on the analog input, than weeks later the owner brought me back the system to change the remaining three OpAmps on the analog Output and three more caps around the volume control chip.





In the second mod i had a better solution to install the filter capacitors, closer to the original positions. I have carefully drilled holes on the PCB and used plastic hex spacers and plastic screws to avoid creating short circuit between the two sides. The wires should be cutted back as short as possible. From the bottom of the PCB i have removed all the SMD capacitors, because a few of them have been burnt out by unknow reason (bit early for a year old System) and after the multiple filter capacitors there's no point in keeping them.

This system had the original speakers and no doubt they have enough reserve left to perform pretty good with the new setup. The replacement of them is certainly beneficial but not essential.

The owner of this Z-5500 (after the first day of listening) told me, he loved the rich experience of the new sound. Now the music has body, he found the high-mid as beautiful, and only noticed that maybe the Sub have less dominance on the same settings but only on low volume. He used his previously modded XtremeMusic card for a few days than tried an SB Titanium what I had modified for somebody else and gave him for a tryout.  My phone rang  shorty and deluded by the sound he said: “Tell your men he will NOT get this card!”  






The third Mod

Actually it’s more than the twelfth.  I Got lucky and found a lot of broken amplifier boards and I couldn't resist to have more fun and also looked forward to the opportunity to learn how to repair broken Amps. Since the beginning I was wondering what’s the real use of the OpAmps in the subwoofer, because there are 3 of them after the DACs in the pod on the signal path already, and as an audiophile I like to avoid anything unnecessary. As far as I know no schematic is available for the system, so I started tracing back the way of copper on the boards, removing, measuring components checking datasheets, do all the necessary reverse engineering. Then as a conclusion i decided to leave 3 OpAmps completely out of business. Replacing them with 0.47uF film capacitor making the sound clearer than any OpAmps in the same position and no decrease of the volume, or undesired side effects. It also means less stress on the voltage regulators and the other OpAmps benefit from the more stable energy. Worth to mention, easy to do and costs about 10€ less.





For the surround all 6 electrolytic capacitors completely removed the SMD components included. As you see on the photos only the 2 OpAmps and 4 caps for the Sub are changed and the belonging SMD components remain untouched. Be careful if the copper pads coming off or get loose, because it’s easy to cause a hidden short circuit with the remains. I was using foam like tape, sticking to sides under the 0.47uF capacitor and later a few drops of epoxy on the corners, than I connected them to the jumper wires on the input of the TDA Amps and on the other end I cut off the glue near the incoming wires and used the copper on the surface to solder. Looking on the pictures it is obvious, but what you cannot see is that I also removed 5 small ceramic SMD capacitors on the signal path and connected the 2 pads. More precisely the C100, C200, C300, C400, C500. From capacitors I suggest to pick something proper for audio, and the round shaped axial films are a handy choice indeed. Avoid tantalum or ceramic.





WA83 Yellow & Black  --to-- JP406 Rear Left

WA81 Brown               --to-- JP206 Rear Right

WA80 Blue                  --to-- JP106 Center

WA82 Purple               --to-- JP306 Front Right

WA85 Grey                 --xx-- Sub

WA84 Yellow               --to-- JP506 Front Left

Technically the rest of the modification is identical to the previous one.

I have not mentioned earlier the effect if you solder the 0.22uF 63V film capacitors (the blue boxes) in parallel to the pins of the electrolytic capacitors (belonging to the TDA amps). The sound becamemore clean and free flow, actually it’s a nice add-on.

For this system I used mostly ElnaSilmic II and for the filters ElnaFor Audio capacitors and a Nichicon KA for the pod what is new form the company. I got rid of the the NP 100uF 10V capacitor and used Nichicon ES. The sound of this setup is really up to my taste. Clean, soft, warm, rich and the bass is powerfull, going deep, hitting hard, and detailed. If you have walls to break, this is the way.






*After the modding:  *
The audiograde electrolytic capacitors have a burn-in period. Depending on type and brand you are using it may appear a bit harsh, booming, distorted etc. and clearing off after some active use and becoming nice clean and warm. Most of the improvement can be expected in the first 5 days, and some more refinement later. The owner of the first system experienced improvement up until two months after the complete mod.
I’m a bit sceptical about the sensible effect of the burn-in period for Operation Amplifiers.  
Maybe sometimes you will leave your favourite sound system disconnected for a period when you are away, and after that you will probably notice a difference in the sound. One hour of running will bring it back to normal, the musicians let run their equipment for hours before concerts for a good reason.  

*Some interesting links about the Z-5500:  *
Z-5500 VS Z906  
http://soundnews.ro/2011/05/29/logitech-z906-review-english-version/
[MOD]Z-5500 Rewiring satellites
http://www.overclock.net/t/211128/mod-z-5500-rewiring-satellites

I would like to thank to Narasim and Kanmouse to let me experiment on their beloved sound systems and took the risk of an amateur, enthusiast modder. And for Nyunyu to help me with the smaller, but tricky parts of the first mod.



FAQ:

What part of the mod is the best bang for the money?
OpAmps 40% (special in the SUB)
22uF & 47uF capacitors in the SUB 30%
The two main filter capacitors 15%
The rest 15%

Do you know any webshop to buy all the components in one place?
I do not. I gave up looking for it long ago.

My Z-5500 looks completely different inside than on your photos. Why?
The Logitech Z-5500 has three versions (inside) and components are more or less the same, so the mod should work.

I have a Logitech Z-XXXX speaker system, can I do something similar?
Usually you can.

Can I do some modification like this in a different brand speaker system?
Basically yes. Changing components to something better is not a new revolutionary idea or discovery to improve the sound. Of course a lot depends on the design how far you can go. For example a printed circuit board full of tiny SMD components gives you only limited options. OpAmps are an ideal target for a start.

What soundcard you recommend for the system after a full mod?
The best choice is a soundcard with audio grade capacitors with swappable OpAmps, or a modified SB X-Fi Titanium can push the system to its limits.
Here you can find how to do it.
http://www.head-fi.org/t/589078/almis-x-fi-mod-hotrodding-sound-blaster-x-fi-models

What ratio you used to build the filter capacitors?
In the second mod 10:1, so it means 10000uF-1000uF-100uF-10uF-1uF-0,1uF.

What is the better, to upgrade or buy a newer Logitech speaker system?
The newer model may have the chance to contain more advanced design and key components, and offer benefit over the older brother.
This old model upgraded with High-End components is offer something special what you will not find at all in this price range.

I’m interested in upgrading my Z-5500, but I do not have the skill. Where should I start looking for to find somebody to do the job for me?
I have only a few ideas to start: People who repair household electronic equipments like Radio, TV, electronic component, computer or mobile phone shops. Places to buy/rent instruments or sound equipments. Ask your friends, relatives.

The fuses constantly blow after some modification, but everything seems to be ok. What could be the reason?
Can be many reason like: reversed polarity of a capacitor, misplaced mica insulation between amps and heat sinks, not proper fuse (the original is 2A slow blow), short circuit caused during soldering on the PCB, faulty or damaged component(s), new cap damaged by too long screw etc.

How can I fix damage on the PCB?
Please check my other thread for the answer under “Fix for damaged PCB”.
http://www.head-fi.org/t/589078/almis-x-fi-mod-hotrodding-sound-blaster-x-fi-models

I have Z-5500 with broken control panel, is there any workaround to make the system work without?
Yes, a cable exists to make the system work without the control panel. You can make it or you can find it on eBay.
http://www.ebay.ie/itm/Logitech-Z-5...=US_Audio_Cables_Adapters&hash=item4ab3465340
http://www.diyaudio.com/forums/chip-amps/110310-hacking-logitech-z5500.html

I have a problem with subwoofer Hum any idea what’s causing it?
This thread might have some useful information.
http://www.neoseeker.com/forums/1/t501181-logitech-5500-subwoofer-hum/



_If you need I’ll try to help, according to my skill and time: ramachandra@citromail.hu_


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## X172

[deleted by self]


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## X172

[deleted by self]


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## ramachandra

Hi, My favorites are the Elna capacitor because the great experience of the bass. I have developed addiction to they beautiful sound. Nichicon caps perform better in the midrange but somehow the bottom is missing for my hears. Of course it can be compensated manually by the control pod, still not exactly the same. To be future proof the Elnas are the better investment, just in case you decided to change the surround speakers later. 

I think the main reason behind the different design is to save money with the smaller size PCB, by installing most of the components to one panel. I see no other difference between the two. Maybe your version is even more comfortable for modification, because the more available space.

Great to have an experienced friend for soldering. Many people turn away from modification because there is nobody around to do for them. Please be careful with the small mica insulators between the amps and the heat sinks, to not leave them out, and to be sure they are in the right position. As i see it is a common mistake to make, and the result is smoky TDA Amp. Double, or triple checking do no harm.


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## X172

[deleted by self]
 http://s21.postimg.org/z7o5zo5nq/sub1.jpg
 http://s21.postimg.org/l2icxuwme/sub2.jpg


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## X172

[deleted by self]
  
Capacitors for the amplifier and preamplifier panel
_  - _*13x 22uF 50V *_           http://www.hndme.com/productcart/pc/viewPrd.asp?idproduct=2600&idcategory=13
   - _*12x 47uF 50V *_           http://www.hndme.com/productcart/pc/viewPrd.asp?idproduct=2302&idcategory=13
   - _*1x 10uF 50V *_            http://www.hndme.com/productcart/pc/viewPrd.asp?idproduct=1981&idcategory=13_
 $6.50
 $9.00
 $0.45

Control panel:
_  - analog input
     - _ *6 pcs 47uF 25V*_     http://www.hndme.com/productcart/pc/viewPrd.asp?idproduct=316&idcategory=13
     - _ *6 pcs 10uF 16V*_     http://www.hndme.com/productcart/pc/viewPrd.asp?idproduct=2173&idcategory=13
   - analog output
     - _ *6 pcs 47uF 25V*_     http://www.hndme.com/productcart/pc/viewPrd.asp?idproduct=316&idcategory=13
     - _ *6 pcs 22uF 16V*_     http://www.hndme.com/productcart/pc/viewPrd.asp?idproduct=2511&idcategory=13
   - volume control
     - _ *2  pcs 10uF 16V*_    htt p://www.hndme.com/productcart/pc/viewPrd.asp?idproduct=2173&idcategory=13
     - _*1 pcs 47uF 16V*_    http://www.hndme.com/productcart/pc/viewPrd.asp?idproduct=1928&idcategory=13_
 $3.30
 $1.50
 $3.30
 $1.80
 $0.50
 $0.35

Main Filter Caps
_  - *2x *  http://www.ebay.com/itm/-/220926258668?item=220926258668&cmd=ViewItem&category=122649&ih=012
 $33.50_

Cont Pod Filter Cap
_  - *1x*   http://www.ebay.com/itm/ELNA-Kenwood-75V-4700UF-Audio-Snap-Capacitor-/290447928725
 $9.99_

Operational amplifier
_  - *7x*   OPA1602AID http://www.mouser.com/ProductDetail/Texas-Instruments/OPA1602AID/?qs=sGAEpiMZZMtxdzBvM0rKcYXt6U0S38grJ2EL3JJYijg%3d
 $27.51_


*$97.7*


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## ramachandra

To be honest, i do not think you need a crossover after the new OpAmps, because they will sort out the core of the problem, not the symptoms. The systems i have modified have 5 OpAmps on the board, because the Sub have two in that version and 3 for the rest.

I only found low resolution pictures from your version of the Z5500 and i have not compared the quantities, so it is great you discowered it will require one less OpAmp, and i think comparing the numbers of the capacitors could be vise too. Basically you need to change almost all the electrolytic capacitors to the equal capacitance (uF) audio grade caps you chose, the voltage rating also the same, or higher. The two black square component on the bigger board are voltage regulators, and they stay as is.

The photos are excellent from your system and if you have one more from the other side in this quality maybe coming handy to have one day.

 You can leave the film capacitors, because they have only tiny effect on the sound. For the two owners the possible best sound quality was a priority, and they did not mind if it cost a bit more, just to give a chance to have the best outcome. It is some times just a fight for 1% improvement.

I can not open the links to the eBay items on my tablet, still as i can see you found ewerithing required for the mod, and also found sellers to buy only necessary quantities. Well done!


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## X172

[deleted by self]


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## guily6669

Do you know how can we use the Logitech Z5500 Control Pod without subwoofer???
  
  
 I wanted to use the control POD to decode Dolby surround from my Xbox360 and use my headphones with it.
  
  
 Creative has a nice sound card for decoding Dolby Digital with tons of features, but it also lacks outpur quality and costs ~100€, so I wanted to use my POD just for headphones only.
  
  
 Everything is working, but the Sub-woofer makes huge interferences with everything, so I wanted to use the Control pod alone without the huge subwoofer.
  
  
  
 When I turn the speakers ON even without sound, somehow the wireless signal gets completely OFF even if I put my laptop touching the wireless antena (the router is more than 1 meter away from the sub-woofer).
*Keep Cool*


----------



## changgeoo

yes,The two chips you see in the middle aren't apparently OpAmps, they look different.


----------



## ramachandra

Interesting problem. Usualy people want to use the Sub without the pod. 
	

	
	
		
		

		
		
	


	



 What you need in theory is the pin 10, 13, and the pin 14, 15 for the OpAmps. If it works, i suggest to use good quality transformer and caps for the job, specialy for the analog circuits.
 At the moment i do not have any Z arround to test.


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## guily6669

Thanks for the info.
  
 But do I really need 18V to turn the control pod ON just for using it with headphones?
 Won't the huge amperage 12V PC power supply make the control pod to turn on??
  
 I only really have a PC power supply, if it's enough the PC molex cable are as following:
  
*RED        * = 5V 
*BLACK    *= GRD
*YELLOW* = 12V
  
  
 Would it work if I solder something like this:
  
 RED to PIN 10
 Black to PIN 13
 Yellow to PIN 14
  
 Also how can I get a -18V source????
  
  
 ps: All I wanted is just to use the control pod alone with my xbox 360 connected with optical cable and use it's headphone 3.5mm jack out without having to connect the pod to the sub.
*Keep Cool*


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## ramachandra

Unfortunately you need power for the OpAmps and the rest of the chips both to make the pod work, and i do not see any easy way to make it happen. The OpAmps can run from +12V (and GND) alone if they have to, but i have reasons to think +5 volt is not enough for the rest of the circuits for the stabile operation, and more than +8V can cause damage or overheating. So i recommend to build the necessary circuits or leave the project.


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## guily6669

Damnit... I think I will have to skipt then 
	

	
	
		
		

		
		
	


	




.
  
 I'm not that good to build full circuits, and need a few for getting +18 -18 and 8
  
  
  
  
 It's sad that every god damn DAC I see either needs PC to work, or doesn't have Dolby 3D decoding surround to a 2.0 headphone amplified output (and the ones with dolby I seen were all at like 500$). I think I will buy the crappy CREATIVE Recon 3D.
  
 It has crappy output, but at least has quad core CPU for effects, and probably the most custmizable sound card ever, since we can connect it to a Xbox360 for example, it will decode surround and it lets us change every detail in sound (like increasing more voice, gun, car, tyre...... there is a online database with different setups for different games).
  
*But THANK YOU anyway, totally worth the information.*


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## ramachandra

A modified X-Fi Titanium is a better sollution. (Details in private)


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## Flipi

Hi guys. I´m trying to fix my sub by changing the 10000 uF capacitors, but cannot separate the pcb from the heat sink (i cant see the way).
  
 Any help appreciated.
  
 Thanks.


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## ramachandra

Simple. Looking from the back of the sub, first you need to remove all the screws holding the right heat sink. The next is inside, the 10 long screws on the longer sides of the PCB (holding the TDA amps to the heat sink). And finally, one screw holding each side on the shorter ends (on the top of the panel). Than you can move, and remove the right heat sink completely and lift up the PCB one side. Done.


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## paranoiarebirth

hello! i'm looking for solution on my z5500's hissing sound and stumbled upon this very interesting topic about z5500. and i can't help it but to be a member of this forum so that i can post to this forum. btw, please pardon me if my english is bad. i'm not an american nor brit.
  
 anyway,as what i've said, i'm looking for solution on my z5500. i have gone through two appliance repairmen nearby our area and they told me that the IC connecting the pcb and the heatsink causes the hiss and needed to be replaced (all of it). but what i have read on the internet, any of it's large capacitors may be loose and must be soldered once again. i told them what i read on the internet but still they insist that it's not the problem. one of the technician said that caps don't easily become loose nor busted. some technicians here in our country are not telling the truth. instead they are telling the customers that their units have big problem so that they can charge for a higher cost and i don't want to be fooled by their tactics. so if i may ask, can you tell me what seems to be the problem with my unit?
  
 and since the topic is about upgrading z5500, is it possible to change and add a second sub? i read that z5500 has 8 ohms sub, can i install 2 bridged 4 ohms sub and what sub wattage should i consider? and also, can a z5500 be modified to be powered in 12vdc so that it can be installed in a car?
  
 please enlighten me. again, sorry if you may find wrong grammar on my post. thanks in advance!


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## ramachandra

Hi, Where is the source of the noise you hear exactly, and when? Unfortunately many things can cause a problem you have, even positions of the cables.
  
 I know one guy who complained about a constant noise from the Sub when the system is turned off just on the control pod. He checked the two main 10000uF filter capacitors and one of them had the top cracked up. It means for the cap the game is over. On other forums i found the Su'scon caps have a tendency to fail without external signs, so no way to be sure anything without proper equipment, or replacement.
  
 I have to agree with the repairmens in general about the the strength of the soldering. In most situations the the legs of the components rather break out from the body instead pulling out from the PCB, but it is not true about the Z5500. I bought 12 Amplifier board for repair and upgrade recently, and thanks to the poor packaging many of the big caps completely break off form the boards in one piece during transportation. Just for fun i have done the same with few others to see, and happened so easy. Cheap stuff......
  
 The Sub have two TDA amps, if one of them failing it make sense the repair men want to change them both, but the other channels have one each, so to change all 7pcs is clearly not necessary. Providing schematics with products for repair purpose went out of fashion in the age of throw away customers. I can imagine easier to replace all the TDA Amps instead wasting time with reverse engineering and get the clear picture how it works and pick the wrong one.
  
 You can find many videos on YouTube what other people used, to replace the speaker of the Sub. The original is: 188 watts RMS 8 ohms 100Hz 10% THD. Using it in the car is technically possible with a 220V inverter, still i doubt it is wise because not designed to use up the available power on the most effective way, like a car amplifier. A simple modification to make it run from 12V is unlikely.


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## paranoiarebirth

thanks for the reply! 
  
 about the hissing/humming sound, it only comes when i select analog. if i connect a digital cable (optical/coax) and select digital input on the z5500, it's also present. no digital connection present, no hiss.
  
 they opened my z5500 yesterday for checkup on what might be causing the problem. while they are doing this free diagnostic check, i also checked the 3 caps (2 large and 1 medium) by placing my fore-finger on top of each of the caps and gently shaking it if it is loose. the larger ones aren't loose as what i felt. the black (medium sized) is a bit shaking. but the technician said that it is not the culprit, . he said that a capacitor can be a bit shaking but it's still working fine, instead he insisted that the ic connecting the heatsink and the board causes it. i think he just want to charge me for higher cost that's why he's telling me that since if he solders the loose cap, it won't be that costly.
  
 can i troubleshoot that myself? i mean, can i power on the z5500 and hold the black cap firmly for a better contact with the board so that i would know if it's the real culprit? wouldn't i be electrically shocked holding that while powered on?
  
 edit: z5500 already repaired. i insisted them to re-solder the large caps first but if the humming still persist, then that's the time that they will do what they think the problem was. they couldn't believe that my unit was now ok by just soldering it once again.
  
 btw, i'm planning to hack a bluetooth headset/receiver or fm receiver and tap it on one of z5500's stereo input and hide the headset components inside the control pod. is there an available 5v source on z5500's control pod to supply the bluetooth receiver and a 5v fan?


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## ramachandra

That was a smart move to pushing those guys to do the re-soldering first. 
	

	
	
		
		

		
			




  
 Now i have done some experiment on the pins of one big cap, to see why they are get loose easy, and as i see the solder is not stick to them properly, because the quality of the metal used to cover the pins.
 The 2 biggest caps are stuck to the panels with a strong glue, but as i see the plastic covering the metal body is not always strong enough to withstand the vibrations and spit, then it is depend on time when the trouble starting.The third is almost the same just some of them got not enough glue to last (belong to the control pod).
  
 The pod get +18 -18 and +8V from the Sub, and the panel inside have few voltage regulators, and possibly have 5V available for the chips. There is a real chance the fan generate unwanted noises and as i saw in amplifiers it has a separated power source from the analog circuits. From the point of sound quality and stable operation i recommend external power source, like USB (+5V) and you can install a connector for the USB to the back of the plastic housing, and the lead can run parallel with the analog cable from the PC.


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## paranoiarebirth

hello once again sir ramachandra! i think my z5500's main caps starts to get loose again. there are times when a boom in bass generates an unwanted noise. as i recall, the previous also started with this one. and so i'm planning to upgrade my system but only one at a time. i'll start with the 2 main caps. can you tell me what are all of these? http://cdn.head-fi.org/5/5a/5a5115e2_PSUcapacitors.jpeg
  
 by the way, is upgrading one at a time possible or i must upgrade all if i change one component of it?
  
 thanks!
  
 edit: what are these blue square ic? http://cdn.head-fi.org/f/f0/f0d17c24_LogitechZ5500aplifierpanelbottomviewafterthemodding.jpeg


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## ramachandra

The first link is the main filter capacitor and i do not think you should spend your money and effort to build a similar. I have made it for a system, what is already had better speakers and a modified soundcard, and i just attempted to push out the max from it. If you wish to upgrade your Z's main filter capacitor with the smallest hassle as possible use Nichicon FW or Nichicon KW (better), than the sound becoming a bit softer, more musical. With Elna for Audio it is going even further, + the bass will improve, and the sound is more involving. Unfortunately will not fit directly to the panel.
 On the second link the blue boxes are capacitors, some of them on the signal path, some of them on the bootstrap. The advantage using capacitors parallel is simple, the  smaller caps are react faster to voltage changes than bigger, and able to filter out noises more effectively, or let high frequency sound pass easier on the signal path. Only can do a little difference for the system so i suggest to leave it to the end when you have nothing better to do, or leave it all. It is completely your choice how you upgrade the system, no need to do everything in the first time. I currently have few upgraded board and I'm looking for broken boards to buy in return.


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## flatop

Sir are thees parts you list the best i can buy and are they the most functional i can buy to date,for your mod ?.
 I am very impressed by your knowledge of this system.I have 4 of them and would like to upgrade all of them.
  
  Thank You             flatop.


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## ramachandra

The Elna Silmic II is the best you can get from audio grade electrolytic capacitors from the sound point, and compared what they do and what they cost it is cheap. The easy source is eBay and Mouser in my location. Replacing OpAmps i suggest to use 5pcs 0.47uF K73-16 Soviet military film capacitors. Perfect for other areas as well if the size is fit.
  
 For the Sub still the Opa1602AID is my winner under the circumstances, because using Opa2228P result a deeper nicer bass, but no space between the wires and other components. Plus require an adapter and the chance is there to becoming loose if not stabilized.
  
 The Elna for Audio (or Denon) as a main 10000uF filter capacitor provide a really cool bass, I was not entirely happy with Nichicon KG, KW according to my taste.


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## Mecanicles

After looking a little on the internet regarding my problem, i decided to post here:
 I recently bought a second-hand Logitech Z5500, it sound quite well, the only problem is that it doesn't sound as loud as it should be, for its power i think it should be louder.
 Maybe you have an idea?
  
 Thanks


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## ramachandra

Checking the driver or settings of your sound card worth a try first, than compare the loudness to other Z5500 or Logitech speaker system if you can. I have many ideas, but the system is complex enough so i do not see the point to start a list and cause confusion, specially if nothing wrong.


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## Mecanicles

Hello. I will check the driver, the sound card is integrated Realtek, but i don't think that should a problem, or is it?


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## Mecanicles

I reinstalled the drivers and the problem persists. Any ideas?
 Thanks


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## ramachandra

Integrated Realtek Sound Card is A problem, not The problem  Try to hook up the system to a different computer or use the digital connection. Even an iPod do for testing.


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## andro6600

Hi ramachandra!
  
 First, thanks for advices!  But, the third mod is very complicated for me, i am not engineer, and i am very scared to do it! this is my damaged amplifier board  
  
https://drive.google.com/file/d/0B0U_OGrlerlzZFRkd2IyUVpxbG8/edit?usp=sharing
https://drive.google.com/file/d/0B0U_OGrlerlzV3dNalNHelVVZXM/edit?usp=sharing
  
 My wondering is, am i correct with connections on the second photo, between pins 6-7? Is simple solder bridge will be enough? I don't see any other lines to be damaged, right? I'm hope that the op amp was faulty, and not some other unknown component. Any help, from anybody, will be welcome!


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## ramachandra

No need to worry about the pin 5, 6 and 7, because they are not in use, only the pin 8 is important on that side. You just need a new OpAmp, and to be careful with the heat.


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## andro6600

ramachandra said:


> No need to worry about the pin 5, 6 and 7, because they are not in use, only the pin 8 is important on that side. You just need a new OpAmp, and to be careful with the heat.


 
 Thanks man! So, can i leave them (6-7 pins) free without bridge then? What soldering temperature is right for this purpose? My soldering iron is 200C min. BTW, already ordered new op amp, obviously killed the previous one during soldering...
	

	
	
		
		

		
			




  
 P.S. The OPA1612 are really amazing!!! Tried the surrounds in stereo mode, and man, what a difference! The stereo separation, the brilliant highs, the stage, dimension... Everything is there! I already replaced front and centre satellites, with yamaha ones, and sub with pioneer speaker, now i am thinking about the filter caps replacing, with ELNA for Audio 10000uF 63V as my final mod! The system is really something special now!


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## ramachandra

"So, can i leave them (6-7 pins) free without bridge then?"  Yes, you can.
  
 For chips 240 Celsius is usually ideal temperature for a limited time. I have a long sharp tip for soldering and loosing the heat fast on the end, so often use 300 Celsius.


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## andro6600

Thank you very much, man! 
	

	
	
		
		

		
		
	


	




 Hope everything will be ok, after replacement of the op amp.
  
 Good day!


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## andro6600

Hi, ramachandra
  
 I replaced op amp and everything is soooo good now! 
	

	
	
		
		

		
		
	


	




 I decided to order Nichicon KG 10000uF 63V for main filter, instead of elnas, because they seems suspicious to me, all on the ebay can't find them in Elna datasheets, and i am concerned being fakes. Ordered Silmic II for 47uF 50V, but they are very expencive, so can i use instead Panasonic FM for 22uF 50V? Are they good? Some people say the FC are better, or Nichicon KZ? What you suggest, KZ or FM(FC)?


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## ramachandra

Most of the Elna capacitors are few years old factory surplus on eBay and not made for the public, so you will not find them on data sheets, and the look also varies when and were they are made. I bought, used, listen hundreds of them, even opened up few and i found them genuine. If you really want my opinion, chose the Elnas and stay away from the inferior Panasonic, and use only Nichicon if there is no other choice. On the end you will not regret a penny.
  
 http://www.ebay.ie/itm/2-X-ELNA-FOR-AUDIO-10000uF-63V-ELECTROLYTIC-CAPACITOR-/400702240596?pt=US_Amplifier_Parts_Components&hash=item5d4bb6f754
  
 http://www.ebay.ie/itm/10pcs-ELNA-SILMIC-Electrolytic-Audio-Capacitors-22uF-50V-/221073139710?pt=LH_DefaultDomain_0&hash=item3378fc67fe
  
 http://www.ebay.com/itm/10-pcs-ELNA-SILMIC-II-RFS-47uf-50v-Audio-Electrolytic-Capacitors-/251534961646?pt=Vintage_Electronics_R2&hash=item3a90a6ebee
  
 Or you can try Mouser for the smaller caps. I do not know other source than eBay for the 10000uF Elna for Audio.


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## andro6600

Thanks,
  
 i will order then elnas 22uF, but meanwhile, till they come, i'll give the panasonics a try, since they are really cheap in my local store and see how they perform.


----------



## MonarchX

Why do all that instead of buying better speakers? Is a cheap way of creating a drastic sound quality improvement? AFAIK, Z-680s and Z-5500s are not Pro-level or even audiophile-level speakers... Even Kilpsch Pro-Media speakers aren't considered to be that great by audiophiles...
  
 Also, soundcard mods were mentioned! Are there any mods for ASUS Xonar DGX soundcard (besides UNi drivers)???


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## ramachandra

"Why do all that instead of buying better speakers?" Not much to gain with good speakers hooked up on a poor amplifier, the current speakers are not the main bottleneck for the system. The Z5500 still have little competition on the market today from the price point, the modified for the 40-70€ extra have non at all.
  
 I think you can change an OpAmp and the 2 caps belong to it for the front channel on the ASUS Xonar DGX + install a better clock, nothing else really. Try to look around on Head-Fi.


----------



## andro6600

monarchx said:


> Why do all that instead of buying better speakers? Is a cheap way of creating a drastic sound quality improvement? AFAIK, Z-680s and Z-5500s are not Pro-level or even audiophile-level speakers... Even Kilpsch Pro-Media speakers aren't considered to be that great by audiophiles...
> 
> Also, soundcard mods were mentioned! Are there any mods for ASUS Xonar DGX soundcard (besides UNi drivers)???


 
 Because i already bought a new better satellite speakers from Yamaha! 
	

	
	
		
		

		
		
	


	




 And they really do make drastic improvement, but now i just want to get most of the system. I know that, i probably could buy separate receiver second hand for the money, but this is more fun to mod, and see the maximum of this set!


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## HulkHogan

I bought the whole system at a thrift store for $30-ish.  Will try this mod out, thanks!


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## jayjayuk

Hi there... i am new to this forum and modding electronic equipment. i bought a z5500 from ebay (broken) and fixed the d-sub connector to make it work again.
  
 At the minute i have one full z5500 system (all working except center speaker) and another sub box with the amplifier (which i got from my brother)... the sub driver is missing as he blew it up driving the sub from an external amp... which beforehand he blew the plate amp up for the sub... just the sub was not working so he removed the board and tried swapping a tda7294 for another one and forgot to put the mica sheets back in... alot of smoke later and it went into storage which i now have... so i have two projects here... an upgrade for the full system... and a fix for the blown amp. so lets get started...
  
 the full (main) system i have all works fine except the center (i messaged you @ramachandra about front left... but i swapped an op-amp out of the broken system to see what would happen... the front left works fine but now there is no sounds/just popping from the center speaker) anyway i have 5 X opa1612aid on the way to fix that... all other parts from my main system will be transfered to the blow amp when they arrive.
  
 the second blown amp is just about fully stripped down apart from smd's alll the tda7294's are out... i have 10 of them on there way. i am also about to purchase 16xelna silmic ii 47uf 50v & 16xelna silmic ii 22uf 50v which will go in my main system... so the old caps will then go to the blown system... if the blown system will come back to life then i wil upgrade it aswell (eventually). and the old r4580i out of my full system will go into the blown amp... i will add two tda's and one op-amp at a time to the blown board and power on and test as i go... i know i will need another op-amp (because my center doesn't work) but this will have to wait as i want to get my full system upgraded first and slowly fix the blown board. the blown board has some smd resistors missing 3 x 81A but i will just use 1/4w metal films to get it running and the replace with smd after i know it works... i also have a few bad/broken tracks on the blown board which are for the tda's most of which are broken don't go anywhere anyway... some of the ones that do (2 of) i can fix quite easily... there is another problem though... when i had it turned on testing it with only one op-amp in... and only two tda's in to check the center... on one of the op-amps tracks it was arcing to the board... i had removed the op-amp from this position and i could see small blue flashes so the only thing i could do was to lift that pad from the board... now it is lifted i cannot put it back down without it arcing... is there something i can do with that? if there is not some kind of insulation i can put under the pad then the only thing i can think of is to rip the track up which goes to an smd cap and solder a wire stright from op-amp to cap... or i might try your cap mod to remove op-amps as that would get round it aswell.
  
 at the minute i have all WIMA cap's on the underside of the board 250v+ and i have replaced all 1/8w carbon resistors with 1/4 metal film and replaced the v-regs resistors and 1/2w with same wattage but metal film. i have replaced 220nf on the preamp board with 630v axial caps and one on the underside of the board (green cap) with a 630v axial but i had to go through the top of the board and solder on the underside... its no problem i just used some epoxy on the cap to hold it.
  
 i will keep you posted on how my modding goes... the control pod will be the last thing that i do... but i might change the op-amps in the control soon(ish) aswell (those opa1612aid's start really totting up when you need many of them... the cheapest i found on ebay was £3.50+£3.00 P&P i have bought 5 so far. i will be getting the nichicon KA 4700uf 25v for a direct size replacement for the 4700uf pod cap... and i will be using nichicon 10000uf 50v for the main filter caps... as i dont really want to mod the board in the same way you have done just to get big caps in... plus it cheaper and i have a few other mods on at the min aswell... a graphic equalizer to mod and another graphic i need to fix... so cost cutting is essential for me at the minute.
  
 @ramachandra i see you have some modded boards on ebay... i assume you took those boards from the actual heatsink (plate) which leads me to my next question... the blown board i have has got the heatsink plate but i dont have the bars to secure the tda7294's and i dont have the mica sheets or the screws for the bars... do you have any of these items spare that you are willing to sell? please PM me about that if you want to sell them... thanks.
  
 i will check in after each new mod i do to the full system and progress on the blown board
  
 EDIT:
  
 If someone here has one of these with a control pod... the next time you open it up could you check to see how hot the +18 & -18 volt regulators are? i was showing my amp to someone and turned it on with the pre-amp board out and it grounded the d-sub connector and would not play sound... it popped a resistor on 79m18a went from 36R to 30R ... i have replaced the resistor and everything works again... but these two voltage regulators seem to be running hot... as in after it has been turned on for about 1 min you cannot keep your finger on them for longer than 5-10secs (its becomes uncomfortably hot not instant blister hot) i was just wondering if any one elses ran this hot? if not i have a couple of these v-regs i can throw in but i wanted to be sure there was a problem there before i change anything... any info anyone can give would be appreciated... these v-regs are near the two 10000uf filter caps... Cheers


----------



## andro6600

Hi again,


Ramachandra, here little update to my mod, and some more questions for you  So far i replaced caps on the pre-amp with wima MKS2, and 22uF 50V Panasonic FM, because easy to find and i get them super cheap and immediately, and give them a try. After MKS2 i noticed, that the sound become somewhat soft, with better mids, but the lows lost some of the punch, and i am not very sure if i like it more. Adding the Panasonics, made the picture even more softer, warmer, somewhat more audiophile. The bass is kicking  really soft, but lost the definition, and some power, and sound like damped. I like it more open raw sounding, like it is from the guital cube in front of me. So the two caps are not going very well for my taste. Now, what to change? Like the softness of Panasonic caps, don't wanna lose that. Is the replacing of MKS2 will correct the problem? And with what caps? I saw your mods with axial caps. What type, brand and specs are you used, and can you please tell me what is the sound signature with them? I want to be as close as possible to studio reference sound, so need a very detailed low range, my mid-highs are quite good now. Also, can you tell me for what position  47uF and 22uF are used in whole system? I want to experiment with some other options, till my Elna's and Nicnikon came.


----------



## jayjayuk

@andro6600 there is (by my counting on the board next to me) 10 X 47uf 35v caps are for the op-amps r4580i (there will be 2 caps for every 1 op-amp and there is 5 op-amps) ... there is also 2 X 47uf 50v which are for the +18 & -18 voltage regulators. these voltage regulators also have 1 X 1uf 50v each (so that is a total of 2 caps for 2 regulators)... there are a total of 13 X 22uf 50v one of them is sat just in front of the two big main filter caps... the other 12 are place all along the edges of the board with the tda7294 amplifiers that have the metal bars attaching them to the heatsink... these 12 caps are for the tda7294's ... there is also 1 X 10uf 50v that is in the corner of the board near the filter caps you will see two diodes side-by-side in the corner of the board... this is the only one that is different... it is sat like the rest of the 22uf caps but this one is different and it is a 10uf 50v.
  
 i purchased wima caps for the underside of the board... except one which i used an axial polypropylene through the top and soldered on the underside... the rest i have bent over and epoxied in place. on the pre-amp board i have used 630v 224j axial polypropylene caps i changed all 7 on the pre-amp board... and changed the resistor on there for higher wattage and tighter tolerance metal film resistors... just waiting for the silmic ii's and the opa1612's to arrive and i will turn it back on and have a proper listen  keep us posted on your modding
  
 Cheers


----------



## andro6600

Update: today i swapped back the original pre-amp capacitors, and the sound definition in lows is back again! This surprise me a lot, because everyone in the audio forums, thinks ceramics are the worst thing to the audio!? But i found them to be much better to the MKS2. I know the polyesters are not that great either, but i thought everything else is better than ceramics. As it turns out in my case they are good. For now i am planning to keep them, at least, till i find something really better. They work extremely well with panasonics, bass is very well defined and the panasonic caps add some very pleasant softness to it. Its much more to my liking! Nice!
 @jayjayuk, why you are using such high voltage capacitors in the pre-amp? Is this better, or doesn't matter till voltage is higher than nominal? Cause i can find much more polypropylene caps in high voltage rating than 63-100V. And is there something beneficial in using axial vs standart metalyzed ones? Also, i want to know if someone can tell me(@ramachandra maybe you know) the specs, model manufacture of the original ceramics, just in case if something go wrong with them (too many solder-desolder) The letters on them are 224Z LK, but can't find anything on the net about.
  
 Cheers


----------



## ramachandra

(jayjayuk) I see you found your project. 
	

	
	
		
		

		
			





 I suggest to not suffer with OpAmps unnecessarily, just do the Third Mod and you will save time and money. There is even a more simple way i have not mentioned in the thread, because i wanted to get the best result out of the system, not just do some upgrade. Basically the the C100, C200, C300, C400, C500 SMD components are 0.47uF ceramic capacitors, if you leave them untouched and just use a wire where i used the big 0.47uF axial capacitors you get the very same result, except the sound quality. Later you can upgrade further if you wish.
  
 I know many people love the control pod. But, if you use a cable and connect the system directly to a good analog sound source and use 5pcs 22K resistors on the signal path for the surround instead ordinary carbon film pots, you make far the best Z5500. Require only 2 OpAmps! 
	

	
	
		
		

		
		
	


	



 Bass redirect need to be turned on in the Creative software. If the bass is to much for the original sats, about 10uF NP caps in series should be enough to cut it back. Or other 2 way speakers capable to handle it will turn out perfect.
 I have made a "Pod" from a project box and i have installed a LED, On/Off switch, Jack socket into. The switch serve as instant mute too, if something go wrong to set the proper volume in Windows. While the system sleeping the Jack socket is working for a headphone, when the system is on, the jack disconnected to be sure not interfere with the sound.
  
 You are right, I have what you need. You can cover the sipping cost to your location, i need nothing else.  (details in private)
  
 From 12 faulty boards i got 4 with problems related to those regs. Normally they are not running too hot, so maybe they have suffer damage or the short circuit ruined the capacitors belong to them and they struggle to maintain the proper voltage. All the 12 OpAmps hooked up on them so you can figure out what could happen if they fail and let the juice just go. Existing short circuit is also an option to consider.
  
 (andro6600)  In the first time I have used cheap Pilkor MKT film capacitors in the Zobel network and the owner liked it. Usually the Wima MKS doing well for audio, look like this position is an exception. For my friends i have used Polystyrene capacitors (Excellent sound characteristic, out of production, difficult to source) and on the boards i had for sale  K73-11 160V and  MMWA 250V axial capacitors. To be clear i do not own the system, so my hearing not exactly up to the level after few weeks listening against who have the system for years, so i trust your judgment. The only thing is the sound is usually getting better after the a proper burn in period, so maaaybe there is a chance for improvement.
  
 If you asking what i suggest to try, i recommend the 0.22uF K73-16 63V Soviet military film capacitors. They are almost as good as a piece of copper wire by listening and not generating noises according those who have done experiments with them and have the proper measuring equipment. You will find the Polyethylene terephthalate is not highly recommended for audio purpose, but i have to say the shape, construction and size of the caps just matter as much.
 http://www.ebay.ie/itm/0-22uF-63V-PETP-Mylar-Capacitors-K73-16-Lot-of-4-/200902521600?pt=Vintage_Electronics_R2&hash=item2ec6b93300
  
 I have found 3 different ceramic capacitors on the preamp boards this far. On the pre Pid 636 SMD ceramic, after that ceramic disk, on the latest series MP0/C0G. I have not dig deep into the word of the ceramics just experienced and told to avoid them for audio, so i have no more info on them I'm afraid.


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## andro6600

Ok guys, i just ordered the soviet military capacitors for pre-amp (@ramachandra thanks for advice) and we'll see how they perform. I just wondering something. The HPF in the amplifier is set too high, especially if you using better satellites, as i do, and they can not show full potential. So, you guys seems to know quite a lot about engineering, and since the HPF is combination of capacitor and resistor( and op-amp eventually) do you know where on the board is placed, and is there something that can be done to lower cut-off frequency to the satellites? I thing this is gonna be huge step up in the performance.


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## jayjayuk

@andro6600  i cannot help you with that... i am just a beginner who is modding stuff... but i have two of these boards so know my way around them quite well... more and more as i work with them.
  
 i used some cheap caps from ebay and they was 630v and i knew i could fit them in so i bought them... i am trying to find some polystyrenes to go there but the cheapest i have found on ebay is £10 for 2 X 0.22uF polystyrene's from they 80's i think. i will keep looking for better ones but right now i am trying to get the main components in for the main and make some big upgrades all at once.
  
 i will post some pics when i get some new stuff in... still looking pretty bare right now.
  
 Cheers
  
 EDIT:
@ramachandra i will keep that in mind about the smaller caps being 0.47uf... i will take that route on the second blown board before i put the r4580i's in it just to make sure everythings working before i put the op-amp's in... cheers for that... i have soldered wires on the pre-amp board bypassing the control pod (because i have been having problems with control pod... sorting that now) so i have heard the difference and i like the sound more when the control pod is out of the picture... that is why i want to mount on the back 3 X double rca's and a switch that will select between the control pod and direct input into the rca's i have mounted... i am half way through drawing up a design for the board that will do the switching and also switches to go 5.1 or mix into 4.1 quad using the front left and right for everything. you mentioned that you have made a pod for this system... basically that is what i will be making but integrating directly on the back off the plate amp (thats why i wanted a spare plate to drill and mash first) if you get time would it be possible for you to share some pictures of the pod you have made? would be interested in taking at look 
  
 Cheers


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## ramachandra

As i read from private messages the mica sheets becoming problematic for many modder. When i have done the First mod i have learnt the hard way how messy can be, thanks to the thermal paste. I just turned the board to one side without cutting it off from the transformer and Subwoofer.
 Later when i got a dozen i thought i have to do it somehow different. The wires was already cut of so i placed the boards to the bath and give them a wash with a paint brush and white spirit, than i sprayed them with multi purpose cleaner and washed them with water, than repeated the process few times. I left the boards to dry overnight on the radiator. The next step was to install terminal bars to the wires so it become easy to connect, disconnect from the rest of the subwoofer. The fragile mica insulators fall out of the options, so i used masking tape (made from paper) over the heat sinks and nothing else. The TDA Amps never had sort circuit or fried, still i do not recommend as a permanent solution because the paper deteriorate in time, and thermal transfer is not necessarily up to the level of the original. But do fine during the testings and until the new mica sheets arrive if some of them get damaged.


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## jayjayuk

my mica sheets are all splitting at the edges... they are fine for now tho... i will keep that in mind as right now i have the board in and out alot... i dont disconnect from transformer... i just put the sub on my bench and unscrew the amp and work on it like that... gets tricky putting the bottom screw and nut in to hold the circuit board though.
  
 if the masking tape is made from paper then paper is an insulator of heat? just though i would ask
  
 Cheers


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## ramachandra

@andro6600 What you looking for is not on the amplifier board. It is in the pod and i do not know where to look. The whole pod is crowded with SMD, but as i remember the volume control chip can handle it alone so maybe not much can be done about it. With the Elnas the bass will improve on the sats. If you want some more get SB Titanium to mod, can turn out as good as the Z.
  
 @jayjayuk I try to get some photos for you from the owner. I was abroad and i used what i could get from the the local store. Not pretty. 
	

	
	
		
		

		
		
	


	




  Working.....
  
 The thickness of the masking tape is not enough to be concerned, at least not in the short therm. Paper is a good insulator of heat.


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## andro6600

ramachandra said:


> @andro6600 What you looking for is not on the amplifier board. It is in the pod and i do not know where to look. The whole pod is crowded with SMD, but as i remember the volume control chip can handle it alone so maybe not much can be done about it. With the Elnas the bass will improve on the sats. If you want some more get SB Titanium to mod, can turn out as good as the Z.
> 
> 
> @jayjayuk I try to get some photos for you from the owner. I was abroad and i used what i could get from the the local store. Not pretty.
> ...


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## jayjayuk

@andro6600 so you have some elna's on the way... which caps did you buy? capacitance and voltage rating? and what did you end up paying? for 47uf 50v and 22uf 50v for the main amp 16 x of each it cost me £23.
  
@ramachandra please if you can... would like to see the pod. i was also thinking about putting 3.5mm jacks on the back aswell with a switch between rca and jack... im still unsure on my design right now... want it to be basic and simple with a few options and still have 5.1... i will quickly run out of room on the plate if im not careful


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## andro6600

jayjayuk said:


> @andro6600 so you have some elna's on the way... which caps did you buy? capacitance and voltage rating? and what did you end up paying? for 47uf 50v and 22uf 50v for the main amp 16 x of each it cost me £23.
> 
> @ramachandra please if you can... would like to see the pod. i was also thinking about putting 3.5mm jacks on the back aswell with a switch between rca and jack... im still unsure on my design right now... want it to be basic and simple with a few options and still have 5.1... i will quickly run out of room on the plate if im not careful


 
 I bought these http://www.ebay.com/itm/131189288110?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
 and these for main filters http://www.ebay.com/itm/131189283371?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
 I must say, they are quite expensive, but hope they worth it! I am going to try the combination with my Panasonics, and eventually buy Elna for the 22uF position.
  
 Cheers


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## jayjayuk

just to make you aware if you are not already... those nichicon's are to big to slot straight into the board and you will have to modify it so that they do fit... solder wires to them on a standoff board or something like that.
  
 these are the elnas that i bought...
  
 http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=360946019675
 http://www.ebay.co.uk/itm/16-pcs-47uF-50V-ELNA-RFS-SILMIC-II-AUDIO-Capacitor-85-piNEU-Kondensator-Stuck-/360943345072?pt=LH_DefaultDomain_193&hash=item5409e65db0
  
 came to £23 ... i will be buying filter caps or possibly caps all round for pod... have not decided yet... see how these 22uf & 47uf are on the op-amps and tda's
  
 i did not want to mod the board like the op to get big caps in but i think i might and get some big elna for audio or elna for denon and like the OP use some more in parallel to the big ones. here are the caps i was looking at for direct replacements on the 10000uf and 4700uf...
  
 http://www.ebay.co.uk/itm/Nichicon-KA-Audio-4700uF-25V-radial-105-capacitors-UKA1E472MHD-2pcs-/261479327054?pt=Componenti_elettronici_passivi&hash=item3ce161e54e
 http://www.ebay.co.uk/itm/2-pcs-Japan-Nichicon-FW-10000UF-50V-Audio-Capacitor-for-audio-cap-/320852400459?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item4ab44b194b
  
 Cheers
  
 EDIT : 
 Bargain = http://www.ebay.co.uk/itm/28PCS-22uF-50V-ELNA-SILMIC-II-RFS-for-HiFi-audio-silk-capacitors-Thailand-Made-/261287134910?_trksid=p2054897.l4275


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## andro6600

@jayjayuk, yes, i know that KG wont fit into the board, but planning to solder wires, as ramachandra did in one of his mod, and mount them to the subwoofer case. Hope this wont affect their performance, i don't wanna screw the board eventually. I considered Nichicon FW for direct replacement, but i know in audio the bigger- the better!  
	

	
	
		
		

		
		
	


	




  Nevertheless FW will be superior to original ones, no dough! Wonder, is there any benefit with changing 4700uF pod capacitor?
  
 EDIT
  
 Look what is inside Sony Str-da5000es


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## jayjayuk

so i have been looking on ebay for polystyrene caps to fill the pre-amp board... there is 7 224's on there and 1 224 on the under side of the board... i found these on ebay... let me know what you both think... they will be a very tight squeeze to fit in... might have to go as far as putting the resistors on the under side of the board to off-set the caps...
  
@ramachandra i see you use the 0.47uf polypropylene of these for the op-amp by-pass... what do you think about the quality of these russian caps? would these polystyrenes be worth buying?
  
 http://www.ebay.co.uk/itm/8x-0-22uF-250V-5-Hi-End-Polystyrene-capacitors-K71-4-/200960061884?pt=Vintage_Electronics_R2&hash=item2eca2731bc
  
@andro6600 i think the more i do to mine the more i will end up putting big caps in it aswell. i will more than likely build a board with caps in parallel like @ramachandra has done. 
  
 Cheers


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## ramachandra

(andro6600) This is the datasheet of the volume control chip: http://www.datasheet-pdf.com/datasheetdownload.php?id=508654 located near the pot right under the knob. I'm not saying upgrading the pod will be a dramatic improvement, for my hears the rest of the annoying noise and fog vanished, just the sound remain.
  
 (jayjayuk) The Nichikon KW have the same size as FW and a bit more refined. I got the images about the "Pod" i made. First time i connected the Z5500 to the sound card without volume control and everything was great other them loudness. Dow on 10% was still unpleasant so i placed a cheap 50K 6 channel pot to the box, and the owner sad it is doing worst than the unmodified Pod. So i decided to buy 5pcs 22K 5W wirewound resistors and use them on the signal path instead, the Sub required none. So one switch turn the Sub on/off and a LED, switch the 2 front channels between the jack and the Z5500. I have used no jacks or RCA on the box to save money and have less unsoldered contact. On the end of the cables there is a D-sub connector and 3 jacks.
  

  

  
 I have never tried those polystyrene capacitors, still i bet on that the western equivalent could cost a fortune. It is true about most of the Soviet military caps used for audio.  Maybe you should wait for andro6600's opinion on the K73-16 he bought.


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## andro6600

@jayjayuk wow! Those are some big boys! I think however, it'll be tricky to fit in.Otherwise, according to everyone, polystyrene should be ideal for audio.But then again, you have to try for yourself. Mine are on the way, and after couple of weeks, i'll share my thoughts about the sounding.
  
 @ramachandra, thanks for the sheet, i will investigate the chip and the possibilities.


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## jayjayuk

@ramachandra i have also been looking at the kw series aswell... but they are hard to find on ebay (for me anyway) at 10000uf 50v same for the 4700uf 25v... maybe i need to search more 
 that control pod looks cool... very simple and effective design... my would be something like that but on the back of the plate... so then you just have to use rca's or jacks (have not decided yet... maybe both go in)... i like options... its just the only thing i can thing of using from isolationg one lot of wires from one point to another is relays or optos... i just dont know if the optos will add resistance to the wires and if it will have an adverse affect on the sound in the end... i will have to look some stuff up and some datasheets and see what i can find.
 i might wait i might not hehe... depends how impatient i get because i want to try them... i did some measurements last night and i would have to move the resistors to the underside of the board and possibly the wires that connect the pre-amp to the main board... it would be a mod that i would do but only if i thought they made an improvement would i keep it this way... something i need to ask you... 3 things actually... i noticed in one of your mods you used polystyrene they maybe look like siemens 220nf... can i ask where did you source these from and how much? as these 220nf styroflex are quite hard to find... all the lower values are cheap but i cant use them anywhere in this project. also if i did buy those russian styroflex the case is metal and i have to run one of the leads down its side to connect to the board... will there be a problem if one of the leads touches the case of the capacitor? should i insulate down one side of the cap as i run the lead down it? these caps are very tall so staggering them from on side of the pcb to the other is not an option as there is not enough space on the back side of pre-amp board.... oh well.
 i have noticed that the 220nf 630v axial i have used on the underside of the board (which is now on the top side going through) it creates a hum on the sub... if i move my finger closer to the plastic casing the hum gets worse until a peak when i touch the plastic... then if i touch the lead of that cap (or any 630v cap) or the plate the hum goes away? have any idea what i can do to sort this?
  
@andro6600 they are quite big which is making me look for others first before i actually purchase these ones.. if i can not get any others then i will mod these in... i know i can get them in re-arranging stuff just it wont look nice... but i will do it  yes please let me know what you think about the sound with the polypropylenes as i might buy some of these aswell as they can go in either board i have while the others go in the other board i have... i am just not sure about the lead of the cap touching the cap case.
  
  
 Something arrived today  the 5 X opa1612 i dont know if i should get them in now or wait for my elna's to arrive and do it all at once... decisions decisions... i know i wont be able to wait haha...
 i will most probably be buying more of these in the end... if any of you two know where i can get these cheaper than where i have bought them from i would be very interested in saving some money 
  
 heres the ones i bought...
 http://www.ebay.co.uk/itm/Burr-Brown-OPA1612-Soundplus-high-performance-bi-polar-op-amp-soic-8-pin-package-/251501882803?pt=LH_DefaultDomain_0&hash=item3a8eae2db3
  
 here they are on my kitchen side 

  
 Cheers
  
 EDIT : 
  
 as polystyrenes are hard to find @ 220nf and a low voltage to fit in the pre-amp board... would there be any adverse effects if i used say a 240nf or a 270nf instead of a 220nf?
  
 Cheers


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## andro6600

I am wondering the same about metal case of these caps. @ramachandra, maybe you can enlighten us is that a problem, or we need some insulation over the body? Is it ok with just insulation tape?
  
 @jayjayuk congrats for the opamps! They are really superb, and made most of the difference. Be careful with the soldering iron, because i screw one of mine. And with desoldering old ones too.


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## jayjayuk

yes @ramachandra we need info about the metal caps casing and your experience with them and best practice of installation... thanks.
  
@andro6600 i was thinking insulation tape aswell... just run a small length down the side of the cap for the lead to run down... not that it would be a problem to do but always better to know what needs to be done first. yes i am usually carefull with the soldering iron TBH... the r4580i i just took out (for center and front left) is broken anyway as the center does not work, i took this op-amp out of the blown board i have as the original problem with my main system was the front right was quieter than the front left when i had changed the op-amp over the front right was fine back to same volume as front left... but then there was no sound out of the center speaker... just pops and crackles with no audio at all... where as before the center worked fine... anyway the r4580i i just took out i chipped with a screwdriver... i use a sharp screwdriver to get under it and ease one side up... let the op-amp cool and then do the other side until the legs are completely off the board... then i switch to snipe nose pliers to get the other side 4 legs off... worked well so far but this time it chipped the op-amp on both corners... no worries though as this one was broken... just need to be careful on the next ones as they are going in the blown board (still waiting on tda's)
  
 Cheers


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## jayjayuk

ok... problem... the first op-amp i changed was for the center/left front and it still does it... which it did not do it before i changed the op-amp... the center was working correctly... now the center comes on... then changes to audio&crackling then if i leave it on it will drop the audio and crackle really loud and bad.. this is only on the center channel... the front left now works fine... i have soldered wires directly on to the pre-amp board and cut the pod out of the picture... so it is not the pod (which i am happy about) but if this still does this with a new op-amp it has me thinking what it could be... possibly the tda? seems to get worse the longer it is run... i have checked the electrolytics around the center OP&TDA and they check out fine... so i am thinking its either SMD components or the TDA ... first thing i will do when my TDA's turn up is take out the center channel and put a brand new on in... if it still does it then it must be SMD... i have been over the solder joints twice over now... i am sure its not a bad joint... do you guys have any input?
  
 i am not sure what to think... i did short the pre-amp board on the plate and it blew a resistor but i replaced that and things worked as they did before so i cant see that being a problem as the center did this before the short.
  
 i will put the caps back in for the OP&TDA and then just bridge C100 --> WA80 and see if it works... if not then more ta do... if so then probs around the op-amp area.
  
 Shame...i thought the new op-amp would sort things


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## ramachandra

This is the KW for the lowest price i have found. Taking up 4-5 weeks to get it.
 http://www.ebay.co.uk/itm/2pcs-nichicon-audio-capacitor-FW-10000UF50V-/111293035453?pt=LH_DefaultDomain_0&hash=item19e994f3bd
 The KA: (I bought many cap from this seller and shipping cost is low.)
 http://www.ebay.ie/itm/4700UF-25V-NICHICON-KA-105C-2pcs-/111352316091?pt=LH_DefaultDomain_212&hash=item19ed1d80bb
 I bought OPA1602AID in bulk from Mouser around 2.65€ each a while back and the shipping free beyond 70€ to Ireland and they have most of the capacitors. An ideal option for 2-3 people to buy components together.
 This seller on eBay had the polystyrene capacitors and he is not selling capacitors this days. Ask, and you may get lucky. The brand Siemens indeed. You do not need to worry about small capacitance difference the 240uF just perfect I'm not sure about the 270uF without a try.
 http://www.ebay.com/usr/dos107
 The hum look like a ground problem. Maybe the legs are too long and picking up noises, but before you do anything else try to move the cables, the system is more sensitive without the Pod and how you place them is matters.
 I put the capacitor into a piece of heat shrink tube a bit longer than the body, so the legs are not contact the metal cover, and no need to worry about short circuit on the PCB.


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## jayjayuk

ok... there has been many problems on getting these op-amps in... still not done... i am pretty sure two of them came broken  as everytime i put the soldering iron on them i check with my finger to see how hot the chip got and i never let it get that hot as i melt the board solder abit first then slide the iron upto the leg and remove... i have once peace on the rear speakers... and i have two pieces on the sub... the track is broken bad for the center/front left but that is no issue as i feel quite at ease with fixing broken tracks. i also broke on of the op-amps as the leg came off it (but it was the one i was moving around and giving abuse to) so now i have one left to put in... maybe me putting it on the center speaker blew on side? i am about to try in on the front right which requires one side only to see if it works... the people who i bought them off are now out of stock... so as of right now i am one down... but the center and FL can wait as i need to do some repairs on that anyway... i think i will wait for the tda's to turn up for that and change the center tda amp as nothing i do can i get that center channel to come on... although it is giving the same effect as the problem i was just having meaning a broken op-amp... but the center is different... when i put an op-amp in on the center it will work for maybe one minute... then it will start popping a crackling... so i will work with that when the tda's arrive... they might take a while.
  
 i am just glad i have got the sub working again... one of the new op-amps... i know i dont heat them enough for them to burn.. so all i can think of is bad solder joints? (time and time again... unlikely) or bad op-amp from ebay... quite possible.
  
 still more to do... will check back in when i have more done..
  
 Cheers


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## ramachandra

Is the soldering iron good for chips what you are using? I'm just asking because I have ruined few OpAmps with my ordinary 30W iron when i was far from home and had nothing better to use. The pins are carry the heat quick and a too hot iron overheat them inside under a second. At home i use a temperature controlled ESD safe station on 240 Celsius and low melting point solder. Soldering paste or flux is a great help to create proper joints.


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## andro6600

Ok, small update on the mod. I  replaced the 4.7uF 50V capacitor on the pre - amp board with one of my remaining of Panasonic FC 10uF50V105C. I hope that going higher on the uF wont damage in any way the system. I come to conclusion that changing any of the caps on pre amp, result in significant difference in sound. This cap alone made the sound a little more full in the mid-low area, as i said before, the FC are really smooth sounding. The highs are also very pleasant. Somehow the sound became more integrated between sub and satellites. Then, i decide to replace the control pod capacitor with one that i had, some cheap china Sancon 4700uF63V 105C, just experimental. It turns out, that this removed in some degree the fullness between sub and satellites, but not by much. Looks like, the cap tends to tighten the bass, witch is not a bad thing, but still wondering that i like it more. I'll give a caps time to "burn in"(i am not very certain about this thing tough) Eventually i'll order other 4700uF, from reputable manufacture. I want to mix up the brands, to avoid one brand audio signature. What you guys thing about Nippon for that position?
  http://www.ebay.com/itm/1PCS-50V-4700uF-50V-105C-Radial-Electrolytic-Capacitor-19x40mm-/181419680679?pt=LH_DefaultDomain_0&hash=item2a3d74a3a7    are they good? And what about the replaced 10uF cap? Is this going to harm the system (or performance) in any way?
  
 Cheers


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## andro6600

@ramachandra, i see you mentioned 2 pieces of film capacitors MKT 1uF 63V for the voltage regulators. What is their purpose exactly, and why you decided to use non polar caps instead of electrolytics? Are these a good ones? Because i am about to buy them   http://bg.farnell.com/epcos/b32529c105j/cap-film-1uf-63v-5-radial/dp/1692372


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## ramachandra

The Nippon Semicon caps have a well deserved good reputation in electronic industry and some of the series are used for audio purpose, but they are not exactly made for audio, at least not present on the wishlist of the audiophiles. In the past the company have made caps specially for audio an some of them still in circulation on eBay. Because i found no information how this caps perform and they are getting old i give up on them.
 http://www.ebay.com/itm/Nippon-Chemi-Con-Audio-Series-Capacitors-4-700uf-25v-Audio-Grade-Caps-/331224512493?pt=LH_DefaultDomain_0&hash=item4d1e84f7ed
  
 The standard electrolytic capacitors have effect on the sound of course, but pointless just to pick another and expect a real upgrade, more-less the lifeles agressive metalic sound, poor soundstages description fit to them. Here is the great example:
 http://tech.juaneda.com/en/articles/electrolyticcapacitors.html
 http://www.head-fi.org/t/528380/electrolytic-capacitors-used-in-audio-dc-blocking-comparison-tread
  
 The 4.7uF 50V cap on the preamp board is part of a circuit responsible for the stand by function. I have changed that cap to a 47uF by mistake and cused no harm i can not confirm or deny effect on the sound.
  
 I have used the 1uF film capacitors by few reasons istead the same value electrolytes. 1. I have many of them and fit to the board. 2. Film capacitors are usualy better for audio because the more linear frequency and voltage responses. 3. More durable.
 Common failure story for PC motherboards: a cap fail belong to the regulator, regulator struggel to sustain voltage for a while than give up and let the unregulated voltage go, processor fry. I found few simalar problems on the broken Z5500 boards so i rather safe than sorry.


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## andro6600

Thank you, for your info! It is really helpful to me. About the 1uF film caps, somewhere on the net i read, that the Vishay MKT1822 is a really good one. So i am going to search it. Here is extremely difficult to find good audio parts, and have to order either from ebay, and wait long, or some other stores, that come with a space high delivery prices, to my country. 
	

	
	
		
		

		
			





 I am very exited and inpatient about this mod, that's why i try every part that is available to me. I am hoping this week my Elnas and Nichicon KG will arrived.


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## andro6600

Is it a problem if i replace 10uF 16V caps on volume control with my 10uF50V? And is it a problem in general, i want to going for a higher voltage caps for all positions, because of lower ESR and higher ripple current? I think not, the capacitor can store only amount of voltage, that specified circuit has given, right?


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## ramachandra

The Vishay, EVOX/Rifa, ERO, Wima, Philips film caps have a good reputation for audio in general.
  
 The Voltage rating only mark the maximum what a capacitor can safely handle for X hours (described on datasheet). The bigger the difference between the voltage present and the rating is the better, of course not from the size/cost point, just slower ageing, lower ESR.


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## andro6600

Ok guys, today i made some more modding. This time not everything gone so smooth. So, i bypassed the TDA caps with 0.22uF 100V MKT Vishay BC
  

  
 Then, i replaced the pre amp cap 4,7uF 50V, that is responsible for control pod on-off, according to @ramachandra , with Rubycon RX30 4.7uF 100V, 130C. Also the voltage regulators caps, with Vishay 1822 MKT 1uF 100V. But after power up the system, the fuse blow immediately! I replaced it,  however i forgot to connect the powering wires(red and yellow, removed to be able to unscrew the last bolt from the heat sink) And the pod display became full of bars. Then the VGA connector to the sub, made some sparks, and i turned the power off immediately! It turns out that the one of the lines of the pre-amp panel was burned out! I manage to fix it with some thin copper wires, and solder them. Then i find out that one of the voltage regulators pins is too long, and thought, maybe this is made some short circuit with the heat sink plates. So i cut them shorter. And after powering up the system, everything seems to be ok, but not! After a while, maybe some 20 minutes, the sound unexpectedly stopped, and the display, again was full off bars, and not responding at all. I had to power off from the switch. I decided to bring back the 4,7uF 50V original cap from the pre amp. Thisnot helped either. After ~20 minutes, same story. And now i am clueless?!...  
	

	
	
		
		

		
		
	


	




  What is the problem? Is it possible that the voltage caps are too over the top with voltage? Is it possible the bypass caps are also part of the problem? I know the ramachandra suggest 63V, but i decided that doesn't matter if the voltage is higher. Please help, i do not know what to do now!


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## ramachandra

First thing firs. I think you need to progress slower and change only few of the components in one move and do more checking, testing. Because you need to give yourself at least a chance to figure out what is went wrong, than you know where to look.
  
 As i see the images i think you had problem a bit under WA200. That is the bootstrap capacitor of a TDA Amp, if that capacitor fail the TDA Apm is blow (ugly) sooner or later, but first can ruin the preamp panel, blow transistors for example. Between the WA500 and WA600 around the 2 pins the PCB look black on the image.
  
 Use the diode tester function of the multimeter and search for short circuits on those pins and on the others you recently touched. Do not trust your eyes at all.


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## jayjayuk

@andro6600 have you by any chance had the control pod open? and been in and out of there alot? i had a similar issue to what you are describing and mine was because i was moving the control pod LCD alot and the wires broke on me (the second time was hard to tell because i could not see under the white glue) but i replaced that connector with a plug and socket type connector i got of something else and never had that problem again. i thought to myself (not knowing how it works) would the display just not work? but twice it happened to me and twice it was fixed by repairing that connector. just check that connector and make sure it is ok... i know you have not said you have been in there in your post but i can remember that i had a problem like that... i was sat listening to music on low volume for about half an hour while i was on the laptop and the sound just went off... then i bypassed the pod and everything was fine... so i had a look at the pod and found the wire broke... so i fixed it once then it happened again so i swapped the connector for a more robust one that i could unplug when needed. did not do it again after that.
  
 little update on mine... on my main system i broke the tracks for the front right and the front left and center (2 op-amps total) and getting them things in and out again was getting worse and worse and once they was in i had to use a link wire for the broken tracks. so i bought some soic to dip adapters from ebay and epoxied them to the board (near the original and not over any small ground points on the board) i then used ethernet cable (multi core cable not single strand) to link back over to the correct smd components (i used the test meter first to find out where everything went and which pins where joined) i removed all the tracks on both of these positions and just soldered the wires directly to the smd's... then tested continuity from the smd component to the chip leg... and then again tested the other side of the smd components to make sure the smd was ok and my solder joint (wire to smd) was connecting to the track on the board... all is ok and all wires are epoxied in place (does not look nice... but its a fix) all wires read very low resistance.
  
 The new op-amps have arrived today and i will be taking extra care of installing these ones... the last ones i was rough with them.. no anti static wrist strap and had them in my hand... and when i put them in last time i had the op-amps hot... where you could not keep a finger on them... i have since got a new soldering iron (regulated one) and had practice on installing the op-amps without getting them hot (removing them is a bit different lol) so hopefully if nothing else is broke... it should be back up and running soon.


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## andro6600

@jayjayuk, I've opened my pod 3-4 maybe 5 times, and yea, me too discovered that the cable from board to lcd is very thin, but, why the signal stopped? How it is related to lcd? And my pod not responding at all after that, i cannot turn of, neither from remote or button. Then after switch power off, and on it works again?!... So today i checked carefully all  my soldering  on the amp pcb with the multymeter for short circuits. No shorts! Re do some of them and solder the voltage regulators caps under pcb. Also apply new termal paste to TDA and new mica sheets, because i was thinking that the problem is maybe some overheating. And tested again. 

  

  
 This time everything last a little longer, about 40 min. And again same story. I am going to put back the old caps for voltage regulators. Maybe  non polar caps aren't good for my system?... i don't know... Don't think that the bypass can be a problem? Or may be the big Sancon 4700uF 63V cap that i replaced before for the control pod is problematic? I remember @ramachandra
  said that this can cause problems pod lost settings? But before last intervention, i've had no problems?!? 
 @jayjayuk, Hope, that everything will be fine with your new opamps. The are really pain in the @ss, to solder desolder without specialized tools. Can you post some pics from your mod of the pod cable, to got more visual?
  
 Cheers


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## andro6600

Ok, tested with old caps for voltage regulators= same effect!!! Damn! So, only two things remain - either the bypass caps causing it, or as @jayjayuk said, the problem is in the pod cable. Or worst, something unknown is malfunctioning(really hope not)


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## jayjayuk

if you dont go in the control pod that much that it is probably not that cable... and i thought why would the lcd cable stop the audio from working? i thought just the screen would go off or play up... but that was an issue before the issue i have now... i just thought i would mention it as it might help you.
  
 i have all the op-amps in and i still have the same problem... what works is --- front right/left one of the rear speakers --- what does not work... one of the rear speakers and the sub... have not tested center yet as i am focusing on the sub mainly... i did notice a problem which was on the pre-amp board there is a 224j cap near the edge of the board on its own... i replaced it with a tall yellow propylene and from flipping the board over and stuff i created a bad joint on one pin and the other part actually broke the track (this is turning into a nightmare lol) but i have now fixed that... i put the ceramic back in as it wont take as much stress as i am moving it about. eventually i am sure i will get there.
  
@ramachandra i am not sure if that cap would have caused problems elsewhere... can you maybe shed some light on that? i can actually hear the sub... but i have to turn everything up full and even then it is very faint... i am not sure if it is the op-amps... i can remember when i took out the front right and the pad arced somewhere so i switched off and sorted that but the front right works and the sub does not... when the tda amps turn up i am just going to change the ones for the sub (as i will have three spare anyway) and go from there with the sub... as i cant really take these op-amps out without burning them up... if i try not to burn them up i use to much pressure and rip tracks. i am pleased that the fix i did for the already broken tracks have worked ok though... thats one thing... i am currently all over the board on diode test checking certain points for shorts and continuity... and when the op-amps was out i checked the smd's around the op-amps and they seemed to be ok and was connected to the track... so the only couple things i can think of is bad solder joints (which i am checking all over right now to try and find anything or the op-amps or the tda amps... we will see what comes of it.
  
 i will post some pictures of my the main board but i wont it working before i start taking photos... i do need to put some more smd led's in my pod as the old ones are old and dimm so when i have it open to put them in i will take some photos of the inside of the pod for you to take a look at.
  
 EDIT:
  
 this is the flux i am using...

  
 should i be cleaning this stuff off? or is it ok to leave on? the rosin core from my solder also leaves a residue on the board... sometimes it is sticky and other times it is hard like crystallized... should i also be cleaning this off? if so what should i clean with if i dont have alcohol to clean with? will this residue and flux paste cause a problem? when i was probing near the op-amp track i noticed that without touching the pad i could get a reading of something like 150k resistance when i put the probe close to the track but not touching it... i read that water can be used... is this ordinary tap water? and if i get some water that is suitable for cleaning the board... can i leave all the components on the board while i am cleaning it? like the caps and amps?
  
 Cheers


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## andro6600

Man, i removed all the bypass caps, just to exclude them from the problem, but this was of no use. This time, the sound stopped even at 10 minutes! I am sad now. Don't know where else to look at, guess something gone wrong after i forgot to connect the two cables from the square element. This one

 The yellow one(going to the between main filter caps), and the orange one(that is behind the black one) What is this element and what the two wire are responsible? 
 It is very interesting, first with all the additional bypass and voltage regulators caps, sound stopped at 20 minutes,then after revert back the voltage regulator caps, the time before stopping was doubled(40), and after removing bypass caps, time was 10 min. Got no idea. I thing it is time for the system to go to service...sad day really. And my soviet military caps just came today...
  
 @jayjayuk, i thing your problem with sub is at op amp. When i burned mine, a also hear a very quiet sound, almost none from the channel. 
  
 EDIT: Now i tried again, and this time, sound stopped at 4-5 min. The swicth off, then again at one more bar volume, and stopped after 2 minutes. Guys, how this is look to you? There is something in relation with the caps of the tda maybe, is it possible that one or more are damaged, but no visible signs?


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## jayjayuk

i have not tested it but i am sure that silver block is a bridge rectifier... if the orange was left off then there would be no power to it and that should not be a problem... just reconnect it and all should be fine in that area. to be honest i think you need to rule out your pod as a possible problem... to do that you need to solder the pins together on the d-sub connector and then attache a wire to one of the inputs and let it play and see if the problem is still present... i mite just be that your control pod is playing up and happend at the time you are modding stuff... i always rule the pod out first as i could be playing with the amp for no reason. you need to join pins 6 -> 7 -> 8 -> 13 to enable the amplifier... i then use some rca sockets i got of some donner equipment and solder them to where i want the input to go and plug the jack into the sound source... so the ground on the rca socket (or cable depending on what you have to use) should also be connected to pin 13 which is ground... then its just connect the center wire to one of the inputs... heres a picture that i use for reference every time i cut the pod out of the equation...
  

  
 this always works for me... i use some telephone cable single strand to connect 6/7/8/13 together.
  
@ramachandra  would know more than me at this point... but i will do some reading... some caps block ac and let through dc while the others block dc and let through ac... also a polarized electrlytic capacitor releases energy one way and not the other (not sure about this) but if this is true then would there not be an issue putting a non polar cap in parallel with a polar cap? as for whatever the non polar cap could hold as charge would be allowed to be released anyway in the circuit (forward or backward) where a polar cap only releases forward? this is just something i thought about and will look into a little more as i am still fairly new to electronics... i would doubt what i just said would be your problem @andro6600 as @ramachandra  has already done alot of these boards and had no trouble with this setup or parallel caps (one as polar and one non polar) so probably nothing to worry about... just something i will read up on a little later. my 0.22uf's turned up today... will be getting them in once i have sorted this problem i have. hope you get your amp sorted aswell @andro6600
  
 Cheers


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## jayjayuk

heres some pics of the pod so far... the pics are a bit blurry as i am using a galaxy tab 3 7inch and the camera is not great.

  

  

  

  
 the big heat sinks i cut using a hack saw lol but they are above any other components by a good bit or i would not of put them on. the smaller heat sinks i bought from ebay... the fan i cut the back grill out but left a cross section in with the bit that sticks up so it still supports the board as it was meant to. just puttin the led's in now  
  
 Cheers


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## andro6600

@jayjayuk, nice mods to the pod! Like the big heat sinks!  
	

	
	
		
		

		
			





   I, myself too was thinking about the same.
  
 About the rule the pod out, not a problem to do, but how is this going to help, i am pretty shure that the amp itself will work, because and now it does, just sops after a while. And if i cut the pod from the picture, what is going to tell me that something going wrong? When there is nothing to stop it? Obviously, the problem appears when something in the system getting more hot, or change self parameters, and this causing the pod freak out. That's just guessing though. I inspected the board carefully, and have doubts about voltage regulators.
  

  

  
 They seems like been burned out, and the pcb tracks also look suspicious. Could it be the culprit of a problem? Also i removed my last mods and find out that the stopping is happening a lot quicker. Thus tells me, that the extra voltage of the new caps helps to hold a system for a longer period. But i do not know how to interpreting this?


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## jayjayuk

when you cut the pod out and use the sub headless... then you see if the sub does stay working and the sound does not go off... if the sub does work correctly then the problem might be in the pod... looks like black patches around those regulators? im no expert but like you say that might be something to look into... maybe run the system untill it does go off and then quickly check to see what those regulator are putting out.
  
 it just seems so far that you are changing things in the sub a lot and if you say the sub will run on its own with no pod connected and still work ok then maybe you are looking in the wrong place? so your pod might of gone faulty just as you are modding... i have read some bad things about these pods online and i am just really waiting for mine to go 
  
 also from tests... if those regulators are under strain then running the system headless will keep those regulators next to cold as they dont have to run the control pod... so if you run the system headless and it works its either the pod or those v-regs that are staying cooler (possibly)
  
 let me know how you get on.
  
 Cheers


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## ramachandra

jayjayuk
  
 I think there is some mess with the OpAmp, it was a typical symptom on SB X-Fi cards when they run without power. When i tried to bypass those OpAmps for the sub and i got the same result what you experience. Lets hope you have not damaged the SMD components with the previous iron you had. I have no solution for that situation, maybe a broken board useful to map and measure the surrounding circuits, create a PCB and hook up.
  
 Cleaning off the flux is not essential, just the proper way to do the job. Months later it is getting more difficult. I like to be able to examine what i done, not just guess all fine. You can try to get alcohol, or clean petrol from the chemist, acetone or nail polish remover is also work. Stain removers usually the mixture of this materials and more effective. If you have nowhere else to turn use ordinary white spirit from paint shop. Smelly, dry slow but do the job. This liquids are not conductive so the devices can run without letting them dry properly, but most of them highly flammable so precaution is advised. Water is not really helfull, and not esay to get rid off the resin even with the materials i have previously mentioned.
  
 You have done a pretty job with those heatsinks. 
	

	
	
		
		

		
		
	


	




    
  
 andro6600
  
 Looking the new photos i do not see what i mentioned earlier. On the preAmp board the burnt track is look like belong to the +18V going to the pod, and the smoke is also near the positive reg. The nearby resistor is under the cower of a black wire, and i will be not surprised if burnt or discolored. So i think you had a short circuit, and if i understand well the system was on when you connected the Pod. So one possibility is the metal screws or the metal on the connector itself caused it when ended up on the wrong spot of the D-SUB connector. Lucky for you the 78M18 voltage regulator is common enough and i suggest to replace. The Negative is looking alright and lets hope it is also from the inside, because I bought few of them and i paid almost 25€ for 5 pcs because they are rare and out of production. If I'm right any parts of the system around the Pin14 also a good subject to examination included the voltage regulator provide the +8V for the Pod (Pin10).


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## andro6600

@ramachandra, do you know exact model and specs of the regulators, and resistors and eventually suggest alternatives, maybe even a better ones?And what the markings on the two pins side means? Are they some production numbers, or?
  
 here, the picture more informative 

  
 But look back in my pics before modifications, they look the same way
  
 EDIT: Just tested without the pod, as @jayjayuk said, i soldered together 6-7-8-13 pins, and soldered mini jack cable to the (5-9 front left and right)-13 Ground pins. But only front left was working. Anyway, i played some music from my phone for 5-6 min, nothing stopped, but when i checked voltage regulators, they were extremely hot!!! And everything else was barely warm. Is it normal or not? I thing exactly this is the core of my problems, maybe something go wrong with them and they overheat, then maybe some internal temp protection is activating and they stopped? Is this make any sence?


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## ramachandra

Here you find the datasheet of the regulator, and as you see it has an internal thermal overload protection indeed.
 http://www.ic-on-line.cn/view_download.php?id=1678317&file=0340\ts78macpr0_2296562.pdf
 At the moment there is nothing necessarily wrong with your Z other than that damaged regulator. Repairing electronic usually start with examination, taking measurement, than keep changing-checking the most suspicious components and hope you had a lucky guess until the faulty part(s) found.  You need a couple of instruments and spare parts around, and the pain coming with experience and you will find it useful if your study is electronic.
 Before i have spent on the original regulator i used what i have around and i tried MC7818 and MC7918 the TO-220 type, and i had to install a heat sink to them. It was unstable, a recipe for disaster so I only used for testing a couple of times until i got the right parts. The L7818CV and L7918CV not as good for audio as the MC regs but they are common, dirt cheap, generate less heat, and you have a good chance to find it in a local store.
  
 The trough hole resistors have a color code and you do not even need to memorize the codes and calculate, there are many websites to do it for you.
 http://www.digikey.com/us/en/mkt/calculators/5-band-resistors.html


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## andro6600

Damn, i was soldered wrong pins. 6-7-8-3 together, and 5 -15 for signal from jack. Now i corrected this and running the system over 1 h 30 min already, and the sound didn't stopped. The regulators, however are still extremely hot, especially the positive one! Nothing smells burned on the board. All the other parts seems to be in normal temps. So, what to think? Why these regs, don't stopped, being so hot? 
  
@ramachandra , @jayjayuk, what you think about this, is it good? I cannot find any other option for local order. But the operating max temp is only 85C instead of 125 in original ones? 
 http://bg.farnell.com/rohm/ba178m18fp-e2/linear-reg-fixed-18v-0-5a-to-252/dp/2343131
  
 I also checked the pod for signs of a problem, looks like it is ok. Nothing burned, smoky, smelly or melted.Caps looks alright too. But i am going to replace the two laydown 10uF16V  on  the upper side of the pcb with 10uF50V Panasonics, that left. I don't know what are they for, but the new caps are better than originals, so don' think it hurt something


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## andro6600

Some good stuff!  
	

	
	
		
		

		
		
	


	



  

  
 So! In one word - AWESOME! For the little time that i can test before stop, my toughs are, that the overall sound is more realistic, the bass is deep and tight, soft but not overly. The midrange are somewhat more in front, the highs are little bit harsh, but i kinda like it. I suppose that caps need some time to burn in, so i have no patience to fix the problem with regulators.
  
 Cheers


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## jayjayuk

i have another board here... with basically everything off except SMD... i have checked alll components to the other boards readings and the all match up except for one capacitor where it reads fromm 220 to 0 and jumps between the two... where the other stay at a constant 170uf +- a few but some variables arnt the same... the caps are in on the second board where as on my main board the 47uf caps are out at the minute... dont know if that would make a difference but i will have to stick em in and check... other than that one cap all the smd's are reading fine according to the other board and all have good continuity to the board... something i have just noticed... is as i have been scratching the rosin away from the board... i have actually scratched the board away (where it should be green between the pins it is now brown and lower than the surrounding green board... not sure if this would create a problem but when i had probs with the front right and center+FL .. i have modded some boards in and removed there tracks right back upto the smd components... then soldered wires straight onto the smd components and they work fine... i have clearly been to rough with this and think the only way forward now is to check that one cap out (with both boards being the same and having same components on them) and then look at removing the tracks and doing what i did last time... it dunt look good but it worked... and these little adapters have bigger pads and are easier to work with... we will call this now my practice board  lol as the other board is now in better condition (shame)... we will see what happens... i have noticed that the sub peices go under the board like you said and go to the caps on the underside and on the other op-amp return to the top side of the board to go to the square bulk of resistors on op-amp U14 ... i will take all tracks into acount (U14 being the only one more diffucult) and make sure things connect back up properly... in everything else i have done i have never had some many problems like these op-amps are giving me... i am sure in the end it will return to life 
  
 when i run the system with no pod... i know my regulators done even get hot... its only when i use the pod... then the regs burn up... i measured something like 75-85 C (cant remember) from the heatsink i have sat on my regulators... which from the datasheet is optimum temp range... i could not test properly without the heatsink as could not attach the probe properly. i found some v-regs from china... they are the exact same ones that are used in the z5500 (they are hard to find) but they are only sold in packs of 20... i messaged the guy and asked if he would do 10 of the 79m18 and 10 of the 78m18 and he said yes... but they was going to cost alot and i was just sourcing at that time just incase... if you want i can post you the links for the items... but when i added up it was going to be something like £20-£30 for 10 of each. if you end up wanting to get some in then please PM me.. as maybe we can put some money together and get some in of both types... upto you on that one.
  
 the regs might just be getting old and running hot... then thermally cutting out... if they are getting hot with no pod connected then i would look into that as all i can tell you is mine run really cold when no pod is used... you might have to let the system use the pod and cut out like you say it does... the measure the voltage from the regs and see if they are putting the voltage out.


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## andro6600

Hi, @jayjayuk
  
 Glad to see that you got another board to experiment with. It is good to have one spare! 
	

	
	
		
		

		
			





  About the regs from that china guy, that is too much money spent for me, this mod cost me already bunch of money, and don't wanna spent extra. Instead i am going to search for alternative replacement of the reg if they are really faulty. But thanks anyway.  
	

	
	
		
		

		
		
	


	




   And i just discovered that the pod freezing even without any signal put in. Just switched on!!! And the system make that little "pop" sound when switching on, even at volume set to 0, and without any cable plugged in the pod. Is this normal? I don't remember, be like that before(i mean before all mods i have made)  Unfortunately, left the multymetter in work, and can't measure if the regs put correct voltage. @ramachandra  said i can use L7818CV and L7918CV , but they are pulling 1A out, not 500mA like originals. I wonder if that would be a problem? I can order exact model for positive, but negative one is really hard to find even L7918CV! 
  
 Cheers


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## jayjayuk

yes i could find the positive one easier than the negative... when you say just switched on and it make a pop... do you mean when you had the pod connected or when it was bypassed? if when it was bypassed then you could hear a pop from the main switch being toggled as the amps are instantly turned on and off with the main power switch... the pod is responsible for the on delay of the amps as so any interference from switch is not picked up when turning on and off... if it does it when using then pod then i am not sure... i never noticed mine pop when i used the power button on the pod.
  
 if you have a datasheet for the 78ma18a and the 79m18a that is used the z5500 can you please send me it as i can not find it online... even sellers online that i have seen say no datasheet for this item?
  
 Cheers
  
 EDIT: at the minute i would not mind a couple of pops out of the sub to be honest haha


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## andro6600

http://www.ic-on-line.cn/view_download.php?id=1678317&file=0340\ts78macpr0_2296562.pdf,  http://www.alldatasheet.net/datasheet-pdf/pdf/217320/TSC/TS79M18ACPRO.html   here thanks to @ramachandra! I noticed that the little "pop" sound appears only when analog input is selected, and also i didn't noticed ever before,because using only digital, but there is a very audible noise from the speakers, in analog.


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## jayjayuk

@ramachandra i have found a resistor at r623 which should be 100R but it was reading 220R ... i checked on the other board i had and it was reading 100R and the markings also said it was a 100R (01A) which is on the sub op-amp -18v in so i swapped it for the one off my other board... its in and reading 100R... but i have a problem... on around the op-amp U15 there is a resistor R618 which is marker 2606 ... the calculators say its a 260M ohm resistor and working it out also says 260M ohm ... but when i test both of mine on both boards they read 90K ohm should i leave them or should i suspect they are both bad and get some more to change them.
  
 also i only checked the smd's right near the op-amps not near the caps... so i am checking everything i can now and using this other board as a parts board for now. just dont know what to do about the 260M ohm resistor where both are reading 90K with tight tolerance between them... any input would be appreciated.


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## andro6600

So, little light in the tunnel!  
	

	
	
		
		

		
		
	


	




  Today i get the multymetter, and check pre amp board again. And all the resistors was gone! All not reading resistance. So guess thats the problem. Tomorrow i am gonna get some from local store. I am hoping that running system this way for a while didn't broke something else. And guessing that the voltage reg also overheat because of that! Crossing fingers! I checked the resistors with calculator, and there is 6x10K Ohm, 3x200K, 1x100k and one that is with only one black stripe, that i cannot check! 
  
 This one under! Can you give me the info, please ? All resistors are +/- 5%, but in my store there is also wattage, and i don't know what wattage are they. Also for 200kOhm, in my store are only 220K. Is this be a problem? Also is the more wattage be a problem or benefit in any way?
  
 Cheers


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## ramachandra

At least one of the pin of the component need to be disconnected from the board to get proper readings about resistance, capacitance ect.
  
 jayjayuk
  
 I'm not familiar with the codes used for them. If the two boards you have identical, comparing the readings sped up the job and probably no need to desolder.
  
 Andro6600
  
 I do not know how many watts the resistors are on the preAmp board. Judging about the size 1/8W. To be on the safe side use 1/4W. No need to worry about tolerance, this is not a precision measuring equipment. The resistor with the single black code is a jumper wire, because the machine installed the components can not handle plain wire, so it is shaped as a resistor.
  
 The voltage regulator from Farnell is looking good. The junction temperature is not necessary the same as operating temperature as much as i know, and somewhere else i found the original reg have the same operating temperature.
 For example the 1A only mean the regulator can handle it, and not mean it is drawing it from the psu. If the power requirement go beyond the limit is when the problem staring for the reg.
  
 Here is some information why and how components are fail and why the damages are irreversible:
 https://en.wikipedia.org/wiki/Failure_modes_of_electronics


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## andro6600

@ramachandra , so basically i can solder bridge wire on the place of one striped resistor? Good. I pulled off  the resistors from board, and they still read nothing! Other resistors have the value, even on the board, and the faulty ones lost the outside cover from both sides. So they are dead for sure. Also, just for insurance, i am gonna order that voltage regs from farnell, if you said that they are compatible, just in case old ones still overheating.
  
 Lol, this mod gonna teach me a lot about electronics! I am going to make a Masters degree!  
	

	
	
		
		

		
		
	


	



  
 Cheers


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## jayjayuk

@andro6600 that 1 X 100k you have there is wrong... i have it down as a 100R and i have had all mine out and tested original with multimeter ... the original resistors are 1/8w carbon... i have changed all of mine for 1/4w metal film... no bad done by going up wattage as long as they still fit ok... they just dissipate heat better and therefor can resist more current before failure. as @ramachandra said the one with a black stripe is just a jumper wire.
  
 here is the list i did for them when i first calculated them by colour... then took them from preamp board one by one... measured resistance and if my first calculation was wrong i would look at the color again and see where i went wrong...
  
 6 X 10K 1/8W 5% (brown,black,orange,gold)
 3 X 200K 1/8W 5% (red,black,yellow,gold)
 1 X 100R 1/8W 5% (brown,black,brown,gold)
  
 the other resistors are...
  
 7 X 2.2R 1/2W 5% (red,red,gold,gold)
 2 X 36R1/4W 5%   (orange, blue, black, gold)
  
 5 X 2.2R are on the pre-amp board behind the new caps you just put in.
 2 X 2.2R are near the tda amps for the sub (near the main filter caps).
 2 X 36R are the ones at the +-18V regulators
  
 i think i found the problem with my setup... i have not been using the 2 center screws that center the board and as i clamp one side to the heatsink and then the other side... there has been a big gap on the second side (between tda amp and heatsink) because of the first clamp pulled the board over... so on one tda (the sub and a left rear) it had broke the pins on the tda amp on the sub tda all the long pins had no continuity from the bottom side off the board to where they enter the tda chip... so about 8 pins on the sub tda and about 4 pins on the left rear... so i am waiting for my tda's to turn up from china (seems like its taking forever) but its a big relief as i am pretty sure that i will have had those op-amps in right (at some point) but it was the tda at fault... i am pretty certain when i get new tda's in it will be a runner again 
  
@ramachandra yes both boards are exactly the same so from one to another is easy... even if i cant get a good reading on something then there will be a patter... like a steady rise and then sit at a resistance... although not perfect... it is a good reference as if it sits at another reading there could be something work checking up/down stream from that point. makes it easier... and that resistor i have changed it... i will just get my main system up and running again and then i will get some smd's in and replace the ones i have taken from that board... i took the 2606 out and it still was reading 90K so i will just replace with 90K
  
 the tda amp was the find off the day for me... will center the board from now on.


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## andro6600

@jayjayuk, it seems that totay is a good day for both of us, finding the reasons for the problems! 
	

	
	
		
		

		
		
	


	




  Yes, you are absolutely right about the resistor, i was mistaken. It is very helpful to have all the resistors values. Thanks! I decided to replace all the caps in control pod, that @ramachandra didn't mentioned, with Panasonic FC/FM series,but doubled the voltage of the originals, just for good sake, if not to make any big difference in sound, just to be shure, that they are good quality, and more reliable.


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## jayjayuk

@andro6600 i am not sure but i think i might know what your problem is... i did this once lol... i was showing my system off to someone and had the pre-amp board out and it shorted the d-sub pins to ground heatsink... at this point it fried the -18v resistor near the -18v regulator... the resistor went from 36R to 30R and the sound would play for like 10-20 seconds and then stop... after i changed the resistor all was fine again... maybe you should take both 36R resistors out and check with test meter. as my resistor did look dark like yours and only when i took it off was there a piece of casing missing from the bottom and the test meter said it was reading 30R so i changed... other than that it just looked a little dark... i had a resistor on the other board look worse than that with lots of the casing missing and it still read 36R so definitely need o take them off and have a look at them. if you are going to replace them then i would put in 1/2W 36R i only used 1/4W because i already had them from a big pack of lots of values that i bought.
  
 also... the blown track you have on the pre-amp board... i have a second board (which as of now if it works... is the good board lol practice makes......... a mess haha) which the same track had blew out on... but this was because again... on initial testing to test what was working (in the end only center so i ripped everything of the board and waiting for new parts) i again shorted the pre-amp board (must learn to tie pre-amp board down!!!) but it was to the square silver bridge rectifier (as there was no heatsink and it was just on my bench with transformer hooked up... this made a big spark and when i had looked what had happened it had burnt that track from the board... so i wonder what happened to yours for you to burn that track out as its not really a small track?
  
 for my system i have ordered some more tda amps from the UK... i removed 4 all together from my main system... i am not waiting for china any longer so i bought some from UK which should turn up in couple of days.
  
 Cheers


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## andro6600

@jayjayuk, this looks like exactly mine case. Now that you've mentioned, i will replace and the voltage resistors as well. They cost nothing anyway. So, what you suggest, metalized or carbon casing?

Sent from my C6603 using Tapatalk


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## jayjayuk

personally if i am changing it anyway... i will go with metal film 1% and go up a wattage size so in this case i would get 1/2W metal film 36R 1% for the v-regs (as long as i can still get it in nicely)...
 if you get the two 36R resistors out and then check them... if something is wrong then change them... the stock carbon resistors can read anywhere from 34.2 --> 37.8  where as the metal films will read between 35.64 --> 36.36 ... so the metal films are closer to the resistance... i know if those resistors drop to 30R than you will see problems as i did. personally i would just try changing both resistors first and then run the system and keep checking temp on v-regs to see if they are any better... if not then change the v-regs... its strange that yours you say are running very hot with no pod connected... like i say mine run cold... if when you change then they still run hot then maybe there is a problem somewhere else on the amplifier board? or maybe this heat is to be expected? when my tda's turn up from china i will know more as i will have two systems to compare against.
  
 Cheers


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## andro6600

@jayjayuk, you were right man.Thanks!  
	

	
	
		
		

		
		
	


	




 Indeed the problem was in regulators resistors. First, i changed the pre-amp board resistors, and tried, but no luck. Then i opened the whole amp board again( man i am sick from that 
	

	
	
		
		

		
		
	


	




 ) and desolder resistors, checked them, and they was reading 36 Ohms, but change them any way. I bought the 0.63W metalized 1% resistors for all positions. And "Oh miracle" The system is up and running for more than 1 h 30 min without stopping!!! YESSS! Voltage regulator are still extremely hot. I ordered bunch of different kind regs:
  
 http://bg.farnell.com/rohm/ba178m18fp-e2/linear-reg-fixed-18v-0-5a-to-252/dp/2343131
 http://bg.farnell.com/taiwan-semiconductor/ts7818cz/ic-v-reg-18v-7818-to-220-3/dp/7174063
 http://bg.farnell.com/taiwan-semiconductor/ts7918cz/ic-v-reg-18v-7918-to-220-3/dp/7202202
 http://bg.farnell.com/taiwan-semiconductor/ts78m18cp/v-reg-18v-smd-78m18-to-252-3/dp/7207646RL
  
 So, my wondering is, to replace both, but i see the TS7918CZ pins are placed differently from original 79M18A, pin 2 is input and it is said that this is connected to pad?! Original one have ground at pin 2, witch is connected to pad? How is that possible? 
  
 EDIT: BTW, what are caps in pre-amp panel are for? The five caps obviously is for speakers, but remain two?


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## jayjayuk

good to hear you got it sorted  or running continously again at least. i realized when i had ur pic up... i was mainly looking at vregs... but then i noticed discoloured resistor and it rung bells lol. when u get those regs and try them please post what works well and what does not. not sure about pin config but if comparing the pins on datasheets is not the same then i would say not to put that one in. not sure what those caps are for ramachandra might know what they do... i have not really started tracing tracks yet but i am very close to doing so.


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## andro6600

Here, the schematic of pre amp panel

 Unfortunately the TC7918CZ is the only negative regulator that i can find... But @ramachandra said that it is compatible if i understood him right... Also if you said that yours are overly hot, than maybe it is normal.... Beats me!


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## jayjayuk

thanks for picture. my regs are only hot wen using the pod... you said yours are running hot when by passed aswrll? mine run cold when by passed. mine do get hot when running the pod but i am also running a 200ma fan on the pod aswell.


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## jayjayuk

ok... tda-amps turned up today... and well well... after 3 million op-amps later it turned out to be a tda that had snapped... the sub is working again and sounds mint... got all opa1612's in... elna silmic ii 50v 47uf & 22uf ... got the 0.22uf's on the underside... it int looking like a showcase model as i have been messing about with these op-amps and getting very annoyed... i have broken quite a few tracks but i have patched stuff up (two caps laying down) but hey... whos gunna see it? i will just epoxy everything in place and i will know for the other board... i will take more time and know my errors from this last one. two 47ufs are layed down because i broke the solder point on underside but the connection is topside anyway.. so i lent it over and soldered the two caps in place (more epoxy). so in the end... i have all six channels back online at equal volume and the sub works... so its a big relief for me as it got to the point where i dint think it would work again and kept glancing at the other board thinking "should i start using that one instead" lol... but i got there in the end... i will just change the two main filter caps and the pod cap and call it a day with that board... its all working again and i dont want to have more headaches with it... the second board will be the main focus now. the problem with the other channels was tda amp related aswell... as all i did was put 4 new tda's in where the old worst ones was and everything is good... sounds good just to hear it going again never mind the upgrade 
  
 here is 
  
 a pic of it... looks like a bad job (and it is) but i just wanted it to work again whatever it looked like in the end... and it does 
  
 i have not added thermal paste yet... i also broke two ferrite rings off the rear speakers... but i took an old inductor with same size from another board and re wound (three times) the ring... all works fine.
  
 all that messing about with op-amps and that was not the problem... will take more pictures when i have it out again... but for now... i want to listen to it (not for long tho as no thermal paste) everything is sounding pretty good 
  
 thanks @ramachandra for this thread 
  
 Cheers
  
 EDIT : PICTURES
  

  

  
 for the underside of the board... i have some shielded cable sat here... just have not put it in yet... will do that when i change the last three caps... the blue cap in the middle i broke both holes for the cap legs and the connections was on that side so that was not nice to fix... had to use single strand telephone cable which i soldered to the track and then made little circles where the cap legs go in... i then soldered the cap to these rings and epoxied it in place... alot of this mod is not nice but mostly because i was impatient and getting annoyed with the op-amps. still... it works lol.


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## ramachandra

I know some work still ahead, but I'm already happy to see an upgraded board what i have not touched. You have done a serious job on those OpAmps to make them work, and i think the rest of the mod will not be a challenge for you to complete. I'm really looking forward to see the rest. Well done!


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## jayjayuk

i know it does not look great... but it works... it would not of turned out like that if i caught that tda amp a little sooner... oh well... on the next board it will have all new tda's and new op-amps... i know on the first board i will have had them in several times working it was just the tda. on the second board there is only about three tracks broken so that one will look better but i dont know how far i will go with second one... maybe just keep it stock and compare... then if this board i have just done goes down i will just transfer the caps and stuff to the second board as the first board is not really going to take another hit.
  
 them op-amps took time with the little wires (still managed multi core though... was going to go single strand at first) and i wanted the ends to turn 90 degree so i could get the most contact area to the solder joint on the smd's then epoxy in place (waiting for more epoxy lol). i am going to change that bottom v-reg aswell... the contact pressure is not great as i put thermal paste on then epoxied the sink to the board... the top v-reg i mixed epoxy with a bit of thermal paste and held it down for 10 mins as much pressure as i could... the top one gets hotter quicker probably because of the better contact so thats why i want to change the bottom one (when i do the big caps). i am just putting thermal paste on the tda's right now... i want to go set it all up in the house and test it out on something... will be blasting it most of tomorrow 
  
 learnt alot from it... for a start that i am not nearly careful enough lol... and about the way it works... i kept thinking i was blowing them op-amps with either heat or static... so i switched to a gas soldering iron and earthed myself to the socket... dangerous option but i dont have anti static stuff and i was on the edge with this amp so i did what i could.
  
 again @ramachandra thanks for this thread.. would not of even attempted any of this if not for reading this thread. Cheers.
  
 EDIT:
 it made it alot easier with the second board sat next to me... if i forgot anything or was not sure of something... i could just look at the second board to see what i wanted to know... also good for testing one board then the other.


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## jayjayuk

Hmmm.... took it in the house last night and set it up... had it running for about 15 minutes and the rear left just producing audio and started doing the suck/pop thing again... annoying... i will just leave it for now... i am not messing about with op-amps again just yet... i have one brand new one left... it could be that as when i put the one in for the rears i did not use the gas soldering iron... the rear right works fine its just the left... all other channels work fine and upon the initial few tests all channels work... it just went bad? i will investigate when my tda's turn up and just change the tda for the rear left and if it is still bad i will pull the op-amp and check smd's ... if everything is ok i will put the last op-amp in that i have to see if that sorts it... sounds like an op-amp as when i first changed one (because the front left was quieter than the front right) it sorted the front left out and made it level with the front right... but the center produced no audio and just this suck and pop sound (the cone moves deeply in and out slowly then gives a loud pop now and then) that was the first time i saw this behavior and it was when i changed the op-amp... nothing else was done... for now i will just use the system. it is strange how it worked at first on a few tests running for longer than 10mins and its like it just goes down and then thats it... i wont hear audio out of it now untill i open it up and change something.
  
 Damn... but i am now on the right path... at least it is one problem with one channel that is one op-amp to one tda... before its like i had multiple problems with everything... least i am on the right path and should be an easy quick fix once i have the parts and open it up again... the other tda's are not clever anyway... i have bought in total 14 X tda7294's enough for two full boards so i might just have all new tda's in both boards.
  
 EDIT:
  
@ramachandra do you know what the three transistors are for on the pre-amp panel by any chance?
  
@andro6600 hows your system holding up? still running ok?


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## andro6600

@jayjayuk, hi! Why don't you just put everything in the new board you have, seems like there is quite a problems in the old one. And  about the problem with rear left channel, don't thing it is in op-amp. And it is just one opamp for both rear channels, and if you say that everything was running for a while, then maybe, something overheat and make a mess. And if the opamp is broken, in my case there is almost no sound, barely audible. BTW, i like the bottom side of your board, seems clean and elegant. Good job!  
	

	
	
		
		

		
		
	


	




 I've had problems too. This board is likely very crappy and the tracks rip off very easy, if i go too over with the heat. But the f@cking taiwans, made every cap legs bend to the track, and i can't heat them properly with heat pump, and got to apply a little more force pulling, and then the track is almost goner. I changed almost every cap in the control pod, besides that ones that @ramachandra said to be replaced. For them i considering either Nichicon FG, or KZ. Also for the TDA caps. I have heard recently one AV receiver Sony,with my speakers, and it turns out, that the Sony was much more mud sounding in high range, with a lot less clarity and definition, but mid-low end was much better then mine. Overall i liked the sound(just sats, no sub) and Sony was entirely with FG caps. So, now i am wonder witch ones will fit better - FG or KZ. Datasheets said that KZ is premium grade, but FG got very good bass. Here my system for now, the bypass caps will be putted back after i decide what caps to place in that position.
  

  

  
 The main filter caps are now replace with Nichicon KG.  Now i am in auditioning the results with elnas and KG. I know that they need some time to settle, but my first impressions are very positive! It is amazing how precise and defined sound became, The lows are good, deep, hitting absolutely correct, very tight and with fast response, witch however, in some occasions results in some lack of the... how to put it, maybe sustain of the bass, to fill the sound gaps between sats and sub. Like the notes are damped very fast after they hit. But all and all, i am very satisfied. That's why i amd considering FG series instead of elna or KZ, because i am afraid that over detailing of the sound will become not so peasant. I need to add some mid-low present to the sats, because they are more of the transparent side, and sounding more like in surround, i want them more direct.
  
 Also wonder this- the pre amp 5 caps are for speakers. What if i increase the capacitance of the, i red that this may give a better lows? Is that correct? Also i replaced the two caps that are separate with MKS2, cause with axials, the brightness was over and needed some round and smoothness. @ramachandra what will be, if i use the MKT, that i have bought for bypass, for that position? Because you recommended  MKS,MKP films?


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## jayjayuk

yes this board does seem to have some problems... but i am not just here to mod... i am here to learn as well... so if i brake something i will fix it and make it work again (in the end). i think this time it is actually in the op-amp as i had this issue before and all i had changed is the op-amp for center / front left and the center channel did this then when i changed first op-amp... now the center is working and i did not change the center tda amp.
  
 looks like your mods are coming along nicely... i know what you mean about the bent over cap legs... i use a small point tip and let the solder melt and then flick the leg to the upright position but every now and then this goes wrong and grabs the solder point and pulls it up with it. i broke alot of tracks on op-amps but i will do the next one better.
  
 i currently have mine open again and have bypassed the pod so just the amp is running on its own with rca's connected to the rear channels... i will test to see if it happens now and if so i might start looking at the pod.
  
 Cheers


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## ramachandra

jayjayuk
  
 All 3 transistors are the same and as i remember 2N4401 is the code printed on them. (Better to check) If you can not get them there are similar alternatives like BC337, BC338, BC547, 2N2222.
 http://www.onsemi.com/pub_link/Collateral/2N4401-D.PDF
  
 andro6600
  
 I think you need to wait to get the rest of the components, because it may bring the results you looking for. Many people says the Nichicon caps have brilliant mids and nothing else realy, so they are not the path for better bass or decrease the brightness. I do not know your sound preference, still i think you may like the Silmic II more instead of FG.
  
 I have not played with capacitance in the Zobel network, so i can not tell the result. As far is i know it is exactly designed for the original speakers and require some calculations to set it right. I can imagine it is not the best setup for your new speakers. One function is the circuit is to protect the TDA Amps from feedback suppression (I'm not sure i found the proper English translation) so technically you can use the system without it. Not included in most TDA DIY Kit so I will not be surprise if everything turn out better if you live it out of business.


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## jayjayuk

ok... so the problem seems to have gone away... i took the amp off the back and thought about changing that op-amp... but first i used a d-sub connector i got from ebay and linked the correct pins and attached my rca's to that instead of soldering to the board... then i can just plug it in the back of the amp and change the d-sub when i want to test different channels. bypassing the pod all was running ok so i decided to try the pod again... everything was running fine for about an hour... took it back in the house again and everything is working... so i guess i will solve that problem if/when it resurfaces. all is running good now  just have a graphic and tv to look at now while my tda's turn up for the second board... i will post back in when they turn up.
  
@ramachandra yes 2n4401 is correct... but as the problem as gone for now... i will wait... could just be dodgy conection on pins in the d-sub... i tightened it in the first time and now it is not... just slotted in with weight of wire pulling down. if the problem comes back i will look at changing them and some other stuff before i have to go at the op-amp.
  
 Cheers


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## jayjayuk

now a new problem has come to light... been reading alot about it... as i have moved the op-amps away and used wires to connect to the board... i think the op-amps are to far away from the caps and is causing oscillation (i think) all op-amps stay sort of at the same temp... around 40c... one off them for the sub heats up quicker than the others but settles around the same temp... after an hour off running the system the audio cut out on me... then i turned it off for 20 seconds and turned it back on and the sound came back on for about 5 seconds... so i opened it up... the two 47uf's on the v-regs are getting very warm 40+c and rising (so i turned off) i am not sure as of yet why the system is killing the audio or specifically which device is thermally cutting out... but most of the caps on the modded op-amps run warm/hot while the caps for the rear speakers are nice and cool... at first i thought maybe the op-amp is oscillating because the system is not tuned for these op-amps but then why would everything around the rear speakers be ok... seems more like an issue with me moving the op-amps.. i have read online to put a 0.1uf cap between the rails or two caps on a rail each to ground (the original setup has that cermaic smd very close to the op-amps legs that go straight and it has one on each rail... so the first thing i will try is one straight across the rails... if that is the same then i will try one per rail... if still no luck there is not much more for me with this board as i dont have an oscope and even if i did... i would need to do alot of learning with it anyway... so after this it will be all focus on second board when the parts arrive... i though everything was fine  oh well.


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## andro6600

Ok, i checked the v-regs again today, because this thing bothers me a lot. And for my big surprise, they became hot even without pod connected, just power switch on!!! At least the problem is clearly not in the pod. And all the caps for op-amps and V-regs are warm too, when playing, the TDA caps are cool however? Now that is not normal in my opinion. And is it normal, the power supply to make that little buzz noise, just in standby mode? I am guessing that there is really some short circuit here, but don't know how to find it. It is suppose to be somewhere in the spots that i solder new components, but can't really see anything wrong with them. Is it possible some of the diodes to be faulty after the short i made? How to measure them properly? And what values they need to be?  What to do now? 
	

	
	
		
		

		
		
	


	




  
  
 EDIT: Little update info, i checked the voltage of the regulators, and on the input i got 35-36V, and for output -18V! Isn't this a too big of a difference between input and output, and perhaps the reg dissipate the extra voltage difference in heat? If my understanding is correct, this means under load (36V-18V)x0,5A=9W that reg is absorbing and dissipate in form of heat. What are your values guys? If i put the bigger wattage resistors for the v-regs, do the help to dissipate part of the heat? Maybe heat sink is needed for that ? And this empty places for the capacitors, do they meant to be for the input of the regs, and if so, can i solder there also 1uF 100V film caps? In the v-reg datasheets, they say, that input capacitor is needed when there is appreciable distance from the main filter caps, for stability, and in my case, it is just like that?


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## andro6600

I am going to order the 3 op-amps for the analog output of the pod. I am thinking of TI OPA2134   http://www.farnell.com/datasheets/1762538.pdf   because it is much cheaper than OPA1612, but looks like the differences are very minor, in the same time looks better to R4580.  Also considering LM4562 http://www.farnell.com/datasheets/1814389.pdf  But as i can see, there is a difference in schematics of the two? Is it compatible?  @ramachandra, @jayjayuk what you thing of it.


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## ramachandra

jayjayuk
  
 Make a shield from paper and aluminum food wrap on top, than connected to the ground with a wire and cover the critical area(s) It will decrease the noise if it coming from the outside.
 Or do the "Third Mod" and save yourself from all the headache 
	

	
	
		
		

		
		
	


	



  
 andro6600
  
 Just wait for the new regs to arrive. Of course not doing harm to check the surrounding components meanwhile. The diodes have a number printed on them for identification, and the diode tester function on the multimeter is suitable for checking. Standard diodes conduct electricity to one way only. Most of the transformers are not dead silent, nothing to fix. The LM4562 is a noise bag in the circuits i tried, the sound is is ok. I do not know the OPA2134, it is also from the SoundPuls family so you can not go too wrong with it.


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## andro6600

Thanks ramachandra

The new reg TS7818CZ and TS7918CZ are already in, and running! I took the risk to put the negative one, soldered with pin 2 (in) to the plate. I checked every manufacturer datasheet, and everyone is configured with pins 1 ground, 2 in, 3 out. I thought that must be at pin 2 ground. But everything is working for now, and, don't know if i am just fooling myself, but there is a difference in sound after changing them. Became more linear and rich, especially in the low mids. Sounds somehow modern. But, maybe my Elnas starts to "sounds" better. Don't know!  But the regs still are hot, even on standby. I don't know if this is normal, never checked them before mods, but from the calculations is obvious, that the dissipation power is quite a lot. My logic tells me, that something draining current from regs, even on standby. What that could be? Aren't just op-amps, that could be draining?!Isn't they suppose to have build in mute function? If that is true, how to find which one is faulty? BTW,ordered the two big heat sinks with 4C/W resistance.At least now i can put them in TO-220 package. Hope this helps.

EDIT:
Just checked what current is leaking trough the system. Without the pod, just switched on it is 0.05A. In STANDBY with pod connected it is 0.12A. With pod switched on it is 0.18-0.19A. Are these values the normal? @jayjayuk, could you please check your system what values reading? Calculations tells, that in that case, there is about 2W dissipating power in standby, and that is too high for such small device, and obviously heat sink is needed. Also, these two resistors, are they before the inputs of the regs, and if so, can i just put there bigger resistance, to lower the input voltage? And what value is needed to lower with 6V for example? 

Sent from my C6603 using Tapatalk


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## jayjayuk

i will be back to this thread soon... i dont want to mess about with it anymore until the new tda amps turn up and i get some caps for the op-amp bypass (the third mod) i have had enough messing about with it lol i just want it back up and running again... i will report back in when the parts arrive


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## ramachandra

andro6600
  
 As i experience there is relation between speed of the regulation and heat produced, Watts and size ect. Your impression about the the new regs is normal and you may experience also difference with others. Resistors have effect on the current flow not the Voltage and increasing the resistance will keep the regs colder, but the question is how much interfere with the power requirement of the chips. The TO-220 is big and only good for testing, unless you find a way to keep them cold enough and safe from breaking off from vibration.


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## jayjayuk

tda's turned up today... at first they had the listing for 50xtda7294 = £17 .. when i messaged them they said the listing was wrong and before i purchased they changed the listing to 10 X tda7294 = £13 ... so when they changed it i purchased anyway as it was still the best buy i could find on ebay... but when they turned up today there was actually 50 X tda7294 which only cost me £13  so worth the wait as now i can do both boards... i will purchase some 0.47uf's for the third mod in next couple of days and wait for them to turn up and get back on this again... i put some 0.1uf caps on the op-amps rails and now it comes on for second and then goes straight off... so i removed all the extras i put on and will wait for the 0.47uf's and then start checking all the components again... its weird how not just one channel goes off like one channel either op-amp or tda is over heating... it all just shuts down and all i have checked so far is if there is voltage going to the op-amps... the situation got alot worse when i put the 0.1uf caps on the op-amp rails... wont be doing that again... i will be going for the bypass on both boards... if checking all the other components does not turn up any results then i will bypass the op-amps and check again... if still the same i will be putting a full new rack of tda's in as i have enough of them now.


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## andro6600

Ok, new problem. Today i replaced 22uF with Elnas, and bypass them with 0.22uF 100V Vishay. Everything was good, but after power on the sub, the control pod didn't turn at all!!! What is wrong now? The power supply make this buzz sound, so i am guessing that it is working. 
  
 EDIT: So i figured out. It was blown resistors of the regs. I find that one of the legs on the two regulators, the tracks under them was broken.( I knew that's going to happen, because of the heat sinks) So i manage to fix them soldering direct to the one side of corresponding smd, then used moment glue to stabilize them more. For now, i am gonna leave that way, until final completion of the system. Here some pics: 

  

  

  
 I wonder, is it a problem, that two heat sinks are connected to the side ones, because the plate of the regulators maybe can make a short circuit? On the +18V, plate is ground, but on the -18V is input? Is this gonna cause some problem?Do i need to isolate the aluminum buses(maybe some painting) to prevent the eventual short? I kinda like them that way, because they dissipate some extra heat to the sides.


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## ramachandra

I'm impressed about the way as you managed to keep the heatsinks in place, and you found a good size too to keep the regs cool enough. The board is almost complete. Nice job! 
	

	
	
		
		

		
			





 The negative regulator need an silicone insulator indeed. The sinks look stable enough still better to not underestimate the Sub. If you connect the two sinks together it will minimize the vibration, and the stress on the copper tracks. A U shape metal strip between can do the trick. What do you think about the sound with the Elnas now? As i see the pair Nichicon KG is arrived and in place too.


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## andro6600

I considered too, putting the strip between the sinks, but thinking of plastic instead of metal, just to be sure that no shorts can occur, even the sinks are anodized. 
About the sound. Man, i can't explain how much i am impressed! First thing that blows me away, was how good is separation of the channels. Everything is positioned perfectly, the difference is almost the same as with changing the opamps! Insane!  In the lows, things become even clearer than before, some little deepness added, and you were right, that Elnas will fix the problem with the low mids of the satellites. Now there is more thickness in that frequency range, and this helps for the better integration between sub and sats. And while before, sounding was kinda loose, wich is nice sometime, but the definition was not there, now it is very tight and the definition is outstanding! Especially with the movies, effect is even more! Nice! And the last, the timber. Every instrument sounds much more accurate and natural. Somewhat everything is more musical! To sum up things, presentation of the system is quite close to the headphones filling! I love it now!  

Sent from my C6603 using Tapatalk


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## ganjouille

Hi!

Very nice work! Respect... Maybe i will do some modifications too. But first I want to put the z-5500 in my car.
My plan is to put the power stage out the box, to take the sub membrane? Out and fix it in the back of my car, and use the case as subwoofer 

Maybe I will use the other speakers too, or at least a part of it...
I think I need the pre-amplifier stage for recieving analogical signal.

But, my first questionning is about power supply. What is the best way to feed the amplifier with a car supply at 12V DC?!

And can I shunt the digital section and only use analog input? Without the pod and the rotary button?
Can I regulate each channel gain/volume directly on the pcb with variable resistors?

I you have some schematics of the power supply section, or any informations about my project, thanks a lot I'm, not really electronician, but more from electrical side. I have a bit lnow-how it works, but not enough to have fully clear seeing... (

Sry for the bad english...

P.s: I live in switzerland under 230V/50Hz
[@]ganjouille.dk@gmail.com[/@]

Thanks for help


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## jayjayuk

@andro6600 i thought about the same thing... to put the sub into my car... they way i thought of doing it was either by using an inverter to step the voltage up from 12v to 240v and use the 240v in as usual into the sub (as long as the inverter has the correct current capability to handle the load (on the back of the sub i THINK it say 1.5A) or the only other way i was going to do it was to wind my own transformer (which i would really like to do for some reason  ) use some big thick wire and put quite alot of turns on winding and then calculate how many turns on the primary side relative to the amount of turns on the primary side to give me the voltages needed... i dont think it should be to hard... i know for definate there is an 11.4v tap-tap (on its own) and i think the other is somethings like (would have to check) 16.? to center tap, so from 16-0-16 which gives 32v (now i think it is more than 32v but those voltages would need checking... they are written on the transformer anyway so would be a case of looking. they are the two ways i was going to go when i had finished my sub.
  
 yes you can bypass the control pod using the pins on the d-sub connector 6-7-8-13 then solder rca's to the correct pins for the line in (using pin 13 as the ground for the rca's) this is what i was going to do.
  
 i read something online that a car sub is different or the frequencies are cut differently because it is a car and the shape of the car relative to the seating positions... so they can actually use higher frequencies to create lower frequencies by the time you hear/feel it in the seating position... you maybe want to read up a little bit on this first... i read a few pages when i was looking for a replacement sub for the second board as i have the box and amp but would need a sub, then i read that as i wanted to know if i could use a car sub instead. just a thought before you go slamming it in... this logitech rattles everything in my house.. the staircase... the wardrobes upstairs... the girlfriends temper  so you might be sat at some traffic lights and you go to move of to find your wheel bolts have vibrated out and your wheels fall off  hahaha
  
 Cheers


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## ramachandra

This is what i found about the original Z5500 transformer:
  
 Input: AC 120V or 110V 60Hz. (US version)
 Output:26.2V-0V-26.2V(5.7A) +14V-0V(0.5A)
 Power: 300 W /VA
 Dimension :115mm Diameter x 45mm High
 Weight:2.2Kg
  
 Other than the input the rest should be the same for the European.


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## jayjayuk

yes i had the voltages wrong... i had a feeling they was wrong... i have another toroidal transformer which i must have remembered 11.4v from. yes mine is 240v... i would match the output voltages and the current capability for each output and it should fire up in a car.


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## andro6600

Ok guys, my mod is finally complete!  
	

	
	
		
		

		
		
	


	




 Here are full modifications i made to the system.
  
 First, replaced satellites with Yamaha NX-E400 for the front, and NS-P60 for center and surround.

  
 Then i replaced speaker for the sub with Pioneer TS-W260D4, witch is one of the most significant upgrade sound wise.

  

  
 And i put some extra damping in the closure with cotton wool, with careful listen to the effect and needed quantity. This is also VERY important to the overall sounding in the lows, and even for my surprise, the difference was huge!
 This two upgrades, took the system from barely usable for music listening, to a comfort state. Good!
  
 WIRING: Change the thin cables to the sats, with professional Proel Speaker cable, AWG 14  http://www.musicworld.bg/en/c_2288/i_2466/Proel_HPC740.html
 which brought some nice detailing of the sound.
  
 Also replaced internal wiring of the sats with this one. For the sub internal wiring, i used same cable but AWG 11. Now i am sure that the system runs some quality cables.
  
 RE-CAPING: The POD: Replaced everything except the analog in caps with Panasonic FC/FM series, with doubled voltage. The op-amps for analog out are TI OPA2134.

  
 The AMPLIFIER: Everything on the main board with Elna Silmics. For the main filters - Nichicon KG. Op-amps TI OPA1612AID - incredible improvement! On the Pre-amp for the front speakers used Wima MKS2, for the center and surround K-73 16, because fronts were too bright, and Wima caps are more thick and round sounding, this way i made them more similar to sound signature of the rest. 
  

  

  
  
 Also, replaced all resistors with metalized ones, at 0.6W, and voltage regulators with TS7818CZ and TS7918CZ, and managed to cool them well enough. Also replaced mica sheets of the TDAs and new termal paste. About the bypass caps Vishay MKT, i decided to leave them out of busyness, because they made the sound somewhat restricted and lack of refinement of the Elnas. As is seen, i stabilized all caps with hot glue.
  
 And last, i re - cap the crossovers of the front satellites with polypropylene Mundorf. Because of the sound signature difference between surrounds, i decided to change cross frequency, and lower the value of the caps from 8.2 to 6.8uF and 3.3 to 2.2uF to lift the frequency a bit higher, and now the sounding is more matched, and also i find them better sounding this way.

  
 So! After many hours of work, reading on the net, waiting components, millions of times opening and closing the box, soldering, desoldering things, the final result is AMAZING! The system now has real high quality, at par with at least middle class AV system, or dare to say, maybe a little better from some. Overall sound is rich, modern, detailed, powerful! Real pleasure to listen! Thanks to you guys @ramachandra and @jayjayuk! Thank you for the help, and responsiveness! Wish you well!


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## ramachandra

Now that's what i'm talking about!


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## Baserunner

Hi,
  
 With great interest I was reading this topic over and over again today. My problem: experience. I stuffed the sattelites with cotton wool and hear a slightly warmer sound, so that's good already 
  
 I would like to know what part of the modding is the easiest to do with the best results possible. I don't think I want to fiddle around like in mod number 3. So as I understand, the best thing I could do is just to replace the opamps in the sub and in the control pod? I opened up both today to have a look, but saw that I have a different configuration than the ones on the pictures in this thread.
  
 If I decide to go and have a shot for better sound quality, I'll post pictures 
  
 Thanks in advance for your reply.


----------



## andro6600

@Baserunner , hi!
  
 You are correct, the most valuable difference, with minimal hassle is to swap the opamps. This doesn't need to disassembly the main board(witch is the most annoying part) I suggest OPA1612, or at least OPA2134,(assuming you got the R4580 opamps in the board) witch is not that precise and detailed, with not as good imaging, but still much better than stock R4850. The other best thing is to change wires to the sats, with something quality and as thick as you can, with lowest impedance as possible. For more quality bass, you can play with the cotton wool in the sub enclosure, and decide what quantity is needed to make the bass maximum integrated with the sound and less boomy, damping the inner corners makes wonders for me, but you have to try what is best for yourself. You can also get a better set of sats, and replace sub speaker. That is the painless way to upgrade your system performance, without digging in the deep, as we did. But, believe me, if you start this, once you've heard the improvement, you going to want more modification! 
	

	
	
		
		

		
		
	


	




 Good luck!


----------



## Baserunner

Okay so I went out and bought myself an okay soldering kit, because I decided to go for it  I soldered before, but not a lot so I need to watch some more youtube videos on that part I guess. If you guys have any video footage of the process, please share! I'll buy 12 OPA1612's, so if anything goes wrong, I have a spare one left.
  
 About the wiring, this is something I can do in the future I guess. I might move houses within half a year or so, so it's not wise for me to think about that at this time.
  
 The sub hole on the side is stuffed with socks at the moment, which makes a tiny difference in the boomyness of the sound. I have a lot of cotton wool left, so I could go on and try and stuff the inside with it. What did you do with the hole on the side? Do you maybe have pictures of the cotton wool in your sub?
  
 Thanks, and I'll post back when I received all the gear


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## andro6600

There is a plenty of youtube videos for desoldering IC's. Here a good one  https://www.youtube.com/watch?v=tlSY1uaw0GA
  
 About the sub - you don't wanna port stuffed, because this is also engineered for dissipation of the heat from the electronics inside the enclosure. And the enclosure itself is measured for the particular speaker, to be vented type. Basically, a thin layer cotton wool on the naked sides will be enough. If you want to reduce the air flow in the port, you can place a layer wool right under the port. But again, everything is up to your current placement, room acoustics and your personal preference. What's best for me, may or may not suits your needs. 
  
 Cheers


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## jayjayuk

So i got back on this about a week ago, things are starting to go alot better now. i was being stupid and not using anti static equipment and not cleaning the tip, the problem was the tda amps i was soldering right/carefull enough. i focused on one and threw about 8 in one position (front left) and they keep running hot for 10 secs then would shut down (no sound) after which they just shut off without getting hot at all, i got past this problem with new equipment and clean tip and they have gone in one after another on both boards i have and all work fine... except for the sub on the second blown board i have but that will get worked out.
  
 on my main board i started to rip the track up for the voltage feed to the op-amp, in the end it got so bad that it was either transfer to the other board and work on that, or take a chance on the op-amp bypass for the sub (U15) where i got up the data sheet and joined the + inputs to the outputs, i also remove one shunt resistor R618 and R617+R619 - at first the volume was low for the sub so i lost something... then i removed R617 and R619 and put a bridge across all the terminals for those two resistors (this is the input signal being dropped so is ok for op-amp) the volume improved but it is still low and does not punch as much as it once did, also for people soldering in op-amps. you can use what i said on U15 to bridge it first, then you know if U14 is in correct (this is what i am going to do with second board) then remove the bridge and work on U15 until it works. i am upset about the loss but i have a plan for that, and i am glad everything is working again as it should, all the sats sound fine and good, i have designed a board to be able to put an op-amp back on U15 which i broke as i think it needs to be re-amplified after it has gone through the first part of the signal filter for the sub.
  
 i have also been drawing schematics for this amp board, they will be separate and not professional as they are the first ones i have drawn but i hope that they will help someone if they become stuck like i have and will be able to trace things better. i am still working on a full schematic for the sub (i have done one full op-amp, i am at the point where it runs over to the second op-amp then towards the tda amps) all diagrams will have the components values and codes (except the very small caps, i need to get a new meter to read the low values) but so far i have ready real pics of the board, then a diagram that i have drawn showing the connections for the op-amps and surrounding components for all the sats, thats what i will be posting here today, and also the board i have drawn up for repairing the U15 with components on the board using wires to connect back to the original board, but all the fussy stuff will be on the secondary/break-out board like the 0.1uF caps for the power rails as close as possible to the op-amp rail pins (4&8). so here goes...
  

  

  

  

  

  

  
 Those are for the sat speakers... this next one is for the sub, which i took a camera pic and drew directly on the camera pic to show where the connections go on the top side of the board, the full sub schematic will have all the component values in.
  

  
  
 in the end i will have full schematics for this amp board (not control pod lol) they will all be separate for each separate channel except the sub which splits into two but this has to be done as one anyway so in total there will be 6 different schematics for the 6 channels starting from the input at the D-Sub connector right up to the output terminals for the speakers and subs so i am going to do full schematics but also littler ones like the ones posted so can focus on just that area at a time if needed. i will also post fixes that i have had to do. here is one fix that i will be building to replace my broken U15 area which as of now i have bypassed... (i think if i removed some inline and shunt resistors down the signal path from U14 to U15 then i could get the voltage back up and have the power back, but i want to draw up some schematics before big changes happen lol)
  
  

  

 (EDIT: Take note of the Negative (N) marker for the electrolytic caps)
  
 took some time to do just this what i have posted and there is lots more to do... hope someone finds it useful.
  
 Cheers


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## jayjayuk

@andro6600 sorry i did not comment on your mods, i have been looking through the forum now and then and keeping track but i have been using these pages for info while i have been frustrated with my own dooings lol.
  
 great mods you have applied there, i like those heatsinks and those regs, in a word... BEAST. hopefully mine will go that way aswell, still alot of work to do but it is now finally getting there. i have another amp which i am very hopefull to get running soon aswell and i have the box and no sub for it... how much did you pay for that sub if you dont mind me asking? i want a good sub driver but i have never really looked at different drivers to know what is good or not so i ask advice  what i was thinking was keeping one with the logitech sub in and another one with a different sub, i want to do the schematic for the board and then study it over the datasheets and see what i can change to really push those tda amps, once i have the schematic i will not really be bothered about hard experimenting with it as i will know better where to look and replace the components once i know the values.
  
 good to see you overcame your problems with it and all is working fine and to your liking.
  
 Cheers


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## andro6600

Hi again 
	

	
	
		
		

		
			




  
@jayjayuk, you have done incredible work on schematics man! Respect! Seems that you've got some pretty good knowledge in this, i am sure it will be extremely helpful, if someone want to mod or just repair something broken in the system! Meanwhile, i made little more upgrade on the pod, with Elna Cerafine at 50V, for the op-amps, and Nichicon LF(polymer) for volume control. Just wanted a bit more "live stage" feeling in the sound, and Cerafines seems to meet my needs, from what i've red. At the moment they are not break-in, but initially impressions are just i expected. And the effect from this polymer cap is, bringing highs a little more in front, maybe adding little sharpness to them, but i like it! 

  
 I had to cut a bit of the back cover of the pod, because the Elnas are too big, but no worries. 
  
 About the sub driver Pioneer, i got it for 70 euros, in my country, and with little playing with the cotton wool, as i said before, the results are amazing! Hope, everything will turn right for you too, man! 
  
 Cheers


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## jayjayuk

thanks, it is taking some time to do them, i did a little more on the sub schematic last night, got upto the U6 tda amp, done most of the pins on the U6, i have found how the system works the amps together... the U6 is the positive feed (non inverting on pin 3) which uses the wire on the back of the board to go from the bootstrap cap on U6 and takes it straight to the negative feed (inverting input pin 2) on U7 then pin 14 on U7 is bootstrapped to pin 6 and you get the negative feed for the sub. i am learning alot from tracing a drawing it. like the op-amps, they just loop in and out of each other while passing through the capacitors then one out feed on U15 is fed to pin 3 on U6, i thought it was going to split the signal before and let one tda invert and the other non invert, but i was wrong.
  
 cool mods on the pod, i will eventually go that way aswell of replacing the caps in the pod but my pod rarely gets used at the minute, i just attach rca's to the pre-amp panel pins to where i want the signal, and trace audio using an earphone and meter probe, this is how i knew op-amp U14 was working which is why i took a shot on the U15 bypass as i knew it was that area that was the only problem.
  
 i will have to keep my eye out for a sub to go in the other box i have and get that board up and running... all is coming together and what seemed hard for me to get working is now very easy.
  
 i had to cut a bit of the back of my pod to give the fan more air flow, it works perfect and with the fan off the pod gets very hot after about an hour or two, but with the fan on it is constantly cold, i hope i dont have to loose the fan to get big caps in there  .
  
 keep checking in with the new mods you have done, your system must be sounding  
  
 Cheers


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## jayjayuk

Here is the next one, i got carried away chasing the mute and standby pins of the tda7294 amps so i started at pin 8 on the pre-amp panel, pin 8 leads to most of the pre-amp board so i just did the pre-amp board now, will carry on with the sub schematic next.
  

  
 EDIT : some things i cannot test right now, like the smd capacitors as my meter is not good for capacitors with low values, so the two things missing from the schematics will be smd cap values and zener diode ratings as i can not see the markings clear enough to tell what the zeners are.


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## A-Force

Hi!!!! I have a big problem with the sub woofer from the beginning with z5500. I think that the sound of the sub woofer isn't flat at all.. so many years i ve tried everything from eq settings to all the different places in the room in all rooms of the house...even in a different house...and the only place where you get the most accurate and deep bass is when you put the woofer to the one corner of the room and your listening position is on the opposite corner. So i bought and a second z5500 system in order to have two woofers because i 've read with two the bass is better and more accurate all across the room and not only in the corner...BUT... with two the bass was even worse..  full boooooomm and the low range was missing..the bass was terrible. the same happened and to the outside where there are no room resonance. so i decided to go and buy 2 proper woofers(i was thinking of 2 crystal audio thx-10subs) and have at last good bass. before i do this i was hoping maybe there is still hope with this mod. i ve read somewhere here that the opa2228p will result in deeper and nicer bass... i found that there are some models like opa2228u that they are soic(D) and not pdip(p) and probably they don't need an adapter. Do you think the mod with this chip would be better instead of the opa1602aid for the two op amps of the sub?? do you have another recommendation maybe for the deepest bass without booooom? thanks in advance and i hope to find a solution at last... :-/


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## jayjayuk

@A-Force i am new to this and have not done much experimenting with op-amps so it would be better for @ramachandra to answer your question 
  
  
  
 Here is the next schematic... it is of the power supply area, from the transformer's outputs to every point that supplies power to the sub and pod... i have terminated them stating that they are the COMMON for wherever they will go to the circuit board. i have done the sub schematic which includes the power supply area and the pre-amp board, but i have not double checked the sub part yet so i will post it after i have double checked everything is ok... here is the power supply...
  

  
  
  
 EDIT:
  
 i have a new test meter on the way so when it turns up i can check the values of the smd capacitors and make the changes to the schematics and change the pictures here... what i thought was zener diodes are actually normal diodes but they are the glass signal type diodes, still have to get the codes for all diodes aswell, so diodes and smd caps are missing, but as i said, i will fill these in as and when i find them out


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## ramachandra

A-Force
  
 During the years Logitech made some big or small changes like switching mostly from Su'Scon capacitor brand to Tbor, and i found boards where the OpAmps for the Sub is not connected to each other on the PCB (maybe the latest PCBs) so the bass is a bit different. I had OPA228UA Soic only as sample a while back and I was not impressed, certainly not the same as the OPA2228P or PA. This far the OPA2228p have the best Sub-bass i have ever heard. One of my friend is also confirmed, this chip is without competition for the modified Sub for his other project. If you lucky the space near the wires let you use adapters for the OPA2228P chips. (The OPA228P is the mono you need the stereo OPA2228P)
  
jayjayuk
  
 I see you take it seriously. Probably no better schematics on the Internet yet for the system or i have not found it.


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## jayjayuk

@ramachandra i have not found and as of yet either, the most i have found is for the pre-amp board, and parts of the pod for the signal coming into the pod and through the relevant circuitry and out of the pod to the sub (but no full schematic for the pod either). the schematics i have drawn are not the best lol as these are the first ones i have actually drawn like this so there is alot of room for improvement... but least from these you will be able to see clearly how the components are connected and what values they are (in the end) so hopefully they will help anyone working on this sub.


----------



## jayjayuk

OK... so i have double checked it and everything seems to be ok, missed one resistor (R627) but i corrected it  this is the full schematic for the sub circuit which includes the power supply section and the pre-amp panel all in one. when my new meter turns up i will go over smd caps but they will be exact readings of the ones on my board as there are no smd markings (is the best i can do) then just the diodes, but it is getting there. was a lot quicker to check it as i have it in this picture to find my place from the schematic to the board so it quickened the checking up.
  
 the TS|BS  and BS|TS indicate when the track runs from one side of the board to the other (i have missed some in some places but it was mainly for me when doing it, as the board markings are also in the schematic so you just go from one marking to the next)... gets a little hard to follow if just looking at it but once you start following tracks on the board it all makes sense 
  
 SUB CIRCUIT SCHEMATIC
 ----------------------------------------


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## A-Force

Thank you very much for your answer!!!!! 2228p it is then!!! do i need only two of these in the sub or should i replace the sub op amp in the control panel and the sub op amp in my audio card(sb x-fi titanium) as well in order to get the proper result? Should i prefer mouser or eBay is fine?     http://www.ebay.com/sch/i.html?_from=R40|R40|R40|R40|R40&_sacat=0&_nkw=%22opa2228p%22&_sop=15     eBay has many different looking chips as you can see with different writings on it.. i dont know what to pick :-/


----------



## A-Force

Thank you very much for the answer!!! 2228p it is then  should i buy only two of them for the sub or i have to replace also the op amp belongs to the sub in control panel and in my audio card in order to get the proper result?  mouser or eBay is fine? i saw e bay has many different writings on the chips...i don't know what to pick.  any recommendations?  http://www.ebay.com/sch/i.html?_from=R40|R40|R40|R40|R40&_sacat=0&_nkw=%22opa2228p%22&_sop=15 (sorry for the second reply...)


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## ramachandra

http://www.ebay.com/itm/2pcs-OPA2228-OPA2228P-ICs-/180575202092?pt=LH_DefaultDomain_0&hash=item2a0b1eeb2c
  
 If you upgrade your soundcard, Pod, Sub with better OpAmps it is certainly result more accurate bass, crisp clear more musical sound. The only thing is OpAmps is alone about 40% improvement for the bass you really need to work on the caps too. The caps is the real badass for the bass and dynamic but the stock OpAmps unlikely let it happen so they must go first than you can do more later if you like. My advice is to star a full mod on your Titanium card and leave the rest after that. If you buy in bulk Mouser is preferable, at least to my location no shipping cost beyond 70€ and take no more than couple of days to receive.


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## A-Force

thanks for the reply my friend!!! you are the best!!! That s what i am going to do...   (you didn't understand my question although) i meant on the titanium instead of 4x opa1602aid maybe i should put 3, and 1 opa2228p for center/sub channel, and the same to control pod for the best result? or i only need to put them only in the sub (replace the 2 op amps of sub with 2228p) and the others(titanium, control pod) 1602 :-/  i was thinking to do the 3rd mod but i cant find the military caps k73-16...is there an other recommendation to buy? my priority is the deepest bass from the sub woofer. as for the control pod cap.... is this cap play role for the bass or only the main filter caps(Elna for audio 10000uf 80v) and the 4 caps of the sub op amps (silmic ii of course  ) for the titanium the tcxo 0.1ppm is the best because i know the 0.3 is better from 1ppm for a bit more money. sorry my friend for many questions. it is because i don't want to make any mistake with the choices :-/ Thank you again.
  
 p.s. the modifies titanium.. you think it would be better than the new asus stx ii 7.1 or at least comparable, for the z5500?


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## ramachandra

I have never had any ASUS card, but i have some experience about the components on the STX and i do know what not to expect. The Nichicon FG is good, still not the league of the Silmic II, the PCM DACs are refined and gentle with a nice 3d touch compared to the Titanium's Cirrus Logic what is a rough beauty in comparison. When i see the JRC letters on OpAmps i always sure replacing them is essential, the rest of the National OpAmps usually ok. The ASUS card have a DAC chip for every single channel so it result better clarity but do not have an ultra precision clock so it is going against it if not good enough. The modified Titanium is my pick unless you ready to work on the STX.
  
 For a complete mod i only recommend the OPA2228P in the Sub of the Z5500 or on the Titanium (if the speaker can handle it for both 
	

	
	
		
		

		
		
	


	




)  Better to not use it in the Pod by 3 reasons.
  
 The eBay's search engine is playing the fool today, still i fund them:
 http://www.ebay.com/itm/0-47uF-160V-PETP-Mylar-Capacitors-K73-16-Lot-of-10-/201120413110?pt=Vintage_Electronics_R2&hash=item2ed3b5f5b6


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## A-Force

The caps you used as i see in the pics are 63v. these you suggested are 160v. you think they are the same size or bigger? will they fit? for the control pod cap what is your recommendation?
 To my second z5500 system the front left speaker stop working years ago. you think after the mod maybe it will work again? (you can barely hear it only when the speakers are full volume and the other speakers are disconnected. it has the volume of cheap headphones)


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## ramachandra

The 160V a bit bigger, no problem. On the image you can see what capacitors i have used for the pod and also you find in the description under "*You may need:*".
 Use Silmic II if you prefer warm analog sound or Cerafine if you like accurate with less coloratura. The best "upgrade" for the Pod is to live it out of business and use a direct cable connection to the Sub from the soundcard.
  
 I think the OpAmp belong to the front left channel is is dead in the Sub (common problem) and the K73-16 will fix it. If not you may need to replace the TDA Amp near the thick yellow wire.


----------



## jayjayuk

has anyone noticed that on this sub... the rear speakers are variable with the pod? and also the center speaker.... but only when the center and rear's are set at about half volume are they level with the front speakers... like the front speakers have got more attenuation on them? last time i did this test i used RCA's and bypassed the pod and it was the same... so the attenuation is in the sub... i have also bypassed the op-amps for sat's and it is still the same so its not those either... i will check a little later on as i have just got up but there is one shunt resistor left right before the signal goes in to the non inverting input on pin 3 on the TDA7294 IC... my guess is that this shunt resistor is going to have a higher resistance than the rear and center speakers... but i will have to check this a little later on. how i see it is... if the rear and center can go louder and the board and drivers can handle it... then it is the exact same configuration on the board and divers except the attenuation... so i will try and get the front speakers back to the higher level like the others... or at least figure out three quarters and put them there so you can have extra boost on the front than factory but still be able to go past that with the rears and center... i will check back in with results... on my second board everything works apart from the sub (got parts on the way) so i can test this on there. got a mixer to fix right now that... bad PSU plus my good soldering iron has broken so waiting for another.
  
 Cheers


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## Abdiel

Hello guys! 
 I've registered so I can discuss about Z-5500 modding.
  
 I too have one system ripped apart at home and doing testing and whatnot with it.
 My idea was to create entire new amplifier board with separate 6 amplifiers, using Control Center(pod) as a volume/input control and Dolby Digital encoder. The idea was also to make new speakers just for this upgrade, making the front speakers capable of delivering more low frequency. As I would recreate all speakers and amps for 5.1 system, I wanted to make a smaller 2.0 set which I would also control with the pod.
 But, I guess that's not gonna happen...
  
 I've created a new amplifier with TDA7294 and connected it to front left(or right) channel(before op amps in subwoofer amp plate) to check what kind of signals do I get. I used larger speakers, and sound was lacking bass. So I connected it to sub, and it was full of bass but also you can hear some voices...bad 150Hz crossover. 
  
 Anyone knows how to enable LFE for sub to go to front speakers and lower the bass cut-off frequency from 150Hz to 80-100Hz? 
  
 I've studied all chips on the pod board, CS42526 is an input selector, maybe it's doing some ADC(assuming all of this), NJW1150 is a volume controller and CS494003 is a DSP, which I guess is doing all the hard work around here(also cutting the frequency).
 You can add more bass/treble with NJW1150 on front speakers(needs to be controlled over I2C, bypassing Zilog MCU(I've worked with Microchip, Atmel and ARM but not Zilog)) but the end product would be the increase of frequency of 150HZ and more.
  
 Final option is to use few opamps and mix the sub output to front speakers. Not sure how well would that work or sound.
  
 Anyways, if someone has an opinion on this, feel free to elaborate with me.
 Currently I feel disappointed, even if I can control NJW, I can not get a full range frequency on front(or even all) speakers.
 Anyone hacked into DSP? If yes, lemme know! 
  
 Greetings from Croatia!
 Cheers


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## jayjayuk

@A-Force i am pretty sure your problem will be with the op-amp as mine went quieter than the others and when i put a new one in it fixed it.
  
@ramachandra i have done the op-amp bypass on my board and have it running... but for some reason i think when i turn the volume up before it had more power to give when the op-amps was in... i think this might be because the attenuation resistor just before the tda amp now does not have enough resistance for the direct connection... so it is shunting the voltage down to much for a direct connection from the input signal... what do think about this? i was thinking of changing the resistor for a higher value as to not let so much voltage drop... i will post back the results when i have tried it... but for now... i built that board i posted here to fix U15 and use wires to connect back to the main board with and everything is working fine again... been running for about to hours now... been sat on my bench in pieces for ages now so just enjoying it before i do anything else lol... inside that sub does not look pretty as there is alot of broken tracks and fixes here and there... i am just glad it is working again. i bought a bag of 50 x R4580i from ebay for £15 as i could not keep throwing OPA1612's in as they are expensive to keep popping... so went with the cheaper (original) option until things are smooth again... then i will by a couple OPA's to put back in the end. it is sounding pretty good... that hum i told you about seems to be gone... i have not changed main filter caps... maybe a bad ground or position of the cables inside like you said... but so far i am happy with it except for that i think that the overall power on the sats has dropped across the range so i will look into that


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## ramachandra

When i come up with the idea of the Third Mod i was afraid of this might happen and i tried it out on a front channel, and I left the other untouched. Than I have compared the two sides and i have not noticed any downside, the Pod was modified. Some of the SMD around the OpAmps can interfere i think, that is the reason i got rid of them completely. I'm interested when you progress further what will be your conclusion, i can be wrong. The cheaper OPA1602 sound more alive than the more expesive OPA1612.


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## jayjayuk

i will have to experiment with op-amps at a later date... i did not do the comparison you did as i was having problems with op-amps so i bypassed all in one go... if you say they are the same then i will accept your testing but i will continue to try and change the attenuation... i will try this ony my second board... i have all sats working just need to work on the sub area... i was also thinking (a big shot but i have been thinking alot about it) to get a board for the tda amp and use it in the same config as the sub (straight off the bootstrap to the inverting input) and then use that output as the negative for the sat speaker (just change the negative from the main ground to the inverting amplifier and it will give the sats an extra 50Watts (i think) but thats a mod for when i have tried other things... first i am going to try the attenuation resistors near the TDA's to boost the signal... this will only be a very small change in resistrance as i dont want to do it to much and the unit thermally shuts down... i want a bit more power but i still want constant use... which leads me to attenuation resistors or a sub tda board for an iverted negative to the sats... i will keep posting in every now and then with results... the sound is not greatly decreased i just mean when the volume is all the way up it seems like it had more to output when the op-amps was in... but the whole board and that end attenuation resistor was initially set for the op-amp in place so now the system is different and may need further modding of that resistor... tests will tell  i do like the idea of powering the negative thought... that would boost this system very well i just need to find a suitable board on ebay so i can plan and place all the components on.
  
 i also noticed that the front speakers (as stock) are attenuated to half the set volume of the pod's center and rears... so you have to set the center and rear speakers on the pod at half so they are the same as the front... this is done in the sub as i have used rca's on the sub (to bypass the pod) and the attenuation is still present so it is in the plate amp... and with the op-amp bypass there is only two components left before it goes to the non inverting pin on the tda amp... that is an smd capacitor and smd resistor both of with are connected to ground so it will be the resistor that is the attenuation (i need to check this though as if the resistors on the front are different values to the ones on the back and center then i can change them and get the same level) although i want to keep it slightly under the full level of the rear and center.
  
 i will get back on this soon as i have a couple of mixers to look at and fix at the min.
  
 Cheers


----------



## Abdiel

So, no feedback about crossover frequency?
 I hope someone will comment about it, I would really like some opinions.


----------



## andro6600

abdiel said:


> So, no feedback about crossover frequency?
> I hope someone will comment about it, I would really like some opinions.


 
 Hi,
 about the HPF of the satellites, @ramachandra said to me before, that the filter is most probably in the volume control chip. But i don't have the knowledge to fix this. But anyway, i am not very sure, that the system has actually HPF. I tried satellites with test signal 20-20KHz, and i definitely can hear frequencies about the lowest satellites border, but they are somehow fading, but very slowly from about the 100Hz below. I mean, they are there, not cut, but with less gain that is suppose to. So, the only easy way to me was, to get the sats, that reproduce low mids very well, in other words, you need speakers that go down as low as possible, so they can remain very linear and accurate in the low range (also the Elna caps do helps a lot) This is not exactly the solution, but with right combination of mods, and sub placement, so that you can get impression that lows are coming from sats, not the sub, the result is impressive! But i also would like to know, if something can be done, for that problem, because, my sats, are quite decent, and can go very low, and it's a shame not to. 
  
 Cheers


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## jayjayuk

@Abdiel  sorry i am fairly new to electronics and have not looked into filters yet... although i can see my self getting right into them after i have finished playing with attenuation and possibly doubling the tda7294 chips as to have the same config as the sub but with no filter... i have a plan for this but looking hard to fit it all in. please if you can... send me the pdf documents/datasheets for the chips in the pod and i will take a look.
  
@ramachandra i got the second board fully working last night.... the only problem is i am missing a capacitor to ground which if logitech stuck to the datasheet components should be a 0.47uf 0603 to GND but i do not have one... it does not make a difference though... chip runs for hours and does not get hot or sound different to the other speakers or get hot any quicker so all is fine but i will be getting a cap to put back in... that was on the rear channel and the main broken tracks (to which i had to use a 680R metal film instead of a smd 681R) is on the rear channel so i left them and have started playing with the front channels for comparison.... heres what i am finding... i was initially wrong about the attenuation of the speakers (front/all others) the attenuation is done in the pod probabbly so the fronts dont over power all the other speakers and you have control over it. i had got some smd resistors in to make the board for U15 on my first board so i had alot spare.... the original resistor R500 (i think) is a 22.1K smd 0603 right before pin 3 to the tda7294 (non inverting input)... so i figured i would start by changing its value... to have less drop (audio drawn away) i wanted to increase this resistors value so less would pass through it to ground so i put a 31.6K resistor in there (spares that i had from around U15, R617 or R619 is 31.6K) and it changed it just slightly... i was looking for big sound attenuation difference or very slight visual (cone movement) difference... what happend was i can hear the sound is slighty above the unchanged channel i can also see that the cone is moving alot sooner... so if i start at low volume where i cannot see the driver move to the bass and slowly increase the volume until i can see the movement then the channel with changed resistor will be visable and audible first (although the second is not far behind) i am going to try something else a little later on (as i have spare chips so why not) i am going to try puttin a 90.9K in there and see if there is a big difference i will then try and leave this resistor out completely and see what happens...also on the tda7294 chips people can save on caps here as there is 2 22uF's for one tda amp... one of them is bootstrap but the other is either mute or standby (cant remember which) but it is seperate to the signal path... i think money can be saved on caps here as they dont enter the signal path.
  
 More tests are coming... i only got this fully working last night and did one test but now i have two boards that fully work... i have an idea... snap all tda7294's out for the sats only... then cut pin 2 and 3 half way back... then solder wires on these pins and solder the chip in place as usual... but swap the wires over so pin 2 goes to hole 3 on the board and pin 3 goes to hole 2 (so the inverting and non inverting are swapped around) then i will have a plate amp that has the sub output as normal but all the sat speakers will be inverted so i have the negative... then i can mount another d-sub 15 pin connector on both plate amps and do the necessary wiring so standby and mute work and i will have two working together.... so i will have a 5.2 system where the original sats will have an extra 50-80W (not sure about the gain here) and i will also have an extra sub output... all of this i am pretty sure i could do... things like how to wire to both speaker output terminals i have not thought about but this will not be a problem if i sit and think about it... the main problem i am having is if i get all this to work (which i am pretty sure i can) i dont know how/where i can mount the second plate amp as there is no room on the box to do it and i dont want it separate from the sub box as this would make it so i can wire everthing internally and not use extra d-sub 15 connectors to connect the two together and everything will be neat and tidy... but i cant loose the plate either as the big heatsink will potentially run another sub driver and be inverting the sat speakers... so i need that plate with sinks on... more thinking on this is needed (possible another wooden box mounted/bolted to the top of the original so i can fit the plate amp on top and drill a big hole between the two boxes on the inside for the wires to pass through) i like this idea but its just getting everything together so it looks good....
  
 more to think about and more to do... i will report back when i have more news...
  
 Cheers.


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## Abdiel

@jayjayuk
 There are 3 main chips.
 DSP: Cirrus Logic CS494003
 Volume control/ADC: Cirrus Logic CS42526
 Volume control: New Japan Radio NJW1150
  
 DSP is licensed and you will not find any info about it.
 CS42526 and NJW1150 are the things you can look into, but if you don't have no experience in electronics, there is a chance you will not find anything. You can download PDFs via google search.
 If you do find out something, write it here. I've also asked some other people to help, so who knows, maybe we all find a way to enable real full-range on all speakers. 
  
 Also, doubling the amps will really get you nowhere, you don't need more than 50W per channel, for sub yes, but for all the rest, not. You could maybe change a transformer and give more volts to TDAs gaining more power, but you will get a higher THD and TDAs will heat more.
 If you insist on doing it, maybe a best option would be to make a new amp plate. Also, change the transformer, original one is around 200VA, to 300VA or more, depending how much power you wish to achieve on all channels. Remember, original satellites only pull around 10W.


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## A-Force

my order arrived from mouser in just 3 days!!!! i am going to start the mod to the speakers and to the sound card!!!  can you tell me how can i bypass the control pod? i mean which cable to connect where? and what i need from equipment and stuff? i think that if i leave it out of business i am going to have less work to do instead of upgrading the original control pod and the sound is going to be better according to your conclusions. thx in advance!!! 
  
 p.s. the crossover for the speakers is in the original pod? i mean without it you can adjust the frequency with the sound card?


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## Abdiel

@A-Force
 Yes, crossover is in control pod. There are some limitations to low frequency on TDA amp(used capacitors) and pre-amp is limiting some, but they are nothing compared to frequency cut which is coming from control pod. I suspect that DSP is limiting frequency, but currently i don't have time to investigate more, but I will soon.
  
 Yes, if you bypass control pod and use sound card, you can somewhat bypass crossover frequency of the pod and set your own. But be aware that 3" tang bands used in satellites can't reproduce low frequency, the reason why crossover freq. is at 150Hz.
 You can use cables which are sold on ebay, just search "z5500 bypass control pod cable" or similar search, you will find em.


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## ramachandra

You need a D-sub connector few jacks and the length of the cable(s) you prefer between your PC and the Sub. Try not to use cable where all the wires running together and only the outside have proper shielding (to avoid crosstalk). You can get jack extension leads cheap, and cut it on the middle. The 2W 22K resistors are not essential just recommended instead some sort of degrading volume control. Best if you get wirewound or at least metal film, more watts not a problem. If the space matter, you can use 1/4W metal film and hide them under the cover of the D-sub connector. The connection working without any resistors just too loud even on 10% in the Windows, so better to be careful in the beginning.
 You need to use the bass redirect in the Creative software to set up the proper bass setting for your Sub. No resistor required for this channel.


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## A-Force

And if i want to connect the audio card to 2 z5500 systems?


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## ramachandra

The same thing, you just need one more cable, and find a way to connect bot to the sound card. I suggest to use 3 jack adapters like this:


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## jayjayuk

ok... just checking back in with the story thus far... i have been playing around with op-amplifiers making them operate in different ways and generally getting to know them. i had the idea that if i use a board i have (the original blown board that i fixed) i was going to try and cut pins 2 & 3 on the tda amp to invert the signal... this is easier said then done as there is not much space and possibility of short... plus the tda may of need to be setup differently for an inverted signal... so that idea stopped when i thought to use op-amps to invert the signal first... they then go to the non inverted tda amp and the end result is still an inverted signal.... so i have had to use little PCB adapters (soic20 to dip20) as the boards to put the op-amps on and the components... the design is like the original op-amps but is now inverted.
  
 The first test i did was on my test board... i used both the rear channels for the test... left one as standard and used an op-amp to invert the signal of the other rear channel... i then put a speaker on the left channel (red+black) and the right channel (red+black) to make sure they sounded the same which they did... i then put the speaker on the red terminal of the rear left and the red terminal of the rear right... straight away i could tell the sound volume increased straight away and it sounded alot clearer and detailed sound... i like this mod alot. i have also kept the 0.47uF capacitors in the original post (third mod) which is after the op-amp and goes to the input of the tda amp. this setup is just like the original but like i say inverted. i still have more work to do as i have only done the rear channels and the front... i need to wait for more boards to finish the center channel... i will then (have someone else) cut a hole in the side (or top) of the sub so the plate amp can go on... then i will mount the transformer and do all the necessary wiring to tie both amps together... at that point i will have both plate amps... one will be inverted to the other so i can have all 10 outputs separate... or i can use all the red terminals between the two plate amps so they are bridged and have more power. i will also be looking into a bridged & parallel configuration for the sub... so the subs load will be spread across 4 tda amps instead of two... this will keep the heat down a bit more... or i might just put speaker terminals on the back of the plate amp and give another sub output... i could even use a switch to change between the two. another good thing about bridging these amps is will get double the slew rate from the tda amps when they are bridged.
  
 here is a couple pictures so far... it does not look great (like most of my mods on this system lol) but i am aiming for the functionality rather than visual appearance (good job really lol) i got the board epoxied onto the other board last night and soldered all the wires into place then did alot more epoxying as i needed to secure the wires... will be good when it is done... i also bought another working sub/amp from ebay for £15 (+£15 P&P) so i will have one sub with two plate amps on to bridge them to drive more load... and also i will tie the second sub/amp in parallel with the control pod..... anyway... here is the pics.....
  


  
  
 i have not tested this yet as it has been on the main board like this... but i did test each op-amp right before i did this and all outputs was fine and had no noise when the volume was turned down so thats a good sign so far... i am going to wire it into the other sub/amp temporarily just to see how things go... the main thing is getting the sub box cut... i dont want to cut it because i am not good with wood and i want it to be rite first time... i will report back in when i have done some more mods/testing ... things are progressing very well with this at the min... after i have done this i will eventually change the main filter caps and stuff like that... just this mod has had me intrigued for a while now and it is finally coming together 
  
 Cheers


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## A-Force

HEY guys PROBLEM  Only the stereo op amp (the 3 pins as you can see)...the other op amps + caps are working perfect!!! And by the way after the mod the sound is....AMAAAAZIIIINNNGGGGGG!!!! I cant believe my ears!!!! I m looking forward to start the woofer mod now to improve it even more!!!! This was my first time to do this stuff so i make a mistake (hopefully the last). So what s the solution to this situation? if i fill the holes with solder is it going to work? And something else...if i do the 3rd mod can i bypass the control pod or the 3rd mod works only with the control pod?


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## ramachandra

Check the other thread "*Fix for damaged PCB". *The third mod working with or without the pod.


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## sanscorp

Hi all,
  
 Quick intro: I'm Sander, 28, from the Netherlands.
 I'm not an audio enthousiast and the mods on the first page go way beyond my scope, but I do like some bass and the Z5500 packs quite a punch.
 I also do like a free sub and upgrade, p.s. I allready owned a Z5500 set but that's currently occupied by my girlfriend who studies and spends more time behind the pc then I do.
  
 I'm sorry to bring this old topic up again.
 I have a headless Z5500 sub, I got it from the dump for free, changed out the fuse and created a simple cable to be able to play audio with a 2.1 setup.
  
 I have a 100k lin stereo pot but I'm waiting on my order to arrive: stereo 10k log pot.
 The sub is controlled by a 22k mono lin pot.
  
 I'd like to control the master volume but can't find the "6 channel potentiometer" mentioned in post 59 on page 4 (bottom).
 Is there a simple and most of all cheap way to control the main volume?
 And if so, is there a schematic available how to wire it up?
 I do have plenty of electronic shops arround, but none of them are "specialized" in audio components.
 I'm also not willing to spend a 100 bucks on wire wound pots or whatever  Looking for a cheap fix (10 euro, 15 dollar range)
  
 thank you in advance!
  
 Sander.


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## A-Force

hey guys is it possible to the op amp to be half broken? i mean from the front channel of the audio card i hear only right channel and the left channel is dirty and lower volume. is it posile that the op amp is faulty or i make mistake to the bridge of the broken pads?


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## ramachandra

Hi Sander, this is all i found on eBay at the moment:
 http://www.ebay.ie/itm/6-Way-Pot-Six-Gang-Potentiometer-Linear-and-Log-Types-Splined-Shaft-Various-/120789129838?pt=UK_BOI_Electrical_Components_Supplies_ET&var=&hash=item1c1f97da6e
  
 I had seen 6 channel ALPS volume control with remote control in the past like this. Try to contact the seller maybe he know something:
 http://www.ebay.ie/itm/2-channel-Remote-Motor-ALPS-Volume-Potentiometer-Control-Adjust-50KA-12V-led-/400777575280?pt=US_Amplifier_Parts_Components&hash=item5d50347b70
  
 Now the only problem is you still able to control 5 channels and the Sub need a separated pot, because the volume will be not in balance with the rest. At least that is happened with the 50K pot i used, 20K maybe better still i doubt it will work out as expected for 6 channels together.
  
  
  
 A-Force I suspect a contact problem, use the diode tester function on a multimeter to be sure the bridge is working and the pins connected to the next component. If they are connected still no luck use a new OpAmp.


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## A-Force

Thank you for the answer!!! I don' t know which tcxo to choose...can you help??
 http://www.ebay.com/itm/1pcs-Vanguard-TCXO-0-1ppm-24-576MHz-Ultra-precision-Golden-Oscillator-AQ-/121321461708?pt=US_Amplifier_Parts_Components&hash=item1c3f5297cc
 http://www.ebay.com/itm/1-pcs-TCXO-0-1ppm-24-576MHz-Ultra-precision-Golden-Oscillator-for-DAC-audio-DIY-/141408940110?pt=US_Amplifier_Parts_Components&hash=item20eca1304e
 http://www.ebay.com/itm/Low-jitter-TCXO-24-576MHz-Phase-Noise-135dBc-1KHz-Tentlabs-compatible-/301229184989?pt=US_CD_Players_Recorders&hash=item4622a897dd
 or should i choose something cheap like http://www.ebay.com/itm/ONE-PIECE-PRECISION-0-3ppm-24-576MHz-DIP-TCXO-/141421463859?pt=LH_DefaultDomain_0&hash=item20ed604933
 I don t know what s more important...phase noise or ppm.


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## ramachandra

I suggest the the second link. The first is more expensive, the 3. is only 1ppm and 4. is not reveal enough info about the precision and can be above 24ppm


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## A-Force

whats the phase noise of the jyec tcxo? i thimk that is worse than the -125db of the vanguard that's why they didn t write it. what do you think.


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## ramachandra

The phase noise is the imperfection of the generated signal (jitter). I do not find the datasheet, the seller maybe know something.


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## A-Force

he knew you were right he sent me pdf!!! anyway... between the tda chips and the heat sink there is a white paste and some plastic... whats the real use of these plastic pieces? is it necessary in order to work?


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## ramachandra

The small sheets called mica insulators, the white stuff is thermal paste to fill the gaps. The Mica is a mineral, not related to plastics. The purpose is to insulate the TDA Amps and voltage regulator from the ground and each other, and let the heat pass to the sinks. Misplacing or leaving them out is a smoky mistake.


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## Kuro-Neko

abdiel said:


> So, no feedback about crossover frequency?
> I hope someone will comment about it, I would really like some opinions.


 
  
 I am too searching for a way to get around this problem. I really like the pod so getting rid of it isnt an option.
  
 I have been studying the chips too and from what I can tell the most logical place to start is the NJW1150. According to the datasheet the chips tone control could be bypassed by simply making a bridge before the tone control input on the chip to the output side, and you will get to keep the volume control ability. However I am not confident enough in my soldering to try this yet due to the need of desoldering smd components so if anyone could test this theory it would be great!
  
 The NJW1150 has two tone control inputs and outputs, one for left channel and one for right. This is great because one can test the difference between the right and left speaker!
  
 The datasheet can be found here: http://pdf.datasheetcatalog.com/datasheet/newjapanradio/de05058.pdf
  
 Looking at page 2 you can see the RTIN and RTOUT (pin 4-5) that need to be bridged. This should disable tone control for the right channel.
  
 Also there is a very suspicious feature on this chip (look at page 9) that suggests that one could change cut-off frequency by replacing 2 (right/left channel) smd caps, what kind of cut-off this is i dont know but it is certainly interesting!
  
 "There has to be a way!" Right?


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## Kuro-Neko

I successfully removed the two smd components and bridged the input and output on one channel using the old resistor, and after fading between the channels and trying different inputs and settings i came to the conclusion that there was no difference AT ALL!!
  
 It's as if i never changed anything in the first place, which is very odd! I expected at least a difference in volume but there is nothing, I'm not even sure if I should try and solder the components back as i can't tell any difference between the channels.
  
 It's still sending all the low frequencies going to the fronts, center and back (using 6 ch direct) straight to the sub. Almost as if theres a frequency splitter rather than a crossover. I also discovered that when lowering the volume for either R or L front the sub is fading a bit, this kind of makes me believe that the frequency cut is not in a chip but somewhere on the signal path on the board for each channel. Just a theory though. 
  
 This unfortunately rules out the NJW1150 as the culprit, unless it does it in the volume part (which i think is highly unlikely) the crossover is somewhere else. Any ideas?


----------



## A-Force

For the tcxo if i conect it directly to the power suply will it be benefit the titanium and if i conect it should i conect only the 5v or the gnd too. Thx in advance!!!


----------



## Abdiel

Well, no, NJW1150 is not the culprit. It's a simple volume regulator, it can only modify bass/treble on front channels, so center and rear channels are not included, which rules it out. 
  
 I would say DSP is the one which cuts the frequency. Unless someone knows how to modify it's firmware, we can't do nothing about it. 
  
 There is one guy on this thread, Lukasz Kijak:
 https://www.youtube.com/watch?v=o194EKRPc34
 Who wrote this:
 "_No I don't have because I'm using reprogrammed control pod where I can set low and high pass frequencies. DSP that is used in that control pod allows much more advanced settings than just simple Dolby PL Movie/Music. I will soon make a vid and a tutorial on how to mod this speakers_."
  
 I've tried to contact him on several occasions, but no response from him at all.
 It would be very nice to have that video tutorial.


----------



## Kuro-Neko

Yes it probably is the DSP that controls the H/LPF, however I find it quite strange that the bass going to the fronts are powering the sub. A filter would not do this, if you set a HPF to say 100hz it would fade out the frequencies below that to zero (depending on what octave the filter uses how fast this fading is).
  
 This is not quite what is happening, the frequencies below "100hz" are sent to the sub, not just faded out to zero. This happens regardless of what setting is used, usualy on a regular system if you use an effect like the neo 6 music it will send a stereo signal to rear, center and sub to create a kind of virtual surround. However the sub wont fade in volume if you mute one of the channels, it still plays exactly the same.
  
 Something to try: Run "Direct" with effect "6 Ch Direct" on the pod.
  
 Set front speakers to full-range and bass redirect off.
  
 Play a song and notice that the sub plays pretty strong, not like when in "PLII Music" but still strong. Then try muting one channel, notice the sub fading alot!
  
 Set front speakers to non full-range and bass redirect on with crossover at 80hz.
 Play the same song and notice that the sub does not have the same strength at all, it sounds very dull and non-existent.
  
 Strange? Yes very! Running PLII Music works very well and does what its supposed to, however this mode certainly contains a true HPF.
  
 Another thing that is even more strange is when I decided to solder the components that I removed for the NJW1150 back to utilize the DC cut feature in the tone control (nice feature for saving speakers ), I removed the bridge leaving the circuit open and for testing purposes fired it up and guess what? *STILL* got sound on both channels! Tried all inputs and effect and there was no difference, the channel wich had the circuit open worked flawlessly. So the tone control of the chip is NOT in use at all.
  
 Yes i have seen that video and it sounds very, VERY interesting! I do know that the pod is programmable as I found this a while back:
  

  
 I have a theory of bypassing the DSP for Direct input utilizing the volume control chip only, this would let us use the DTS and Dolby on digital and get rid of the frequency cut when listening to music. Still just a theory I'm working on, reverse engineering the pod for a novice like me takes time. 
  
 Just a heads up: Try connecting headphones and crank it up, the sound is full of bass all the way through the registry. 
  
 Great thread! I love to bounce ideas like this, who knows maybe we'll solve this? It's the only thing holding back the z-5500 after this awesome mod!


----------



## A-Force

hey guys!!! i finished the 3rd mod!!! all 5 speakers are playing but i have some noises coming from sub(doops, krou-krou etc) just a little while i notice something i didnt do...i only remove c100,200,...,500, 6 caps and 3 op amps not everything( i mean the small caps around the place of the 3 op amps)...is this the problem what do you think?? i cant think anything else i triple check everything...


----------



## A-Force

i just remove the small caps around op amps. the problem still there but in a smaller degree. i also notice that the sub with full volume is playing low volume like it s not full power, ... any ideas?? please help!! where should i look????


----------



## ramachandra

Try to find a different position for the cables outside the Sub. Sometimes the system can pick up noises from the surrounding equipment, cellphone, Wi-Fi, power cords etc. Without the control pod the System becoming more sensitive than before, nothing serious.
  
 I think one the OpAmps are not working as it should, or something not OK around one of the TDA Amps belong to the Sub. Or can be a broken TDA Amp too.


----------



## A-Force

thanks men appreciate the help!!!whete are the subs tda s?? and how can i test one if it s broken? the woofer plays but 1/3 of it s power maybe even less...  is it possible the problem is caused from a faulty cap? because the speakers are playing just fine what should i exclude from the search? i m getting crazy here :-? i guess the preamp is just fine so i dont look there... i didn t mention before that i test the system opened so i be sure it s working before i closed it and put all the screws. i also closed it with my hand (not screws) but the prob still there... maybe the prob is that i didn t remove the 1uf electrolyte caps near power regulators or because i replace with the 16 v 10 uf cap in the corner or the 35v 47uf near op amps... the volts are same as factory but you said 50 v... maye the 3rd mod it depends on extra volts. also i only used 2 filer caps not 12


----------



## ramachandra

If all the soldering joints are checked OK try to swap one OpAmp firs than see what is happen, then the other if necessary. Next the TDAs. The black and red wire coming from the big speaker connected to the two TDA Amps on the sides you looking for. Without proper equipment for testing you can swap components nothing else.
 Voltage ratings have nothing to do with Voltages present in a circuit. Only show what the component maximum can handle. The 2 main filter capacitors are fine too.


----------



## maxxximatoze

The Z8F3202AR020 is the main microcontroler unit that drives all the chips on the pcb and the lcd display. It has 32K of flash memory inside the package where is stored the firmware, it can be programmed in C with ZDS II software and the special Z8 Encore! Smart Cable which is connected to the debug pin of the chip and PC serial or usb port. It also drives the DSP CS49400 (datasheet hard to find, PM if you need it) but this one has it own firmwwre stored in SST 37VF020 2mbit flash (256Kib), the code responsible for all audio filtering (parametric EQ, tone control with DSPC 32bits) and dolby/dts decoding (done by DSPAB 24bits) etc...
  
 There is three "connectors" onboard (cn1 cn2 and cn4), there are certainly used to program these two chip at the factory. I don't know the pinout.
  
 If someone is able to dump the two flash memory to get the two firmwares, maybe some mod would be possible, not easy but possible if these flash memories are not read protected...


----------



## A-Force

ramachandra it s the op amp you were right!!! thank you!!! it is fixed!!! it s weird though... after all the eforts it was fixed by accident when i remove the solder with solder wick... i guess the op amps need low amount of solder or a better one who knows because i have this kind of prob with audio card... many tries until it s working...  THANK YOU again!!!


----------



## Abdiel

Unfortunately I don't work with Zilog, no time to learn that too, but there is a possibility I could read the 37VF020. It would take a lot of time, but it's doable. If it's encrypted, we can do squat about it.
 Not sure why CS49400 would need it for it's operation, but I guess if you have it's datasheet, you would know better. 
  
 My money is still on CS49400, it certainly is cutting the frequency.


----------



## Kuro-Neko

I found that the Zilog dev kit (Z8F64200100KITG) isn't that expensive and can be found at mouser for 34,56€, I was thinking of getting it later and learn it when i have the time. However I know absolutely nothing about coding in C so it would be better if someone more experienced looked at it.
  
  
 And on to what i have been doing! 
  
 After tracing paths on the pod pcb and measuring points for hours many "what if's" popped up in my head but one struck me hard, what if i could bypass the CS494003 for the front speakers and keep input, volume, sub, surround control and dts decoding on the pod?
  
 I decided to sacrifice the analog input on the side of the pod as i never use it. I desoldered the closest smd resistor opening the circuit and connected the pad to one input of the opamp responsible for the front speakers.
  
 Picture: http://i.imgur.com/K1f8vAL.jpg
  

 The result of this was incredible, there is no frequency cut at all and the sub still works with bass redirection and surround on and front speakers set to full-range running 6 channel direct. However volume control for fronts only works from 50% and up on the pod and as I haven't changed the caps for this opamp or even the opamp yet I thought i heard some crunching on higher volume. So I got another idea!
  
 I soldered the first resistor back and removed the last resistor for the side input and then connected it after the opamp just before the NJW1150, I also connected the other channel.
  
 Picture: http://i.imgur.com/W8Z0D5Y.jpg
 Backside: http://i.imgur.com/65dA51t.jpg
  
 The result? Simply amazing, you have no idea what this system is capable of until you try this!
 The amp board has the great "third mod" as seen on ramachandras last pic in the guide since i bought it from him, this brings out the true potential of the mod and the sound is simply awesome. It now sounds better than very expensive audiophile systems i have heard.I have a pair of Marantz HD680 (8ohm 100w max) connected to the z-5500 and it sounds truly beautiful.
  
 Are you thinking that the Marantz speakers is a waste on the z-5500 and it won't be able to push them? WRONG! The z-5500 speakers is actually very powerful, it has no problems at all pushing the speakers to their limit. The bass in the fronts kicks so hard I don't even have to turn on the sub! 
  
 Now there is not only good things that come with this mod and these are the minuses I currently know about:
  
 - Volume control for front speakers only work from 50% and up. under that you'll have to lower on your computer. Apparently either the CS494003 or CS42526 adjusts volume from 1-50%, can't help to wonder why they did it like that. :/
 - Front speakers will ONLY work with the side input regardless of what input you choose, even the analog in on the back is muted. (I don't know why but I'm trying to find a solution to this)
 - Changing effects on the pod will not affect the fronts.
 - DTS/DD won't work on the front speakers.
  
 The best would be to access the Zilog and alter the CS494003 settings however if you can live with the above setbacks I can't help but recommend it until we gain access to the Z8. 
 I do NOT recommend doing this if you use digital and use DTS/DD as it will not work!
  
 If you try this mod, be careful as you do it on your own risk! I'm not responsible if you mess something up. And be sure to turn the speakers OFF when connecting/disconnecting your cable to the side input, or you may damage your speakers!


----------



## Abdiel

@Kuro-Neko: very nice ideas! 
  
 You will not get anything if you access Z8. I mean, you will, but the main thing we should be getting access is DSP and it's crossover routines/filters and whatnot. I don't believe Z8 tells DSP how to cut frequency, I think that cutting the frequency is done natively in DSP code(CS494003 is audio decoder followed by programmable 32-bit post-processor DSP via Cirrus Framework and it's libraries) since satellites can't perform well below 120 Hz. In other words, I believe DSP is hard coded to automatically transfer all frequency below 150 Hz directly to sub-woofer channel, and clearing it from the rest of the channels.
  
 It's no wonder you are getting good sound out of TDA7294 at full range, it's a good amp. Just google what people do with it and everything will be clearer.
  
 I've seen CS494003's datasheet and it's rather complicated. It will take weeks or even months to make something out of it if you have no experience at it. I don't have, so... I think best thing would be to drop the idea.  Even if we make something meaningful out of it and out of Z8, we still lack Cirrus Framework to code the DSP with another crossover frequency value.
  
*Someone freely correct me if I am wrong about this!*
  
 I've already ordered NJW1151, NJM2755 and OPA1602AIDs to make my own stereo amplifier(in future multichannel), using TDA7294 with 2CS5200/2SA1943 pair as output transistors. It will be digitally controlled via remote control and iOS/Android apps using Bluetooth LE 4.0. For now I'm abandoning Z5500 modifications since getting full range at fronts is not possible without so many drawbacks.
  
 If anyone cracks and re-flashes the DSP, I'll be back into it. I have so many ideas for Z5500 modification, but I will not go near it if I can't make fronts work at full range.


----------



## Abdiel

@Kuro-Neko: You should try using sub output and direct it to front speakers. You can take the signal from last opamp in control pod from where sub channel is going to amplifer. If I'm not mistaken, that signal needs to be raised for 10dB. After you amplify it by 10dB, use another set of opams to feed the front channels that signal. You can do the same for center channel.
 After that, you can add one active crossover to sub channel which will limit it's frequency to 100Hz(or 80Hz) and below.
  
 Pros:
 - full range frequency on front channels and also center channel if you wish(rears can be added to!)
 - subwoofer will work with frequency of 80Hz and below (no more voice from sub!)
  
 Cons:
 - nothing (yay!)
  
 If one would do this mod, I would advise caution since 78M18 and 79M18 voltage regulators may not provide enough current for few new opamps. If you have done other mods and removed few original opamps, you are safe.  Another option is to change 78(9)M18 with versions that can provide more current.
  
 Looking forward to hearing a feedback from you guys.


----------



## blue2010

Hi Folks,
  
 i'm very interested in modding my Z-5500. I got the parts needed to mod the control pod the same way Ramachandra did it (6 OpAmps and the capacitors).
 I found somebody to do the mod for me and now everything is fine except the front left and front right channel. There is no sound other than a buzzing, like "bzzzzt", when i turn the volume up or down. The other channels are working fine, so no problem with Sub/C or RL/RR - i'm really frustrated now.
 The buzzing noise is only coming in analog mode. When playing digital, front left and right are working but are very quiet (like 30% volume of center speaker)
 My question is, what are the possible mistakes we could have made?
  
 One thing happend, the yellow wire from the control pod connection cable did break, but we soldered it again to where it belong (maybe we didn't do it well?)
  
 i hope somebody can help
  
 thanks in advance
  
  
 blue2010


----------



## Abdiel

@blue2010: Hm, I'm no expert but I would check opamp you changed for front channels. Try with old one. Check all traces, maybe there are some shorts. Also check the polarity of capacitors. There is some mistake around opamp, I would bet on it. Good luck!


----------



## blue2010

Yes, i was already thinking in that direction. Ramachandra told me to check the OpAmps too.
 Does anybody know which OpAmps are responsible for the front channels?


----------



## DaddioJ

hey guys new to the forums. but not a nooby to electronics. so i wanted to take on this project and bought all the parts. but for the life of me couldnt find 1 pcs 4700uF in 75v. or atleast 1 they wanted to sell bulk. so i purchased a Nichicon Muse FW in 35v which is still higher then original. is this ok? i also bought these for the preamp home this will do
  
 http://www.ebay.com/itm/151519620282?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
  
 final question. i use optical out 99.9 percent of the time. are the caps useless to change when using optical? and not analog?


----------



## ramachandra

What you chose is fine. There are few caps in the pod under the analog input what you do not need to touch, the rest is used by both connections.


----------



## DaddioJ

Thanks for the reply .


----------



## DaddioJ

ramachandra said:


> What you chose is fine. There are few caps in the pod under the analog input what you do not need to touch, the rest is used by both connections.


 
  
  
  one other question. i got the main caps 10000uF but they are snap ins so they will be much bigger. i was going to lay them down on the pcb and glue them in place. but i heard people using the GE silicon type 1 wont harm electrical components. GE claims its neutral cure  any experience with this? or any recommendations?


----------



## blue2010

blue2010 said:


> Yes, i was already thinking in that direction. Ramachandra told me to check the OpAmps too.
> Does anybody know which OpAmps are responsible for the front channels?


 

 We fixed the analog part. It sounds like as before again. But the problem in digital mode still remains. Front Left and Right channel is very quiet, about 30% of original volume. Will check the digital OpAmps soon, but still - is there anything else which could be resposible for this kind of problem?
  
 Cheers


----------



## jayjayuk

@blue2010 have you bypassed thetr control pod so it is just audio signal going straight into the sub's plate amp? rule out a volume problem in the plate amp first by sending audio signal directly to the plate amp (solder wires to audio ground and left + right input on pre amp panel in sub) if the sound is ok and level to the others then problem is in control pod... if it is different then the problem (or a problem) lies in the sub plate amp... i had this issue on one of my front channels and it turned out to be an op amp... i changed it and that one worked but i used to much heat and another one broke.. eventually i got the opamp in ok and that sorted the problem (but then my own errors led me to other issues with main amps)
  
 it will probably be one of the opamps... i bought some r4580i on ebay i got 50 of them for £15... so this was ok for me as i needed to know i was getting them in right and i needed some i could waste just in case i was doing it wrong... now they go in perfect every time... infact i dont know how i broke so many of them before  lol
  
 but use an earphone to see where the audio goes bad and look at those components... thats how i solved all my problems on my plate amp by tracing the audio with an earphone.
  
 Good Luck.


----------



## A-Force

Ramachandra what caps did you use on the back side of the amp to replace the green ones? i also have problem with mica sheets...i need to buy new ones. any tips/sugestions?? Thanks in advance!!!


----------



## ramachandra

No shortage from mica sheets on eBay, you can get a big sheet and cut to the sizes you need. I have mostly used ERO MKP, Phillips MKP, Evox MMK, Wima MKS capcitors. Polystyrene, Silver Mica to replace the 100pF ceramic disk on the middle. The 0.1uF C613, C614 is on the signal path so if you put good axial film or MKP capacitors to those positions the Sub will benefit from it a bit. The rest is not necessarily a returning investment because the Sub is working on a narrow frequency range and harder to spot the improvement.


----------



## DaddioJ

would upgrading the cirrus logic chip to a better one help anything too? just curious


----------



## ramachandra

The CS42526 probably have only 3 pin compatible alternatives. Upgrade is a point of view. This is all I got: http://www.cirrus.com/en/pubs/proBulletin/42516prodbull.pdf
 The 2 other ADC's and DSP look like have no alternatives, or at least I can not find.


----------



## DaddioJ

seems like the only difference would be current one is 6ch later one is 8ch


----------



## DaddioJ

ramachandra said:


> The CS42526 probably have only 3 pin compatible alternatives. Upgrade is a point of view. This is all I got: http://www.cirrus.com/en/pubs/proBulletin/42516prodbull.pdf
> The 2 other ADC's and DSP look like have no alternatives, or at least I can not find.


 
  
 slightly off topic i recently got a second set. z5500 i noticed this one POPS when turning on and off any switches. we have very good power. and my other set never did this. do you know what might be responsible for this?


----------



## ramachandra

I do not know for sure. My first guess is the positions of the cables. There are people with the same or similar similar experience and happen after a period of time so I have the reason to think it is  related to the aging electrolytic capacitors. Probably you are about to recap the system anyway, and for our benefit please let us know if it worked.


----------



## Gimbal

Hi, this is impressive, read the hole thread and are about to do no one upgrade, Q: what about voltage? can i go higher with a bigger transformer ?, the TDA7294 accept 40V+-
 KR Anders


----------



## ramachandra

You need to keep an eye on the heat what the TDA Amps will produce, and there are few other tings to worry too. Like the increase of the heat on the +18 -18V regulators. According the the datasheet of the TS79M18 the maximum input voltage is 35V so it is not vise to exceed. I do not know how much more current the SMD resistors can take on the panel, probably the ceramic caps are rated to 63V. Because the original speakers sometimes fail with the unmodified system I have a bad feeling what will happen when you try to pump more Watts out of them.


----------



## DaddioJ

ramachandra said:


> I do not know for sure. My first guess is the positions of the cables. There are people with the same or similar similar experience and happen after a period of time so I have the reason to think it is  related to the aging electrolytic capacitors. Probably you are about to recap the system anyway, and for our benefit please let us know if it worked.


 
  
 all done with the 2nd unit. All Nichicon KW series Every Cap. and all OP amps Changed. sounds Amazing!   but Popping is still very Present. only when its connected from something. say a TV. via optical and so it the HuM, when off and switch on.  even without the Sub Connected. and turned on. still Hums
  
 P.S.
  
 it seems i have a "Singing" transformer . i should have kept the extra one i had. Damnit


----------



## XenonMB

Hi,
  
 i came upon your thread after searching online for a cure for the "humming" problem many people have after prolonged use of their z5500s.
 First off all, awesome guide and thanks so much for it. I orderes the 10000uF and 4700uF for my z5500 and today i opened it up and removed the old ones but i saw what had previously been out of my sight due to the old 10ks being in the way.
  
http://imgur.com/DBcuqJP
  
 i soldered the new caps in just to try and see, but as expected the same humming is still present so i guess this burnt c27 is the problem. can i replace it? what exactly should i get as replacement if possible? i can't tell the rating/uF, does anybody know?
  
 Thanks in advance for the help and thanks again for the great guide


----------



## ramachandra

My guess list:
  
 First you need to get rid of the burnt cap to make sure no short circuit present, ceramics tend to fail in short. Maybe that is all you need.
  
 Recheck the new solder joints, or even scrape off the green film from the copper tracks around the pins and extend the area of soldering. Oxidation cause bad solder joint sometimes.
  
 Get 0.1uF X7R or MP0/C0G ceramic or film capacitor minimum 63V for replacement. (Somehow I think this is not the solution if the humm is present, because this small caps are there to filter out high frequency noises)
  
 Check the bridge rectifier.
  
 Another but low possibility is the capacitors around the two 18V regulators, if they are getting close to retirement the noise of the regulators filtered out poorly, and have an effect on all the OpAmps in the system. 
  
 The source of the humming is important, because if it coming from all the speakers your system have a problem with power supply probably, or if it coming from the Sub or other speaker(s) alone that will narrow down the choices.
  
 (look like the question I have answered have been deleted meanwhile)


----------



## DaddioJ

ramachandra said:


> My guess list:
> 
> First you need to get rid of the burnt cap to make sure no short circuit present, ceramics tend to fail in short. Maybe that is all you need.
> 
> ...


 

 the humming I have is from the sub alone. if I remove the Coil. no more hum. I tried to isolate with rubber but still seems to want to hum. only replacement might be the cure. for a better quality coil. also is it possible for the coil humming connected with pop when using fans or lights?


----------



## ramachandra

The core of the transformers usually made from sheets of iron to eliminate certain problems of the solid core. The core of the toroid transformer in the Z-5500 supposed look like a big rolled up spring just as on the image.
  

  
 Normally it is kept together really tight and if it get lose this is what happen: https://www.youtube.com/watch?v=lUt8rE9tYo0 There are people who can make and repair transformers, and if you are lucky enough there is somebody close to your are to fix it. I do not know the pops, look like some sort of ground problem to me.


----------



## XenonMB

my humming is coming from all the speakers and is unaffected by the volume control on the pod. that's why i concluded its the filter caps (10k and 4.7k). Pretty much all the posts and advice i read online said thats the symptoms for those failing or being defective. i got mundorf MLytic 10k and 4.7k 63V as replacement. they have a pretty good reputation here, but as i said the humming is exactly the same as before so i'm not sure whats causing it, and the burnt cap is all i could see so far that is obviously defect


----------



## scratje

Hello All,
  
 I want to introduce myself to this community.
  
 I'm new here but follow this thread for over one year now with deep respect to Ramachandra for your very nice and detailed thread.
 I own a Z5500 system since 2005 with great pleasure but want it to be more hifi audio, since i only use it for music and watching 5.1 movies in combination with a vintage pioneer A91D stereo amp and this is a truly high-grade amplifier.
  
 I am not totally new to soldering ic's, recapping and upgrading (i did it to my A91D) so last sunday i decided to go for the first and second mod.
  
 First i tried to order from Mouser (their Dutch branch) but they charge €40 for shipping below a total order of €150. (the distance between them and my home is less than 70km!!)
 After some searching i found Digikey in the States and they charge no shipping costs to the Netherlands above $100, so i orderd all of my Silmic 2 (lots of spare ones)  and opa 1612AID from them, which will arirve tomorrow so that's really really fast.
 The 2 Elna for Denon 10000uf 50V and  Nichicon KG Super Through TYPEIII 4700uf 50V will ship from China and are expected to arrive within a month but In the meantime i can start with the control pod and see(hear) if all has gone well.
  
 For now i'm very excited to begin modding, so wish me luck an i will keep you all posted


----------



## scratje

Today i received all the components from DigiKey and started right away with desoldering the opamps from the control pod.
 For desoldering i used desolder wick en after that i reheated each pin seperately and gently lifted it up wiht a needle.
 I discovered that the opamps were superglued to the circuit board so removing them was a little bit tricky but they all came off without damaging the circuit board!
 After that i solderd the new OPA1612AID opamps and tested the analogue outputs and digital optical input and so far so good with nice sound improvement already  
	

	
	
		
		

		
		
	


	




 
 Tomorrow  i will start recapping wih the silmic 2 and hopefully it goes as well as the opamps!
  
  

 
  
  
  

  
  
  
  

  
  
  
  
  
  
  
 Update:
  
 Today i did the recapping wiht Silmic 2 in the control pod and everything is working nicely!
 Sound is very good for now and next i will go for the recapping and new opamps in the sub.
 For now i'm very statisfied


----------



## scratje

Ramachandra, one question for you please.
 I noticed that in the list of capacitors, you mention 2 pcs 10uF 16V for the volume control but in the image you mention 2 pcs Elna Silmic 2 - 22uf 16v.
 I soldered 2 pcs 22uf 16v and all is working fine so can it do any harm?
  

  
  
  
  
 Today i started with the sub and just like member X172, i too have a different version with a seperate circuit board for the opamps.
 I changed the opamps and all capacitors on this board and tested the sub with great result and a big inprovement to the sound!
 Later on i will recap the mainboard and make preparations for the Main filter capacitors which are still underway.
  
  
  
 Pics from my version of the circuit board with seperate board for opamps
  

  
  

  
  
 Operation succesfull


----------



## ramachandra

Mouser only charge 20€ from the UK to Ireland, and below 70€ no cost for shipping. Digikey, Farnell more expensive here. In Hungary maybe Farnell is the cheapest.
 Sometimes I wonder why there is so few options out there to get the bigger Elna for Audio filter capacitors, or any kind of Cerafines. I bet the the DENONs only factory surplus like the Elna Kenwood, Elna Pioneer and not made for the public to purchase. We are lucky because few seller have them mostly on eBay and affordable, plus the sound is well compensate the shipping time. By the way, good to see your precise work, I'm looking forward to your updates.


----------



## ramachandra

"I soldered 2 pcs 22uf 16v and all is working fine so can it do any harm?" There is no Z5500 here around to check, but as i remember it is part of to the tone control. If there is no negative side effect on the sound no reason to worry.


----------



## scratje

ramachandra said:


> "I soldered 2 pcs 22uf 16v and all is working fine so can it do any harm?" There is no Z5500 here around to check, but as i remember it is part of to the tone control. If there is no negative side effect on the sound no reason to worry.


 
  
 Thank you for your reply.
 I have checked a pic from the original circuit board and there are two pcs of 10uf 16v on it.
  

  
  
 Thank you for your compliments about my precise work so far!


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## scratje

Finally ready now recapping the mainboard and very pleased with the beautifull sound.
 The only thing i maybe will not do is to recap the main filter caps because it is very risky to remove them without damaging the main board.
 Tried to cut away the glue and used the desolder wick but they will not come loose in any way.
 Perhaps it is possible to cut the caps from above and disassemble them so i can reach the connection pins inside the caps but when this does not work i will be stuck with a useless mainboard!!
 If according to Ramachandra the improvement from recapping the main filters is about 15% i don't think taking the risk is wise and for now the Z5500 has a huge improvement in sound quality already.
  
 Very happy with this great tutorial and deep respect for Ramachandra's work!!
  
 I'm using a X-Fi extrem music card now and in the near future i will be replacing it by a Creative sound blaster ZxR, so maybe there will be more improvement in sound quality


----------



## ramachandra

No point to remove the filters before the replacement show up. Cutting the blue plastic cover around, or off from the capacitor's body will help to set them loose. (If the whole plastic coming off better to mark the polarity, just in case if something not turn out for you as expected with the replacement.)


----------



## EdgeSRB

Hi all!
 I have problem with my z5500,I bought control pod PID629 for my woofer 608 (before this i was using it with control pod bypass and everything worked like a dream... but when I connect original pod I don't have sound in direct input 6 channel mode on any speaker,but in stereo and stereo x2 I do have sound. I have opened Control pod and everything is looking fine (I'm not the expert),tested vga cable with multimeter and all wires are ok. The z5500 is connected to my PC with analog cables. What can be the problem? Didn't tried to test with coax and optical cable yet btw. Please help.Best wishes.
 P.S Sorry for my bad english.


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## scratje

Maybe a very simple thought....... On the backside of the control pod is a little black switch. You must set this to 6 chn direct.


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## EdgeSRB

Nope, the switch is on 6 channel position, I wish that it wasn't...
 In stereo and stereo x2 I can hear a little hiss coming from the speakers but in 6 chn or any other mode no, dead silence....
 And if I plug headphones in control pod 3.5 jack I can hear sound in 6 chn and in all other modes(on headphones of course)... 
 UPDATE: I have openned the sub and find 1 burnt resistor
 http://www.dodaj.rs/f/35/gy/3EmNwHu5/img20150218203737.jpg
 Could this be the problem?
 Edit: I have replace that resistor(it was working even in that condition- I've checked with multimeter) but still the same problem... Everything else is in good condition, I have triple check every chip,capacitor,resistor and wire...


----------



## ramachandra

There are SMD ceramic capacitors on the back of the panel, one of them belong to the burnt resistor. Check it for short circuit. If required replace it to a 220nF capacitor. It can save one of the TDA Amps to fail, and not related to the pod.
  
 According what you describe I think the DSP is not functioning right. The chip can be faulty or the related component(s), or not getting the necessary power for the stable operation.
 I suggest to open the pod and check the Voltages under load. You need to find a ground whit one probe and use the other for measuring. First check what the Pod get from the sub, it should be close to 8V before the regulators (LM317D2) and after the regulator it should be tight to 5V or 3.3V. I'm not sure the requirements of the DSP (no proper datasheet), but this two values are the most common for chips. Make sure you do not make a short circuit wit the probe by accident (easy). To be honest maybe better to return the Pod to the seller if the voltages check OK. Even it is working fine with the digital connection it will sound disappointing after the direct cable connection you had, (unless the volume control is poor on the cable).


----------



## EdgeSRB

Thanks on answer ramachandra but turning back is no option in my country, when you bought something you bought it for good. I checked those SMD caps on the back and they look good on the eye. I will check the control pod.


----------



## A-Force

Ramachandra what matrix board should i use(dimensions) from mouser preferably and what is your recomedation for filter cups...i have two elnas 10000uf. The 10uf, 1uf, 0.1uf it s best to use k73-16???or the small is better to use elnas\nichikon?


----------



## ramachandra

When I done the firs mod I was asking one of my friend (he build amplifiers), what should I do to get the best results from the filter capacitors. He suggested me to build similar what I have done. The more balanced steps you have between the biggest and the smallest cap is the better in theory, to achieve an ideal capacitor.
 I had 5cm X 7cm boards for the 4 electrolytes in the Third Mod, and more caps need wider board of course. You just need to measure the diameter of the capacitors to see the minimum you need. Minimum means all the caps fit, but it not means if you put the hex spacer to the corners you get a good location on the PCB to drill holes, so bigger board give you more freedom to pick the right spots, then you can find the optimal arrangement for the capacitors. Prototyping boards breaking easy after a cut on the surface and sandpaper can take care of the rough edges. The Elna For Audio you have is perfect, the film capacitors are superior compared to electrolytes for audio purpose in general, but size and capacity is problematic. As I see beyond 1uF the electrolytes are easier to use. In theory the same brand and series are better because the similarity of the internal materials and dielectric, in practice you get different sound by mixing brands or series.
 No point to stick to K73-16, if you have easier access known brand MKT capacitors.


----------



## A-Force

So should i put all electrolytics silmic ii? these cups are for the sub chanel only or it is for satelites too?


----------



## ramachandra

"So should i put all electrolytics silmic ii?" Yes  "these cups are for the sub chanel only or it is for satelites too?" Both


----------



## DaddioJ

i changed the capacitors on the pre amp board. i initially had bass. then i lost it. i re installed the old ones and still nothing. very little. what else would cause this. i do not have the newer pre amp board. its the bigger older one


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## ramachandra

If you only changed capacitors and all the joints perfect, check the +18 -18V regulators on the main PCB, if you had short circuit earlier they may be damaged. Both of them have a resistor near by on the newer boards to limit the current they get, and in case of short circuit they change color or even get burnt on the middle and tend to change resistance.  So maybe need to be replaced.


----------



## scratje

I finaly was able to remove the 3 main capacitors on the main board and replaced them with the Elna for denon and nichicon super through, but then i got a very loud humming sound!
 Put the original capacitors back on but the humm does not go away so now i am wondering what is the problem!?
  
 Any ideas?
  
 Thanks in advance


----------



## DaddioJ

well i scratched this exta z5500 to the side for now. scrapped all the landings. and everything is prefect. made sure all the traces are intact... will check more later..  i know the Z906 are not as good. but i went ahead and purchased them. i guess i will mod them as well 
  
  
 ps. on the z5500 unit. all the satellites play loud and clear. just hardly any sub. very subtle bass


----------



## A-Force

Today i tried to make the bypass cable but when i conect it, it didn t work. it make a very loud whistle. (the voloume on windows 2%...) i don t know whats the problem... i solder together pin 6,7,8,13 and all these with the ground of the 3 cables... no switch because the sub has already one. the 5 chanels with wirewound resistor 22k5w. i saw one difrence...in your schematic the second line of pins(6,7,8,9,10) are a little right, in comparison the first line...mine is a littlle left!!!(from the sodering side). i guess the schematic is for the soldering side... where is my mistake ramachandra?


----------



## ramachandra

"Put the original capacitors back on but the humm does not go away so now i am wondering what is the problem!?" Once happened with me. I had to scratch off the green film from a wider area for the two 10000uF capacitors to have a bigger surface to solder. Lets hope I'm not wrong and the caps you got fine, Check the capacitance and ESR if you can.
  
  
 "ps. on the z5500 unit. all the satellites play loud and clear. just hardly any sub. very subtle bass" So it is only the Sub not the whole system. Two OpAmps and two TDA Amp belong to the Sub, if one of the 4 components are not functioning the result is what you experience.


----------



## ramachandra

A-Force
  
 I think there is no mistake except mine with the alignment of the (6,7,8,9,10) pins on the image, they should keep left. You are right.
 Is your system not the older pre Pid 636? Because that need another cable like this: http://i674.photobucket.com/albums/vv107/przano/Schematics/NoPots_zpsff820a87.jpg


----------



## EdgeSRB

@ ramachandra I have opened control pod and everything is looking fine, no burned chips or anything... Just one note, when i connect headphones to the control pod but I dont plug them fully and than i CAN hear sound on them at the same time even in direct mode or PL2 Movie /PL2 Music. I can hear difference in this modes but still CAN'T hear anything on the speakers except in stereo/stereo2 mode, does this mean that control pod is fine and all chips (the control pod doesn't shows headphone mode on the screen  )? I sow that my control pod have capacitor that I haven't seen anywhere on the web... the pic is not mine but everything is the same except the bare wire (i think its the ground wire) is not connected  on the bottom of the other wires like on others control pod's http://www.dodaj.rs/f/2G/pa/CJEst1Q/7319cee4logitechz5500ins.jpg  I have solderet that ground wire to the last hole but same thing no sound in 6 chnl direct or PL2 modes, just stereo, and upon powering z5500 it transformer is making weird noises so i unsolder it... P.S what pid number is your z5500?


----------



## A-Force

RAMACHANDRA mine is "PID R022" the first system(it is the system that cannot be turned off...instead of standby it has  headphone mode and in order to close it you have to turn off the switch on the sub) and the second is r837. so... i guess it should work on the second one. for the first what should i change? in the schematic you show me it has an 7805 voltage regulator...do i need to order this in order to work?


----------



## EdgeSRB

@A-Force  Yes you need that voltage regulator in order to z5500 work, it converts +18v to +5v. You should check with multimeter vga plug on the sub and find pin with +18v and make bypass cable and add voltage regulator like on schematics that ramachandra posted. I found on other forum pinout for z5500 pid743 I think its the same for your sub or pod. Good luck.

 Shielded

 Yellow - Left Front - 5
 Blue/Black - Centre - 4
 Black/Yellow - Left Rear - 3
 Grey - Sub - 2
 Brown - Right Rear - 1
 Purple - Right Front - 9
 Black - Neg - 15
 Red - Positive - 14

 Non-Shielded 

 Red - +8v Logic - 10
 White - Enable - 8
 Blue - Enable - 7
 Orange - Enable - 6
 Light Green - Ground - 13 
 White Black - MUTE - 12
 Green - On/OFF - 11


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## DaddioJ

guys who likes the tweeter mod?


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## ramachandra

EdgeSRB
  
 Try the digital connection, if it work better than nothing. Otherwise you need to find repair men or somebody with a scope and the skill to use it to determine what is wrong. A scope can reveal where the signal is stopping. After that there is a chance to work on the problem.
  
 A-Force
  
 The first number of the Pid show the year of production and the two others is the week in that year. As I know the first Z5500 made in 2004 and remain in production until 2012. Because the production not covered a full decade there was no need to come up with a 4 digit Pid number. Your system the PID R022 is made in May 2010, and the R837 is made in September 2008. For example a Pid 636 is made in September 2006 and that time the design was changed to the new from the old version and there is no big change inside since.
 So the cable have to work on any new Z since the date. It must have proper shielding and the ground connected on both end, and you need to keep it away from power cords because can pick up weird noises and the length also play some role. Obviously the on/off is working for you, so try to focus to the two front channels in the beginning to make it work, even without the resistors. If still no luck you can get one cable from eBay.
  
 DaddioJ
  
 I definitely like it 
	

	
	
		
		

		
		
	


	




 With 2.2uF Nichicon ES it will improve further.


----------



## DaddioJ

ramachandra said:


> EdgeSRB
> 
> Try the digital connection, if it work better than nothing. Otherwise you need to find repair men or somebody with a scope and the skill to use it to determine what is wrong. A scope can reveal where the signal is stopping. After that there is a chance to work on the problem.
> 
> ...


 
  
 i got a 2.2 in there now but not a Nichicon.  also i ordered some new tweeters to test make it more of a finished product. my Z906 came today and i must admit. it sounds really FULL and awesome! i was expecting to be disappointed but i was not.! but heres the question. is it worth modding the caps. and opamps now that i am going to have a tweeter setup with the original satellites? i will have more pictures when thats done. also with all this glue i am not sure if its worth the headache. there are some Nichicon caps in there but not all. and nothing special it seems


----------



## EdgeSRB

ramachandra said:


> EdgeSRB
> 
> Try the digital connection, if it work better than nothing. Otherwise you need to find repair men or somebody with a scope and the skill to use it to determine what is wrong. A scope can reveal where the signal is stopping. After that there is a chance to work on the problem.


 
 Thanks on the answer, I will try with optical cable. Can you please tell me PID of your Control Pod, I think that maybe the wires in my pod is not on the correct places, because I sow on some forum that one guy bought replacement Control pod PID 750 for his woofer PID 748 and he only heave sound in Stereo/Stereo x2 ,just like me... Maybe the wires need to be soldered on different places in pod... If you have pre 636  control pod can you please take a picture of the wires so I could compare to my pod?! 

 P.S on other forum i sow this... He have 2 z5500 one with big Pre amp board(dead Control pod) and other with small (with working Control Pod).
 "Ok so i opened up both systems to see how I need to wire this up.
 Here are pics..
 The one with the HUGE riser pre-amp card is the old one, then the one with the small card is the new one. Big difference eh? To combat line noise they added a magnetto level out spikes on the AC voltage aswell as a few inline caps to eventhings out (top left hand corner of new amp).

 Now here is my issue. After tinkering with the old one I can only run Stereo and Stereo X2 with my new control pod (The new setcan do everything ofcourse). So I figured it was a wire difference. Both amps have the SAME colour wires and numbering system. I only found 1 difference between the two. There is a Yellow and Yellow-Black wire that is switched. On the new one its WA115-WA113 (respectively) and on the old one its WA113-WA115. I couldn't follow the leads as it goes through an excess of mosfets and controllers. Could this be whats stopping me from using surround? I figure stereo is a direct connection which is why ithas no problem working but I need to go through different areas of the amp to get surround? Even using direct sound and not the built into the amp sound? Oh and their new design took the controllers off of the giant riser pre-amp card and put them on the main amp board...this is how they were able to make it smaller.
 " 
 Could replacing position of those 2 wires could solve my problem? Sorry if I bothering you...


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## DaddioJ

new tweeters. new mod. more of a finished product. i didn't have a stepping bit. so its a tiny bit unfinished. i will get the bit before i do the rest so they look perfect. still have to put it back together. and solder the capacitor


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## DaddioJ

omg! i cant believe how the speakers sound with this tweeter! def worth the upgrade!  Dayton Audio  ND16FA-6


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## ramachandra

DaddioJ
  
 The Z906 can benefit from a mod like any gear without audograde caps, still I would not like to working on it just to see how risky to remove the black stuff spilled over the SMD, and the tight spaces for the new capacitors is not inspiring either. In my eyes the whole system is a creation of money saving because the design aim the opposite direction what is necessary for good audio. Switching power supply, plenty SMD on the PCB is not on the wishlist of the audiophiles. The class-D amplifiers evolved in the recent years, still a good question how much compared to the old existing parts in a good setup. The Nichicons in the PSU probably from the PW series and OK for music, with the TEAPOs the Logitech is close touch with the bottom of reliability. If you decide to mod this system some parts may not like the 1:1 swap to audiograde caps, and better to discover what is belong to the controlling electronic and analog section first.
  
 EdgeSRB
  
 I do not have the images you need, I only worked on 2 new pods, and I had an old amplifier board here a while back.


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## scratje

Finally ready!
  
 Trying resolving my loud humm ik blew up two TDAamps at the moment i turned the sub on.
 The only thing i can figure out is the new thermal paste i put on the heat sinks, being conductive because i put too much on them and the TDAamp legs  got "wet" with it.
 After soldering the new ones and now using heat conducting tape instead of thermal paste, i went looking for the cause of the humm.
 It apeared that one soldering was bad and had no contact with the board.
 Now the humm is gone and everthing is working fine.
 The only thing i hope will disappear is a little distortion at high frequencies with female voices on high end recordings.
 Before looking into that i will wait a week for the burn in of the new filter capacitors and hear if it will go away.
 In what way is the length of the wires to the capacitors of influence to sound and distortion?
  
 In the meanwhile i bought another Z5500 for a low price and this one has the mainboard as described here and since i have a lot of spare capacitors i will mod this one also.
 I only have to order new opa1612aid and the two main Elna for Denon capacitors.
  
 Very happy for now with my high end surround system


----------



## DaddioJ

scratje said:


> Finally ready!
> 
> Trying resolving my loud humm ik blew up two TDAamps at the moment i turned the sub on.
> The only thing i can figure out is the new thermal paste i put on the heat sinks, being conductive because i put too much on them and the TDAamp legs  got "wet" with it.
> ...


 
  
 i like it 
	

	
	
		
		

		
		
	


	




. i have to find another Z5500 set at a good price


----------



## gelo

Hi friends
 I´m from spain sorry about my english
 I have a z5500 with the problem of the voltage regulators,  i will solve it .....whith L7818CV and L7918CV in TO-220 format (7918 is the problem R22 burned)
 I want to make a basic mod to the system  ,  i only use it with the pod , using the optical input , my question  .....is necesary to mod de pod  for this input? only the mod of sub maybe change or upgrade the quality of sound? caps and opas.
  
 Very good works!!
  
 Thanks !!


----------



## DaddioJ

ramachandra said:


> DaddioJ
> 
> The Z906 can benefit from a mod like any gear without audograde caps, still I would not like to working on it just to see how risky to remove the black stuff spilled over the SMD, and the tight spaces for the new capacitors is not inspiring either. In my eyes the whole system is a creation of money saving because the design aim the opposite direction what is necessary for good audio. Switching power supply, plenty SMD on the PCB is not on the wishlist of the audiophiles. The class-D amplifiers evolved in the recent years, still a good question how much compared to the old existing parts in a good setup. The Nichicons in the PSU probably from the PW series and OK for music, with the TEAPOs the Logitech is close touch with the bottom of reliability. If you decide to mod this system some parts may not like the 1:1 swap to audiograde caps, and better to discover what is belong to the controlling electronic and analog section first.
> 
> ...


 
 well there was on OP AMP which was the same old OP AMP from the Z5500 R4580I series. I changed that. i am not sure which it controls. but all is good as far as sound. now there are A/D converters  3 for center/sub /RL RR/ and FR FL.    whats there now is 
  
 http://www.akm.com/akm/en/file/datasheet/AK5386VT.pdf  are these of good quality? i was looking at these maybe for replacement.
  
 http://www.mouser.com/Semiconductors/Audio-ICs/Audio-A-D-Converter-ICs/_/N-4gxil?P=1z0yr4yZ1yx6n13
  
 also do you think replacing the caps with audio grade would be a good idea?  i am assuming the caps on the opposite side of the power board are all in the signal path?


----------



## EdgeSRB

@Ramachandra Ok.Thanks!
 @ scatje Awesome work!!!  Can you please tell me what did you solder to fix humming?


----------



## ramachandra

scratje
  
 Your solution to hold the capacitors is genuine and congratulation to the complete mod. 
	

	
	
		
		

		
			





 This is the first working mod on the older Z we know about!
 "In what way is the length of the wires to the capacitors of influence to sound and distortion?"  Because this are the main filters you can expect increasing hum as the wire length increase. Some noise can be generated in the surrounding wires if they are running to close to them. Just give the time for the capacitors to burn-in.
  
 gelo
  
 You do not need to bother with the component on the analog input in the Pod. The rest is for both connections and OpAmps do a great improvement for clarity and put the bass to the right track. At least change what you have in the Sub if you want to go for the best part.
  
 DaddioJ
  
 Not as easy to swap the ADCs as the OpAmps because Pin compatibility is an issue. The AK5357, AK5358, AK5359, AK5381 and AK5386 is belong to the same family and just judging according the numbering no point to turn back.
 I do not know the Z906 enough about to pictures to encourage you to do this or that. I have no doubt for a second it can benefit from the better components, but I also remember it took me many hours to understand the Z5500 before I have done anything with it.


----------



## DaddioJ

ramachandra said:


> scratje
> 
> Your solution to hold the capacitors is genuine and congratulation to the complete mod.
> 
> ...


 
  
 you dont think any of these would work?
  
http://www.mouser.com/Semiconductors/Audio-ICs/Audio-A-D-Converter-ICs/_/N-4gxil?P=1z0yr4yZ1yx6n13
  
 i think i might be will to try a cap swap.  according to the pdf the ADC's are tssop 16 but i am not understanding much else.
  
 but i think i get what your saying now as far as compatibility . theres also a D2audio D2-71583-LR. i would love to find alternatives


----------



## scratje

DaddioJ, Ramachandra, EdgeSRB.............. thanks guys for your compliments!!  
	

	
	
		
		

		
		
	


	



  
 Never knew i was the first one to complete this mod on the older system so now we know how to do it.
  
 EdgeSRB
  
 The loud humming i was talking about was not the slight and faint humming these systems have but a very loud one.
 It appeared that when removing the old capacitors, i damaged the solder holes so there was no contact between the top and the bottom of the board. Because i only soldered on the bottom pads, one of the wires had no connection to the top, where the conduction has to take place.
 So pay attention to the soldering and make sure to solder on both sides!
  
 With the new main capacitors, even the slight "standard" humming is gone now and the sub is dead silent.
  
  
 Ramachandra
  
 I will wait for a week to see if the distortion will go away.
 The distortion is a high crackling (clipping) noise which i can slightly hear at high frequencies on high end recordings with female voices or harp
 I can imagine that there will be noise generated to the capacitor wires so maybe it is possible to use shielded wire with connection to the ground?
 At first i was afraid that when blowing up the two TDA amps, the opamps took some damage too but since the distortion is on all sattelites and the sound is awesome for the rest, i assume the opamps are ok.
  
 My new Z5500 with newer mainboard will be the next one to mod and there is allready some work to do in this one because the backlight on the pod is not working. I saw a guy on youtube soldering two blue leds to the sides of the display and that worked so i will be doing that first. 
  
 Happy modding to you all


----------



## gelo

scratje
  
 I changed the SMD led on Pod display, its easy and low cost ,you can recycle from a old mobile telephone or buy 6 new SMD leds ...the light its better.
  
 ramachandra
  
 What do you recommend me to change in the POD??  i dont know which are the ones that have to mod.
  
 The fault on sub  was in DB15 female (POD) the wire on pin 14 unsoldered and in short circuit  cause on pod display 2 lines with full pixels and in a few seconds R22 burned 
 I changed the 2 Vregs and a new R22
  
  
 Thank you so much!!!


----------



## ramachandra

DaddioJ
  
 "you dont think any of these would work?" I think all of them will fry. 
	

	
	
		
		

		
		
	


	




 The Cirrus Logic get the power on different pin and the surrounding circuits need to be redesigned to make it work.
  
 In relation to ADCs i have 2 story. A while back i had some interesting conversation with a musician, and he was looking for suitable ADC for his recording work, and we compared samples made with a 1000€ ADC and on few others down to a 200€ and the difference is tiny.
 I bought a SB Titanium to find out what the mod do with the ADC. First i have used a jac-jack cable and i have recorded the sound of the card with itself. I have successfully done the mod included the analog input and the ADC. For sound cards the requirement of the burn-in more obvious, the bass is exhausting the mid range is off the scale and distorted etc. I was eager to compare the two and i have done another recording straight as i have finished. On my best external DAC i have done the comparison and the difference was unbelievable. Close to nothing. Even the TCXO played no role to improve clarity. Since that i do not pay much attention to the ungrateful ADCs.  They have their own plan, or i really messed up with the recordings.
  
 On the datasheet of the D2audio you will find the alternatives. Beyond my experience to help you with advice on this.
http://www.datasheetarchive.com/dlmain/Datasheets-SFU4/DSASF4000-1741.pdf
  
 scratje
  
 Something popped up in my mind. There are flexible pipes used for plumbing and inside and out is made from plastic, between made from copper. If you cut off the plastic a bit on one end you have a surface to solder a wire and connect it to the ground and no need to change the wires you currently use. I do not know the name, but there are cables for audio where the ground wire have a shield connected only on one end of the connection, this can be the same. The first Z i have done had the same symptomless with the Cerafines, the top of the mid range had distortion most noticeably, and gone after couple of days.


----------



## ramachandra

"What do you recommend me to change in the POD??  i dont know which are the ones that have to mod." Simple. What is under the level of the jacks on both sides you do not have to touch. What is below is good for you. Start with this 3 OpAmps marked with yellowish green on the image: http://cdn.head-fi.org/4/4d/4d86461d_LogitechZ5500controllpanelOpAmps.jpeg


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## scratje

Ramachandra, thanks for your info about the schielding.
 As for today, the distortion is less than yesterday so i will be patient.
  
 Gelo, the glass surface does not come off the display board so there is very little space to desolder/solder and i wil go for 3mm blue leds 3.5V to both sides.
 I can connect them to the blue power led of the pod because that's also a 3.5V.


----------



## DaddioJ

ramachandra said:


> DaddioJ
> 
> "you dont think any of these would work?" I think all of them will fry.
> 
> ...


 
 yes i did tons of research for hours! and i learned quite a bit! pin layouts . i also learned a lot about ADC's and so on. so i completely get it now.  as far as the D2audio chip is concerned. it doesn't seem like a alternative will come easy. as the company on sells in big quantities.. i would like to get my hands on there premium ADC. as far as AKM is concerned they make some really nice premium A/D converters. i emailed them if they have any updated premium chips that are pin compatible. i will await there answer.  
  
 also the tweeter mod alone is pretty amazing. so i will finish them. i will also take on the cap mod and see what happens.  also this is very subjective. but what would you recommend.  nichicon KZ series. or Silmic II  ?   and the Silmic II only goes to 470UF 50v for that size.  so i could only do one side with Silmic II and the other side  1000uf 63V would have to be Nichicon KZ


----------



## gelo

scartje
  
 Make a mark on pcb and lateral of bus rubber with a permanent ballpen ( for reposition in correct side ) and remove with caution the rubber in pcb with plane screw driver may be stuck due to pressure......(sorry my poor english) put the lcd in some place and replace the new leds ...caution with polarity of them.
 I hope it is useful
  
 Ramachandra
  
 I want to begin to recap and replace the opas in sub. Your image from sub main board is correct? one opa for rears two for subwoofer one for center+left?? (i dont understand this) and one for right
 in rears are not priority for me.
  
 thanks for your help!!


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## ramachandra

"what would you recommend.  nichicon KZ series. or Silmic II  ?" Silmic II, or Cerafine is my preference The Elnas improve the Sub-bass, the mid-range, high frequencies, the Nichicons excel in the mid-range and even ahead of the Elnas and nothing else really. On the signal path the difference is less between the two brand.
  
 "Your image from sub main board is correct? one opa for rears two for subwoofer one for center+left??" The image is correct, this is how they are wired on the PCB. The Sub have two TDA7294 in bridged application and require two OpAmps to run.


----------



## DaddioJ

ramachandra said:


> "what would you recommend.  nichicon KZ series. or Silmic II  ?" Silmic II, or Cerafine is my preference The Elnas improve the Sub-bass, the mid-range, high frequencies, the Nichicons excel in the mid-range and even ahead of the Elnas and nothing else really. On the signal path the difference is less between the two brand.
> 
> "Your image from sub main board is correct? one opa for rears two for subwoofer one for center+left??" The image is correct, this is how they are wired on the PCB. The Sub have two TDA7294 in bridged application and require two OpAmps to run.


 
  
 the only problem i have with Cerafine. is. i would have to source them from ebay. and then the question comes to play whether or not i am getting Genuine Caps. i might just stick to the Silmic II  unless theres a place i could get the Cerafine thats a know place


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## ramachandra

The look of the Elna caps depend where, when they made and often confusing people. I have bough few thousand capacitors on eBay even opened up some of them, so far so good.


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## DaddioJ

ramachandra said:


> The look of the Elna caps depend where, when they made and often confusing people. I have bough few thousand capacitors on eBay even opened up some of them, so far so good.


 
 i am having a hard time finding another z5500 because people are just out of there minds on ebay. trying to sell beat up systems for Enormous amounts of money.  i almost had a brand new never used set. until someone came in with a crazy bid and outbid me of 350  there becoming scarce


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## gelo

scratje
 Replace with white leds, the blue leds cause bad contrast , this is my display with recycled white leds from old nokia phone.The light is better than original
  
 i cant upload images or links .....copy this to see my display https://dl.dropboxusercontent.com/u/49580238/IMG_1195.JPG


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## gelo

scratje
 Replace with white leds, the blue leds cause bad contrast , in my display with recycled white leds from old nokia phone the light is better than original
  
 I cant upload images or links to show you


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## scratje

Gelo, do you know the voltage to the leds?
 On mine i have 7.3V which seems to much to me and that may be the cause of them not lighting up.
 Also still hesitating to remove the Zebra band from the display!


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## EdgeSRB

@ramachandra I have measured voltages on voltage regulators in control pod https://www.flickr.com/photos/124702258@N03/16753925595/ ( this is picture of my friend, He measured voltage on his working Control pod, the voltages are the same on mine)
 I have also measured voltage on wires in Control pod like in this video https://www.youtube.com/watch?v=jlsThzpK1J0&t=884 ( except he put red wire of multimeter on ground, so he got reversed voltages - negative), I write  mine and his voltages too (corrected)
  
 Voltages of MY Control Pod:
 wa2-ground( reference point)
 wa3 -17,49v (negative voltage)
 wa1 17,15v (positive voltage)
 wa9 2,75v
 wa8 0,0v
 wa7 0,0v
 wa6 0,0v
 wa5 0,0v
 wa4 0,0v
 wa10 7,98v
 wa11 0,0v
 wa12 0,0v
 wa13 2,72v
 wa14 2,72v
 wa15 -x (no connection)
 wa16 3,28v

 Voltages on HIS Control Pod:
 wa2 ground(reference point)
 wa3 -18,23v (negative voltage)
 wa1 17,40v (positive voltage)
 wa9 0,29v
 wa8 0,0v 
 wa7 0,0v 
 wa6 0,0v
 wa5 0,0v
 wa4 0,0v
 wa10 8,11v
 wa11 0,0v
 wa12 0,0v
 wa13 0,0v
 wa14 2,84v
 wa15 - x (no connection)
 wa16 3,28v
 You can see that everything is the same except wa9 ( I got 2,75v and he got 0,29v)  and wa13 (I got 2,72v and he got 0,0v)
 wa9 is thin gray wire ( i think that is pin 2 SUB IN), and wa13 is thin blue wire (pin 7 Amp Enable), how can this be than...?
 I dont know what PID is on Control Pod from the video....


----------



## scratje

Sorting things out.
  
 After listening for two weeks now, the distortion on some high end recordings did not go away.
 The most recordings are great (98%)  but some female voices distort on all Chanels and only on 6ch direct with surround at max (why not on optical input?)
 After some thinking i decided to put back the stock 4700uf filter capacitor so no extentions on this one and changed the wires from the 10000uf Elna capacitors from twisted to full copper.
 Now the distortion is a whole lot less but still there on one particular recording.
 I do not know if i may put a link here, but you can listen this online sample at low bitrate and these female church voices should sound clean.
 At high volume this recording will distort in my case.
  
http://www.prestoclassical.co.uk/r/Dorian/DOR93232#listen
  
 It is the 11th recording, O Clarisima Mater and you have to play it on high volume
 It is not my kind of music but for testing this one is ok and very nasty 
	

	
	
		
		

		
			




  
 My second Z5500 which is not modified, does not distort on this sample so it is not the recording being bad.
  
 I will order nichicons 4700uf and 10000uf with smaller dimensions to solder directly onto the circuit board and then test if this removes the distortion.
  
 I'll keep you posted


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## ramachandra

EdgeSRB
  
 The 7.8V on the first reg is OK, the 6.14-6.15V is low. I do not know the circuits and there are two diodes beside the others so some voltage drop possibly related and normal. The second pin belong to the adjust, not to the output what you need to check. You can see the pins "Figure 2: Connection Diagram" the "D2PAK" http://datasheet.octopart.com/LM317T-STMicroelectronics-datasheet-111654.pdf
 The volume control NJW1150 require 5V and 7V the CS42526 codec need 3.3 and 5V the two CS5351 the same. So we have 3 regulators and 3 voltage requirements already and what you measure should be around this values. I do not expect different requirement from the rest of the chips.
http://pdf.datasheetcatalog.com/datasheet/newjapanradio/de05058.pdf
http://www.cirrus.com/en/pubs/proDatasheet/CS42526_F2.pdf
http://www.cirrus.com/en/pubs/proDatasheet/CS5351_F2.pdf
  
 I found this image about the wiring inside the pod.
http://skyxu.org/wp-content/uploads/2010/10/z5500pinout.jpg
 I'm not sure about the WA9, the Output voltage swing of the R4580I is +-13V still i do not expect to find there more than milivolts with a multimeter in practice. I can be wrong.
http://www.ti.com/lit/ds/symlink/rc4580.pdf
 The WA13 is the mute for all channels and if your pod was on mute maybe OK. Mute is turn on automatic when no signal detected from the selected input.
  
 scratje
  
 I hear no distortion in the vocals just the loud background noise with external DAC.


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## A-Force

i found on ebay this:  http://www.ebay.com/itm/2CH-Remote-Motor-ALPS-Volume-Potentiometer-Control-Adjust-50K-6-W-Remote/111333858449?_trksid=p2047675.c100010.m2109&_trkparms=aid%3D555012%26algo%3DPW.MBE%26ao%3D1%26asc%3D29385%26meid%3D264231d5e2554013adfdf58a081a680d%26pid%3D100010%26rk%3D3%26rkt%3D14%26sd%3D160613440162  Could this replace the control pod what do you think???


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## ramachandra

No. This is only for 2 channels, there is another ALPS for 6. The Sub will need a separated pot because the volume not stay in balance with the surround.
  
 USB volume control is a better solution.
http://www.ebay.com/itm/Desktop-Laptop-Computer-PC-USB-Volume-Sound-Control-/260741355183?pt=LH_DefaultDomain_0&hash=item3cb56556af
https://www.youtube.com/watch?v=1jaUeBErJrs
https://www.youtube.com/watch?v=oXf83AfR4JU
  
 This are coming with remote control:
http://www.tomsguide.com/us/htpc-remote-possibilities,review-663-2.html
  
 The software volume control not the ultimate option because the lower volume achieved loosing some bits as i remember, but possibly the best you can get without dig deep into the world of volume controlling. There is always a tradeoff. For example:
http://www.crazy-audio.com/2014/01/hardware-vs-software-volume-control/


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## scratje

Modding my second Z5500,
  
 After waiting for over a month, all parts have finally arrived.
 Before diagnosing my first mod, i want to mod the second Z5500 and hear if i get distortion on the high frequencies on some recordings (see my first mod).
 So far so good with a full mod (not the main filter capacitors for now) and no distortion at all.
 I also did a repair at the leds from the control pod and soldered 6 blue leds, which look very nice to me without a severe contrast issue 
	

	
	
		
		

		
		
	


	



  
 Now very pleased so far with the second modded system and in the next few weeks i'm going to experiment with the main filter capacitors.
 I have nichicon kw 10000uf 50V (dimensions same as originals) and the elna for denon 10000uf 50v so i can experiment a little.
  
  
 I'll update in a few weeks.


----------



## scratje

Time flies............. 
	

	
	
		
		

		
		
	


	



  
 Did hard work this week and finalized my second Z5500 (new version)
 For the main capacitors i used Nichicon Muse KW 10000uF 50V and  Nichicon 50V 4700UF FW.
 In this system i used opa 1602aid and elna silmic 2 capacitors.
 The bolts are secured again and capacitors fixed with glue.
 For the heat transfer from the TDA amps i used special heat conductive pads (0.25mm) with more direct contact and a whole less messy so in the future it will be easier to modify!
 The sound is very good without boomy bass and i can turn the bass much more higher too on the pod now in contrast to the Elna for Denon which have a deeper bass.
 For the solution with the blue leds, here is a picture with the solder points. This way the display will be dark with the red standby and light up when switched on.
 For now ready to investigate my other Z5500 so i will be back soon


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## burnas3

,I am very upset,my Z5500 is down,the pod displayed Mute On-Over Temperature.Is there any solution for this problem?Thanks


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## scratje

Ready 
	

	
	
		
		

		
		
	


	



  
 Now my second Z5500 with older circuit board is working without any distortion!!
 Replaced the wired Elna for Denon capacitors with the Nichicon Muse KW 10000uF 50V which fit in the original solder pads and now all the wierd distortion on some high end recordings is gone completely so it must have bin the extended  capacitor leads, causing this!!
 At the first attempt the Z5500 was dead silent so i had to figure out what was causing this and it turned out one solder pad from the 4700uf filter capacitor had no continuity with the multimeter.
 After repairing this with a reapair rivet, now the connection is good.
  
 So this is my second full working modded Z5500 now, one with new circuit board and one with older board 
	

	
	
		
		

		
		
	


	



  
 I now have one spare Z5450 to try modding in the near future so i will be back once i have done that.
  
 For now i am very pleased with my two Z5500's


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## ramachandra

"I now have one spare Z5450 to try modding in the near future" Judging about the signs, no audio gear safe around you anymore either. Welcome to the club


----------



## ramachandra

burnas3
  
 I'm not familiar with "Mute On-Over Temperature" error. Contact problem mentioned on other forums and moving the wires maybe help. Contact spray sometimes do a miracle. Perhaps related to the LM217 +8V adjustable voltage regulator in the Sub. Near 4700uF 25V cap.
  
 I found this thread, and this is look like a hot fix not a solution:
http://www.computerbase.de/forum/showthread.php?t=1358502


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## scratje

Hey ya all 
	

	
	
		
		

		
		
	


	



  
 This week i started disassembling the Z5450.
 Looks less complicated so far with less components.
 For this sub, Logitech used two dual channel TI R4580i so the same as for the Z5500 and one other, a 14 pin quad channel NJM2060.
 The main filter capacitors are one Su'scon 4700uf 25V and two Samxon 10000uf 35V.
 The other capacitors are low grade Capxon and ceramics.
  
  
 Ramachandra, what would you recommend for this mod?
 I am thinking to replace the main filter capacitors with one Nichicon FW 4700UF 50V and two Elna for Denon 10000uf 50V which have the same dimensions as the originals.
 The Elna's, i have spare from the first attempt to mod the Z5500 and the 4700uf must be ordered.
 For the opamps i can use two spare opa1602 and for the quad channel i want to order an opa1604 when compatible (looks like they are from the data sheet)
 The NJM2060 has 14 very tiny leads, so desoldering and resoldering a new opa1604 will be a challenge 
	

	
	
		
		

		
		
	


	



 For the other capacitors i can use mostly spare Elna Silmic 2 from the previous mod but will have to order some new ones.
 The 1uf 50V capacitors can be replaced only with same voltage for Silmic 2 and 50V or 100V for Nichicon Fg.
 For the 47uf16V i have enough spare 47uf 50V.
 For 22uf 35V i have some spare 22uf 50V.
 The 22uf 6.3V can be replaced with spare 22uf 16V.
 For the ceramic capacitors i don't know the need to replace (optional for the Z5500)
  
 The original Samxon main filter capacitors are low profile and with the Elna for denon capacitors the circuit board frame will not fit onto the sub anymore so i will have to make a 40 mm spacer to get it to fit again but that's no problem.
 Also the new silmic capacitors are higher than originals and won't fit between the board and the backplate, so i have to solder them to the front of the circuit board, where there is enough space.
  
 By the way: i took a look at the control pod a few months ago and there were no opamps or audio path capacitors in there.
 Will soon open the pod again to take a closer look and take some pics!
  
  
 Some pics......................


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## ramachandra

I think you already know what to use. If you try better then Nichicon FW the sound will be more refined. The way towards the higher grade is:  FW=> KA=> FG=> KZ
http://www.hificollective.co.uk/components/nichicon.html
 The OPA1604 just need the lowest fine melting point solder you can get, and plenty of soldering paste. Good solder is a key to succeed.
 This is my priority and not ultimate list to use capacitors around OpAmps from the material point. Construction, brand, function also play a significant role and may change it:
 -Polystyrene film capacitors have excellent sound characteristic in general. Mostly out of production usually difficult to source.
 -Silver Mica is sound cleaner then any film capacitors, but piercingly harsh if used alone, a mixture of 50% film and 50% Mica is a good ratio.
 -Polypropylene KP, MKP film is great for signal path. Easy to get, a bit expensive.
 -Polycarbonate KC, MKC film is hard to come by this days.
 -Polyethylene Terephalate PETP. Like my favorite K73-16.
 -Polyester KT, MKT, MMK, MKS film the most common film capacitors, good for PSU less attractive for applications on the signal path.
 If the ceramic caps are there to filter out high frequency radio garbage, better to leave them, or try to use polystyrene or mica and see what's happen.


----------



## A-Force

i have a very big confusion on what mkp/mkt should i buy. i ve read the internet that the vishay 1837 are very good as bypass caps but on mouser the closer capacitance that is available is 0.1uf. is it ok if i order this for bypass 22uf caps on z5500? maybe you have another recomendation. also what to put in the 1uf position near regulators? and on the preamp the 0.22uf what is your recomendation? there are a lot of diffrent caps to choose from mouser and i don t know what to put where...  please help.  my head is going to explode with so many datasheets i ve read


----------



## ramachandra

The Vishay MKPs good caps indeed, i often get them with DAC KITs.
 Film capacitors have more linear frequency response compared to the electrolytes still not perfect, and as the capacitance of the capacitors increase the ability to transmit the higher frequencies is usually suffer, and building something up from multiple caps is usually result more transparent sound, or bypassing the big cap with smaller cap(s) help the higher frequencies. I can not dig up a good chart at the moment to explain how capacitance and frequencies related. So basically the 0.1uF will work, just don't let pass as much from the lower frequencies as the 0.22uF. If you want more you can add for example 0.68uF or between. The point is to not change the original value significantly and something is better then nothing. Under 0.01uF the benefit is arguable in this position.
  
 "also what to put in the 1uf position near regulators?" Nothing special, use any good brand MKT cap you can get.
  
 "and on the preamp the 0.22uf what is your recomendation?" For the Zobel network there are so many to chose from. Try any good brand MKT or better MKP axial film, or K73-16. If you looking for something special the 160V K42Y-2 PIO is working like a crap filter, really make bad recordings enjoyable, but not the best for bass.
  
 Here you can find how other people rate film caps on the signal path by listening, i put this list here for everybody who want to try something else then my recommendation, or looking for something fancy 0.47uF caps to do the "Third mod":
http://www.humblehomemadehifi.com/Cap.html
http://www.enjoythemusic.com/diy/0411/capacitor1.htm
http://www.head-fi.org/t/284863/orgy-of-capacitors-the-cap-thread
http://jimmyauw.com/tag/jensen/


----------



## MasterCATZ

http://s16.postimg.org/65in4mcb9/CAM00012.jpg
  
 what would I check to find the cause of the tda7294 blowing
  
 for ages my z5500 were making crackling / popping noises so i decided to have a peak inside to see if any caps looked sus , I did not notice anything, During this I have PC's volume down low and the speakers on boost to try and heat soak it  , for some reason the noise was not being made ..
  
 after 30 mins i gave up flipped the power switch and reassembled the back plate with 4x screws and then turned the mains back on , the SUB / speakers were making a large humm sound and it blew before I got to switch the power back off , I am unsure what the hell I could have possibly have done as I made no changes to it at all
  
 one possibility it could have had something to do with not turning them off before killing the  power  and some state of chip was wrong when I provided mains power back to it ? I am unsure what the controller was doing at the time no idea if it switched on or was in standby mode
  
 or the popping noise was from that chip and it finally gave in after heat soak ?
  
 also how would one get a NON FAKE tda7294 ?
  
 211784-0000-A2
 Logitech Z-8 REVA2
  
 *edit*
  
 on another note which speaker would that tda7294 chip have handled ? sub ?
 also if i removed the tda7294 would it be safe to attempt turning the system back on for testing? or would that cause more IC's to self-destruct ?


----------



## A-Force

for the bypass caps what whould you sugest? vishay 1837 0.10uf ( http://www.mouser.com/ProductDetail/Vishay-Roederstein/MKP1837410011/?qs=sGAEpiMZZMv1cc3ydrPrFx9ULflYAhdyMVWtY4Esfn0%3d )  or something like this, that is 0.22uf ( http://www.mouser.com/ProductDetail/Vishay-BC-Components/BFC241642204/?qs=sGAEpiMZZMv1cc3ydrPrF6b39BhxIu4vKrkO7Tq9Sd4%3d ).  is z5500 capable to work properly at a crossover 80hz without drawbacks with better speakers or the amp is designed only for 150hz??? i say this because when i set crossover to 30hz for example there is no bass from the satelites. also is there a limit in how low can the woofer go(subsonic filter in the amp) because i m thinking in replacing the woofer with 2!!! better ones in series from car audio that can go easily down to 20hz. so insead of having 2 z5500 subs, i m thinking to have 4subs 4ohms each one of them in order to get best room acoustic and better spl!! i also read that tda7294 is capable of 4ohms but is the design of the amp let us use 4ohms speakers insead of 8ohms?do you think its a good idea to make proper enclossures for car audio speakers and use them? i have this question because they are very cheap. i bought the second best, 6x9 speaker from pioneer, (5 way speaker 450w peak, 90rms that goes down to 35hz) in a street price and they are truly awsome, but in home cinema speakers, the price for something similar is waaaay higher. i guess you pay the sound signature :-/


----------



## ramachandra

MasterCATZ
  
 I do not know what went wrong. The chance for the TDA to blow straight after you opened up the Z5500 by coincidence is low, i believe.
 If you want to fix it yourself you have no choice just turn it on after careful checking. First try it for 1 or 2 second and listen, and and hope nothing else blow up and no funny sound.
 For genuine TDA try Mouser, probably Farnell and Digikey just as fine too. Judging according to the color of the wire the Front Left got the damage, if all same in the older version.
  
 A-Force
  
 Get the 0.22uF Vishay MKP.
 The TDAs can do 20Hz and I'm not familiar with the limits set in the pod, or the existence of subsonic filter in the amp.
 Instead of 4 Sub maybe you can do better with four 3 ways speaker with a direct cable connection. The four Sub still mono and can improve only a segment of the frequencies. My relative sad with the four small two way JBL sats he have almost no need for the Sub. I'm sure if the Zobel network is properly set to the new speakers (or left out) he even can get better result.


----------



## A-Force

i guess vishay 416 is better than 1837...what is zobel network?


----------



## MasterCATZ

Thanks for the reply ,
  
 how ever now thinking about it I did reconnect a speaker that might have been front right and at the time I was worried that maybe I possibly used an AV lead and not the speakers lead  downside to RCA plugs can no longer remember if it was Yellow / Red / White nut I feel the plug was towards the top area
 I think the wire codes changed as I think the IC was towards the middle more
 I'll take a full shot later on
  
 TBH I never looked into it much further after IC blew I just ordered 2x from ebay for testing  then read about the fakes online and made the post, the IC looked like the larger of them so I thought possibly the sub or centre
  
 ( which are the speakers the popping sound might have been coming from its been a while since I last used the set so memory was a bit foggy )
  
 I might try and fire it up tomorrow with the fried  IC removed and see what happens


----------



## scratje

Finnished! 
	

	
	
		
		

		
			




  
 My third mod of the Z5450 is now complete and working.
 I did replace all the components i talked about before exept for the quad channel opamp.
 Not wanting to risk damaging the very tiny solder pads because i don't have the proper solder iron for this smd work, i left this opamp for what it is.
 The mod works perfect and the sound is great and allmost as good as the Z5500
 I now have to weld a 25mm aluminum spacer because of the Elna for denon's hight.
  
 So now i have two modded Z5500 and one modded Z5450 ..................
	

	
	
		
		

		
		
	


	



 I will keep one Z5500 and the others are for sale so let's see what fans of modded systems will pay for them!
  
 For now i'm done modding these systems and maybe i will do the Creative X-Fi extreme music soundcard mod in the near future to complete my music experience.
  
 Thank you Ramachandra for this great thread and all others for contributing!


----------



## ramachandra

A-Force
  
 "i guess vishay 416 is better than 1837" Only listening can tell that for sure, good specifications alone no guaranty.
 "what is zobel network?" The 5pcs 220nF caps in series with resistor on the preamp panel is the Zobel network. The function is to protect the TDA Amps from feedback suppression. The rest is explained well on this forum: http://forum.diyspeakers.net/viewtopic.php?f=2&t=1364 For example if you want to hook up new speakers for the surround and you know enough information about them, easy to set the network to the new requirements. Online calculators are exist.
  
  
 MasterCATZ
  
 Maybe no harm to change the C506  just to be sure, TDA failures often linked to aging bootstrap caps.
  
  
 scratje
  
 Nice Job! Good to see those big DENONS on board. I was interested what is inside the Pod and tried find images, but none of them good enough to see the components. Probably very similar to the Z5500 Pod. People time to time asking me to do a mod for them, i can direct them towards you if you have the time and spirit. 
	

	
	
		
		

		
		
	


	



 "and maybe i will do the Creative X-Fi extreme music soundcard mod in the near future to complete my music experience" U will not be disappointed. +50% improvement. The risk is somewhat there to damage the SMDs by heat, but this cards are dirt cheap this days. About 22€ as i recall included shipping on eBay. Sometimes i had seen them in bulk from the US.


----------



## scratje

Thanks Ramachandra 
	

	
	
		
		

		
		
	


	



  
 First i want to point out that soldering the Denons onto the board needs a little bending of the leads to fit.
 The spacing is ok but the total diameter of the Denons is a bit more than the original caps so to avoid overlapping, you have to bend the leads a little to bring them off center, one to the left and one to the right!
 The leads are very thick so there is no harm bending them.
  
 At first i thought the control pod had no opamps but at your request i opened it again and found out that there are also three quad channel NJM2060 in there.
 The layout is different from the Z5500 control pod and i am not sure which capacitors are in the signal path.
 Ik guess the 47uf 25V, 22uf 10V and 22uf 16V around the opamps and analogue inputs are the ones to replace and caps around the volume control chip JRC NJW 1150.
  
 Opening the pod is easy.
 First remove the foot which is fitted onto the bottom (pull it off).
 After that you see six screws which need to be removed.
 Than you can lift the upper side off the pod and than push the main cable in and pull the under side down to get the circuit board free.
  
  
 I took the time to do a layout image of the pod so you can see what's in there........................... 
	

	
	
		
		

		
		
	


	



  
  
 Layout

  
  
  
 The heat plate in the upper right corner can be removed.


----------



## ramachandra

Thank you for the good photos.
  
 In the Pod of the Z5500 there are 6 OpAmp, here 3 quad doing the same job probably. Cost effective, not the audiophile way.
 Same DSP, Codec, volume control, the Zilog Z8F microcontroller is new, i can not read the code on the Cirrus chips, but i guess the same too.
 Interesting, the connectors are soldered manually and some other components. We had seen cleaner PCB i guess.
 No SMD electrolytes so even the Codec can see some new Elnas and Os-Con on the digital part.
  
 I think this Pod wanna feel the heat.


----------



## scratje

Ramachandra,
  
 Here a new pic of the layout.
  
 two Cirrus logic CS5351KZZ a/d converter http://datasheet.octopart.com/CS5351-KZZ-Cirrus-Logic-datasheet-55585.pdf
 a Cirrus Logic CS42526CQZ 6channel codec http://datasheet.octopart.com/CS42526-CQZ-Cirrus-Logic-datasheet-53453.pdf
 a Cirrus Logic CS8421CZZ 32-bit, 192 kHz Asynchronous Sample Rate Converter http://datasheet.octopart.com/CS8421-CZZ-Cirrus-Logic-datasheet-42648.pdf
  

  
 I think it will not hurt to recap all the caps around these chips so i will order them 
	

	
	
		
		

		
		
	


	



  
 I found a nice webshop in the UK, HIFI Collective, and they have a lot of caps http://www.hificollective.co.uk/componentshome.html
 The shipping costs to the Netherlands are low and no customs so far from the last order i have made.
  
 By the way, pics showing the sub with 25mm aluminum spacer.........
  
  

  
  
  

  
  
 I'll be back


----------



## ramachandra

So the CS5351KZZ ADC is the same.
  
 The hificollective has also a good selection from the fancy film caps i have linked above. I think it is a bit expensive at the moment, thanks to the weak euro. Well, it depends on the quantities really.
  
 Making thing from metal is not a challenge for you obviously, it is look like part of the original setup. I like the precisely cut corners, i do not think mine can turn out this good in the shed.


----------



## A-Force

hi i m thinking to take out the back of the woofer with the amp and make a new box for the amp only ( both amps because i have 2 z5500) and make one box for the 2 amplifiers. inside the woofer there is something else beside the speaker i think is the power tranformer. When i make the new box is there something to consider about the position of the transformer for example do i have to place it away from the amp or there is no problem to place it near by? The 2 transformers from the 2 systems is there a prob if they are one next to the other? Any advises apriciated!! Thx in advance!!


----------



## ramachandra

Usually strong magnetic field surrounding transformers, without a proper shield necessary to keep them away from the Amp and wires what is not directly connected to them. Advised to not cross or run together wires belong to them with others either. Keeping a distance between the two toroids is not necessary, but if you have enough space can't do any harm.


----------



## scratje

Back again!
  
 I have bin bussy lately doing other things (3d designing) so not much time.
 About the Logitech Z5450; i sold the system before modding the control pod, so i won't be able to tell if that mod is necessary 
	

	
	
		
		

		
			




  
 In the meanwhile, i came across a Chinese website that sells inverted blue/white replacement LCD displays for the Z5500.
 I was not totally satisfied with my blue led mod, so i ordered two of them.
 This display is just like the display in the Z5450 and i am very satisfied with it.
  
  

  
 Here is the link to the website that sells them.
 Service is good, i might say...................... ordered two of them but only got one.
 After i emailed them, they responded within a few hours and admitted they had made a mistake.
 I could choose between a refund or resending the second display (for free) so i chose resend.
  
http://cart100.com/Product/35873223262/Genuine_Pegasus_TM202QDCU6_LCD_LCD_scree
  
  
 Happy modding


----------



## artsgr

Hi ,all.
  
 I have to admit that "ramachandra" you have done a magnificent job.
  
 I have the old version of  5500 with the opamps on the plug PCB, and the power transistors on the bottom PCB.
  
 It is almost the same as "scratje" mod.
  
 I need some help in order to do the "third" mod  version by exchanging the opamps with the capacitors.
  
 I dont know witch opamp is for what.
  
  
  
 Thank you in advance
  
 Aris


----------



## Benny-x

This really is a fantastic thread, and I'm so happy to see people keep posting in it. 
  
 I've got a different brand of active monitors/speakers coming in, Emotiva Pro - Stealth 8s. Once I get comfortable with them I'll take the leap and open them up and see how I can mod/improve them inline with these Logitechs. I'm definitely going to need some help in 5-6 months when that happens, so I hope you guys are still interested in this thread then. I guess I'll have to get the wiring schematic for it before that so that I/we can study what to do with it.
  
 When the time comes I'd be happy to post up all the details and pics and stuff of the mod procedure, in case anyone else ever wants to take a stab at it with the Stealth 8s, and of course to just provide more reference points for modding active speakers. 
  
 Congrats on the OP for the great work and advice to everyone and to the guys who have done it themselves since then.


----------



## ramachandra

Hello Aris,
  

 Once I had an amplifier board from the older version. In those days I had working on several newer boards simultaneously what I bought or I got from my customers. This older was just sitting there, I did not know what should I do with it, knowing it is an unwanted hassle to repair and experiment without an old Pod. Meanwhile I salvaged some parts from it to fix the faulty. After I have done the others my enthusiasm was running low, yet I had all the components to go ahead with The third mod on it, and my plan was to improvise a cable to do the testing.
 It was complete, but by mistake I have soldered back a faulty regulator and the troubleshooting didn't go well either. Most of the TDA Amps had a smoky day. I thought I had fun enough, and took what was worth to be saved and get rid of it.
  
 That time not much happened on this thread and I have no photo (or deleted) from the finished preamp board unfortunately. The Third Mod is easily doable on it. I have marked the important areas with different colors. I had to borrow the image from scratje, so your board have skinnier blue caps on it.
  

  
  
 Red: Belong to the Surround, they all have to go, after that you have space for the 5pcs 0.47uf film capacitors.
  
 Blue: Belong to the Sub. Change the OpAmps + electrolytic capacitors, and the green films & ceramic capacitor if you wish.
  
 Purple: This circuit is turning on/off the Amp. Changing the two electrolytic caps all you can do.
  
 Yellow: the pins of the D-Sub connectors soldered to the PCB, you can find the pin outs on the first page of the thread. Use the diode tester function on a multimeter to find the 5 pins of the surround channels and connect one leg of the 0.47uF film cap to each.
  
 Orange: The color code in the Z haven't changed since the old, so in the description of the Third Mod you can identify the 5 pins of the surround. Then all you need is to connect the remaining 5 legs of the 5pcs 0.47uF capacitors to the same channels.
  
 On the back on the preamp panel you find the SMD caps belong to the Zobel network. Remove them and use the 0.22uF film capacitors according to your preference.
  
 For me the main Elna for Audio filters yet was able to sit between the wires on the prototyping panel, on the location of the two old 10000uF Su'Scon caps. The rest is just to swapping  capacitors on the Amp board to audiograde. There is one difference if i recall correctly. One cap is a 33uF maybe 50V, on the new it is the 16V 22uF.
  
 This is how i remember after 2.5 years later, and like I have mentioned I have never been able to find it out if it worked correctly or not. I don't remember which OpAmp is for what.
  
  
 One more thing. The same treatment apply to the C100, C200, C300, C400, C500 as in the new version. I think the numbering is identical in both.


----------



## artsgr

ramachandra said:


> Hello Aris,
> 
> Once I had an amplifier board from the older version. In those days I had working on several newer boards simultaneously what I bought or I got from my customers. This older was just sitting there, I did not know what should I do with it, knowing it is an unwanted hassle to repair and experiment without an old Pod. Meanwhile I salvaged some parts from it to fix the faulty. After I have done the others my enthusiasm was running low, yet I had all the components to go ahead with The third mod on it, and my plan was to improvise a cable to do the testing.
> It was complete, but by mistake I have soldered back a faulty regulator and the troubleshooting didn't go well either. Most of the TDA Amps had a smoky day. I thought I had fun enough, and took what was worth to be saved and get rid of it.
> ...




Thank you so much for the immediate reply and your help!!

Due to summer vacations (two kids ) the project needs to wait for two weeks.i will come back with pictures and info A.S.A.P.

BR Aris


----------



## Z5500owner

I just recently started "working" on my Z-5500 again. It has been laying in the attic for some time (as in years LOL).
 My Z-5500 PID is R:605 (so from what I understand it is one of the first revisions 200*6* week *05*).
  
 I bought this Z-5500 as defective. But before I bought it I did some research on the internet and found many Z-5500 during that time had blown a CS42526-CQZ chip inside the control pod. The unit would go on, display would show information, just no 'sound' due to the blown chip (small venting hole where the magic smoke got out I guess)
 I managed to score a replacement part (allthough it had a higher revision compared to the original part).
  
 As I am not skilled in SMT soldering (lol, I'm not even a novice in soldering at all). I managed to get it replaced. But somehow it got f*ed up, because allthough the chip got replaced, the unit wouldn't powerup at all (not even standby).
  
 Few months later I managed to buy another control pod, but this one is PID:R850 (200*8* week *50*), so a POD from the new version. Connected this in the hopes of getting a full functioning Z-5500. But offcourse, no success (I was unaware of any revision changes during that time). My symptoms are similar to those of EdgeSRB, I will only get front stereo (and front and rear sound when in stereo:x2 mode). Digital input not working.
  
 Quote:


ramachandra said:


> EdgeSRB
> 
> I do not have the images you need, I only worked on 2 new pods, and I had an old amplifier board here a while back.


 
 Hope these are clear enough, if you need more detailed ones (from certain areas), please let me know
Excuse the 'tinypic' as I couldnt upload these to the forum 
  
 PID R:605
 http://tinypic.com/view.php?pic=30xkgtf&s=8
(this image is not mine, but shows all wires connected. From what I can see, this one is the "old version" <- missing yellow wire + component top right corner)
 http://imageserver.qik.nl/dukebox/z5500pod.jpg
  
 PID R:605 vs PID R:850
 http://tinypic.com/view.php?pic=16bfw43&s=8
 Notice the difference in the top right corner (yellow connection and  SMT component)
  
 PID R:605 vs PID R:850
 http://tinypic.com/view.php?pic=o6kapi&s=8
 Notice the difference in (what I assume are) power regulators / controllers.
  
 15 pin SUB-D Pinout (PID R:605):
  
 01 - Brown
 02 - Grey
 03 - Yellow / Black
 04 - Blue / Black
 05 - Yellow
 06 - N/C
 07 - Blue
 08 - White
 09 - Purple
 10 - Red
 11 - Darker Green (non shielded)
 12 - White / Black
 13 - Lighter Green (shielded)
 14 - Red / Black
 15 - Black
  
 Now its back to browsing the internet to get some more information


----------



## ramachandra

The images are not good enough to precisely identify wire colors, if you post me the WA numbers/wire colors (on the back of the PCB) for both, i will be able puzzle something together. The only two differences between the panels is a good start.


----------



## Z5500owner

ramachandra said:


> The images are not good enough to precisely identify wire colors, if you post me the WA numbers/wire colors (on the back of the PCB) for both, i will be able puzzle something together. The only two differences between the panels is a good start.


 

 Hi ramachandra, thanks for the reply 
  
 To be honest, these are the two noticable differences between the two PCB's. I really should do a component by component comparison just to be sure. But these components are tiny, need to find myself a proper magnifying glass 
  
 Regarding the wire colors :
  
 15 pin D-Sub connector female :
 http://stuartconnections.com/products/Computers/Peripherals/LCDs/Dell_2001FP/CD/GRAPHICS/15PIN.GIF
  

 PID R:605 (first revision)
 PID R:850 (second revision)
 Pin
 Color
 Function
 WA#
 Pin
 Color
 Function
 WA#
 1
 Brown
 Right Rear
 WA8
 1
 Brown
 Right Rear
 WA8
 2
 Grey
 Subwoofer
 WA9
 2
 Grey
 Subwoofer
 WA9
 3
 Yellow / Black
 Left Rear
 WA7
 3
 Red
 VDIG
 WA7
 4
 Blue / Black
 Center
 WA6
 4
 Green
 DGND
 WA6
 5
 Yellow
 Left Front
 WA4
 5
 Yellow
 Left Front
 WA4
 6
 Not Connected
  
  
 6
 Orange
 Mute center
 WA16
 7
 Blue
 Enable amplifier
 WA13
 7
 Blue
 Standby
 WA13
 8
 White
 Enable mute
 WA14
 8
 White
 Enable mute
 WA14
 9
 Purple
 Right Front
 WA5
 9
 Purple
 Right Front
 WA5
 10
 Red
 +8 V
 WA10
 10
 Red / White
  
 WA10
 11
 Dark Green
 On / Off
 WA11
 11
 Green / White
  
 WA11
 12
 White / Black
 Mute
 WA12
 12
 Black
 VREGSS
 WA12
 13
 Light Green
 Ground
 WA17
 13
 Blue / White
  
 WA17
 14
 Red / Black
 +18 V DC
 WA1
 14
 Brown / White
  
 WA1
 15
 Zwart
 -18 V DC
 WA3
 15
 Black / White
  
 WA3

  
 The information for the R850 POD (regarding function) has been scavenged from the internet, the picture has also been posted in this thread :
 http://skyxu.org/wp-content/uploads/2010/10/z5500pinout.jpg
  
 So as far as my observations tells me, to make a R850 POD into a R605 POD :
  
 - Verify R850 wiring colors vs function (as the information provided on the internet doesn't seem to be complete / incompatible)
 - Verify all components are similar between boards
  
 If above steps provide the correct information (pinout compatible, components compatible)
 - Remove orange wire (connected to WA16)
 - Remove yellow wire bridge (connecting CN1 <-> CN4)
 - Remove SMD component near WA16 (0 Ω Resistor bridge/link if I am not mistaken)


----------



## ramachandra

We are thinking the same way, this list is exactly what i wanted to make. The image is look convincing as a leak from the factory, and maybe it is, still the description of the wire colors and functions are messed up. http://skyxu.org/wp-content/uploads/2010/10/z5500pinout.jpg If I'm wrong, the cable i have made to replace the Pod for the new version is not supposed to work, and that's not the case. I have the feeling the "PID R:605 (first revision)" Functions apply for both, the few wire colors are changed only by practical reason. The extra WA16 orange is maybe related to the on/off function the WA2 black wire perhaps part of a better shielding for the new Pod.


----------



## Z5500owner

My thoughts exactly 
  
 What baffles me though is why the old vs new revision POD (or more as in connecting a new revision POD to an old revision SUB) will give that functionality error (only analog stereo / stereo 2x available) and all digital inputs not working. At least in a few threads I found on the internet this always comes up.
  
 The PCB's for both are indentical (or at least the markigns on the PCB are identical), just some components are different :
  
 Voltage regulators :
  
 R605 : LM317
 R850 : LM317D2
  
 A quick glance over the datasheets reveals to me that it was only a package size switch
  
 Amplifiers :
  
 R605 : R4580I (56MA5C964)
 R850 : R4580I (BAKD3FYG4)
  
 Guessing the last part is somewhat related to fabrication date or something
  
 My suspicion is that probably the firmware is responsible for this ?
  
 R605 : Firmware version unknown due to not powering up 
 R850 : Firmware version 2.1
  
 Allthough I did not come to this board hoping to find a solution, it would be sweet if we somehow by brainstorming could make a "simple" fix.
 I am "lucky" to have both type of revision boards on hand and can make "detailed" pictures / comparison if needed to provide all the information (too bad I dont have DLSR) but for now my Olympus 3040Z does the job.
  
 As a lot of information had been shared here, I just wanted to do my part and provide some extra information which I could not find anywhere else (or my GoogleFu skills are not that great 
	

	
	
		
		

		
		
	


	




)


----------



## ramachandra

Lets hope the firmware have nothing to do with the 5.1 sound or the digital input. A while back jayjayuk done a great job to draw a schematic from the new preamp panel. https://d1jesv1uvhg9i4.cloudfront.net/a/a5/a5dc69f0_MB_Z5500-PRE-AMPBOARD-SCHEMATIC.png If the conversion of the the Pod doesn't bring the breakthrough, try the other way around, build the circuit and convert the old Z to the new version. I'm looking forward to your progress.


----------



## Z5500owner

ramachandra said:


> Lets hope the firmware have nothing to do with the 5.1 sound or the digital input. A while back jayjayuk done a great job to draw a schematic from the new preamp panel. https://d1jesv1uvhg9i4.cloudfront.net/a/a5/a5dc69f0_MB_Z5500-PRE-AMPBOARD-SCHEMATIC.png If the conversion of the the Pod doesn't bring the breakthrough, try the other way around, build the circuit and convert the old Z to the new version. I'm looking forward to your progress.


 
  
 I will heat up the old soldering iron tonight .
  
 As a first step I will confirm Sub-D pinout vs wiring color vs WA# connection by desoldering wire by wire and use the multimeter to confirm. I didn't do anything with the new POD, as I didnt wanted to tamper with the "working" POD yet 
 Regarding converting the old one to the new one. The old one is "broken" and I am in no position (toolwise and experience) to desolder the CS42526-CQZ and resolder a fresh on one it (still got 2 spares lying around.... somewhere 





). At least I can use the old one as spare bin for SMD components if I spot a difference between the two (and offcourse document it for future reference)
 I wished I had a scope / logic analyzer (and the know how how to use them haha) here so I could at least verify if and what changes when I start tampering with the POD.
  
 After verification of pinout / colors / WA# I think I will first start with opening up the bridges (yellow wire, SMD component).
  
 Are there any other things I could do with just my simple multimeter ?


----------



## ramachandra

"Regarding converting the old one to the new one." I mean make changes on the preamp panel. The circuit simple enough to build, and you need to disable the existing on/off circuit, then connect the new to the pins of the D-Sub on the back, according to the schematic. So, if the conversion of the Pod fail, this is an option.
  
 "Are there any other things I could do with just my simple multimeter ?" I have good use for the diode and capacitance tester, to compare identical circuits when I looking for a fault for example. The readings on the in circuit components are usually inaccurate, still supposed to be almost identical on the two PCB. This may sped up the compatibility check.


----------



## artsgr

Hi all. I finnaly got back in lab so I am uploading some pics to help me solve the riddle ...


----------



## ramachandra

Nice! I had never seen the earliest version inside. I only expected to find RCAs on the place of the spring clips, but this PCB is something else and hold two extra unoccupied spaces for OpAmps, resistors are installed there, probably for nothing.
  
 Judging about the arrangement, the green films and the single ceramic disk on the bottom is belong to the Sub, so that area need the upgrade. The 3 pieces on top is part of the 5 remaining channels. They have to go + belonging components. If i have this board I make good photos first for safety, then I stick to the back the 5 pcs 0.47uF cap, connect the pins to the D-Sub and desolder the necessary wires from the PCB, and connect them directly to the other pins of the 5 film cap.
  
 I suggest to not bother with the OpAmps on top first, just see how the mod is doing, then get rid of them. (They may have an audible effect on the sound as long as they stay connected)


----------



## rxracer

First of all, wow.... you seriously know your stuff about the z-5500.  Hence the reason i'd like to ask for your opinion regarding the issue with mine.
  
 I re-wired my system yesterday and noticed the left rear was popping, crackling, and had no sound.  Then after about a minute or so I hear a mild 'whoop' sound, like when you power of some speaker systems. Then all sound stopped, and the control pod LCD showed 2 rows of black bars.  Like the volume at full bars, but 2 rows.  The entire space of the LCD screen.
  
 So I fiddled around a bit.  And here is what I've observed.
  
 1. Plugged different speakers in the left rear channel.  Popping remained.  Conclusion.  Issue is with the left rear output, not the speaker.
 2. Turned the system on without sending a signal through.  Control pod worked fine. Black bars never appeared.
 3  Plugged just one (center) speaker in and sound played fine for over 30 minutes.  After that got kinda tired of watching a show with just one speaker, but considering how quickly the sound shut off with all the speakers attached I'm confident it would have worked indefinitely.  To be thorough I also did this test with the speaker in all the outputs except for the left rear.  No issues.
 4. Added the 2 front speakers and the problem came back.  Sound shut off after same amount of time.
  
 So I kinda have 2 problems.  The crackling/no sound from the left rear, and the system hanging after a minute or 2.  But I can't help but think one is causing the other.  Since neither issue was there before, and both appeared at exactly the same time. 
  
 Does the fact that it runs fine with the center speaker, but shuts down when you start adding more seem like there is some sort of overload deal going on.  There is obviously at least one faulty component, but I'm no electronics expert.  I do know my way around a soldering iron, but I kinda need somewhere to start.  I ran quite a few searches and someone suggested the pre-amp.  Does make sense as the speaker outputs are connected to it (I have opened the sub and identified the main components).
  
 I can't help thinking the biggest clue, if I knew exactly what I was doing, is that I do actually get sound for a minute or 2 before it stops.  I have read a number of posts from other people with the 'black bars' issue, and none of them get any sound at all.  They get the black bars the moment it's turned on.
  
 Sorry for the long post.  Just wanted to give you as much info as possible.  While I could forget it and go buy a new sound system, I have no doubt that when I find out what's wrong it will be inexpensive. Maybe time consuming, but I'm fine with that love fixing things myself   Plus, I'm really keen on doing a bunch of your cool mods.


----------



## rxracer

double post


----------



## rxracer

Ok... so kinda scratch most of the issues above.  After opening the sub and gently looking around with a torch for anything fried the system has now decided to become basically inoperable.  Now, it no longer works with one speaker, and does the black bar thing with or without a signal or speakers attached after a minute or 2.  In a way it might be easier to diagnose.  Now there is just one issue. 
  
 Is there an overload kill switch other than the fuse?  Cos I noticed that just a few seconds before the pod screen does it's thing and power to the speakers cuts out, the slight hum from the sub gets louder, before ending in that 'whoop' sound.  Sort of like it's leading up to the cut out.
  
 Also, are some of the smaller capacitors and microchips supposed to get BURNING hot?  I actually saw a little smoke coming from one of the capacitors for a second.  And the whole board generally has a faint burnt plastic smell.
  
 Here's the sound the malfunctioning speaker channel creates -


----------



## Bojamijams

Sorry to hear that RXRacer.. I was very excited to try this mod out but your stories remind me that I'm not good enough to play with this stuff yet.


----------



## ramachandra

A bit of sniffing on the board and the location of smoke you had seen is help to pinpoint the place worth to investigate. Cracks, oily liquids matters. Because this problem started after the new wires, the logical guess is a broken TDA7294 near the thick white wire.
 If you do not mind a maybe wain experiment, unscrew it keep bending it until all the pins break make sure the remaining pins are not causing short circuit and screw back the rest, then turn the system on. If it stay stable you have found the faulty part. The remaining pins are easy job to remove with the iron and solder pump. A new TDA7294 is cheap. If it worked, get rid of the 22uF electrolytic cap near the wire too when you install the new amplifier.
  
 There is a list of other things to try we have already mentioned on the thread, like checking voltages under load, try new OpAmps, use a pod replacement cable, recap, or do the third mod just to narrow down the possibilities.


----------



## rxracer

Thanks heaps for the advice ramachandra.  Yeah I traced the left-rear to to the white wire, was thinking something connected to that would be the issue.
  
 I've always wanted to expand my limited knowledge of electronics, and despite paying just $60 forthis unit, I hate giving up.  This has inspired me to get off my ass and start studying.  I'm actually picking up a second faulty unit next week for free, so it will make it much easier to diagnose issues, and/or use it for parts swaps since all I know about the other unit is it 'won't power on'.  Could just be a simple fault in the power plug area.  Or a bad control pod.  I'll also be reading this entire thread as it seems to have some great info. 
  
 Again, thanks.


----------



## scratje

Hi ya all 
	

	
	
		
		

		
			




  
 It's bin a while since my last visit here and i want to share an update with you about recapping the main capacitors.
 Because the leads are thicker than the originals i drilled bigger holes in the through hole connections.
 Now. after several months one of my Z5500's started with a loud hum and rattling sound when switched on one morning and i knew right away that this must be from one or more main capacitors.
 I desolderd them and found out that one of the through hole connections between the front and back of the circuit board had been disconnected (broken).
 Because of the drilling the through hole connection must have become very thin and now, after months of playing music  and vibrating, the connection broke.
 I want to advise you all to prevent this by using copper rivets in advance, which you have to fasten tight and solder them to the existing through hole pads.
 After that (the solder will flow into the hole of the rivet) you can drill them clean again and then resolder the capacitors.
  
 I made my own brass tools to fasten the rivets with a hammer but you can also buy them on the web.
 Her a pic of the rivets i used (1.0 mm through hole x 1.4mm) and the brass tools.
  

  
 Intill now i am very pleased with my two modded Z5500's one of which plays in a local pub for over half a year now 
	

	
	
		
		

		
		
	


	



  
  
  
 Greetings, scrat


----------



## Axell2Axell

z5500owner said:


> I will heat up the old soldering iron tonight .
> 
> As a first step I will confirm Sub-D pinout vs wiring color vs WA# connection by desoldering wire by wire and use the multimeter to confirm. I didn't do anything with the new POD, as I didnt wanted to tamper with the "working" POD yet
> Regarding converting the old one to the new one. The old one is "broken" and I am in no position (toolwise and experience) to desolder the CS42526-CQZ and resolder a fresh on one it (still got 2 spares lying around.... somewhere
> ...


 
  
  
 Hi *Z5500owner*!
  
 I have exactly the same problem with my system. I have one of the first z 5500 series that came out. It have served me well over the years, and I like it very much. But now the pod has completly crashed, and I have bougth myself a new one, but it will only play stereo and stereo x2, nothing else and I don't like that. So now I am humbly asking if you have found a solution for this problem and if so, would you be so kind and help me with what to do!


----------



## z5500 digital

Ramachandra
 Thanks for the detailed information and recommendations.
  
 I own a z5500 (pid: R649) ~ 9 years.
 Few mid and high frequencies.
 Previously used a standard cable.
 Heard the faint squeak if to lean an ear.
 When you increase the volume you could hear the squeak better.
 Disable all devices in the house didn't help.
 Changing the source didn't help.
 Improvised shielding did not help.
 All satellites constantly squeaked.
  
 In the summer I decided to upgrade the audio system.
 Updated the surge protector are now "Monster MP HDP 450".
 Replace the standard analog cable to optical cable "Onetech DAT6003".
 Updated standard speaker wire, now Supra Sky 1.6 mm.
 Partly increased audible frequencies.
 The difference is very noticeable.
 If to lean an ear, the squeak from the satellites remained, but the volume control now does not influence it.
 Standard analog cable was probably not the best quality )
  
 I deduce a sound through a built-in soundcard:
asus.com/Motherboards/H87PRO
 As operating system I use Ubuntu and Linux Mint.
 For better control of the channels, used the manual:
help.ubuntu.com/community/DigitalAC-3Pulseaudio
 I can now manage not only stereo, but also all channels.
 The display control unit now says "Digital".
  
 I never dealt with soldering electronics.
 But a simple soldering iron I had.
 And I even know how to handle it )
  
 Now I plan to purchase a external sound card or a modification of the standard system components.
 What better to do in the first place ?
 Does it make sense to buy a sound card for optical connection ?
 Please tell me.
  
 Excuse my French, I'm from Moscow )


----------



## ramachandra

"Does it make sense to buy a sound card for optical connection ?" Probably yes, but certainly better trough analog connection after modification. 
 "What better to do in the first place ?" "I never dealt with soldering electronics." Then you should start on a sound card, definitely not on your Z5500. Some beginners are good from the start, some experienced end up with disaster. Anything possible.
 "All satellites constantly squeaked." I do not know this one. If your system is the 9 years old probably from the first series, they had more tendency to be sensitive to external noises caused by other equipment, or Wi-Fi, PSU of your PC, too long extension lead, something on the street or in the neighborhood. Or can be other things we had mentioned on the thread, like loose or aging main filter capacitors not properly arranged wiring etc.


----------



## laciv

HI, very nice job, thanks for effort. Could you please post schematics of Subwoofer board, mute board and standtby board. Thank you in advance.


----------



## ramachandra

Hello, We do not have any from Logitech, but jayjayuk took the challenge and drawn schematics from the system, u can find them on the 10. page.


----------



## laciv

hello, thanks for quick reply. I have seen the schematics already, just now I learned how to download pictures in original resolution.


----------



## milspeccqb

Thank you guys for all the work you've put into this. I have a Pre 636 Z5500. About three years ago it failed while being used as my home theater system. The Pod still lights up and can be used but I get no sound from any speakers. I looked for solutions at the time but most said the control pod goes bad when you stop hearing sound. I recently picked up one of the control pod replacement devices but still did not hear anything from it.
  
 http://www.ebay.com/itm/320835307449
  
 So now I assume something has gone bad in the Sub. I pulled the board out and took a look. I know the amps can go bad and I know this isn't really a repair forum but do you guys have any things I can look for, some basic diagnostics?
  
 Here are all the photos I took.
  
 http://i.imgur.com/GrsZWND.jpg
 http://i.imgur.com/NB6skPI.jpg
 http://i.imgur.com/4bj5K1W.jpg
 http://i.imgur.com/r7kbPxk.jpg
 http://i.imgur.com/G3UXc1S.jpg
 http://i.imgur.com/A3FIME2.jpg
 http://i.imgur.com/QqQ9OEo.jpg
  
 When I took it off, first time it had ever been removed, I noticed that the red wire coming from the amp to the sub had got caught inbetween the metal plate and the box and unfortunately it looks like the was right over a screw hole. 
  
 http://i.imgur.com/CBeJBMi.jpg
  
 I don't know if that contributed to whatever failed or not. Any suggestions or help would be much appreciated.


----------



## ramachandra

Some of my thoughts:
  
 The first thing you should do is to check the voltages when the system is off and when it is on. You need to find +18V and -18V and +8V in the D-Sub connector. Probably you find no +18V and the reg and the surrounding components need to be replaced.
  
 Let the system run for couple of minutes and unplug it from the socket, and try to touch and find hot components. If there is a short circuit the energy converted to heat somewhere. Can be an OpAmp failed in short.
  
 About the wire you found. It is probably created a short circuit to the ground, so it is possible your Sub not worked properly since the beginning. In theory the TDA amp maybe failed due to the constant connection to the ground, the built in short circuit protection reached the limit to take. If the amp have some sort of short circuit inside that can cause voltage drop so maybe enough to interfere with the requirements of the other components or even ruin them. For example the negative voltage regulator or the chip to turn on the system.


----------



## Strider

@Ramachandra
  
 I didn't upgrade my Z5500 but still have a question about it, because it won't turn on anymore.
  
 The last couple of months it was getting harder and harder to switch the Z5500 set to On. 
  
 The red light under the on/off button on the control pod was visible, but when i clicked the button not happens, normally i can click 20/30x times, or i have to switch the on/off switch on the subwoofer, that normally helps to turn it on.
  
 But now the red light under the on/off button on the Pod is not lighting anymore.
  
 Any ideas what the main cause can be?


----------



## ramachandra

Toughs: The LM217 adjustable regulator is failed, need to be replaced. Possible reason: aging of the regulator and the 4700uF 25V cap near. Other option is failed bridge rectifier. AM152 on the newer version, KBPC1502 (3 blue 1 black wires connected) in the old Z.


----------



## Strider

Thanks for the advice! Where can i find this LM217 adjustable regulator?
 And is there a way to test it without removing it?
  
  
 I tested both KBPC1502s (I have the old version), and they both seem working fine.


----------



## ramachandra

Near the 4700uF 25V capacitor, attached to the heat sink, like the TDA Amps. About half of the length comparison to the TDA's. The reg provide +8V, you can see on the image the pin 10 to check.
  
https://d1jesv1uvhg9i4.cloudfront.net/6/64/6409f5fe_z5500pinout.jpeg
  
 Under load when the pod is attached to the system it may drop if there is a problem, so check it again if it seems OK without the pod first.


----------



## Strider

I checked the pin layout without the pod, and i don't have any voltage on the pins. 
  
 Can you specify on the photo's where i can find it? 
  
 http://i68.tinypic.com/2yy4n6p.jpg
  
 http://i67.tinypic.com/fdy1w5.jpg


----------



## ramachandra




----------



## Strider

ramachandra said:


>


 
  
 Thanks! But gosh, that is a work to replace! I have to detach the amplifier from the heatsink.


----------



## Augusti

Hey ; I have a system console Z5500 namely IC damage. CS 42526.
 What I want to do, I want to replace the console with a preamp and accurate, but can not remove the amplifier from st-by.
 The pin must be connected to the VGA jack to remove the amplifier from st-by. Thank you.


----------



## CraXyOW3

Hi, been searching this thread for the same or similar problem, but i have not found one.
 My system is so far unmodified, but wanted to start modifying it, thou my center speaker is not working at all.
  
 I saw the c104 smd component was "gone", nowhere to be found, can say it is missing as there are solder residue and all the other similar slots for the others have one.
 So having the "c" marking i guessed it had to be a capacitor smd of some sort, tried to bypass it but then the fuse went immediately.
  
 My question is, what value is the "c104" cap and is my TDA7294 for center output burned? ST's schematics points to a 22uF cap for output on pin 14, could this be the right value?
  
 Appreciate any answers, thanks!
  
 Center's area.
https://dl.dropboxusercontent.com/u/22235170/z5500/20160123_153501.jpg
  
 Overview
https://dl.dropboxusercontent.com/u/22235170/z5500/20160123_171657.jpg


----------



## Augusti

C-104 =100 nF


----------



## ramachandra

Augusti
  
 If I understand correctly you do not know how turn on the Amp without the Pod. There are three options. Buy the proper cable on eBay according the PID of your Z, make one, or just solder the pins together inside and use the main switch for on/off.
 From the PID 636 you need this connection. If you find it too loud add 50K resistors to the ground before the 20K for each channel. Replace the 20K with higher resistance for lover volume or less resistance to make it louder. Think between 0 to 50K for max and no sound. If you use pots make sure you get proper quality, crap will butcher the sound. Alps for example have good reputation. 
 Before PID 636 it require an extra voltage regulator in the circuit to turn it on. This is what i found how to do it. The same thing with pots included.
  
 CraXyOW3
  
 If returning the missing SMD capacitor not solve your problem, i suggest to do the third mod first, replace the 6pcs OpAmps in the Pod next, if the problem still exist replace the TDA Amp and the electrolyte caps belong to it. This should work if the rest of your Pod is healthy.


----------



## scratje

Hi All,
  
 Ramachandra,
 My second modified Z5500 that i sold has been placed in a local pub in my hometown (i practice beer lifting over there) 
	

	
	
		
		

		
			




  
 The music performance is very good but there is one minor problem that i want to fix if possible.
 Due to the fact that the system has to play very loud constant, for at least 8 hours, 4 days a week, sometimes (a few times per month) the system shuts down (control pod led turns off black) and after a while comes back on, which i think is due to the thermal protection of the fixed voltage regulators 78M18A +18V and 79M18A -18V.
 The max temp for these regulators is 125ºC and the current is 500mA.
 Is it possible to change these regulators with a TO-220 1A fixed voltage regulator?
 The max temp. for these is 150ºC and i can mount heatsinks on these ones.
  
 The regulators are MC7818CTG http://pdf1.alldatasheet.com/datasheet-pdf/view/12490/ONSEMI/MC7818CTG.html and MC7918CTG http://pdf1.alldatasheet.com/datasheet-pdf/view/174024/ONSEMI/MC7918CTG.html
 According to the seller at a local electronics shop, these regulators can replace the original regulators and due to the fact that they are 1A, they will not shut down due to thermal overheating that fast.
  
 What is your thought about these regulators and do you tink it is safe to use them as an alternative?
  
  
 As you can see, the originals still look good and not overheated


----------



## ramachandra

"the system shuts down (control pod led turns off black) and after a while comes back" It is more likely the LM217T regulator, because as i remember the two 18V reg only supply the OpAmps. There are few more regulators in the Pod for the other chips so if the Pod itself overheat maybe they can shut down the power too. The reason is i think the other regulators there are all hooked up to the +8V of the LM217T is, the big step down from 18V to have 5V for example, what is alone can produce lot of heat and i don't remember any big resistors to limit the current for them.
  
 "Is it possible to change these regulators with a TO-220 1A fixed voltage regulator?" Yes it is. During my mass repair pastime i was using MC7818CT and MC7918CT while the proper replacement was on the way from Asia. The MC7XXX series are my favorite for OpAmps, I have them in my external DACs, they even beat the expensive SALAS regulator from certain point. Previously andro6600 come up with his way to keep TO-220 regs in place, what you can find here. Not a challenge for your talent.


----------



## scratje

Okay Ramachandra and thanks for your advice.
 I used thermal pads  on the tda's and LM217T instead of the mica foil and thermal paste so this could be the problem with thermal shutdown.
 I've read about the thermal pads, performing less good than mica with thermal paste.
 I wil change the thermal pad on the LM217T back to mica with thermal paste now.
 Maybe the problem wil be gone then.
  
  
 the thermal pads i have used


----------



## aineiasm

Hi everyone,
  
 This topic lead me to become a member of this community.
 Regards to everyone who contribute in growing knowledge by sharing it.
 Recently I got as scrap a Z-5500 with the following problem: Power button on the pod is lightning red when I turn the main switch on the subwoofer "On" and when I press the power button on the pod,it comes "On" only for a sec displaying "*Input : Direct   Effect: Detecting... *" and then goes back "off" again. I have checked the voltage coming out of the LM217T and is steady 8V. Checked the if it reaches the pod connector and its ok. Also removed from the board and checked C11 4700uF/25V and it was ok. By pressing "*Input*"+"*Effect*" buttons on the pod for 5sec, I get the screen turn on and "*Diagnostic Mode - On*" message for 5sec and tuns off again. Pressing "*Input*"+"*Settings*" buttons,I get the firmware version*(v2.1.0)* and turns off again. I can turn on the 2nd skin also but again it turns off right after I get the confirmation message. 
  
 Anyone any idea what to check next?


----------



## ramachandra

Connect the Pod, leave the Sub open and measure, if you get less than around +8V you may have faulty bridge rectifier, check what the regulator get, it has to be few volts more.
 If the +8V change when the Pod turn on/off maybe the LM217T getting old and need to be replaced.
 You need to measure ESR for the 4700uF/25V cap to be absolutely sure.
 Other possibility is a short circuit in the Pod, what can draw to much energy to quick and the regulator's heat protection kick in
 Maybe the regulator need more thermal paste, still 5 sec seems a bit short time for the overheat to happen.


----------



## aineiasm

Ok,some update...
  
 I was lucky enough to find an owner of a working Z-5500 and ask him to test my pod on his system and unfortunately had the same results.
 So the problem is located on my pod. There are 3 LM317D2 that I am suspecting for the moment.
 Any other chip that controls the power supply on the pod? Any input or output ports that might cause this kind of behaviour?


----------



## ramachandra

Open up the Pod and use a hair dryer to keep it cold and wait to see what happen. If it keeping longer in business you may get away with a cooler what jayjayuk made. It is on the 6. page.
  
 If it doesn't work and you still have the Pods that can speed up the process to find the fault. You need to write down what you measure and compare. Some components maybe getting hot fast, that can lead you to the source the problem.
  
 "Any other chip that controls the power supply on the pod?" That is all i remember.


----------



## aineiasm

Unfortunately I could check only if my works or not. Don't have the luxury to take it to my lab and compare measurements...
 Everything I have read until now leads me to the Cirrus *C**S494003-CQZ (€15) *replacement if I will use the Pod.
 My other solution is creating a 15pin to 3 stereo jacks and bypass the Pod.


----------



## StevieG

Hi Guys
  
 Briliant thread and aswome feedback here. Let me tell you guys what my problem is with my Z5500 set.
  
 I have a buzz/hiss noise on all speakers and sub, except the centre speakers. when i turn the volume knob on the control pod there is no increase or decrease on the volume and the buzz stay the same. power off control pod, noise goes away. when i plug in optical and no sound is playing i hear the buzz. nothing plugged in digital coaxial and no buzz. nothing plugged in direct, but noise is still there.
  
 I suspect it could be on the sub/amp perhaps, maybe the big caps. i have not opened it up yet, but just wanted to know by the gurus what the [problem can be before i open it.
  
 Any advice please.
  
 Sub PID is R751
 Pod PID is R028
  
 Dunno if it's 1st, 2nd or 3rd generation.


----------



## ramachandra

Probably you need to resolder or replace the two 10 000uF 50V capacitors. The other possibility is a faulty Diode rectifier bridge, but I think better leave it for later. Ageing filter capacitors are more likely the cuase.
 Your Pod and Sub is from the third generation.


----------



## maxxximatoze

Hi all,
  
 Like I said in my previous message some time ago ( http://www.head-fi.org/t/657715/almis-logitech-z-5500-mod-high-end-upgrade-for-the-speaker-system/180#post_11097465 )
  
 - all the logic management in the pod is handled by the Z8 chip
 - the input/ouput is handled by the CS42526 (6 dac and 2 adc completed by the 2 CS5351 and spdif in/out)
 - all the digital audio processing is handled by the CS49400 (for information, when you are not in headphone mode this one is responsible of a digital EQ curve applied on all 5 channels to correct the 5 statellites speakers response to have final almost flat frequency response, so the amp does not have a flat frequency response when used with the pod, and so you cannot use another speaker set than the original one, unless you don't bother to not have a flat frequency response from the amp)
  
 Here is a link to my collection of data about the Z5500, that I have deeply modified from 2006 to 2012, that containing a lot of informations about all the chips like datasheets of all Cirrus logic chips, including CS49400, and reference design (almost the same used by logitech), Z8 datasheet and some software and source code, additionnal datasheets for components I've replaced, there is also the truth table of the mute fonction... So a lot of valuable informations for who wants to know more, especially for who wants go deeper inside the software stack to change the DSP setup or modyfing the core logic or whatever.
  
 If you want to go deep in the Z5500 electronic and software analysis it could be a good starting point !
  
 http://maxime.pierron79.free.fr/z5500
  
 Enjoy !
  
 If you want to know what I have modified on my 10 years old set (and always in good shape not bad for a 300$ set) just ask.


----------



## Nycalex

dang, i have a old logitech z5500 system that i haven't used for over a year. maybe i should try to mod it.
  
 are there no other multimedia speakers that are better than these? and i mean multimedia as in PC specific, not the bookshelf monitors.


----------



## Alketi

Glad I found this board -- hoping someone can point me in the right direction to troubleshoot:
  
 My z5500 symptoms:
  
 1.  Worked fine for years with no troubles.
  
 2.  Just last week, the speakers began making a LOUD popping sound.  At first the pops were hours or days apart.  The first one was actually in the middle of the night while the computer was in Sleep mode.  
  
 The popping wasn't localized to one speaker, but would move around to different ones. Over the next few days it got worse.  Sometimes it would go minutes or hours between pops, sometimes it would pop 5 times in a row.
  
 3.  This popping degenerated into losing audio, which I could regain by cycling the power button on the control pod.
  
 4.  Finally, the audio stopped working.  The control pod still lights up and sometimes appears normal, but if I cycle it a number of times it reads:
  
*Error Loadingt       96--24*
*DSPABT:      Detecting....*
  
 5.  Turning the control pod ON sometimes results in it shutting itself off (back to standby) after about 30 seconds.
  
 A visual inspection of the capacitors in the sub doesn't reveal any that are blown.  And, there's no smell of burnt electronics in either the pod or sub.
  
 I've seen others with the same error code, but no solution.
  
 Any ideas on how to bring this system back to life?


----------



## gogusrl

Found this thread by mistake, spent the next hour reading everything, amazing work guys.
  
 I have a 0451 R / 115395 model (at least that's was it says on the pod label) and always had a problem with a popping noise every time I start/stop playback if it's a 24 bit pcm signal or DD/DTS. This doesn't happen if it's set on 16bit. Using an optical connection with different sources over the years (currently a Asus U7 external soundcard).
  
 This hasn't bothered me over the years because I don't watch many movies and I can't say I notice the difference in quality between 16/24 bits but I plan to move the system to the bedroom for movie watching and I'd like to fix this before they end up there.


----------



## Brain-D

Hello Everyone!
  
 I found this amazing thread while I was looking for a way to fix my Z-5500. First of all, I have to admit that I have been really impressed by the knowledge and the help that many of you are sharing!
  
  
 I bought a  set of Z-5500 three days ago (second hand), they have been working fine for 2 days... As you can guess, I was expecting them to work fine for more than 2 days!
  
 Now, let me expain my problem: 
  
  

The front-right speaker is crackling and popping very loud on a constant basis.
The center speaker is fine
All the other speakers and the sub are crackling and popping on a constant basis but not as loud as the front-right speaker.
  
  
 This video shows exactly the problem that I have: https://www.youtube.com/watch?v=plZXLAwgSFk 
  
 PID: R550
  
 If any of you could give me advice, it would be highly appreciated.
  
 Thanks a lot!
  
 Brain-D


----------



## JesseA

Wish I still had my Z's around to try this.


----------



## Brain-D

brain-d said:


> Hello Everyone!
> 
> I found this amazing thread while I was looking for a way to fix my Z-5500. First of all, I have to admit that I have been really impressed by the knowledge and the help that many of you are sharing!
> 
> ...


 
  
 Update 1 
  
 I have opened the Pod and the Sub to verify the capacitors, they all look in good condition and I did not find anything else so I put back together the Pod and the Sub.
  
 Then when I tested the system again, everyting was working fine. I have no idea what happened.
  
 Brain-D


----------



## Brain-D

Update 2:
  
 The system was working fine yesterday but when I turned it on this morning, the crackling/popping noise is back.
  
 Any advice would be really appreciated!
  
 Thanks,
  
  
 Brain-D


----------



## Alketi

Brain-D, mine had the same symptoms (http://www.head-fi.org/t/657715/almis-logitech-z-5500-mod-high-end-upgrade-for-the-speaker-system/345#post_12531104).
  
 Eventually, sound stopped coming out of the speakers, for which I needed to cycle power.  Then, even that wouldn't fix the issue and my pod would display the error:
  
*Error Loadingt       96--24*
*DSPABT:      Detecting...*
  
 I had no capacitor or other obvious problems inside either the pod or the subwoofer.  And, no smell of burning electronics.
  
 I'm in the process of building a bypass box as described here:  http://www.diyaudio.com/forums/chip-amps/110310-hacking-logitech-z5500-49.html#post3706679
  
 Will update when/if I get it working.


----------



## kaya47

Hi!
  
 I recently bought the z5500, second hand in perfect state, they came with a very good quality custom wires (not the stock ones) and they sound really awesome.
  
 After reading this thread i decided to modify my system as well, what i want to do is changing the Op Amps.
  
 Seeing other`s feedback, i would like to buy the OPA1612AID.
  
*I found these on ebay at 3.44$ / piece - LINK*
  
 Are these genuine or fakes? Most of them are to be found at 8-9$ / piece.
 What would you guys recommend? Where did you buy these parts?
  
 I`m from Europe.


----------



## ramachandra

Popping sound maybe the result of a contact problem of the power cord, switch. Inside: loose main filter capacitors (even if the solder joint look fine), internal insulation is began to break down in a component. When more than one speaker has the problem it points toward the main filters and around the +18 -18V regulators. But before you start taking the system to pieces measure the Volts first.
 Often to locate fault is like finding the needle in the haystack, people who repair household electronic remove, test, soldering back one component after another.
  
 The 16/24 bit problem is maybe broken/damaged optical cable or dust, fingerprint, low signal strength because the length or quality, or the signal divided too many ways. Other options is faulty optical connector, receiver chip or the DSP. There is a tiny tiny chance it has something to do with increased power requirement on 24 bit, what the Pod don't get.
  
 eBay is an expensive source for OpAmps, only worth if you need few pieces. Try Mouser, Farnell, Digikey. Mouser has the Silmic II capacitors even Nichicon KG or KW. Still I recommend the two 10 000uF Elna For Audio or DENON from Asia. The OPA1602AID is cheaper and more alive than the OPA1612AID. Try here.


----------



## z5500 digital

Recently I read about the "z-5500" and learned that inside there is a DAC.
 It sounds better motherboard onboard sound.
  
*Ramachandra*, I remember how you advised card with analog output, but I was planning to buy a sound card with digital output. Now I understand how it works and is ready to follow the advice.
  
 At the moment I am looking to purchase options.
 We have our own ebay - avito.ru.
 I can buy used sound card in his home town to check it.
 I need help in choosing.
 This purchase for further modification.
 The manufacturer's warranty does not bother me.
 I want to experiment.
  
 I saw your article about sound cards modifications.
  
 Could you recommend something relevant for today?
 Select will be here:
http://avito.ru/moskva/tovary_dlya_kompyutera/komplektuyuschie/zvukovye_karty
  
 Have you seen this video?
youtube.com/watch?v=UZCOma1AkZA
 Have you tried something like that?
  
 Audio cable I replaced immediately.
 I would like to know about replacing the power cord.
 Strongly Does this affect the sound?


----------



## Alketi

An update on my dead Z-5500, which was exhibiting popping from ALL speakers, before finally dying and exhibiting the following error on the pod's LCD display:
  
*Error Loadingt       96--24*
*DSPABT:      Detecting...*
  
 I inspected and found no damaged capacitors or burnt electronics smell in the subwoofer.  So, I bypassed the control pod using the following diagram:
  
 http://i.imgur.com/pbGXw2e.jpg
  
 Note that my pod is revision R547.  The pinout differs on later pods.
  
 I built a small box to contain all the rework, and it's now working perfectly.  Sound from all five channels!
  
 If you have popping on all channels, or an otherwise dead control pod, and have inspected the subwoofer for obvious faults, then bypassing the control pod may just fix your issue was well.
  
 The thread detailing this information, with the post that I followed can be found here:  http://www.diyaudio.com/forums/chip-amps/110310-hacking-logitech-z5500-49.html#post3682337
  
 Cheers


----------



## ramachandra

I certainly not recommend PCI cards. For example if the Creative is not making driver, probably you can still use PAX, but the PCI slots are about to disappear from new motherboards. If you do not want a mod, probably I recommend the PCI Express ASUS Xonars, or if you want a mod and cost+risk is not an issue. Otherwise I suggest a Titanium or Titanium Fatal1ty Pro. From DAC point of view I prefer the Cirrus DAC on the Titanium cards. Cirrus DACs are energetic rough beauty compared to the gentle refined PCMs with the nice 3d touch. The Xonar cards with their own DAC chip for every two channel are supposed to be superior for clarity. The X-Fi cards is the choice for a gamer to reach the maximum frame/sec gameplay. From driver point the Creative cards had less trouble according to the rumors few years ago.
 From Titanium VS Titanium Fatal1ty Pro point what you get for the extra money is a piece of iron shield to improve the SNR. Measurements show the difference your hear will not.
 For digital connection any of the cards released in the last 10 years from Creative or ASUS, probably do a perfect job.
  
 The PSU cable is a good question, in theory it is matter, in practice, perhaps.
 The power get somehow to your house from the generator. In Russia it can come from really far, on who knows what sort of network of wires. In the walls of the house maybe there is copper, if the building is old it can be aluminum. Next thing is how good is your extension lead if you use any. Then we arrived to your Z's 2 meter long power cord. If the previous wires are quality and the power cord is made from dirty cheap rubbish (no offense to the Chinese, just a possibility) the new cord is perhaps make a small difference. My friend told me he bought a fancy cord for his external DAC and he was happy with the improvement. Yet I have to try.
  
 On the first post I have mentioned we changed of the original speaker wires to solid core copper wall cable. The result is good. We have not try to replace the spring clips. If you interested in the best connection try gold plated.
 Gold have 3 attractive qualities:
 - looking great
 - no oxidation
 - soft metal create better contact (in theory because the plating is thin)
 Disadvantages:
 - higher price
 - not the best conductor (the next after copper the silver is on top from the elements)
 - no connector beat the solder joint.


----------



## kaya47

Thanks for your feedback ramachandra!
  
 I don`t know if i want to touch the caps as it looks difficult to do.
  
 I see you pointed out the OPA1602AID*R*, is there any difference between them?
  
 I have a few more questions though:
 1. If i only change the opamps with those you mentioned - OPA1602AID, will i notice a big difference? Or any difference at all? Have you compared two systems side by side, one modded and one vanilla (as it came out of factory)? I'm a bit skeptical as some articles point out that swapping the opamps won't make any real improvement to the sound.
 2. What role do the opamps from the console have? Do they have an impact on the overall sound? Or only the ones from the sub are important? - What if i change only the amps from the sub?


----------



## z5500 digital

*ramachandra*
 I also have a question.
 Here, someone tried to "discrete op amp"?
 Do not expensive solutions?


----------



## ramachandra

The *R* coming on reel(s) not in tubes. The same otherwise.
 "some articles point out that swapping the opamps won't make any real improvement to the sound." When I swap within the general purpose garbage, that's for sure. 
	

	
	
		
		

		
			




 "Have you compared two systems side by side, one modded and one vanilla (as it came out of factory)?" No need. The owners had them long enough to be accurate. + My experience.
 The thread holds the detailed answer to the rest of your questions.


----------



## kaya47

Thank you, i didn`t wan't to offend you, if that`s the case.
  
 I have read the whole thread actually and i want to pull the trigger on this one. But couldn`t find any answer to my second question, i know that swapping the opamps from sub would make the most difference, but what if i swap only those not all 11? I don`t know the role of the opamps from the console.


----------



## ramachandra

When the signal travel trough any active or passive components there is some loss, change or degradation, so the logical step is to find the most suitable components or change the design to minimize it and to keep the way we want. Many sound equipment on the shelves not designed to achieve the possible best experience by perception, yet completely fulfill the expectation on the paper and keep the manufacturers/customers happy.
 When you change the OpAmps alone in the Pod the sound is coming closer to that what the source produce + the new components add their own sound signature. The first 3 on the analog input is probably the same story what I have removed in the third mod. (just taking the space, degrade, make the system more vulnerable to faults + increased the manufacturing cost.) The other 3 actually serve a necessary function, to amplify the weak signal coming from the DAC's. If let say you replace all the OpAmps in the Pod alone you get a cleaner sound, if the capacitors as well, it is becoming more alive, dynamic, and sound stages, bass noticeably improve. If you change the capacitors alone the stock OpAmps remain a bottleneck and the benefit even arguable. Basically the same experience like the modification in the Sub just smaller in scale.


----------



## bitmap

sorry to  divert - but if any of the z5500 owners who have had blank/faded text on the control pod and fixed it  
  
 can please respond to the the  following thread ; can't seem to find any solution to this so far...
  
 thanks.


----------



## ramachandra

"Here, someone tried to "discrete op amp"?" For the Z5500 I do not remember anybody even to try different OpAmp(s).
 "Do not expensive solutions?" I have not seen any discrete OpAmps cheap. They are minimum 10X more expensive compared to the OPA1602.
  
 I was looking them for some time ago, even I got 2 small PCBs to make my own eventually. I was unconvinced when I read the opinions. It seems the improvement with the more expensive ones is only marginal or arguable. Of course the test equipment and person is very much part of the unknown factor on forums. Maybe they are the ultimate option for cutting edge gear, or fail miserably against the advantages of a small chip.
 If you do not mind a bit of work the current OpAmps on the market can do better. For example the OpA1602 has no mono version, but if you wire it up as a mono, two of them sound way cleaner, and even handle bass better. The same apply to my old favorite Opa2228P even it has the Opa228P mono version. Even more can be done with them and there is a high possibility the discrete OpAmps not a competition, just on the paper.


----------



## z5500 digital

Please tell me.
  
For Creative X-Fi Titanium (4) + z5500 (11) = need 15 x OPA1602AID (or OPA1602AIDR) ?

Not very expensive discrete operational amplifier:
1.
"http://www.ebay.com/itm/LME49720-Full-Discrete-Dual-OP-AMP-Opamp-Module-Board-For-HDAM-Replace-OPA2604-/231629867518?hash=item35ee3749fe:g:lUQAAOSwgQ9Vr3DV"
2.
"http://www.ebay.com/itm/5V-22V-Dual-Differential-Full-Symmetry-Complement-Discrete-Dual-OP-AMP-Module-/141739124728?hash=item21004f67f8:g:uW4AAOSwu1VW8SAJ"

I would like to try these:
"https://www.bursonaudio.com/products/supreme-sound-opamp-v5i"
But I do not know whether to do it =)

2 x "OPA228P" to put the sub-woofer needed with the Z-5500 ?
In creative x-Fi Titanium is also necessary "OPA228P" ?


----------



## ramachandra

Seeing the Supreme Sound Opamp V5i from the inside make me a bit skeptical to spend $39.00 USD. Unless the chip is really their own unique design as they say. I have never tried those OpAmps on the links, so my opinion is not very useful.
  
"For Creative X-Fi Titanium (4) + z5500 (11) = need 15 x OPA1602 ?" Yes, if you do not want to do the third mod on your Z.
  
 "2 x "OPA228P" to put the sub-woofer needed with the Z-5500 ?" No need. It is produce better sub bass, and can be difficult to install properly. (Untested in the Z, but supposed to work.)
  
"In creative X-Fi Titanium is also necessary "OPA228P" ? Not necessary. You can install an Opa2228P or a pair Opa228P with the adapter(s) for the Sub channel on your X-Fi for the same reason. This chip on the bottom also the OpAmp of one side channel, and a stereo Opa2228P will have effect on both. In 5.1 it is not an issue. (I had to edit this message this morning because I have confused myself with the output jack. Sorry.)


----------



## mihaiil

Really useful thread, *ramchandra*, thank you so much for sharing with us. I have  few quick questions. I'm using only the subwoofer of the Z5500's system with "DIY bypass control" cable so I don't have the control pod neither the full-range speakers. My *first* question is, if I  change the two opamps in the sub, would I be able to hear the difference in the sound (I guess yes?). The *second* question is can I completely remove the two sub's opamps and replace them with film capacitors and if yes, the *third* question is which would be better, new opamps or film capacitors?


----------



## ramachandra

You are welcome.
 "if I  change the two opamps in the sub, would I be able to hear the difference in the sound (I guess yes?)" Correct. You will get a clean, integrated bass, no more buzz.
 "can I completely remove the two sub's opamps and replace them with film capacitors" No. This OpAmps cut the signal in half, and the two TDA Amps in bridged mode get a different part. After the amplification the signal is put together again. A cost + energy efficient way to drive the Sub. (In the other positions the coming signal set back and re-amplified to the same level. That's why capacitors can replace them.)


----------



## mihaiil

Thank you so much, I'm ordering the parts. I also did the mod for my XtremeMusic by your instructions and I'm very happy with the results. Thank you so much again, I appreciate what you are doing.


----------



## Kostas7GTR

Hello,
  
 I tried the mod on  my z5500 also by first replacing the op-amps.
 I first replaced the rear speaker stock with OPA1602AID and i reassempled and check if everything was working fine.
 It was working ok so i removed the 4 remaining stock op-amps and replaced them with OPA1602AID. Now i have a problem... My soldering skills are exelent and the amps seems they were soldered from factory, amps are on the right direction but when i try to test some music the sub does some sounds that shouldnt. If i test each channel seems to be working ok but the sub channel seems to do some "boom" when not needed. So i replaced the new amps and put back the old ones to check if something is wrong and i have the same problem.. Any ideas ?


----------



## ramachandra

Thoughts: If the soldering is checked OK by instrument, no pad is missing, if the board was not removed probably some SMD component got too much heat. Or there is a drop or fragment of solder somewhere. Or while using a good old fashioned soldering gun the current flown on an unexpected path on the board.
 If one of the OpAmps are removed half of the sound remain and will help to narrow down the area of the problem.


----------



## Kostas7GTR

Hello,
 Thanks for the answer, first i have to say i got two z5500 systems.
 I tried to mod the first one as i wrote but when i changed the op-amps on the sub i start getting troubles.
 I have to say i have a Hakko ESD safe station and my soldering/desolddering was done with quickalloy, amtech flux, i was "grounded" wearing gloves and it was done on 250c with good quality flux (i touched each of the op-amp legs for 1 sec max)
 So when i changed the last two sub op-amps on my first Z5500 and plug it back again it start doing boom boom you know like interference cracking noise so i turned it of unplugged it and inspected again.
 Cleaned everything checked for small solder balls that might have dropped but nothing. So i cleaned up removed the op-amps reinstalled new ones with same result. Then i desoldered and removed them and had sub channel ofc "dead" but everything else worked ok. Then i reinstalled the stock op-amps that seem to work so i thought that the new ones were faulty either i caused them problem while i did my best not to.
 Then i removed those stock that worked and reinstalled again brand new ones but had same result... so i gave up on that system.
 Then i took my second z5500 system, i removed the last two op-amps that seemed not to work on my first Z5500 and installed them on 2nd sysytem one by one and guess what op-amps were fine...
 After modding the whole 5 op-amps i tested the system for a day and it was working without a prob.
 Next day i replaced all the caps with elna and Nichicon and tested the system for two days.
 I can say so far difference on sound was HUGE !!! Bass was awesome not boomy like before but fast and accurate. Also my "analog" input game me good sound and my volume of analog part was on pair with the optical. Before i had 4+ lines on analog to get same volume level as i had on 2 lines on the optical.
 Today i modded and replaced the caps on the pod but in the end i run into troubles ...
 All caps were installed without any problem, i run the system for 2h+ and then my rear speakers start giving me interference... even when not playing anything. It was working fine. The 6 caps were moved in front so they dont cause trouble and all others didnt hit any plastic or something. Anyway  after 3+ of cleaning removing bla bla bla i got pissed and installed the other pod i had and i will check it later. Dunno what might caused the problem but not i got a pair of modded pod that does interference and a sub that does the same. The other system is working fine and im enjoying it atm 
  
 Here are some pics of the op-amp i installed:
  
 https://i.gyazo.com/ec48ea9be29e02d2aebee6e0a15b02a4.jpg
  
 And one inside the sub with changed caps and op-amps
  
 https://i.gyazo.com/fd71eb297e47413623f6f33b30070193.jpg
  
 Hope i find whats wrong with both sub and pod to make my second z55000 working again...


----------



## ramachandra

Just by looking the pictures you obviously work like a pro, and know what to use for the job.
 I spotted some differences what I have never tried, and maybe the source of the problem. I had only the two main filters on wires in the first mod and still in that way years later, and giving no trouble since. I never used the 4700uF cap the same way. If you check back around page 17, scratje built a nice capacitor holder for his older version of Z. Later he complained about some distortion and he had to make changes. To keep the story short, the length of this wires possibly play a role. They more likely picking up radio garbage, the main filters less effective to eliminate the transformer's noise, and the regulators need capacitors close as possible in order to function. The LM2172 regulator doesn't have any small electrolyte beside, unlike the the +-18V regulators. It may have an effect on the job it does + produce more heat to keep up whit the needs.
 The other tiny detail is, I was using small value film and electrolytes on the main filters, and this caps adjust quicker to the changes. Perhaps I run into complication without them.


----------



## Kostas7GTR

Hello,
 Thanks for the good words 
 Lets talk about the probelm i faced today with the control pod.
 I didn't take pictures to show you how i placed the caps but i can tell you they were percect arranged and soldered.
 I understand what you say about the 4700 cap but this Nichicon was very fat and there was no way to put him on his original position.
 Also i 3d printed a base as well to put them more close but in the end because the main filters are like 8cm tall i ended moving them on the sub and the 4700cap as well.
 I can say this can cause problems but atm my original control pod from the 1st z5500 unit works like a charm while the 2nd control pod that i mod today with the Elna caps worked for 2-3h and then the rear speakers only when im on analog input start do some cracking noise even when there is nothing plugged it and even when i power-cycle the system and just turn it on so i guess some cap gone bad or something wrong on that op-amp - cap circuit.
 I will check tomorrow to see if i find anything, atm i plug my 1st systems unmodded control pod and i have no problem at all.
 I will check the caps for short circuits and measure their capacity.
 If problem is gone and i will find faulty cap i will reorder and replace but its like tha same problem i have with the 1st z5500 sub (that happened when i changed the op-amps) and now its on rear speakers (and i know its caused by the control pod i modded).
 If you have anything to suggest about the pod im open to suggestions and since i don't have spare new caps i will remove them all check if i have the same problem.


----------



## dogchainx

Great thread!  Wondering if someone can help me with no sound on my system.Lots of information, but I'm not sure where to start. I have a z5500 subwoofer that stopped working on me. Its not the POD, as I have three pods now and all work with my other Z5500 subwoofer.  I opened up the dead z5500 subwoofer and couldn't smell or see anything wrong. No apparently bad caps or dead ICs.  
  
 Here's what works and what doesnt:
  
 -Pod turns on
 -Fuse is good
 -No speaker, or subwoofer "TEST" sounds work.  Every speaker does not work.
 -Can send sound signal to the pod from the computer, and hook up earphones that'll give sound.
  
 So the woofer can turn on the POD, but can not hear anything from the speakers, though hooking up headphones to the POD can give a sound signal. And those three pods all work with another z5500 system woofer.
  
 Is there a simple one or two  caps that would probably be the cause for the subwoofer not to respond that I could replace?  
  
 I see that there's those two large capacitors, then the other small one on the subwoofer board (which is for the pod?)   
  
 Any help would be appreciated.


----------



## ramachandra

Use a multi meter. Probably you will not find +18V and -18V on the D-Sub pins because one or both of 78M18 and 79M18 regulators are dead, or maybe one electrolyte cap failed in short near by. Or damaged trough hole current limiter resistor beside.
 If you are really short on luck, there are few dead OpAms on the panel to replace as the result of regulator failure. 40% of the boards I bought to mod&repair in the past had this kind of problems. Images on post 83 and more info on the page.


----------



## z5500 digital

With the holidays )
 By year-end received a "Creative audigy RX / 5".
 The difference compared to the built in sound is huge.
 Read more about this map can be found on our local forum.
 http://forum.ixbt.com/topic.cgi?id=12:54830.
 I'm willing to do a modification of the "Z-5500".
 I use a "direct" connection.
 Please tell me.
 I need 9 x OPA1602AID and 2 x OPA228P (or 4 x OPA228P) ?


----------



## ramachandra

I think 4pcs OPA1602AID all you need for the Audigy RX.
 Inside the Sub: Use a pair OPA1602AID for the Sub woofer. The rest can be 3pcs OPA1602AID, or better if you use 5pcs 0.47uF film capacitors.
 Inside the Pod: Use 6pcs OPA1602AID.


----------



## z5500 digital

Первое, что я хочу, чтобы изменить Z-5500.
  
 Я правильно понимаю?
 Для суб вы рекомендовали заменить операционный усилитель на "Wima MKP 0.47uf 63V"?


----------



## ramachandra

The WIMA MKP certainly do the job, but you may find the bigger axial films more transparent sounding. I was using K73-16 and K73-11 63V in this positions from eBay.


----------



## z5500 digital

Such hard to find.
 Tell me please.
 I need these?
  
 1 x Elna Kenwood 4700uF 75V (or Elna Kenwood 4700uF 71V)
 2 x Elna Denon 10000uF 50V


----------



## ramachandra

Not that hard: http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=k73-16+0.47uF&LH_PrefLoc=2&_sop=15
 Get the 71V Kenwood, the 75V is too fat. Denon is the best you can get.


----------



## z5500 digital

Soviet film capacitors can be found here in Moscow =)
  
 I wrote about the two types of electrolytic capacitors.
  
 Thanks for clarifying.


----------



## z5500 digital

Tell me please.
 You mean it?
  
 Something else is needed?


----------



## ramachandra

Yes, that's what I mean. All you need is in the "Third Mod".


----------



## z5500 digital

6 x OPA1602AIDR (or OPA1602AID)
 5 x K73-16 0.47uf 63V (or K73-11 63V)
 1 x Elna Kenwood 4700uF 75V (or Elna Kenwood 4700uF 71V)
 2 x Elna Denon 10000uF 50V
  
 What else do I need to buy?


----------



## ramachandra

Listed on the first page.


----------



## Cmiky

Hey! Did the third mode, and at the start was resistors R21 and R22 burnt.What may be wrong?


----------



## ramachandra

Obviously short circuit. Can be small, hard to detect.
 Or misplaced mica insulator(s), solder drop, metal fragment, screw between the pins of the TDA AMP. Component installed the wrong way, left out, damaged, bad solder joint. Long list of possibilities....
 If you find the mistake, you may need new resistors (or worst, regulators too) to make the system work again.


----------



## Cmiky

Hello and thank you for your angagemang!
 I've checked and all components are correctly fitted
 Since
 I have found a bad solder on a cable that goes to the right channel filter capacitors fixture that includes:
 10000uF63V Elna for Audio
 1000uF63V Elna
 220uF63V Elna
 100uF63V Elna
 10uF63V Ero MKT
 4,7uF63V Ero MKC
 2.2uF100V Ero MKT
 1uF63V Wima FMD
 0.22uF 63V MKT
 But wonder if it can burn
 both R21 and R22 resistor.
 R21 to steady done "little" hole in the PCB
 R22 is only burns
 More info
 Changed blown Logitech speakers with sub Pioneer TS-W261D4 ​​is two spolig 4ohm and brygat out between the plus and minus!
 PreAmp panel I have changed ceramic capacitors with K73-160.22uF 160V is it ok?
 The residue was used
 1 pc. 4700UF 63V ELNA KENWOOD
 13 pcs. 22UF 50V Elna Silmic II
 6st. 47uF 50V Elna Silmic II
 1st. 10uF 16V Elna Silmic II
 12st. 0.22uF 63V MKT
 1st. 1uF63V Wima MKS

2st TEXAS INSTRUMENTS - OPA1602AID - OP AMP, AUDIO, BIPOLAR, 8MS...

  
 Kontrol pod, I purchased components not modat than
 It was not cheap can not stop now and throw everything
 SINCERELY
 Cmiky


----------



## ramachandra

"But wonder if it can burn both R21 and R22 resistor." When the filter capacitors have a bad contact you get hum, but If it was a hot ground problem..... I just do not know how the regulators behave without it.
 "K73-16 0.22uF 160V is it ok?" It is.


----------



## Cmiky

Hey!
 I have been looking and looking for several days and finally I found a short circuit at the terminal of C32 47uF 50V kondensator.Det which is strange to short circcut was with removed  cap in the terminal itself, but I could not see with magnifying glass.Det disappeared that I put solder pen in the terminal C32.
 Have a question before I test
 Should there be contact on the PCB between the terminal for filter capacitors 10000uF (between minus C29 and Plus C30 )


----------



## ramachandra

"Should there be contact on the PCB between the terminal for filter capacitors 10000uF (between minus C29 and Plus C30 )" Yes.


----------



## Cmiky

Ramachandra Hi!
 I have found the short circuit, and now it's ok.
 Regulators believe I'm ok
   78M18A input pin 1 is 31.4V, output pin 3 is 17.7V
   79M18A input pin 2 is -29V, output PIN3 is -18.1V.
 Tried start without Pod, and it seemed ok = no smoke from the resistors or something else.
 When I switched on the pod and speakers.
 In the beginning was the noise from the sub. and nothing else.
 Turned off !
 Started again and there came no sound at all.
 It is under tension, no smoke looks ok, but no sound
 With what can I Bratta now?
 Something suggestions?
 Thank you for being kind
 SINCERELY
 Cmiky


----------



## ramachandra

Few ideas:
 Perhaps you can check the sound from the Pod with a headphone. If the OpAmps not getting what they need under the load, probably you gent no sound directly from the Pod. Because circuits in the Pod powered from 2 different sources. The +18V -18V is for the 11 OpAmps, the +8V is for the rest of the circuits in the Pod. Previously on this thread somewhere was mentioned, the burnt resistors was the source of complication, checked OK with the instruments, still it was not enough until replaced with new. Get the same size or bigger to be sure you are not under the necessary Watt.
 Or. If nothing work you can improvise a Pod replacement cable to narrow down the possibilities. If let say as the result of the short circuit most (or all) of the OpAmps burnt out, and you had done the the third mod, the 0.47uF 63V capacitors will work and you supposed get sound from all speakers, except from the Sub. Or if you have not done it, try few new or the old OpAmps.


----------



## Cmiky

I have two POD (a new one) and do not think that both are broken! But they tested at a friend who has an older Z5500 with coaxial speaker terminals in different color POD pid 526.De worked, both optical and direct, but only with stereo and stereox2 setting!
 On my Z5500 nothing, but POD works with headphones!
 Any idea?


----------



## Cmiky

Additions!
 I made the third mode!


----------



## z5500 digital

I heard a clap near the diode bridge.
 But I'm not sure about this, the radiator is screwed.
  
 The control panel works and turns on.
 The buzz is heard from the subwoofer.
 I did not dare to reproduce the sound.
  
 I dismantled the subwoofer.
 I removed the center channel cable.
 I replaced the internal wires for the front two channels and the subwoofer.
 I had to enlarge the hole for the wire to 2 mm.

  
  

  
  
  
  

  
  
  
  
 I had to spend a lot of time.
 Soldering was of very poor quality.
 Wires a little loose.
 I think the problem is in them.
  
 I redid the work several times.
 In addition, I used a bad soldering iron (GJ907) from China.
  
 I found a message about rivets.
 http://www.head-fi.org/t/657715/almis-logitech-z-5500-mod-high-end-upgrade-for-the-speaker-system/315#post_12072214
 I want to try the same thing or find another way for reliable soldering.
 Where should I start the test?
  
*UPD* :
 Temporarily removed the wires of the subwoofer.
  
 I checked the satellites.
  
 Two news, bad and good.
  
 The left channel is silent.
 The right channel plays =)
  
*UPD2* :
 Another good news.
 The left channel is working.
  
 The problem was in bad contact.
 I'll try to do better when the solder comes from the store.
  
 Now I want to make a subwoofer.
 Tell me please.
 Does the "R701" have a thin copper leg that goes to the negative wire (WA700)?

 I covered it with a layer of solder.
  
 When I first soldered the wires, I saw this leg from "R701", but did not attach any importance to it.
 The second time, I tried to solder the wire to this leg from "R701".
  
 Which option is correct?


----------



## z5500 digital

I increased the holes for the wires.
 Now I can insert a 2mm wire.
  
 But there were borders of the printed tracks that I damaged.
 If you insert a wire, a short circuit occurs.
  
 The edges of the holes I insulate with varnish.
 The end of the wire (green cross) is soldered to the nearest point, the negative leg of the capacitor is 50v 22uf (red cross).
 The remaining elements (the pink cross), I connect by pieces of wire with a green cross.
  
 Tell me please.
 Are there any errors in my scheme?
  

  
 original photo:


----------



## Bagheera

Hello! I would like to attempt this mod and am currently preparing to order the components I need.
  
 I am likely not going to do the full mod though - will I get a pretty decent result by replacing only the following?

OpAmps (both in the control pod & the subwoofer)
22uF & 47uF capacitors (in the subwoofer)
  
 And just to make sure I understand everything correctly, I will need the following parts:

13x 22uF 50V Elna Silmic II
12x 47UF 50V Elna Silmic II
11x OPA1602AID or OPA1612AID OpAmp (likely OPA1612AID, I can't find OPA1602AID for as good a price on eBay)
  
 Is all of this correct?
  
 This will be my first time modifying audio equipment, though I've prior experience in soldering, I would feel more comfortable limiting my mod to the above as a start.


----------



## LeWidget

Hi Guys,

 Newbi here to the forums, electronics and anything Audio related. Came across this Topic and must say, wow!, such a fantastic write up, Im very tempted to make these mods.. which brings me to my question.

 I have 2x Z-5500 units...

 1st being my primary unit, works fine, PID R938 (control pod), and R834 for other parts (control pod was replaced under warranty many years ago).

 2nd unit, having an issue with the centre speaker, its' PID is R710.

 With the 2nd unit, no audio comes out of the Centre speaker channel. When I play music or run the 'test', all other speakers and bass work except the centre speaker. I've connected the speaker and the control pod to my primary Z-5500 to help rule them out and they both work fine.

 I've also tested the speaker cable, that too seems fine... so it leads me to believe there something wrong with the centre speaker output/circuit etc.., within the sub itself... but Id on't really know where to start looking.

 I opened it up and took a pic, but a quick visual, everything looks ok (i'll have another closer look when I get a chance)

 Unfortunately I can't post pics (yet).. possibly due to being a newbi and this being my 1st post(?)

 http://i998.photobucket.com/albums/af101/Widget1983/Electronics/z5500%20wireing%20labeled_zpsqpztgdcy.jpg


 Thoughts and suggestions ?

 Thanks in advance 

*[EDIT] *Looks like 1x of the 4x TDA7294 IC's has gone walkabout. Going to order one in to replace, will see how that goes.


----------



## ramachandra

z5500 digital
 "Which option is correct?" The few old photos I have is useless, no Z amplifier board around to check.
 "Are there any errors in my scheme?" If you connected all the pins marked with X together in the square, that should work.
  
Bagheera
 "Is all of this correct?" Correct, but do the third mod instead. Lower cost & risk, and give you better result.


----------



## z5500 digital

*ramachandra*
 I'm worried about the back of the board.
 I saw there a resistor with a 34C marking.
 From him there was a path, thinner than other elements.
 I applied solder on top to increase contact, because it was very thin.
 I'm not sure that this resistor should connect to the wire.
 I'm trying to compare with datasheet, but I do not have enough experience.
 Could you tell me?
  
 http://www.joyta.ru/uploads/2014/10/mikrosxema-usilitel-tda7294-opisanie-m.gif
  
 Hole for negative wire.
  


  
*upd:*
  
 I think I understand.
 Wire contact with a resistor 34C should be.
 After the resistor there is an inverted input (2 legs on the circuit).
 =)
  
*upd2:*
  
 I now have 2 questions.
  
 1. How to remove the transformer?
 Found inside the mount, unscrewed the bolt.
 On the outside of the subwoofer there is a mount, but I could not open it.
 I've seen instructions before, but now I can not find it.
  
 2. What could explode?
 About a month ago, after soldering the wires, during power-up, I heard cotton.
 Slightly louder than a blister film burst.
 Visual inspection did not work.
  
*upd3:*
  
 I connected everything according to the scheme.
 When switched on, I heard a loud buzz about 100 Hz.
 After 2-3 seconds turned off.
  
 What should I check first?


----------



## ramachandra

"What should I check first?" First you should check who is able to help you there with instruments and experience.  I'm not writing this to discourage you, I want you to able to complete the mod. My ability to help is limited from here.


----------



## dragoscojan

Hello everybody! I'm in need of some help if any of you is kind enough to aid me.

I want to add a small fan to the back of the control pod of my Z5500, but i want to power it directly from the pod itself. I'd also want the fan to turn on and off when i turn the pod on and off. In other words, i need a 5V and Gnd point on the pcb of the control pod that gets powered only when the pod is turned on, and not in standby.

Does anybody here can supply me with a photo of the PCB indicating such a point where i can solder my fan wires?


----------



## Abdiel

Hi guys!
I was not around for several years.
I see modding continues till this day. Great. 

Anyways, I found a way how to deal with crossover frequency, and some other things...but it would be an expensive and time consuming path to take.

I still have some Z-5500 control pods at home which I bought in 2013, some are working and will go on ebay and some need repairing.
As I pulled those pods from the box to test them, I remembered this site and people who mod Z-5500, and I also remembered why Z-5500 were bad and why I gave up on modding them.

As several years passed, I googled if someone actually did hack the control pod. Found nothing new.
Searching further for possible solutions brought me to one IC which could change this, STA310. Unlike CS494003 which needs custom programming, STA310 has Dolby Digital and DTS decoding already in it, you just need to control it via I2C. STA310 is an obsolete part and it's hard to get your hands on it, but it could be done. I'm still waiting for some quotes so I may buy few pieces.
Since STA310 is not quite well documented, it's datasheet is in preliminary state, I googled if someone actually did use it for decoding, and I found 2 implementations on http://ep.com.pl/. Just search for DD or DTS decoder and you'll find them.

So basically, one could:
- use CS42526 for inputs (adding up to 8 optical/coaxial inputs, and one analog input)
- use STA310 for DD/DTS decoder (it has a master volume control, bass management(YAAAY!), down-mix to 2 channels...)
- use PCM1680 as DAC from STA310
- use NJW1150 for additional per channel volume control (it also has bass/treble controls for 2 channels which could be used)
...and remake the entire control pod to suit your needs.
Addition to that, one could add USB input and make a control pod on steroids. 

It would take several months to complete, it's not an easy task, but the end reward would be very satisfactory, at least for those who still have Z-5500 systems.
I might take this endeavor if I source some STA310, but do note that DD and DTS are kind of old formats, there are new like DD Plus and DTS-HD to name the few, so this would be simply for educational purposes, it has no value in long term since DD and DTS are obsolete.

While searching for STA310, another option which came to mind is using ffmpeg(has DD Plus) in raspberry pi(or something similar) but that's whole another issue.

Anyways, if this info helps someone in any way, great.
Good luck with modding.


----------



## ngen33r (Nov 14, 2017)

I would like to help with this. I have many broken control pods to play with. Also is there no way to contact cirrus logic to get a copy of the software to modify the settings? We paid for the product which included the licensing. We should be allowed to modify the settings.
I know a development kit is available. https://www.cirrus.com/products/cs49400x/ under the software section. The eval kit would have everything we need to modify the settings. We just need to find a way to get the eval kit.

http://manualzz.com/doc/6567978/cdb49400-evaluation-board-for-cs49400-family-dsp


----------



## Chris2017

Hello ramachandra,

thank you for your great work to improve the Z-5500!

I have read through your whole write-up but I'm not quite confident I understood everything correctly. I'm fairly skilled with electronics and soldering but completely new to audio electronics.

So long story short, basically* I'd like to take on your "Third Mod" but additionally change the OpAmps in the ControlPod and the main filter caps*.
As far as I believe to understand I need to order the following parts:

13x 22µF 50V Elna Silmic II("Addon", parallel to the electrolytic caps in the sub)
8x OPA1602AID (6pcs for the control pod analog+digital and 2pcs for the sub as 3 OpAmps are replaced by capacitors)
7x 220nF 63V axial film capacitor
6x 47µF 50V Elna Silmic II
5x 0.47uF 63V axial film capacitor
2x 50V 10000µF Nichicon KG,FW or KA series (Main filter caps)
1x 4700µF Nichicon KG, FW or KA series (Main filter caps)
1x 10µF 50V Elna Silmic II

Yet, I'm afraid I still have some questions:

1. In the last section of the Third Mod, you say you used Nichicon KA for the pod. So modifying the pod is still part of the Third Mod and I will need all the capacitors for the pod too? *So basically doing the second Mod?*
2. Which 0.47µF film capacitors do you recommend for replacing the sub's OpAmps with?
3. May I kindly ask wether it's possible to get a *high-res image of the finished third mod with labeling of all the changed parts* like you already provided for the first mod?

I'm sorry to bother you with all those questions, any answer is much appreciated!


----------



## ravennoir

Hi Everyone,

I just got a Z5500 from a friend, but it has a issue with the Sub. All the Speakers and Control Pod work fine, just the sub doesnt make any noise

I popped it open and couldnt see anything blown or disconnected

Any tips on troubleshooting what has gone, and if its repairable

Thanks


----------



## DrunkenPL

Hello everyone!
First of all I was amazed how well this mod had been investigated 
I alteady bought all of the sub capacitors and OpAmps from TI. I proceed with the mod but it turned out that probably I am missing one, small open-end wrench to unscrew two screws that holds the PCB in those black radiator rails.
Still I wanted to ask you for advice on how to get the PCB safely or just description of next steps that you take to take it out of those radiator rails?


----------



## Nilski

Nearly 6 years later I’m doing this mod. I have 4 Z5500 and 4 Chromecast Audio devices to do multiroom audio. 
I have done the 3rd mod on the sub. Still waiting for the big caps to finish it. Then I’ll compare them. So far I didn’t notice much difference. What I hope will help is putting passive coolers on the chips in the pods. 
Next what I want to do is get 5V from the pod to power the Chromecasts and I’m thinking of putting in a raspberry pi to control the pods via wifi if I can decrypt the Infra red signals.. 
I wish I could replace the pod all together with raspberry pi but 5.1 multiroom audio isn’t common


----------



## Broosk

jayjayuk said:


>


 
Sorry to barge in and slightly changing the topic but I am a bit desperate about this. Does anyone have an idea what the values of C37 is on the main board power supply? This rectifier bridge burned out on me and I need to replace it. I took the burned rectifier bridge out but but in the process I ripped off C37 from the board. Also is there an alternative to fixing this. I would appreciate any info on this.

Thank you


----------



## Helkan (Dec 31, 2019)

Hi,
At the beginning I would like to write that this is a great thread. A lot of interesting information. I would like to modify my Z5500 but unfortunately I have to deal with a problem first.
A steady squeal (around 6kHz) can be heard from the satellites, whose intensity does not change when turning the volume control. A high pitch noise is heard at every setting (Analog, Optical, Coax), even when all audio sources are disconnected. Apparently this is a factory defect of a certain series of speakers and the fault concerns the electronics in the subwoofer. I unscrewed my speakers but visually all electronic components look like new (especially capacitors) and it has not loosened on the PCB. I have already looked for answers in many foreign forums, unfortunately my question was left unanswered and I would love to fix my Logitechs. I can solder but I do not deal with electronics on a daily basis and I do not know where to start diagnosing / repairing this fault. I will be grateful for any suggestions.
Regards


----------



## Turboman

Hello,

I have a Z5500 that I want to recap the control panel to start out. I'm not very good at what to pick up when considering ESR and ripple current.
I normally order from Mouser, I was wondering if someone could help me on what I should get?

This is what I have picked out for starters on replacing the SMD caps.

https://www.mouser.com/ProductDetai...l57h5%2BWR6x2GL9IQo6XbITuwm1htjAPFOxRuonPDQ==

https://www.mouser.com/ProductDetai...l57h5%2BWRwkharsdXkBRqN58kbc02ijSFiq0oR6mKQ==

https://www.mouser.com/ProductDetai...l57h5%2BWR/z4rXhk7939/sfFIgJqYlbCn4/mirFjBw==


----------



## arismfg (May 18, 2020)

Hi all.

My Z5500 console stopped working properly showing constantly blue squares on the screen with power on (blue light) or off (red light). After looking everywhere, managed to find that the R21 resistor was burnt. Could this be caused due to one of the pins on the VGA output (on subwoofer) being broken (the pin was stucked in the VGA input (on the console cable)? I mean the contact of the broken pin was probably loose. By the way, replaced the R21 resistor and the VGA input (and output) and everything seems to work ok now. But, trying to find the reason why the R21 burnt. If this helps, the voltage on the broken 15 output pin (after replacing the vga output on subwoofer but before replacing the R21 resistor) was 0 volt.


----------



## sci666

Hello, i have a problem with my z5500 as well,

i identified the problem on the  LM217T (?)   this is the 8v regulator right ?

i measured the voltage on this line with a multimeter and if the pod is on it is about 9,5 volts and fluctuate to 12-13 volts, if i turn the POD of it goes up to 15 Volt !!!!

in my second z5500 everything is fine, every time 7,88 Volt.

so is the problem solved when i swop the  LM217T  out ? or is some other part the reason for the wrong voltage as well.

strange is, the unit works fine even with the fluctuating voltage, display is getting a bit brighter and some very quit crispy noises comes off the speakers but nothing else.

thanks guys for your reply


----------



## sci666

So, I swapped out the regulator, no effect, so I did it also with the bridge rectifier. (25v 4700uf also) no effect. I gave no idea. Voltage still fluctuate between 13 and 14 volt! And if the pod is turned off about 15 volt! What else can cause this high voltage?


----------



## Peppie1980

Hi guys. I read the entire topic... wow . Lots of info! I did the mod in the woofer with only the 5x OPA1602, and also burnt the R21 and R22 . Also 2 or 3 diodes,since I can measure them both ways now,  this should not be possible. After the mod a HUGE loud rumbling came out if woofer and rear right speaker while no sound was on. Turned of unit and looked inside to see some stuff burned. POD ain't working anymore either. I will order the new resistors and so forth to check if it will work again


----------



## dman636 (Jul 6, 2020)

Hello. Like many others I found this after my beloved z-5500 started acting up. I was wondering if anyone could perhaps assist in figuring out what is happening and after reading this thread (most of it anyways) I found that nobody had my exact symptoms but some in another thread had similar issues. Here is my issue: the control pod turns off randomly, sometimes after 30 mins sometimes after 2 days. Otherwise the device is perfect. All that needs to happen to resolve it is to turn it back on. It literally just acts like the power was pressed. Nothing goofy on the control pod LCD. Here is what I tried: I thought it may be overheating as similar users experienced, so I put the pod vents directly on my home air conditioning. Last time it happened the control pod was ice cold to the touch, so not overheating on the control pod. I tried toggling settings (5.1 -> 2.1) changing TV input format. I tried making sure the power cables are isolated. Made sure the connections are solid. Blocked the IR completed from receiving signals. Disassembled to check for noticeable damage. Nothing seems to stop it so far and no other visible indications of a problem. Could it be the sub woofer overheating? Last time it happened i felt the heat sink and it didn't feel hot at all. Any suggestions would be greatly appreciated.

Its important to note that this happened shortly after changing the configuration. I went from 2 speakers and sub to 5 speakers and sub and changed the 2.1 to 5.1 toggle in the back. I have since tried toggling back to 2.1 (unplugging rear speakers from the speaker side) and it made no difference.


----------



## Peppie1980

well, thats interesting.
After reading this entire forum i do know that there are voltage regulators in the woofer casing. they do control the POD's power aswell.
I also know the cable can be a bit of  a problem too (dried out, cracks or bent to long in a strange angle)
perhaps the speakers u have attached had a higher or lower resistance (Ohm's) than the unit can handle, and some components broke down inside the unit.
U can not always see it with your eyes, u must measure it.
Let us hear what u have found


----------



## dman636

Peppie1980 said:


> well, thats interesting.
> After reading this entire forum i do know that there are voltage regulators in the woofer casing. they do control the POD's power aswell.
> I also know the cable can be a bit of  a problem too (dried out, cracks or bent to long in a strange angle)
> perhaps the speakers u have attached had a higher or lower resistance (Ohm's) than the unit can handle, and some components broke down inside the unit.
> ...



Thanks Peppie. I am sure the resistance changed, i didn’t even think of that. I ran long speaker wires for the satellites. I will try unllugging every thing as much as possible. As far as the power coming from the sub, would i be able to measure that with a standard volt meter?


----------



## Peppie1980

well, here's where my knowledge kinda ends, and i need to google. sound is a frequentie, and i am not sure u can measure it with a voltmeter.
in this case u will definitely need a multimeter, and measure stuff in the woofer casing and POD i believe.
its too bad this thread is ppretty dead, because there used to be ppl who really know there stuff!

Other than that open up the case and start looking and measuring!


----------



## Peppie1980

today my diodes and R21 - R22 resistors came in, turns out, the diodes were not broken, i measured them on the board, thats why i got a false reading (stupid me) i should have desoldered at least 1 leg. anyway, i replaced the resistors R21 and R22 and the pod works again 
but still very loud rumbling noise from the woofer and 1 satelite speaker as soon as i turn on the unit :S

might be an Opamp or a TDA, i dont know. i placed back the old ones, still rumbling.

think i need to take the main board out and check everything.
also strange... i saw some tiny sparkling from C214 around U12... cleaned it with alcohol and will check again. its a capacitor, so i dunno whats going there.


----------



## sci666

Good and bad news... I checked the resistor r11 and r16, one of it was brocken. After fixing it the voltage is OK at 8v! Yey!  Bad news since I put everything together again, my center speaker is dead!  Have anybody an idea what I can check? I changed already the pod no, effect so it must be something with the sub electronics....


----------



## Peppie1980 (Jul 10, 2020)

god, that sucks so hard. whenever u did something. something else brakes down :|
and we have to do it totally from the beginning without any experience, lol.
it is fun though, i have to admit. really frustrating!
but i just cant let this unit sit there, knowing it can be fixed!

where is R16 anyway ??


----------



## sci666

Hey. R16 is nearby the regulator, under the black isolating tape. And I found the error for the center speaker! 😊 It seems that I ripped off an smd capacitor in the upper corner by inserting the pcb into the cooler plate. I resoldered the broken joint and it worked! 👍


----------



## Peppie1980

Nice job! 
How do u safely remove the PCB ftom the coolerplates anyway? Theres these micastrips and white pasta all over.


----------



## demercy1

This Topic in Wonderful

how can we know if it is really worth selling a logitech z5500 and actually migrating to another sound system, such as the yamaha hs8 studio box, or is it worth taking the time to try to make a mod like this on the topic?


----------



## Peppie1980

For the small amount of money it costs, I think this system is not bad at all. There's no hdmi, true, but there is analog input. For a PC this system is fkn awesome. For your TV in the living room like an LG OLED C9 or better, this system is in my opinion to small.


----------



## mind123

Hello,

First of all, thank you *ramachandra* for this awesome tutorial. I have a Z5500 speakers, and since they are kind of old, the sound does not look so good now. I could buy other speakers but this one has a sentimental value to me, that is why I am looking for an upgrade.

In accordance with the FAQ, I’m thinking about change only the first 3 things:
_What part of the mod is the best bang for the money?
- OpAmps 40% (special in the SUB)
- 22uF & 47uF capacitors in the SUB 30%
- The two main filter capacitors 15%_

Since I will try the mod 3 I will need also 5 pcs 0.47uF 63V axial film capacitors

I am thinking to buy these components. Could you please confirm if they are compatible with the components recommended in this forum?

*----*_OpAmps 40% (special in the SUB)_*----*​*2x TI OPA1602AID: *​https://www.digikey.pt/product-detail/en/OPA1602AID/296-28930-5-ND/2679365/?itemSeq=340644244​​*----*_0.47uF 63V axial film capacitors_ *----*​I need help with this one because I am not sure if it is equivalent.​*5x CDE - 150474J100DC:*​https://www.digikey.pt/product-detail/en/150474J100DC/338-4260-ND/1930578/?itemSeq=340644847​​*---- *_22uF & 47uF capacitors in the SUB 30%_ *----*​*13x Elna America - RFS-50V220MH3#5:*​https://www.digikey.pt/product-detail/en/RFS-50V220MH3#5/604-1122-ND/2171173/?itemSeq=340643573​*6x Elna America - RFS-50V470MH4#5:*​https://www.digikey.pt/product-detail/en/RFS-50V470MH4#5/604-1127-ND/2171178/?itemSeq=340644474​​*---- *_The two main filter capacitors 15%_ *---- *​I did not find the ELNA in this site, that is why I am thinking about Nichicon. I hope that does not make a huge difference.​*2x Nichion - LKG1H103MESCBK :*​https://www.digikey.pt/product-detail/en/LKG1H103MESCBK/493-13364-ND/1964421/?itemSeq=340645324​
Thank you in advance, and I hope that I do not mess up, because like I said they have a sentimental value to me.


----------



## Peppie1980

well,  *ramachandra*  hasn't been here for ages, but i am sure u have the right parts from looking at it. i kinda fkd up mine honestly. I only get a big long hum out of the woofer now. And i am not able to troubleshoot because it is not my field of work. I was hoping someone could point me in the right direction.


----------



## mind123 (Oct 7, 2020)

Peppie1980 said:


> well,  *ramachandra*  hasn't been here for ages, but i am sure u have the right parts from looking at it. i kinda fkd up mine honestly. I only get a big long hum out of the woofer now. And i am not able to troubleshoot because it is not my field of work. I was hoping someone could point me in the right direction.



I am sorry to hear that, you have no idea what you did wrong? I really want to do this upgrade, but I am afraid that something goes wrong, and your problem could be my problem as well. I hope that you find out what is wrong, and maybe someone can help you with that matter.


----------



## Peppie1980

yeah me too. I already bought a new set. so all is well. but i am stucck with one broken set which is easy to fix i think, but i lack the knowledge.


----------



## mind123

Peppie1980 said:


> yeah me too. I already bought a new set. so all is well. but i am stucck with one broken set which is easy to fix i think, but i lack the knowledge.



Did you apply this mods on the new set?


----------



## Peppie1980

I only did the 5 opamps


----------



## mind123

Peppie1980 said:


> I only did the 5 opamps


Ah nice. Sorry to boring you with this questions, but did you find a difference in the sound quality? Do you recommend change only the Opamps, or should I do the full mod 3 like I mentioned before?


----------



## Peppie1980 (Oct 8, 2020)

ah, u dont bother me at all, i love seeing this thread relived again.
am sorry i didn't understand your question. No, i did not have the guts the do the mod on the new set. i might destroy it too and that would be really crappy.


----------



## mind123 (Oct 9, 2020)

Peppie1980 said:


> ah, u dont bother me at all, i love seeing this thread relived again.
> am sorry i didn't understand your question. No, i did not have the guts the do the mod on the new set. i might destroy it too and that would be really crappy.



Ah I see. It would be nice if this thread relived, and the guys that tried this mods shared their experiences. I really want to do this, but like I said before I am afraid to mess up and destroy the speakers :/


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## Peppie1980

I understand! i ruined mine already. if u read the entire thread u pretty much know whatt to do, and i also think that the third mod is easier, less soldering.


----------



## triturbo

Great topic! Wanted to ask if anyone can reupload the pictures in the first post or if somebody made a back-up? Thanks!


----------



## l0NeXuS0l

Hello!
Can I change the opamps on the subwoofer board without changing other components?
You mean, like, they just take the old ones out and stick the new ones in, and everything works?
Doesn't anything else need to change?
I understand that there is a radical change in the sound after replacing the opamps in the subwoofer box.


----------



## DrunkenPL (Oct 29, 2020)

Peppie1980 said:


> Nice job!
> How do u safely remove the PCB ftom the coolerplates anyway? Theres these micastrips and white pasta all over.


I have the very exact same question 
@ramachandra I recall that there were some really nice pics in your first post showing what is where and which caps and opamps should be exchanged to what. I cannot see it anymore. Have you deleted them?


----------



## l0NeXuS0l

https://www.mouser.de/ProductDetail/Texas-Instruments/OPA1602AID?qs=L4ss/yqpMWQH0cZjf6w%2BoQ==



What do you say about this OpAmps? All the information is entered here. and I see it says stereo sound. Does it matter if it's mono or stereo?


----------



## Peppie1980 (Oct 29, 2020)

Hello!
Can I change the opamps on the subwoofer board without changing other components?
You mean, like, they just take the old ones out and stick the new ones in, and everything works?
Doesn't anything else need to change?
I understand that there is a radical change in the sound after replacing the opamps in the subwoofer box.


Yes, u can.


----------



## Peppie1980

l0NeXuS0l said:


> https://www.mouser.de/ProductDetail/Texas-Instruments/OPA1602AID?qs=L4ss/yqpMWQH0cZjf6w%2BoQ==
> 
> 
> 
> What do you say about this OpAmps? All the information is entered here. and I see it says stereo sound. Does it matter if it's mono or stereo?



Those are the correct ones


----------



## l0NeXuS0l

Peppie1980 said:


> Those are the correct ones



But is it good?
I order it from here
from the other site it is very expensive to transport .. 20 euros

https://www.ti.com/store/ti/en/p/product/?p=OPA1602AID


----------



## Peppie1980

From  Texas instrument? Yes, the are chip builders. Very legit


----------



## Hieronymus Blob (Nov 4, 2020)

Figured I'd add this to the mix:

The Eminence Alpha 3-8 replacement drivers for the satellites are a huge improvement
After a few weeks burn in the improvement to mids, highs, and imaging is at times surprising, with the stage now extending well beyond the speakers in all axis.
Bear in mind I haven't done any of the other mods in this thread, other than cotton and proper speaker wire.
They are 8ohm (as appossed to the origonal 6ohm drivers) so adjust your sub.

You'l need to cut \ file down some of the sats housing, and you'll also need a thin metal file in order to file the Alpha's screw holes in towards the centre by ~3mm, but once this is done they fit perfectly.

The imaging is sensitive to placement though.  The origonal unmodded sats could be placed pretty much anywhere I found, but with the Alpha's, placement and orientation makes a difference.

Recommended at ~£20\driver.


----------



## Rama Chandra (Dec 7, 2020)

Hello, This is Ramachandra here.

Because the big changes on Head-Fi website years ago I long lost my access to my account and I can not fix the messed up first post. Unfortunately do not have the original images any longer either, but I wrote a slightly different early Hungarian version at the time. This version still have photos. A link to the "The second Mod" images.

Few years back Elna fakes surfaced on eBay from the bigger 10000uF capacitors. Sometimes the top was covered with plastic and the cut was not the typical sword shape underneath. Adding to the problem Elna rolled out genuine capacitors also with different shape cut on top. I'm not sure what is the current situation, but when you replace those capacitors and that is not give the promised sound improvement, then maybe you have the fake Elnas.

This is an old thread and I'm not planning a return, I just signed up again because this information might be some help.

Cheers


----------



## Peppie1980

Thank you for your time ! We might try and take those pictures to complete this again


----------



## srialmaster

I had a question. If I am going optical from my SB ZxR to my Z-5500s, should I still consider replacing any of the OpAmps? Does the optical interface still use the DAC, or is it bypassed all together?

-Nate


----------



## pikokk

hi and happy new year to all

I have seen guide to improve the Z5500 system

I have one of these systems (the first versions, the ones that still have the rca connectors), from the day of christmas it started me making random disturbances in the center or front right channel
similar to what you hear in this link ( Similar problem video )

looking on the internet I didn't find any certain resolution, so I'm about to start finding the problem, but I wanted to know if you knew what to check.

the capacitors visually look fine, but I want to start changing the 2 large filter capacitors on the power supply + another from 2400uF which, from a quick view, seems to be filtering the voltage for the control pod

do you have any suggestions? before attempting the upgrade I would like to find the solution to the problem
thanks!


----------



## IamJon

My z5500 has also developed a noise disturbance. Would describe it as a wind gust / rumble type noise rather than crackling. The noise comes and goes a bit, not identified what triggers it.

Seems to be on all channels, not effected by volume control or input. Suspect it could be power supply issue but haven't opened up yet. Interested to know what caps you are putting in on the power circuit and if it can fix noise issues.


----------



## pikokk

I still have to try to change the capacitors, but if you open the woofer you will find 2 large capacitors (they are the power filter) and one a little smaller which seems to me filters the 18V that go to the pod 

as a first test I would like to replace these 3, although I doubt these are causing the problem, if it does not work, I will change all the capacitors in both the woofer and the pod (starting with the ones near the opamps)

if i don't solve, i try to change the opamps 

before starting with the modification I would like to solve the problem


----------



## Nevron

Greetings everyone.

I was having problems with my Z5500 sound system since a year ago and i have decided to open it up and have a look. After reading plenty of topics in forums and stuff that usually breaks down i was convinced i could fix it on my own. My problem was that it kept shutting down on its own and it would never come back on. The power button was off instead of read. I have contacted Logitech for a probable control pod supply but to no availability.

What i did so far is to change the 25V 4700mF capacitor to a new Nichicon and the LM217T voltage regulator, new mica pads on the TDA'S with thermal paste and to the LM217T. However it keeps shutting down. I have yet to change the two 50v 10.000mF power filter capacitors since the problem is not fixed, i haven't done that because my solder iron got burned and i am going to get a new one. Also, i have measured all the surrounding resistor R21,R20,R16 and so on and all seems to be okey. I have checked the speaker connections to the subwoofer and they all work fine, the control pod cable is good, the fuse in the back of the sub is good too.

After trial and error i have discovered two ways to bring it back in life. The first is if while the power button in the back of the sub is on and i short the adjustment and input pin of the LM217T, the red light on the control pod lights up and when i press it, it comes on. The second method i discovered to bring it back on, because i was tired unscrewing the sub every time, was on the control pod, if i short the +8V pin on the PCB with the +18V pin. This leads me to believe that in both methods the +8V line is given more voltage and that brings it back online. The actuall read out using my voltmeter for the +8V line is 7,95V, which i think is good for it to stop failing. The +18V and -18V is actually +18,23 and -17,34 at times, which leads me to believe that one of the main power line capacitor may have reached it's end of life.

I just wanted to share my finding to anyone who might have been having this pesky shutdown issue and haven't found a way to at least short term bring it back on. I am also eager to ask anyone that might know what would the actual problem might be. I haven't yet changed the 50V capacitor and i will do so in due time, but would there may be something else i am missing? Why does the control pod comes back when i supply more voltage on the +8V line instantaneously and what may cause the shut down? Is this some kind of power drain through the main processor that requires more voltage?

Thanks in advance.


----------



## l0NeXuS0l

Who wants to do it this way, a video has appeared on youtube. It is very well explained!


----------



## Galimero (Jan 28, 2021)

What do you guys recommend for the capacitors in the pre amp, instead of the 0.22uF K73-16. And do I need 0.22uf capacitors or 0.47uf capacitors? A bit confused. And any good recommendations as a substitute for the main elna capacitors?


----------



## Nevron

Hello again all,

After i changed the two 50v 10KμF capacitor i am having a weird effect. Everything sounds better indeed in terms of bass frequencies that the speakers earlier did not have.
The optical and the digital cable plays fine through out all speakers. However when i use the 3.5mm analogue 5.1 channel jacks, i get sounds from center, sub, rear left and rear right, except the front left and front right channel. I have measured the control pod supply lines and i get the following measurement, for the +8v i get 7.94, for the +18 i get 18.34 and for the -18 i get -17.43. What i changed in the sub so far is the LM217T voltage regulator, the 25V 47KμF capacitor and the two big one capacitor that does the power filtering and R21 AND R22 resistor that looked like it were burned but had 36Ohms on both however i decided to change them with new ones just in case. The actual measurement on the big capacitor pins are both 34.3V. The voltage regulators for the big capacitor read input 34.3, same as the capacitor pin measurement and the output reads -17.43 and +18.34, same as the control pod pins. The digital cable does send signal from all 3 3.5mm jacks, so the issue is related from the control pod down to the sub since all the speakers play fine using the optical or digital input, therefore the problem only resides in the 5.1 sound input (speakers are good and their cabling to the sub).

I am not sure what else to think off about fixing it. I have measured the LM217D2 voltage regulators on the control pod, the one near the volume potentiometer reads 5 to 7 volts output, the one on top which i think is for the lcd screen reads 3.3V output and the one in the middle which i think is for the cirrus logic decoded chip reads 2.5V output.

First, i would like to ask what should be the nominal volt value coming from the toroidal rectifier to the capacitors, should it be around 50V or is 34.3 a good value? I can read on the toroidal capacitor that the two lines going to the rectifier should be 26.4V respectivly, but there is only 34.3 coming out from there going to the big caps.

Secondly, is the LM217D2 voltage regulator on the control panel, the one in the middle, good with 2.5V? I think i read somewhere that it's output should be around 5V, 2.5 for each chip out of two that controls the speakers amp.

Finally, could it be that it is just a short circuit in the 3.5mm jack receiver on the control panel for the two speakers (right and left) in the front? There is not hiss or ground like noise coming out of them, totally silent. 

I am trying to look at the percentage of a) faulty toroidal capacitor, b) faulty toroidal rectifier, c) faulty voltage regulators on the sub that produce the -18 and +18 volts, d) faulty LM217D2 regulator that powers the cirrus logic chip, e) faulty 3.5mm jack input on the control pod.

Any ideas what to look for that would allow me to pin point something that might be out of order?

Thank you,
Alex.


----------



## pikokk

Hi guys,
I solved the noise problems in the right front speaker by changing the 2 large filter capacitors! I'm happy!

i ordered all the material for the first step mod, while waiting i changed the satellites, i replaced them with jbl scs 200 and it already sounds a thousand times better

now I am getting the unhealthy idea, but if I take the cone of the original speakers and replace them with those of the jbl, does it sound better or worse?


----------



## snaxez

Does anyone know values for following components on PID R621 control pod:
C308
C740
R725
R726


----------



## Nevron

Hello,

I have no sound from the control panel side input and no sound from the stereo1 channel. I have tested the audio socket connections on the pcb and no rpoblem there. Speakers are playing fine when i connect to stereo2 and stereo3 (pink and black audio sockets).

Does anyone know what parts on the pcb are responsible for the sound of the green socket?.

Measured the 3 op amps on the bottom, two of them measure at 32 volta, one of the 16v. Is the side input related with the green jack in any way?


----------



## twist3d

DaddioJ said:


> new tweeters. new mod. more of a finished product. i didn't have a stepping bit. so its a tiny bit unfinished. i will get the bit before i do the rest so they look perfect. still have to put it back together. and solder the capacitor


Hey there, I'm interested in doing the same thing. I bought a set of satellites for the system super cheap like 70-80$ with shipping. I didn't want to modify the original ones.
So could you help me with a schematic and some parts you used ?

thanks


----------



## Recorder86

Nevron said:


> Greetings everyone.
> 
> I was having problems with my Z5500 sound system since a year ago and i have decided to open it up and have a look. After reading plenty of topics in forums and stuff that usually breaks down i was convinced i could fix it on my own. My problem was that it kept shutting down on its own and it would never come back on. The power button was off instead of read. I have contacted Logitech for a probable control pod supply but to no availability.
> 
> ...


Hi, I'm Francesco and I'm a new user from Italy.
I'm writing because I have the same problem as you.
The pod remains on standby with the red LED for hours, then when I turn it on, it turns off completely and stays off. Then I switch off the power for a few minutes and the red LED starts again but remains off. With another POD, however, everything works perfectly.

The problem looks similar to yours. Did you find out which component is causing the problem?

Many thanks!

Francesco


----------



## Nevron

Recorder86 said:


> Hi, I'm Francesco and I'm a new user from Italy.
> I'm writing because I have the same problem as you.
> The pod remains on standby with the red LED for hours, then when I turn it on, it turns off completely and stays off. Then I switch off the power for a few minutes and the red LED starts again but remains off. With another POD, however, everything works perfectly.
> 
> ...


Hello dear Francesco,

My issue was that it turned off all of the sudden and while i was turning it back on, at some point the red led would sieze to operate and it would never come back on, until i unplugged the sub, turning the sub back on sometimes it would come alive, but at some point it never came back on. 

What i did was to change a couple of resitors in the sub that looked like they were burned, near the main powerfilter caps, i also changed the two big caps, the smaller one that supplies current to the pod and the near by voltage regulator. Then i changed to pod monitor and some capacitor on the top of the pod, i sprayed some w5 cleaning liquid on it and i heated up the whole pcb with hot air just in case there were some broken connections.

It worked for 4 months, now the original problem happened again. I haven't tested any other pod on the same sub to be sure what would cause malfunction, but testing the pins on the pod pcb i get proper values regarding the current that is supplied it. I have a feeling that some component in the pcb fails or gets disconnected somehow after the pod is wokring for some time and it gets heated up by the logic processor. I have to mention that i also added a heatsink on top of the decoder chip by using some silicon based solution just in case it have some internal failover that was sutting the system down when i certain temperature was achieved.

Now i think i have to reopen the sub to look at the same two resistor i changed in the past, just in case they are fried again.

I can send you more specifics regarding the components i changed if you feel you want to go down the same road i went.


----------



## Recorder86

Nevron said:


> Hello dear Francesco,
> 
> My issue was that it turned off all of the sudden and while i was turning it back on, at some point the red led would sieze to operate and it would never come back on, until i unplugged the sub, turning the sub back on sometimes it would come alive, but at some point it never came back on.
> 
> ...



Hi, many thanks for your reply, my issue is practically identical to yours.
I have a brand new POD and connecting that to the sub everything worked perfectly, so I guess the problem is not inside the sub.
Yesterday opening the old pod and blowing then it started again. Tomorrow I'll get the WD 40 spray and I'll see what happens, IMHO it's just some bad solder.
I was hoping there was some specific problem / component to fix. My z5500 is 15 years old, but Is sad to throw it away, also because at the moment there is nothing better that is worth replacing.


----------



## Galimero

Recorder86 said:


> Hi, many thanks for your reply, my issue is practically identical to yours.
> I have a brand new POD and connecting that to the sub everything worked perfectly, so I guess the problem is not inside the sub.
> Yesterday opening the old pod and blowing then it started again. Tomorrow I'll get the WD 40 spray and I'll see what happens, IMHO it's just some bad solder.
> I was hoping there was some specific problem / component to fix. My z5500 is 15 years old, but Is sad to throw it away, also because at the moment there is nothing better that is worth replacing.


Z906 my dear friend. I have had both systems and used them both for over 3 months and I can say that the z906 isnt less powerfull than the z5500 (some people say its soo bad compared to z5500 etc, well its not). Ofcourse the sub has less power but logitech has compensated this with a more punchy sub. The satellites are almost the same when it comes to sound. The amplifier have had a slightly upgrade when it comes to sound, the mids are a little brighter than the z5500. The z906 costs a little, but you get a good replacement for the z5500. My last words, z906 is very very identical to the z5500 and a perfect choice for a replacement.


----------



## Galimero

By the way I have replaced 5 chips in the sub with the opa1602. After replacing, I tested the system and everything worked fine. So I hooked everything up and listened for some time that day. The next day I wanted to listen to some music, but to my surprise the sound didnt come from the front right sattelite and the rears were bad too. I opened the sub to look what happened but couldnt find anything...  So I retested the system but this time it worked again.. What could the problem be?


----------



## pikokk (Apr 18, 2021)

Hi,
i suggest you change all the capacitors in the sub, if the problem recurs, change the ones in the pod as well


----------



## Galimero

pikokk said:


> Hi,
> i suggest you change all the capacitors in the sub, if the problem recurs, change the ones in the pod as well


Thanks for your assistance m8. I checked everything, from the main filters to the preamp. After some testing etc I figured out, the problem was caused by the aux cable... So to everyone that has the same problem, you dont have to resolder every damn chip and capacitor.


----------



## Recorder86

Galimero said:


> Thanks for your assistance m8. I checked everything, from the main filters to the preamp. After some testing etc I figured out, the problem was caused by the aux cable... So to everyone that has the same problem, you dont have to resolder every damn chip and capacitor.


I was sure that the problem was the pod, because with an other one works perfectly.
Today I knocked the control unit and it started again. So it's definitely a damaged weld, probably the aux cable as you say.


----------



## scratje (Jun 25, 2021)

Hi all.

I haven't been active on this forum for a while now but still own three Z5500 units, two older types and one new type.

For those of you who want to completely modify the older type Z5500 and want to get rid of the big thump/boom/pop when switching other devices in the house, hereby a few pics from the preamp board with Wima MKP10 film capacitors to replace the green ceramic capacitors and the axial 220nF film capacitors to replace the SMD caps.

By sodering the Wima film caps on the backside of the board, you will have enough space to place them properly and it looks more organised too.

The axial 220nF film capacitors can be soldered by first removing the SMD capacitors on the backside of the preamp board  and use jumper wire to connect the solder leads.
Then remove the resistor on the other side and put the axial 220nF capacitor in series with the removed resistor. Look carefully how the signal path goes so the capacitor comes first and the resistor second!

Furthermore i soldered two 100nF 275V X2 suppression caps between the AC leads of both the rectifier and placed a big ferrite ring over the AC main power wires with 3x twist trough the ferrite core.
Secure the ferrite with tie wraps and hot glue to prevent opening and hanging lose inside the amplifier case.
With the two suppression caps and the ferrite ring, the big tump/boom/pops will be almost gone!
In the newer Z5500 systems they did the same thing.

For the other modding on this older type, search my name 'scratje' and you will find how to do the rest with older systems.

I will try to do another mod but it will be experimental.
I want to completely rotate the mainboard 180 deg. so the big caps come near the rectifiers with shorter dc wires so the signal wires wil be more separated and hopefully pick up less noise. There will be some desoldering involved and new wires must be made but maybe the unit will be less humming on the subwoofer driver and hiss on the satellites but this is still a guess.
Maybe a metal cap over the torodial transformer can have an effect too, so there are more experiments to do.

have fun modding


----------



## scratje (Jun 24, 2021)

Back again,

Rotating the main board is succesfull with less hissing now. The signal wires and dc wires are mostly seperated and twisted and where not they are aligned perpendicular to eachother. The 50/60Hz hum from the subwoofer driver is still there but i have made a red copper shield which will cover one side of the preamp board and by holding it in front and connecting to the chassis, the 50/60Hz humming from the subwoofer driver almost disappeared.
First pic is the original board and second pic is the other Z5500 with rotated board.
Pic from assembled red copper shield will follow soon.

Happy modding


----------



## Galimero

scratje said:


> Back again,
> 
> Rotating the main board is succesfull with less hissing now. The signal wires and dc wires are mostly seperated and twisted and where not they are aligned perpendicular to eachother. The 50/60Hz hum from the subwoofer driver is still there but i have made a red copper shield whitch will cover one side of the preamp board and by holding it in front and connecting to the chassis, the 50/60Hz humming from the subwoofer driver almost disappeared.
> First pic is the original board and second pic is the other Z5500 with rotated board.
> ...


Woah, very nice to see that you are able to remove the humming. Keep it up m8!


----------



## scratje (Jun 24, 2021)

Back again,

Today i made a cylindrical 1.5mm steel cover to shield the magnetic field coming from the toroidal transformer and it works perfectly! No matter how close the toroid is to the pcb, there is no noticable 50/60Hz humming.
The red copper schield is installed now also and blocks all radio interference from entering the preamp board.
At boost 11 volume and bass at max, there is very little hiss or humm detectible.
All this is still experimental and has to be installed in my already full modded system but for now i am very pleased with the results so far!

Have fun modding


----------



## Peppie1980

Wow! very impressed


----------



## scratje

Hi all,

Today i installed the copper shield in my fully modded system and it works great!
Then i started experimenting with the steel shield for the toroid but while doing so and with loosening the toroid  i discovered that by turning it clockwise or counterclockwise, i could change the 50/60 Hz humming to very little and the same as with the steel shield.
There is a sweet spot where the magnetic field is causing the least hum so you should try out for yourself.
I now don't need the metal shield anymore! 

Enjoy modding


----------



## Rama Chandra

Done in style as always scratje. 

I'm wisiting the house of my relative next week. His Z5500 what I had modified first, a good while ago. I plan to do some small further upgrade. It may not do much, but I will report back if it worth the effort.

Cheers


----------



## scratje

Hey Ramachandra, welcome back again


----------



## Vladdos

In the pre amp do I need 0.22uf capacitors or 0.47uf capacitors ? A bit confused.


----------



## squish72

So I had one of these in the closet and decided I'd use it as a powered sub in my work out room.   After running audyssy and doing some measurements with rew, I found a big drop off around 30hz.   Is there a subsonic filter in the amp?   I have it running from the sub out of my 818 Onkyo into the sub input of the pod.


----------



## lotec25 (Nov 23, 2021)

Hello,

    So I have the newer model Z-5500 with no OpAmps in the sub and I have a problem. I upgraded the op amps in the control pod and I had no audio to the front or rear. Center channel worked. One of the op amps was backwards upon checking, I flipped it around and the rear surround speakers started working.  But I can't get the Front Left/Right to work. Every speaker works minus Front left/right. Does anyone know what op amps control the front speakers?  There is zero sound coming out of them.  I do have enough to replace the op amps again but i really do not want to waste op amps I don't need to. If you need any information please let me know

Thanks


----------



## scratje (Nov 24, 2021)

Did you have sound on all speakers before replacing the opamps?
Is there no sound on front speakers on all inputs? Try the optical and/or coax inputs.
As far as i know, all the Z5500 have opamps in the sub. On newer systems they are on the mainboard in the sub and for older systems they are on the smaller preamp board.
A few pictures from your system mainboard in the sub and the new opamps in the pod would make things more easy to diagnose and what system you have.
It could be faulty soldering/placement/overheating while soldering/broken solder pads....... hard to tell without measuring/visual inspection.

Not sure which opamps control the front speakers but the three on the picture are for the analogue inputs and the one with the red circle would be the one for the front speakers. 




Newer systen with opamps on mainboard




Older system with opamps on preamp board


----------



## lotec25 (Dec 4, 2021)

So I think i fried one of the Opamps on my old pod. I got some new ones ordered.  But i got a new pod for now, But none of the surround sound works.  I get audio from Stereo and Stereo x2.  But the others ones, Music and Movies i get no sound.  I also get no sound if i do the pink noise.  Anyone have any idea what is causing this? Do I ned a certain revision of the pod?   My new pod says R108 on the stand in the back if that matters.

EDIT:  got my original pod working now, there were a few things wrong with it.  Thanks for the pictures scratje

Thanks


----------



## lotec25 (Dec 5, 2021)

@scratje
Can you show me the other side of this board with the caps replaced please?  Just want to make sure i'm getting all the parts i need to replace them.

Disregard, I found what I was looking for.


----------



## scratje (Dec 5, 2021)

Pods are a gamble to fit your system. As far as i know there are three types of Z5500 with its own type of pods. The oldest types go from 000? to pid nr R199 and have rca plugs on the backside of the sub, then there are the pid nr R200-R635 for the systems with the opamps on the small preamp board (see my pictures) and the newer systems have pid nr above R635. Normally you can not interchange these pods on all systems because the wirering is different.

rca type sub


----------



## lotec25 (Dec 5, 2021)

I have the opAmps on the preamp board on my set.  I've upgraded all the opamps on the Pod and the preamp board to OPA1612AID. All the Caps in the Pod have been upgraded minus the electrolytic surface mount caps, and the 3 big caps on the sub main board have been upgraded. Need to finish up the cap upgrades on the subs main board and preamp board. And trying to decide if I should upgrade the sub in the box, or add another sub through a custom RCA out board inside the sub.

As far as the new Pod, can I just rewire the new Pods cable to match my old Pod? Or is there a lot more involved to get it working?

Thanks


----------



## lotec25

double post


----------



## scratje (Dec 6, 2021)

There are dozens of threads on the net about rewiring and adjusting Z5500 systems to even work without a pod but i never found a usefull one so far. 
I even used a control pod bypass cable from Ebay but the sound is terrible and you lose the handy input modes like PLII movie and PLII music.
Search for a second hand pod and ask the seller for the pid number that will match your system. Upgrading to another woofer in the sub will not allways mean a better sound because of the design of the sub enclosure which has to match with the woofer specifications and the other way around.


----------



## lotec25 (Dec 14, 2021)

So now I am back to my original problem. The speakers are popping and cracking again.  I found a few caps in the pod bulging so i replace them, I also replace the 3 big caps on the sub amp. I also replaced the cord on the Pod cause it seamed every time i moved it it would stop popping and cracking.  But its now doing it again.  I still need to replace the rest of the caps on the sub amp and pre amp but not very confident that is going to fix it either.  It did stop for a while after doing the caps so not sure what to do to fix the issue.  Does anyone have suggestions?

EDIT,  does anyone know what rotary encoder the pod uses?  i checked the solder joints, it's been running now for well over an hour with no popping or cracking, Thinking I should just replace it to make sure something is not going bad on the inside contacts.

Thanks


----------



## Rama Chandra

Hello everyone, I was silent about my experiment in Hungary. I went home and fired up the soldering iron and opened up my relative's Z5500 one more time. I can confirm it got dustier since, otherwise look the same like on the pictures on the first thread. I have no photos to show thanks to my pathetic "spy phone" and I lost all the images.

Basically I wanted to test how much the sound of the Z5500 can improve by bridging the film capacitors on the signal path in the system, then doing a similar job in the JBL (not original Logitech) speakers.

Soldering on the pins of the electrolyte caps some small film capacitors was known to me beneficial for a long time to help higher frequencies, because the films have a more balanced frequency response, and in general smaller caps do a better job to handle high frequencies. I was also aware the silver mica capacitors are one of the cleanest but harsh unforgiving components for audio. Anywhere I used them in my external DACs analogue section there was reason to respect them but very little reason to love them. Polystyrene (styroflex) always done a better job to keep.

Something popped up in my mind years ago, why I'm not using them only on the signal path to help the high frequencies to pass? Then I built an amplifier that way and I could not be happier with the results. Somehow I was not thinking to bring it any further for years.

The time had come and I bridged each K73-16 0.47uF caps with another Soviet era 10nF 500V KSO mica capacitor. This little addition for the "Third Mod" will bring the sound to a new level of clarity or could improve your speakers if you had replaced them. I have to mention here, he still using his old SB Titanium, and already have similar mod over the decoupling capacitors for the same purpose. Only difference there, I used 0.1uF 63V film caps alone, unfortunately. Unfortunately because if I used silver mica in addition at the time the result could have been even a bit better now. I did not prepare with components for this type of surgery, while I was there.

Then the next step was to replace all the old electrolytic capacitors in the JBL speakers. I only used my favourite K73-16 film plus the above mentioned silver mica for the tweeter. What better the tweeter need to produce the best high frequencies? It is clear, it is sharp, it is unforgiving, and bite.

When I was done in the Sub, I recap the front left speaker and turned on the system for listening. My relative was not sure he like the new speaker more, than the old yet. I asked should I stop? He not encouraged me to do so. It was a struggle to squeeze in all this much larger components into the speakers. When I done the other front speaker, another listening test followed. This time he was sure this upgrade is the future.

Then all the satellites was done and getting late at night (I already felt sorry for his neighbours) he went through some music files, and blasted loud his loved movies. He mentioned: I have not heard this detail, that detail, and even on low volume the system produce a clean sound now....

Later on at home, I done the same silver mica trick on my Cambridge Audio speakers, and on another. Now I like this speakers, before I was always disappointed with them. Simply they lacked the clarity to impress a headphone lover like me. When I got this speakers, after an hour listening I could not take it anymore and I was digging out the Chinese electrolyte c(r)aps from the speakers, even that meant warranty is surely void. You could think a reputable company will use something decent for audio. Dream on. After the upgrade this little addition years later was still required.


----------



## felix3650

Very nice thread this one. 

So I got myself a Pod-less Z5500 (newer Pid) along with what appears to be a not working bypass cable (3.5mm jack with volume going to a D-Sub connector).

Any good schematics out there to build my own working Pod bypass?


----------



## YiouJr

Hello to all members of this thread,

I wanted to post that starting from this relatively simple upgrade, I took it some (many) steps further. So, in some long steps, I completely ditched the control pod and replaced it with one of my own design. The reason for this is that pod's DSP has embedded high pass filters for the satellites. In effect, any bypass for the control pod could lead to frying the satellites in high volumes. But in my case I replaced the satellites with high end full sized 6.5" bookshelfs in front and 4.5" for the rear to handle the now present bass. My newly created control pod serves primarily preamplification purposes, using 3 OPA1612, Standby & Mute functions and gain trimmer controls for each channel. I've also added switches for stereo x4 or x6, with center and woofer playing L/R combined. Furthermore, I added 2 LPFs for the sub forming one second order passive filter, with adjustable cut off from 28Hz to the original 125Hz.

Secondly, I removed all opamps from the board along with their smd components. Yes, the 2 opamps for the woofer as well. I re-implemented the circuits for the speakers, which implement DC signal protection instead of replacing them with the 0.47uF cap. Plus, there is already a capacitor in the signal path to the TDAs, and another capacitor in series reduces the total capacitance, and in combination with the 22k input resistor forms a HPF which would be undesirable. I also removed those smd capacitors and replaced them with 2.2uF.
Instead of the 2 opamp preamplification circuit for the woofer I made a circuit with one opamp, with gain and crossover trimmer controls like those I added to my custom head. The reason I also ditched this part is because the crossovers for the woofer let it play in the range of 35-125Hz which is too high. Now there is no bottom range, leading to a SUBwoofer. My current design's cut off isn't steep enough, so I have mine set to 28Hz to avoid those mid tones.
Next, there are 2 22uF caps for each TDA7294. I removed the one in the signal path (the other is the bootstrap), which serves as a subsonic (HPF) filter to further improve the low bass response for the speakers. I soldered the pins together. In the same concept, for the same reason I also removed the 100uF NP cap in the back of the board.
Now that the system handles some real bass it was time to replace the bootstrap caps. The original 22uF isn't enough for hitting down in the 10Hz range. I replaced them with some low ESR 68uF 50V caps, but 47uF should also do the trick.

I can't really describe how the system responses now, those low notes are absolutely hammered.
It seems I am too new to forum to figure out how to upload images, but I guarantee the head and the board look beautiful


----------



## scratje

You almost made en total new amplifier so i am curious to what you did and how with pictures to show.
You can share pictures in your replies by selecting the image button as shown with the red arrow and select an image on your pc


----------



## YiouJr

It doesn't allow me to upload photos directly from my computer, it must have to do with the account being new. It only accepts URL images, and I already tried 2 unsuccessfully.

Anyway, my design isn't flawless, the narrower frequency for the sub (3-28Hz until the cut off) requires a whole lot of more gain and on top of that the subwoofer box is tuned to 40Hz. That much gain introduced some quiet noise. I also want to steepen the crossover, and I'm thinking of introducing one more second order crossover, active this time. I could harvest one more gain of 1.5 this way too.

For such high gains a balanced connection is the way to go, but a little hard to implement with 3.5mm jack plugs.


----------



## YiouJr

scratje said:


> You almost made en total new amplifier so i am curious to what you did and how with pictures to show.
> You can share pictures in your replies by selecting the image button as shown with the red arrow and select an image on your pc


Today that I checked again I can upload images! So, here is my creation!


----------



## RTAA

Guys,

i need small help. So i got z5500 for almost 10 years, but it started to make noise sound from all speakers. No matter of source it was same. 
I took them to repair shop and they said problem is with CS42526 proc in control unit. But since they dont have it they were unable to fix.
Meanwhile i purchased another z5500 set which had same issue. Finally i was able to buy another control pod and connect to rest of my unit and problem gone.
Now i would like to fix my control pod, i got brand new Cirrus Logic CS42526 but from what i was told it needs to be programmed first.
Are you aware of any place i could get firmware from so it can be programmed and replaced in my control unit.
Any help would be highly appreciated!


----------



## l0NeXuS0l

I found this video that made my system silent, after a period of constant noise.
Las link can help someone.



Now I have another problem with the control pod.
When the switch is turned off and I want to turn it on, the control pod lights up directly, I press the button to turn it off, the light bulb turns red, but the display still shows, and I can change anything, volume or effect, when pressing the button the LED turns blue, everything is exactly as it was when it was off, the difference is that the lights on the display turn off.
Another problem is that it has a strange noise in all the speakers, which increases with the volume.
It is not permanent, a small (POC) sound is heard a few seconds away.
It's as if the sound is hanging on.
Has anyone ever encountered this problem?


----------



## Katsukare

scratje said:


> Hi all.
> 
> I haven't been active on this forum for a while now but still own three Z5500 units, two older types and one new type.
> 
> ...


Thank you for these photos, did this modification remove the terrible hissing noise when the unit is powered on without input/sound?


----------



## scratje

Katsukare said:


> Thank you for these photos, did this modification remove the terrible hissing noise when the unit is powered on without input/sound?


No, just to prevent the boom at start or when switching other devices in the room and the 50/60 Hz humm from the woofer will be almost gone.


----------



## l0NeXuS0l

How about connecting two subwoofers to a single POD Control.
I leave a link with the video:


----------



## Samare

Hi,

I've noticed that the Z-5500 consumption is, with S/PDIF:

~10 W when off
~23 W after turning it on (without input signal)
~38 W once it has received some input even it stopped
I've also always been annoyed by the need to turn it on and off.

Now, the JBL Media 200 has an *auto turn-on/turn-off feature*:


> They will turn off when the source equipment (computer or CD player) has no sound output for approximately fifteen minutes and immediately turn back on when a signal is present.



I'd like to achieve that with the Z-5500.

I've thought about using an Arduino Nano or a Raspberry Pi Pico inside the control pod, to poll the input signal and control a relay.
Note that when the control pod is disconnected from the sub, the consumption drops to ~0 W. So the relay could cut that connection, then resume it and turn on the pod when a signal is detected.

Does anyone have any ideas or pointers?


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## YiouJr

Samare said:


> Hi,
> 
> I've noticed that the Z-5500 consumption is, with S/PDIF:
> 
> ...


That's a heck of a brilliant idea! But I would suggest to place it inside the subwoofer, since there isn't much space inside the pod. I don't know about disconnecting the control pod, but you can control the main AC lines to the amplifier, without messing much with the control pod.

I would use the 3-pin 8V regulator that powers the control pod to power the Arduino. Itself is powered by a second independent line from the transformer (blue wires). You can also directly use the pin 10 (+8V DC) maybe adding a step down converter to 5V.
For control signal I would use the stand by signal which is pin 6. To enable the system (thus your relays for the power) the pin is grounded. Use it as an input to your Arduino, and output a signal to two 5V relays controlling the red and yellow AC lines from the transformer to the rectifier.


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