# Audioengine A5+ Speaker Upgrades



## cssarrow

_Greetings Head-Fi-ers!_
   
Here is a simple mini guide for squeezing a little more out of the Audioengine A5+ (should also apply to the A5).
   
*Section 1*: Replacing Chengx & Yihcon Capacitors on Main PCB
*Section 2*: Replacing Unbranded Capacitor/Resistor on Crossover PCB
*Section 3*. Bypass Polymer and Ceramic Capacitors for Cleaner Signal Path
*Section 4*: Improving Dampening Material for Housing & Wires
*Section 5*: Finish Connecting All Wires to Inputs & Outputs
*Section 6*: Sound Quality Review
   
  I've decided to go with Panasonic capacitors as my replacement, but other brands should work just as well.
   
  Here is a collection of suppliers that others and I have found to work well.
  They are not in any way, ordered as a hierarchy chart.

 *Nichicon*
 *Nippon / United Chemi-Con*
 *Panasonic*
 *Rubycon*
 *Sanyo*
 *Mallory*
   
*A5+ Amplifier PCB Capacitor's List:*
   

   
   
_I will not be held liable if you end up messing up your speakers._
   
*Medium End Upgrade*
*(2) Purple*: *Nichicon KG "Gold Tune" Type II 4700uF 35V 22mmx45mm (Type III is better, however hard to find and expensive)*
*(4) Violet*: *Panasonic FR 22uF 50V* *5mmx11mm*
*(6) Gray*: *Nichicon Muse KZ 100uF 25V* *10mmx16mm*
*(1) Maroon*: *Nichicon Muse KZ 470uF 25V* *16mmx25mm*
*(5) Orange*: *Panasonic FR 1000uF 25V* *10mmx25mm*
*(1) Brown*: *Panasonic FR 220uF 16V **6.3mmx11.2mm*
*(2) Green*: *Panasonic FR 47uF 63V* *6.3mmx11mm**(35V was not available, higher volt is fine, just more expensive at times)*
   
*Reason:*
Nichicon KG Type II was picked due to cheaper cost and more accessible.
Nichicon Muse KZ was picked due to the fact that it's a capacitor for audio equipment and is cheaper than most other ones.
Panasonic FR was picked due to it's low ESR, high ripple current, and slim size to fit on this particular pcb (Panasonic FR > FM > FC)
  
*Higher End Upgrade:*
*(2) Purple*: *Nichicon KG "Super Through" Type III 4700uF 35V 30mmx50mm* _(Do not exceed 30mm diameter)_
*(6) Gray*: *Elna Silmic II 100uF 25V** 10mmx16mm* _(Elna Cerafine or Rubycon Black Gate works too)_
*(1) Maroon*: *Elna Silmic II** 470uF 25V* *16mmx25mm* _(Elna Cerafine or Rubycon Black Gate works too)_
   
*I do not recommend going over the sizes that i supplied, which for the pcb, is already oversized, but will fit.*
*You can choose to replace the Panasonic FR, It is ultimately up to you.*
   
*SECTION 1:** (**Replacing Chengx & Yihcon Capacitors on Main PCB**)*

*Stock PCB:*

   
   
*Layout PCB:*

   
*Replaced With:*
*Nichicon KG "Gold Tune" Type II 4700uF 35V 22mmx45mm*
*Nichicon Muse KZ 100uF 25V 10mmx16mm*
*Nichicon Muse KZ 470uF 25V 16mmx25mm*
*Panasonic FR Capacitors*
*Navships's Silver Plated OFC Hookup Wire* *18AWG* (Navship is an ebay seller for hookup wires)
   
*Before: *
   
*Front Side Angle*

   
*Left Side Angle*

   
*After:*_ (Pictures shows dual 22AWG Wires, which i am not currently using) [18AWG SPOFC]_
   
*Front Side Angle*

   
*Back Side Angle*

   
*Left Side Angle*

   
*Right Side Angle*

   
*COMPLETED*​


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## cssarrow

*A5+ Crossover Capacitor & Resistor Upgrade:*
*SECTION 2:*​ *(Replacing Unbranded Capacitor/Resistor on Crossover PCB)*​   
*Stock Capacitors (4.7uF, 8.2u**F, and 22uF at 100VT) (You need to buy two of each, each for each speaker)*

*Stock Resistor: 7W3R3J **(You need to buy two of each, each for each speaker)*​ 
*STOCK: *
​ 
​   
*Replacement Capacitors:* *Mundorf MKP Series Film Capacitors*
*4.7uF 250V 19mm x 28mm*
*8.2uF 250V 22mm x 33mm*
*22uF 250V 29mm x 44mm*

*Replacement Resistor: Mundorf M-Resist Supreme Resistor*
*3R3 20 Watt,  Wirewound, Non-Inductive, +-2% 11mm x 51mm*

*Replacement Wire: Silver Plated OFC Hookup Wire 18AWG*​   
 _*Left Speaker Crossover*_
 *How to remove the capacitors**: *cut the leads, use flat screwdriver to peel it off the epoxy, clamp leftover leads with tool, solder and pull off.
   


*After:*
*Front Side Angle*



*Back Side Angle*



*Left Side Angle*



*Right Side Angle*



*Under Side Angle*

   
_*Right Speaker Crossover*_​   
*After:*
*Front Side Angle*



*Back Side Angle*



*Left Side Angle*



*Right Side Angle*



*Under Side Angle*
​  ​ _(A5+ is now straight wired and soldered to tweeter & woofer, no more multiple crimp connectors in between degrading conduction [audio quality])_​ 
​   
   
   
*Completed*​ 

*A5+ Bypass Polymer and Ceramic Coupling Capacitors:*
*SECTION 3:*
* (Bypass with wire, replace with Elna Silmic II electrolytic capacitors)*​   
*Basis: *
_(Input/output capacitor & resistors)_

_(Brief Layout)_
   

   
   
   
*CAPACITOR RATING*​ *Both Stock Ceramic and Polymer Capacitors are 10uF 25V.*​   
   
*Bypass: *_(Doing it)_
*4 Ceramic Capacitors **&** **2 Ceramic Capacitors are bypassed with a wire. (C9/C10/C7/C8/C18/C17)*
*2 Polymer Capacitors **are bypassed with a wire. (C39/C40)*

*NOTE: You do NOT need to remove the capacitors that you are bypassing. Just simply use a wire from point A to point B.*
*I chose to remove mine. This may or may not apply to you.*

*Setup:*



*Before Removal: *_*How to remove polymer capacitors*_: http://pink.myshoesaretootight.com/mirrors/amiga.serveftp.net/Replace_capacitor.html

   
*Removal Begins: *_(wet soldering iron tip, touch tip to joint, with finger or clamp, pull slightly to opposite side)_


*Removal Finished: *_(Be careful, don't force it too hard, the pcb leads will rip off)_


*Capacitors Removed:*


*Bypass wire: *_(Leftover 16AWG SPOFC)_


*Cut Wire: *_(strip wire, tin wire with solder, and cut into 4mm bits)_


*Bypass Finished:*
_Top View:_


_Front View:_


_Left Side View:_

   
   
 *Upgrade: *_(Improving signal coupling capacitors)_
*2 Polymer Capacitors **are replaced with 4 Elna Silmic II 22uF 25VDC Electrolytic Capacitors (C4/C21)*
*2 Polymer Capacitors **are replaced with 2 Elna Silmic II 22uF 25VDC Electrolytic Capacitors (C3/C22)*
   
*Making two Polar Capacitors, Bi-Polar:*

   

   
*Keeping Leads/Legs Shot Before Soldering: *_(Pre-Out)_
_Don't make it overly short_

   
*Adding Elna Silmic II Polar Capacitors: *_(Pre-Output)_
  Place polar capacitors to slot C21 and C22 on the pcb, and solder with the correct polarity.
  These spots are located at the bottom right of the board vertically to one another.
   
  I decided to bypass mine with a wire instead as there is no DC current measured (in the millivolts) which would be beneficiary in providing better sonics.
  Note: C3 & C4 requires bipolar capacitors for future protection against DC voltages so it's best to have capacitors there.
   
*Adding Elna Silmic II Bi-Polar Capacitors: *_(Amplifier Coupling/Input)_

*Test First before using Hot Glue.*
*Use generous amount until they no longer wobble.*
   
   
*Completed​*​   
   
 ​ *A5+ Dampening Material Upgrade:*
*SECTION 4:*
* (Improving Bass with Dampening Material [Housing & Foam for wires])*​   
*Products Chosen:*
*Open Cell Foam For Housing: http://www.madisoundspeakerstore.com/acoustic-damping/dampers-foam-sheet-27-x-42-x-5/8/ *_(Dampening Material)_
*Defraction Ring For Tweeter: http://www.madisoundspeakerstore.com/acoustic-damping/dampers-felt-defraction-ring-for-tweeters/ *_(Dampening Material)_
*Adhesive: http://www.homedepot.com/buy/paint/caulking-sealants/dap-alex-plus-101-oz-all-purpose-caulk-clear-18072.html#.UQwQv6VZVyI *_*(*DAP Alex Plus Acrylic Latex Caulk Plus Silicone)_
   
*Supplies**: *_(acoustic foam not shown)_

   
*Filling The Gaps:*

   

   

   
*Dampening Left Speaker**:*

   

   

   

*Semi-Dampening Right Crossover​**:​*​ ​  ​ ​  ​ ​  ​ ​  ​ ​  ​  ​ *Dampening Right Speaker**:*​ ​  ​ ​  ​ ​  ​ ​  ​ ​  ​ ​   
*Optional:* _(Tweeter Dampening)_

   

   

   

   

   
*Completed*​   
   
*A5+ Finalization Stage:*
*SECTION 5:*
* (Finish Connecting Wires To All Input & Outputs)*​   
*LETS START WITH WHATS OPTIONAL.*
_(Improving wire quality from mini pcb to main pcb carrying input/out signal)_



 crimp/dupont connectors are eliminated, straight solder (signal improvement)
 Improved wire quality (signal improvement)
 Amplifier IC's stock thermal paste changed to Prolimatech PK-3 (thermal improvement)
 Twisted wires lower electromagnetic interference (signal improvement)
   
*TIME TO FINISH IT*
*Assemble:*

   

   

   

   

 *Solder or use crimps to connect the wires to Woofer & Tweeter*
 *Add Hot Glue if using solder, to help hold the soldered areas in place (heat will loosen the joints).*
 *Put Woofer in, screw in the 4 screws.*
 *Fill Speaker Ring & Tweeter Cup with a generous amount of Silicone Caulk (or alternative adhesive), put on and push down, whip away excess.*
 *Give it a day or two to dry.*
   

 This will help dampen the cup/ring/woofer from vibrations, silicone is very flexible and will not crack, so continuous *loud* music playbacks will not hurt the adhesive nor distort your music.
   
*FINAL RESULTS: *(painted black gloss + extra ferro-fluid for tweeter magnets)

   
   
*Completed*​   
   
*A5+ Sound Quality Review:*
*SECTION 6:*
*(Pros and Cons)*​   
*Let the testing begin! *​ *May the odds be ever in your favor!*​  ​ *Before conducting this test, i would like to thank some people for making this mod possible.​* 
 *Transworld  (XtremePlace) - for his electrolytic capacitor/wire/film capacitor/resistor/dampening upgrade IDEAS*
 *Handy Ray (Head-Fi) & Maxx_Power **(diyAudio). - **for his bypass/decoupling/coupling/dampening/adhesive upgrade IDEAS*
 *​Steve (Handy Ray/Maxx_Power) has been the biggest contributor to this mod, so if there's anyone to thank, it'd be him*
   
*TESTING EQUIPMENT*
*Speakers**:** **Audioengine A5+ on DRUGS*
*DAC:* *NuForce DAC-100, ASUS Essence One "Muses" Edition (Modded), and Musical Fidelity M1*
*C7 Cable:** **Audioengine & Artemis Cables Power Cable*
*RCA Cable:** **Artemis Cables "Silver Bow" (Pure Silver) w/ Valab "Early Bird" Rhodium Plugs*
*Speaker Cable: **Silver Plated OCC 24AWG Wires in Quad Litz soldered to CMC Silver Plated Pure Copper Spades.*
   
*Speakers are wall mounted with Pinpoint AM-40B/B-Tech BT77 mounting sets.*
*They are 8 feet away from one another, horizontally, and 4FT from the ground.*
   
  [size=medium]*MUSIC FILES*[/size]
*Audio files are mainly 16bit/**44.1khz **with a few 24bit/96khz tossed into the mix.*
*Most of the tests are conducted with ZERO loss FLAC Files.*
*I will be using a iPhone 5** for pre-testing purposes (Burn in).*
   
  [size=medium]*BACKGROUND INFORMATION:*[/size]
*I've owned Audioengine speakers for nearly 3 years now, *
*Primarily started with the A5 until experiencing driver & tweeter noise, along with more pesky ones such as the "autosleep function" kicking in when music is being streamed.*
*From those **various issues, i was able to RMA the speakers and receive a free upgrade to A5+ thanks to Marshall from Audioengine.*
   
*The original A5 had a good overall sound for the price.*
*Good punchy bass, sound separation, fast transient response from the kevlar woofers, treble that rolls off at the right moment, and that "Fun" sound.*
*When comparing the A5+ to the A5, since i've had it for years, i could tell the differences spot on.*
   
*First thing i noticed with the A5+ versus the A5 was the clarity and bass response.*
*The new horizontal intake from the back of the A5+ seems to have helped it improve on bass punch impact.*
*Now being rearranged differently, the A5+ also gained in clarity and micro-detail perhaps from the intake modifications or now that there is more room on the left side speaker due to the heat-sink being enlarged and outside of the enclosure.*
*Besides those two key improvements, i haven't really found any differences between the A5+ & A5, however just without the autosleep (now being manually controlled with remote) feature and tweeter noise now gone, i would have gladly paid $100 more for it.*
   
*[size=large]PROS:[/size]*
*After the mod/upgrade, there is no longer just a few key improvements like with the A5 > A5+.*
*There were a series of improvements that i've noticed with the A5+ after the mod was conducted.*
*They were:*

 *Bass/Treble/Transient Response*
 *Clarity*
 *Detail/Micro-detail*
 *Vocals*
 *Midrange*
 *Transparency/Neutrality*
 *Sound Stage*
 *Instrument/Vocal Separation (Imaging)*
   
*Yes, i noticed this within the first 5 minutes of playing a 16bit/44.1Khz FLAC file (Pop Music).*
   
*There were so many improvements that actually hit my sweet spot, i was flabbergasted.*
*Let's start from the top.*
   
*BASS was probably the largest improvement that i've had the joy of hearing.*
*Being a fan of mostly hiphop/pop and all music upbeat, it nailed my sweet spot hard with a 50-caliber round.*
*Before the A5+, the A5 was punchy, but not enough.*
*With the A5+, the punch was there, but there was no impact that my 6th sense could pick up.*
*Now with the upgrades, let me just say, my lungs tremble when i hear the bass response.*
*The transient response from the driver sure did a large ordeal for the bass after the upgrades had been done.*
*I cannot stretch this matter far enough, as i've never truly understood "impact", especially in headphones until i had auditioned the Audeze LCD-2 and LCD-3.*
*For speaker impact, i was sure, this was it.*
*The transitions of the treble were heightened and it's peaked took much longer before it smoothed out.*
*Perhaps because of this, did it play a roll into making the sound more neutral.*
   
*CLARITY/DETAIL improved significantly.*
*There were more micro-details when instruments were being played, end strokes vibration noises can now be somewhat heard, unique voices such as Amy Winehouse and other raspy artists now had more definition to their vocal character. The whole panoptic detail i felt was overall improved.*
*Definition for instruments, computer generated sounds, and vocals was like going from a 720P movie to a 1080P.*
   
*VOCAL/MID-RANGE/IMAGING/SOUND STAGE*
*I am addressing these four things at once, as i feel they belong/benefit with one another.*
*The speakers are put exactly to where they were before mods, the same place they were years ago, and yet, i feel as if the noise floor has lowered tremendously and that there was an expansion in the sound stage.*
*The sound stage widened and depth, blooming.*
*Imaging before the upgrades had been done made the vocals sound very narrow, as if there was a blank space somewhere in orbit between the vocal and background instruments/generated sounds.*
*Before i was able to sit between the speakers and hear vocal from the center, but a little far off between that point and coming to the speaker, there was no dynamic/expansive sound going towards that way that can be heard.*
*The upgrade expanded/stretched out the vocal, and with the help of clarity/detail, was i able to feel more of what the singer wanted me to hear, and because of that, the mid range was improved (being easily heard unlike before).*
*The best way to simplify this is that now there is a more full sound coming from the speakers.
 You can say before was like 2D circle, and now it is a 3D sphere.*
   
   
*TRANSPARENCY/NEUTRALITY*
*All of the above may have contributed to making these speakers sound like neutral studio monitors.*
*I don't feel as though the bass response has helped in this matter for neutrality, but does so for keeping these speakers "Fun".*
*The sound now is less electronic and more analog.*
*Everything hits, and when it does, it feels genuine.*
*Now i could see why people eventually move on to more neutral sounding speakers (monitors).*
   
*[size=large]CONS:[/size]*

 *Time*
 *Money*
 *Health (smoke from soldering will affect your health)*
 *Breakage (possibility of breaking your speakers if not done correctly)*
   
*[size=large]CONCLUSION:[/size]*
*In the end, every upgrade that was made, had the attribute in which provided for me, an improved sound signature.*
*Everything new was more pleasant sounding than the old.*
*It was like transitioning from Fun Speakers to Neutral Monitors while still keeping most of the Fun.*
*Even with the new impactful punchy bass response that is now available, to me, it still sounds better when paired with a sub-woofer that is capable of hitting the 30-80hz region.*
*Just a little more sub-bass would be perfect.*
   
*Completed​*​


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## KimLaroux

> Nichicon Muse KZ was picked due to it's audiophile properties.


 
   
  Haha, sorry but I can't help but find this one funny. 
	

	
	
		
		

		
			




   
  I suppose we could get into quite a discussion if we were to define "audiophile properties" in capacitors. It's just bothersome that those brands don't publish specs in their datasheet...
   
   
   


> Panasonic FR was picked due to it's *low ESR*, slimmer size, and *high ripple current* specifications.


 
   
  Considering the other brands do not publish those specifications, how did you come to this conclusion?
   
  I'd be quite shocked, in all honesty, if "audiophile" capacitors from Elna and Nichikon did not have lower ESR and higher ripple current than the Panasonic. Though the fact that they don't publish these values kinda makes you wonder...


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## cssarrow

ART


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## KimLaroux

Yeah many manufacturers hide the part # on chips. Some even drop black epoxy on them so we don't see.
   
  It's lame, really. There's so much marketing nonsense surrounding "hi-fi" and "audiophile" hardware that publishing objective measurements would limit them in their claims... so they don't. Just. Lame.
   
  I'm not familiar with the A5, but is this a passive crossover on the "behind tweeter PCB"? I thought those were active monitors. *looks at their website* Oh yeah, they do market them as powered speakers... my bad.
   
  Do you plan on upgrading the crossover? It seems to me as this would have greater effect on sound quality. And the options are endless. But then I suppose it would be silly do buy caps with individual price higher than the speakers themselves...


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## cssarrow

TE


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## KimLaroux

The "tweeter capacitors" are part of what's called the crossover.
   
  Active monitors have an electronic crossover before the amplifiers. This divides the signal in two, which then goes trough a dual stereo amplifier. One amp for the woofers and one for the tweeter. Active monitors therefore don't have the large capacitors, resistors and coils that make up a crossover.
   
  Mundorf aren't the most expensive. They are reasonably priced compared to other brands. If you wanted to spend 500$ per cap, you'd still have many options to chose from. But hey, they are audiophile approved. =D


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## cssarrow

MIS


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## cssarrow

Anyone know a good place to purchase speaker dampening material and foam for wires?
   
*Tim*


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## KimLaroux

Quote: 





cssarrow said:


> ​
> *A5+ Film Capacitor Upgrade:*
> 
> *STOCK Capactors:*
> ...


 
   
  I see that you are planning on replacing ceramic capacitors with MKP types. If the ceramic capacitors were used for power decoupling, then changing them for MKP might not be a good idea. In fact, in may me worse. Ceramic capacitors have better performances than MKP for power decoupling.
   
  Also, if you want more people to read this thread, you should add a new post when you edit the original posts. Simply editing will not make the thread show up in subscriptions feeds, and it won't bump it up. In fact, I thought you made no progress because of this. The only reason I'm here now is because your last post made the thread show up in my subscription...
   
  Edited to remove picture from quote.


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## cssarrow

CA


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## KimLaroux

I am not knowledgeable enough to tell if MKS or FKS would be a better choice. I just know, from reading it many times from different sources, that a small value ceramic performs better than film for power decoupling. But when you consider the many technologies used in film capacitors, I would not be surprised to see a film perform better. Going for ceramic is just the rule of thumb.
   
  This is why it's good to expose your thread while you're brainstorming. It's a good way to get the attention of more people, which raises the probability of a knowledgeable person giving better advice.


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## cssarrow

BL


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## KimLaroux

Maybe you could look at the datasheet for the chip amplifiers. Can you tell me their part number? I'm curious what the datasheet recommends.


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## cssarrow

ES


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## KimLaroux

In the picture, you have to invert Regulator and Rectifier. The large IC by the AC plug is essentially a diode bridge rectifier. The two TO-220 packages are DC voltage regulators. Those are probably LM317 and LM337, or 78XX and 79XX.
   
  The ceramic capacitors are related to the large ICs connected to the heat sinks. Those are the amplifiers. 
   
This page says the amplifier chips are TDA7294. It also contains information regarding capacitors which may help you.
   
  I just read the datasheet for the TDA7294. It doesn't talk about types of capacitors.
   
  I searched around the web for what type of capacitors are better for power decoupling in audio application, but there seems to be no consensus. There's just as much hate throw at every types. EIA Class A dielectric seems to be the only "acceptable" type, but those are limited in values. Mouser only stocks one 1 nf but no 0.1 µf.


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## cssarrow

AR


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## cssarrow

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## KimLaroux

I just noticed you edited your last post. 
	

	
	
		
		

		
			




   
  He took a different approach with his modifications. He studied the input circuitry along with the first stages of amplification, and tried to improve this. Many of the capacitors he changed or simply replaced with a wire were coupling capacitors. The audio signal goes trough those capacitors. They are used to block DC and only allow AC to pass trough. In commercial products, coupling capacitors are used as a safety feature, and not always necessary. Since signal goes trough them, they can degrade the signal quality. Essentially, the less stuff the signal has to go trough, the cleaner it will be.
   
  Coupling capacitors create a high-pass filter with the input impedance of the next stage, or with a resistor to ground on their output. Raising their value lowers the corner frequency at which point the filter start to roll off. In other words: Higher value means lower frequency response. Though in practical application, there's a point where raising the value won't give significant gain.
   
  If I were you, I'd save my money and leave the ceramic caps in. Their influence on sound quality is insignificant compared to the coupling capacitors. And since there seems to be no clear path to upgrade them, why bother? I'm sure AudioEngine had a reason to use ceramic capacitors. I mean, at this point we don't even know if changing them for another type won't actually be a _downgrade_.


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## cssarrow

With the MKP2's in hand, i decided to just implement them into the board.
   
  Replaced the Polyester/Polypropylene Correction/Decoupling capacitors with MKP2.
  Replaced Power Supply Ceramic Disc Decoupling capacitors with MKP2.
   
"Ceramic are more suitable for PS decoupling because of their low parasitic inductance and their high losses, which help to dampen resonances of wiring inductances and the decoupling capacitors."
*&*
"Due the higher inductivity of the polypropylene, or polystyrene they are not the godd solution for supply decoupling. Ceramic caps has lower impedance over 1MHz, and they succesfully avoid the HF oscillation."
   
  However, for this small decoupling purpose, it shouldn't be a large difference. 
  Will experiment with other ceramics down the road if i hear any abnormalities with the stacked metal film capacitors.
   
*!Updated Section 3 Pictures!*
   
*Tim*


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## Scallywag

Thanks to everyone involved in this thread. I've been curious about modding my A5+ speakers for a while. I'd run across the schematics, etc., on the web that are referenced but I found them to be a bit over my head. I'm somewhat new to this so the step-by-step directions and the really helpful replies have convinced me to try it out. So... thanks and keep it up, I'll be watching!


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## cssarrow

MIS


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## cssarrow

_*Added one more section for modding.*_
   
*Section 4: Replacing Polymer and Ceramic Capacitors that couples the signal to the amplifier TDA7294 chips.*


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## Handy Ray

Quote: 





kimlaroux said:


> If I were you, I'd save my money and leave the ceramic caps in. Their influence on sound quality is insignificant compared to the coupling capacitors. And since there seems to be no clear path to upgrade them, why bother? I'm sure AudioEngine had a reason to use ceramic capacitors. I mean, at this point we don't even know if changing them for another type won't actually be a _downgrade_.


 
   

 I just wanted to chip in and say that the larger ceramics as indicated by circles in the earlier pictures are not decoupling caps for the power rails, they are coupling caps for the signals (I had to double check to make sure with a meter for continuity).  That is why they are best bypassed or replaced.  I'm surprised that they used ceramics to couple signal....


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## cssarrow

CA


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## Handy Ray

Quote: 





cssarrow said:


> So is there anything wrong on my part for replacing them with MKP2? or would FKP2 do even better since this is for signal coupling.
> 
> *Tim*


 
   
  Check the voltage across this cap with the amp powered on, say on a work bench or something with a multi-meter.  If the voltage across this cap (any of the ceramics in that picture, NOT ALL CERAMICS ONBOARD) is just a few milivolts (mV), bypass it with a wire. 
   
  My guess is that AudioEngine designed this with a very standard implementation (AC coupled) of a pre-buffer-amplifier, and left in the coupling caps, and when the manufacturer made the unit, they decided to use the same cap EVERYWHERE (like the ceramics and polymers) since batch orders of large numbers is cheaper and it reduces total variety of components (this is far too common, with a good designer designing a good unit, then the manufacturer decides to make substitutions, just ask Centrance on why they INSISTED the manufacturer do not swap the opamps on their famous DACPORT).  They are not really needed because in my experience, the DC on those signal lines are, for all intents and purposes, ZERO.  I measured this on my unit with the amp powered up and playing.
   
  Bypassed with no caps at all is better for high-fidelity than ANY CAPS of ANY GRADE.
   
  If I had more time with my unit, I would have spent some time to figure out a way to bypass the internal buffer on the NJW volume control chip, since that part is specc'd far below the 5532 opamps, which immediately buffer that volume control chip anyway.
  
  EDIT: I see where you placed your MKP and FKP's now (with a picture).  Never mind on shunting them.  I assumed you were placing the MKP's in place of the ceramics in my mod.


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## cssarrow

CA


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## Handy Ray

Quote: 





cssarrow said:


> You're saying i should use a multimeter, test the voltage across the MKP2 along with the ceramics, if they are just a few mV, to bypass it with a jumper wire? Since you already did the measurements, shouldn't i bypass them regardless?
> I already upgraded the main capacitors, so i had a feeling the film caps were unnecessary.
> 
> So, first i'll listen with the film MKP2 caps that i already in the board, after wards, i'll remove all film caps and replace them with a jumper wire.
> ...


 
   
  The ceramics you want to bypass are the ones in the bottom part of that picture you took, they are in the signal path.  The ones you replaced with film caps that are red can stay there.  Take a look at the diyaudio thread or the pictures a few posts above, there are two images highlighting which caps are the signal path ones, to improve the sound first. 
   
  I measured every one of those caps highlighted/circled in the pictures, and they have practically no DC content while in the signal path, so you are absolutely safe and recommended to take those caps out of the signal path IF YOUR PCB IS IDENTICAL TO MINE, so just to be sure, you should perform your own measurements, we don't know what AudioEngine's engineering tolerances were, but if you have no multimeter, I would say with a high confidence that you are safe to shunt those caps (ONLY THE CAPS SHOWN IN THE PICTURE) with a wire.  You don't need to replace them with anything but a wire, or just shunt them with a wire and leave the component in place.  I recommend using a set of high quality (Silmic II's) for the circled caps in that image at the signal input closest to the jumper connector (white plastic connector with pins in it), so you can be safe against DC from unknown external sources.


----------



## Handy Ray

Quote: 





>


 
   
  Tim, the RED circled caps are the ones you want to bypass with a wire (shunt them), and the blue circled ones replace with some high quality Silmic II's.  Back to back reduces distortion since Silmic's don't come in already made bipolar varieties (so back to back makes your own bipolar).


----------



## cssarrow

Quote:


handy ray said:


> The ceramics you want to bypass are the ones in the bottom part of that picture you took, they are in the signal path.  The ones you replaced with film caps that are red can stay there.  Take a look at the diyaudio thread or the pictures a few posts above, there are two images highlighting which caps are the signal path ones, to improve the sound first.
> 
> I measured every one of those caps highlighted/circled in the pictures, and they have practically no DC content while in the signal path, so you are absolutely safe and recommended to take those caps out of the signal path IF YOUR PCB IS IDENTICAL TO MINE, so just to be sure, you should perform your own measurements, we don't know what AudioEngine's engineering tolerances were, but if you have no multimeter, I would say with a high confidence that you are safe to shunt those caps (ONLY THE CAPS SHOWN IN THE PICTURE) with a wire.  You don't need to replace them with anything but a wire, or just shunt them with a wire and leave the component in place.  I recommend using a set of high quality (Silmic II's) for the circled caps in that image at the signal input closest to the jumper connector (white plastic connector with pins in it), so you can be safe against DC from unknown external sources.


 

  Very detailed, thanks so much.
  WIMA told me the Red Film MKP2 will do better than the ceramics that i replaced due to metallized film having self-healing properties and higher reliability/load life.
   
  I will shunt the red circles with a wire.
  Is there any benefits from removing the ceramics/polymers and  then shunting them, or is there not?
  I will be using 6 total Elna Silmic II 22uF 25V.
  Four back-to-back for the Input Couplings to Amp.
  Two for Input/Output Couplings to Pre-Out.
   
  Quote:


handy ray said:


> Tim, the RED circled caps are the ones you want to bypass with a wire (shunt them), and the blue circled ones replace with some high quality Silmic II's.  Back to back reduces distortion since Silmic's don't come in already made bipolar varieties (so back to back makes your own bipolar).


 
  Understood.
   
  The guy from the thread is emailing me and assisting me with this mod.
  He says to use two capacitors and connect the positive legs together, thus making it a bi-polar capacitor with two negatives.
  Just like you, he says the Bipolar will reduce distortion that is induced by the capacitors.
   
*Here is a mini map-out of what i will be doing*
   

   
  Either + with +, or - with - should work.  (for making bipolar capacitor from two polar capacitors)
   
  By shunting the ceramic/polymers, wouldn't that lower the overall capacitance? Should i have to make it up when using the Elna Silmics?
  That is the part in which i do not understand.
   
  I will order some Silmic II's today. Is there any other possible mods that you can think of to improve the signal path?
   
*Tim*


----------



## Handy Ray

Quote: 





cssarrow said:


> Understood.
> 
> The guy from the thread is emailing me and assisting me with this mod.
> He says to use two capacitors and connect the positive legs together, thus making it a bi-polar capacitor with two negatives.
> ...


 
   
  Looks good, looks like you have got it all down. 
   
  When you shunt the ceramic/polymers, the capacitance is replaced by inductance of a wire (which is tiny, tiny), and the AC coupling becomes DC coupling, and you get rid of that pesky capacitor.
   
  When you replace the capacitors at the input with home-made bipolars (of 2 silmics back to back), you need a capacitance that is MORE OR EQUAL to the existing value.  So on diyaudio, the value was 22uf x 2, which means the total capacitance is:
   
  Total Effectice Capacitance = 1/( 1/C1+1/C2+1/C3.......), so for only 2 capacitors in series and each one is 22uf, the effective capacitance is 1/(1/22+1/22) = 11uf, which is just perfect.  You can get Silmic II in 25V varieties at 22uf for really cheap from digikey (and stock up on some while you are at it).
   
  Try these mods first, and let us know what you think.  I think you'll notice a difference now that the coupling is just 1 set of high quality caps, all DC inside the multi-stage amplification.


----------



## Handy Ray

As for benefits to shunting vs. replacing them with wires - NO DIFFERENCE.  Perhaps a difference if you are dealing with super high frequencies like in the Ghz range, but not in this case, absolutely not.  It is simpler to just shunt with a wire, and it is gentler to the PCB as a result as well.


----------



## cssarrow

Quote: 





handy ray said:


> Looks good, looks like you have got it all down.
> 
> When you shunt the ceramic/polymers, the capacitance is replaced by inductance of a wire (which is tiny, tiny), and the AC coupling becomes DC coupling, and you get rid of that pesky capacitor.
> 
> ...


 
*Great, that was what i wanted to hear.*
   
  11uF over by 1uF is perfect. I'll get them from Mouser along with some other capacitors for my powered subwoofer pcb.
   
  I will let you/everyone else know how they sound once everything is completed.
   
*In estimation, i believe these are the mods that would make the largest differences in sound.*
_*#1 being the mod that improves the sound the most*_

 *Ceramic/Polyester Capacitor Bypass & Coupling Replaced with Elna Silmic II.*
 *Crossover Capacitor & Resistor Upgrade*
 *Amplifier PCB Capacitor Upgrade (ChengX/Yihcon to Nichicon KZ/KG & Panasonic FR)*
 *Dampening Speaker Housing*
 *Wire Change (OFC to SPOFC) (**Fully soldered joints, no more crimp connectors)*
 *Power Cord & Film Capacitor Upgrade*
   
  Quote: 





handy ray said:


> As for benefits to shunting vs. replacing them with wires - NO DIFFERENCE.  Perhaps a difference if you are dealing with super high frequencies like in the Ghz range, but not in this case, absolutely not.  It is simpler to just shunt with a wire, and it is gentler to the PCB as a result as well.


 
  Thank you so much!
  This will save me so much time.
  I am going to use some 28AWG SPOFC Wire to shunt them.
   
  I believe after all of these upgrades/mods, that there won't be any mod's left for me to do. 
	

	
	
		
		

		
			




   
*Timothy*


----------



## Scallywag

Quote: 





handy ray said:


> As for benefits to shunting vs. replacing them with wires - NO DIFFERENCE.  Perhaps a difference if you are dealing with super high frequencies like in the Ghz range, but not in this case, absolutely not.  It is simpler to just shunt with a wire, and it is gentler to the PCB as a result as well.


 
   
  Forgive my naivety, but how exactly does one shunt with a wire?? Or, for that matter, shunt at all?? I'm not familiar with this but I'd really like to try these mods. Thanks.


----------



## cssarrow

scallywag said:


> Forgive my naivety, but how exactly does one shunt with a wire?? Or, for that matter, shunt at all?? I'm not familiar with this but I'd really like to try these mods. Thanks.




Shunt as in bypass. 
A capacitor has two ends that it is then used to soldered onto the pcb.

The reason for bypassing the capacitor is to get rid of it/go pass it, in this case, getting rid of the crappy ceramic and polymer capacitors, in the signal path which polutes your sound.

Removing the ceramics and polymers and replacing them with better coupling capacitors will heavily improve the sound.


----------



## Scallywag

Quote: 





cssarrow said:


> Shunt as in bypass.
> A capacitor has two ends that it is then used to soldered onto the pcb.
> 
> The reason for bypassing the capacitor is to get rid of it/go pass it, in this case, getting rid of the crappy ceramic and polymer capacitors, in the signal path which polutes your sound.
> ...


 
  So you would literally solder a wire in place of the cap in order to bypass it?


----------



## cssarrow

scallywag said:


> So you would literally solder a wire in place of the cap in order to bypass it?




Yes. 
Solder one end of the wire to one end of the ceramic/polymer capacitor and the other end of the wire to the other side of the capacitor (or the solder spot that the capacitor is on).

When you put a wire in parallel with a capacitor, it effectively removes that capacitor from the circuit. Thus the signal goes through the wire instead, fully ignoring the capacitor, which improves the sound because now it's no longer running through the ceramic/polymer capacitors.

You only bypass the two polymers on the left side, and 6 ceramics in the middle with a wire.

For the bottom right polymer capacitors, only replace those if you're using pre-out on the A5+for something like a subwoofer.
For the right side polymer capacitors, replace those as they're in the signal path, with 4 Elna Silmic II 22uF 25V. 
This way the signal is no longer coupled by the ceramic/polymers, but with the Elna Silmic II which is very very high quality and would sound nice. Especially after 100 hours of usage they'll sound their best.

Note: You have to solder to remove those right/bottom right side polymer capacitors, so that you can solder the new caps on the soldering spots the caps once were on.

*Tim*


----------



## Scallywag

Quote: 





cssarrow said:


> Yes.
> Solder one end of the wire to one end of the ceramic/polymer capacitor and the other end of the wire to the other side of the capacitor (or the solder spot that the capacitor is on).
> 
> When you put a wire in parallel with a capacitor, it effectively removes that capacitor from the circuit. Thus the signal goes through the wire instead, fully ignoring the capacitor, which improves the sound because now it's no longer running through the ceramic/polymer capacitors.
> ...


 
   
  I see. Thanks, this is very helpful. If you don't mind posting a photo example of a shunt in your mod, when you get there of course, I would be most grateful.


----------



## cssarrow

Quote: 





scallywag said:


> I see. Thanks, this is very helpful. If you don't mind posting a photo example of a shunt in your mod, when you get there of course, I would be most grateful.


 
  Yeah, no worries about that. I'm already done with bypassing it, so I'll upload a picture soon.
   
  I post pictures to the degree that anyone can understand just by looking.
  I know that terrible feeling of trying to understand circuitry, so my only wish is to make it easy for you to understand.
   
  This way, you can get the best sound from your product. (A5/A5+)
   
*Tim*


----------



## cssarrow

*To Scallywag:*
   
_I updated Section 4 for you. _
_Please check page 1 for pictures/steps._
   
_*Timothy*_


----------



## Handy Ray

Looking great!  Very clean de-solder!


----------



## Handy Ray

Oh and for the Silmic replacements, I trimmed the legs of the Silmics as short as possible and soldered them onto the pads then used some hot glue to hold them in place.  Try to keep the legs short.


----------



## Scallywag

Quote: 





cssarrow said:


> *To Scallywag:*
> 
> _I updated Section 4 for you. _
> _Please check page 1 for pictures/steps._
> ...


 
   
  Great! So in the photos, under each new gob of solder where a ceramic cap was, there is now a small bit of wire connecting the solder spots, correct??  I want to be completely sure of what I'm doing before I try this. I'm quite comfortable using the soldering iron. Again, I've just never tried this particular kind of mod. Thanks again, this is so helpful!


----------



## cssarrow

Quote: 





scallywag said:


> Great! So in the photos, under each new gob of solder where a ceramic cap was, there is now a small bit of wire connecting the solder spots, correct??  I want to be completely sure of what I'm doing before I try this. I'm quite comfortable using the soldering iron. Again, I've just never tried this particular kind of mod. Thanks again, this is so helpful!


 
  After removing the six ceramic's at the center along with the two polymer's on the top left side.
  Use a tweezer to place the 3-4mm tinned bare wire onto where the original capacitors were
   
  Using a tweezer, hold down the wire and began soldering the ends. 
  Simply wet the tip of your soldering iron with solder, and touch it to each end, hold for 1-2 seconds.
  Wait until fully solid, before removing the tweezer.
   
  It's pretty simple.
  The next part we're going to be adding in the higher grade electrolytic capacitors (Elna Silmic II), so it's going to be a little harder than this.
  I'll make the step by step process even more simpler once my capacitors come in. 
	

	
	
		
		

		
		
	


	



   
   



handy ray said:


> Oh and for the Silmic replacements, I trimmed the legs of the Silmics as short as possible and soldered them onto the pads then used some hot glue to hold them in place.  Try to keep the legs short.


 

  I'll do that too.
  Sometimes when using large Wima Film capacitors, i tend to bend the legs like this " \_ " so it makes room for them. 
   
  Like this for example:
   

  I bet you do the same 
	

	
	
		
		

		
		
	


	




.
   
  Will see if i can get it to sit nicely with short legs, if not, i can just run a wire out.
   
*Tim*


----------



## Handy Ray

Quote: 





cssarrow said:


> After removing the six ceramic's at the center along with the two polymer's on the top left side.
> Use a tweezer to place the 3-4mm tinned bare wire onto where the original capacitors were
> 
> Using a tweezer, hold down the wire and began soldering the ends.
> ...


 
   
  I rested my Silmics flat against the board (on top of some surface mount parts, if I remember correctly) and glued it down like that.
   
  For the other caps that are through-hole, I noticed there is about 1 cm of room behind the board, so if you have too much crowding, or just want to make it easier, you can mount them on the reverse side.  I did that with a few things to free up some room on the top side.  Functionally identical.


----------



## cssarrow

Quote: 





handy ray said:


> I rested my Silmics flat against the board (on top of some surface mount parts, if I remember correctly) and glued it down like that.
> 
> For the other caps that are through-hole, I noticed there is about 1 cm of room behind the board, so if you have too much crowding, or just want to make it easier, you can mount them on the reverse side.  I did that with a few things to free up some room on the top side.  Functionally identical.


 
  1cm is kind of small eh? enough for a polymer cap. 
  I'll most likely use a wire, as it seems to be the easiest way, but i'll have to see one i have the capacitors in hand.
   
  To you and your friend, was the sound improvements that large? _(After the polymer/ceramic bypass)_


----------



## Handy Ray

Quote: 





cssarrow said:


> 1cm is kind of small eh? enough for a polymer cap.
> I'll most likely use a wire, as it seems to be the easiest way, but i'll have to see one i have the capacitors in hand.
> 
> To you and your friend, was the sound improvements that large? _(After the polymer/ceramic bypass)_


 
  The sound improvement was big to my ears.  I didn't have 2 sets to do A/B comparisons, but they definitely sounded better to 3 pairs of ears I had auditioning them on top of mine.
   
  I'll post a picture sometime on how I managed to rig the 2 back to back caps onto a surface mount.


----------



## Handy Ray

Here is how I did my back to back Silmic II's soldered to a surface mount spot of the polymers at the input, demonstrated on an old dead video card:

   

   
  And you want to ideally NOT use wires to lengthen the legs of the caps, because it introduces an extra un-shielded pathway for hum to be picked up from the large toroid right next to it, as well as other external sources and internal sources.  Keep the signal path short, as short as possible.  Anyways, this is what I did, replicated.


----------



## cssarrow

Quote: 





handy ray said:


> The sound improvement was big to my ears.  I didn't have 2 sets to do A/B comparisons, but they definitely sounded better to 3 pairs of ears I had auditioning them on top of mine.
> 
> I'll post a picture sometime on how I managed to rig the 2 back to back caps onto a surface mount.


 
  I've had the A5 for a year and a half, this A5+ was my RMA due to the A5 making a tweeter static noise and sleeping even though my music was being played.
   
  Strange enough, they upgraded me to the A5+, without the sleep feature, it was so much better. I'd gladly pay $100 more for that.
  Having the A5/A5+ nearly 2 years now, i'm pretty sure i can hear even the slightest difference when plugging them in after the upgrade.
   
  Can't wait to hear that big difference.
  Quote: 





handy ray said:


> Here is how I did my back to back Silmic II's soldered to a surface mount spot of the polymers at the input, demonstrated on an old dead video card:
> And you want to ideally NOT use wires to lengthen the legs of the caps, because it introduces an extra un-shielded pathway for hum to be picked up from the large toroid right next to it, as well as other external sources and internal sources.  Keep the signal path short, as short as possible.  Anyways, this is what I did, replicated.


 
  Ah so you soldered it that close. Okay now i understand. With it being that close, the bottom of the capacitor is now more flat, and can easily sit on the pcb.
   
  What i'll do is put some hot glue, let it dry, put the two capacitors over, then glue the sides on. This way the two connecting legs does not touch anything metal from nearby chips/resistors/capacitors.
   
  Seems simple enough.
   
  Ended up getting these: http://www.mouser.com/Search/ProductDetail.aspx?R=RFS-25V220MF3%235virtualkey55500000virtualkey555-RFS25V220MF3%235


----------



## Handy Ray

You can also lay the capacitors on its side, so instead of standing up like that, turn them 90 degrees to lie on the board, the legs absolutely won't touch anything then.  I think that's how 1 of 2 sets of my Silmics were mounted to avoid the surface mounted parts. 
   
  I guess Elna changed the packaging on the Silmics, they used to be brownish like in the picture (those are Silmic II's).
  
  The A5+'s are a sweet upgrade.  The A5's were notorious for overheating under loud use or hot weathers.  The heatsink was internal, and didn't ventilate well.


----------



## KimLaroux

So.. you're "upgrading" the OS-CON capacitors for _two_ ELNA Silmic II _in series_. 
   
  And in another thread. Someone "upgraded" ELNA Silmic II for OS-CON.
   
  It seems to me that all you're doing here is making the signal go trough 2 capacitors instead of a single one. Since OS-CON and ELNA Silmic II are debated to be the best capacitors on the market, we can conclude they are almost the same quality. That said, your "upgrade" is really a downgrade, since you're really doubling the distortion introduced by those capacitors.
   
  Objectively, there is no way this can improve the sound. But then you're claiming that changing a couple inches of wires has a more significant influence on sound than damping in the speaker cabinet. So I'm just gonna conclude you're not being objective, and will leave you to your placebos.
   
  But just as a final piece of advice: please don't go bypass components that you have no idea why they are there. A couple of pages back, someone tried to "correct" me by saying to bypass the capacitors. I was talking about the power decoupling capacitors, but this person spoke about the coupling capacitors. Let's just say bypassing one or the other won't give you the same end result.


----------



## qusp

there is no way you have improved performance if those silmic are decoupling caps (well actually at this size they become reservoir caps), you do know that putting the 2 caps in series like that reduces the capacitance, rather than increasing it right? it only increases the voltage rating, which i'm guessing is not what you were trying to do? you will have created a 'cap' that is more inductive, higher impedance and most likely resonant.

SMD is the superior format for decoupling, hell these days its pretty much superior for everything, yes even audio.

edit: sorry I just read back, I see you know its lowered the capacitance value. it has also increased the impedance, which is now seen in series, so youve doubled the impedance of the silmics, which are already higher than the caps you are replacing.

silmics can be used well in some applications, mostly for if you *have to* use an electro in the signal path, which is why you would connect 2 together to make a bipolar cap to handle the AC signal, for DC it serves no purpose IMO (well unless degrading the specs is the purpose?). 

it is done because there are not all that many high quality bipolar electros made anymore for audio (probably because most stuff is moving towards being DC coupled these days) and if a bipolar cap is needed for AC signal duties, most will use a film cap. 

AC (alternating current) switches polarity twice each 'swing' so a polar cap can distort on the alternate phase, so if for AC signal and film cant be used, this trick was sometimes used to make a nice quality non-polar cap. This has no bearing whatsoever on decoupling DC power supplies.... for power supply reservoirs and decoupling, the SMD polymers you replaced are the better choice.

wow you are replacing ceramic HF decoupling caps with them too? just a little bit of info, even a small 0402 size ceramic capacitor placed directly across pins with via in pad pattern for the PCB (lowest possible inductance and impedance) is only good up to 10MHz. 

the silmics are literally pointless for bypassing HF signals, the ceramics were orders of magnitude better for the job and even those were probably too large. For really effective digital HF decoupling, only even smaller SMD parts than 0402 (0201, like a spec of sand), as well as planar capacitance designed into the PCB power and ground planes is effective. 

for getting rid of/attenuating such noise, a combination CRCLC is required. Something like the Murata EMIFIL products

it is clear, funnily enough, that audioengine have a better idea about how audio hardware and basic electronics functions than your friend. who woulda thunk that?


----------



## Handy Ray

Quote: 





qusp said:


> there is no way you have improved performance if those silmic are decoupling caps (well actually at this size they become reservoir caps), you do know that putting the 2 caps in series like that reduces the capacitance, rather than increasing it right? it only increases the voltage rating, which i'm guessing is not what you were trying to do? you will have created a 'cap' that is more inductive, higher impedance and most likely resonant.
> 
> SMD is the superior format for decoupling, hell these days its pretty much superior for everything, yes even audio.
> 
> ...


 
   
  I don't think you have read the whole thread...   The Silmics II's are in a signal coupling situation, the ceramics that were surface mount were used for signal coupling (in my mod, as indicated by the pictures with circles around the caps), and the back to back config effectively forms a bipolar cap, getting rid of some distortion, i.e.,:
   
  "If used as AC coupling capacitors (i.e. as high-pass filter) they do generate appreciable distortion at low frequencies. As a rough guidline I’d expect them to start with serious distortion (above 0.001 % at +20 dBu) at about 10x the cutoff-frequency. Or the other way round: choose the cutoff-frequency no higher than 2 Hz. At the same time this figure will mostly avoid time domain waveform distortion due to low-frequency phase shift. DC bias will increase distortion even more. Bipolar electrolytic capacitors (both as “true” bipolar capacitor or implemented with two polar ones back-to-back) show greatly reduced distortion and are recommended if space and cost allows their use. Obviously if used e.g. as smoothing or bypass capacitor in power supplies this distortion characteristic is far less problematic."
   
  From the analog guru Samuel Groner, whose contributions to objective studies on a LARGE variety of opamps still enlightens us to this day.  Although this is fairly well known and textbook material. 
   
  While I'm sure AudioEngine has a good assortment of knowledgeable engineers on staff, the product is a compromise between the engineering team, the cost-cutting admin-bean-counters, and the OEMs who actually manufacture the product.  ALL OF THESE PEOPLE gets a say on what the product should be designed like.  So many examples of corner-cutting resulting in substandard equipment that was engineered well are out there.  In fact, Centrance in their development blogs for the DacPort even said that the OEM making the DacPort wanted to substitute (among other things), a JRC opamp for the OPA1612 in their design to save a buck or two on a several hundred dollar product.  It took a lot of insistence from Centrance to get the OEM to stick to the plans by the engineers.  Pioneer's excellent Andrew Jones designed speakers is another example, where the engineers had to physically go down to the factory there they were made to MAKE SURE the speakers turned out they way they designed it, and wasn't tinkered with along the way.


----------



## Handy Ray

Quote: 





kimlaroux said:


> So.. you're "upgrading" the OS-CON capacitors for _two_ ELNA Silmic II _in series_.
> 
> And in another thread. Someone "upgraded" ELNA Silmic II for OS-CON.
> 
> ...


 

 First of all, the polymers were not OSCONs.  OSCON is one of Sanyo's brands if memory serves me correctly.  They are marked by Sanyo's markings.  These are who knows what make type of polymers.  Secondly, polymers are way better than electrolytics (typical electrolytics) at HIGH frequency, as in MHZ to GHZ range (and piss-poor at audible frequencies, particularly the bass region).  You see them in digital circuits all the time, motherboards, GPUs, etc.  However, polymers are terrible at coupling audio signals.  The fact that these were surface mount gives it away, the reason why you surface mount tank capacitors is mainly to reduce lead inductance at very high frequencies, typical of digital circuits.  This is the inappropriate choice here, since the frequency spectrum we're interested in coupling is far, far lower, where there are TONS of good coupling choices in terms of capacitors that way outshine polymers.  In this region, electrolyte distortion is the main consideration, where Silmics, Black Gates, etc are all optimized for.
   
  For the 2 caps back to back, the reason is that the single caps are polarized, and one "pole" of that capacitor is responsible for a lot of distortion temporally (the cathode and anode are not equal in how much distortion they create, because fundamentally, the cathode and anode in a polar cap are different).  When you couple two of those capacitors together back to back, you form an effective bipolar capacitor with symmetric distortion products which minimizes the total distortion (if the capacitors are similar, which they are in this case).  But don't take just my word on it, ask Walter Jung and Samuel Groner, people we all should respect:
   
  http://www.reliablecapacitors.com/pickcap.htm
  http://www.sg-acoustics.ch/analogue_audio/parts/index.html
   
  Lastly, the objectivity in my mods comes from the fact that AudioEngine chose to use inappropriate coupling capacitors.  Again, don't take my word on it, look at the links above and read up on ceramic capacitor distortion for yourself.
   
  I have already investigated the circuit where I commented, all the positions I have adviced to shunt (or bypass with a wire) are signal coupling situations.  This is KNOWN to objectively improve the sound by eliminating capacitive distortions all-together if there is no DC on the lines, which I have also made sure of.  I never made mentions to shunt power supply bypass capacitors, I assumed the OP meant the same ceramics I talked about in my pictures, THEN LATER ON, the OP uploaded the pictures pointing out where he installed the MKPs and FKPs and I immediately replied on it.


----------



## cssarrow

*Yes.*
   
_*Handy Ray*_ _(Steve)_ and I had a small misunderstanding regarding the ceramic capacitors for the power supply versus the signal coupling areas.
   
  I mainly replaced those (film & ceramic), due to the hatred of those specific colors. and since i was upgrading many other things, i decided, why not?
  Of course i had to change the tags to _(Not Required)_ since it would be a waste of money for most people.
   
  As for the polymer/ceramic bypass "upgrade". I had no intentions of doing this mod or even considered it, until i bumped into Steve's thread located at :http://www.diyaudio.com/forums/chip-amps/217335-audio-engine-5-amplifier-modifications.html and decided to ask for his assistance.
  Due to his inactivity on the forums for years, i had high doubts of ever getting a reply from him, but something miraculous happened.
   
  Anyways, i would not have done this upgrade, while being blindfolded (knowing very little about circuitry), if it wasn't for him. Since he's very knowledgeable on his subjects, and having done this mod to his own A5+ Speaker Set, in addition to hearing an improvement with 3 other individuals, i decided to go for it.
   
  Even though this is my thread, and usually it's up to that person to know what they're doing and conduct the upgrades, Steve has been my catalyst throughout all this catastrophe.
  Jacky's Audioengine A5+ Mod: http://www.xtremeplace.com/yabbse/index.php?topic=111705.0
  Jacky who i also contacted on a few occasions, had given me help due to the various detailed pictures of the crossover upgrade.
   
  I published the mod steps on my primary page, because i was sure that the objective was indeed an "upgrade".
  I would not want to lead anybody astray.
   
_Best Regards,_
   
*Timothy*


----------



## qusp

Handy Ray, I was commenting on the photos posted recently, since they were posted several times and people were talking about following recommendations and buying bunches of Elnas, I made the fairly reasonable deduction people would be replacing the 'crappy ceramics and SMD polymers' as is the current mode. 

oscon has become the generic name for polymers it seems, I dont use it and I agree with you, terrible signal coupling caps and DC leakage is an issue, but myself I try first to build DC coupled, then film if I have to, I wouldnt use an electrolytic ever. I build from scratch mostly these days or with designs ive chosen, so I dont have to put up with bad decisions (of course I sometimes _make_ them)

as a side note, there are some very good and very linear thin film SMD caps starting to appear, these will be a good alternative to film caps. ive used them for compensation and clock supply decoupling with very good results, but only available in small values as yet.

my apologies for the misunderstanding re the lineage of the photos, the photos were posted, a blog mentioned, conversations mentioned and odd decisions illustrated, so I replied to them. I wasnt aware the odd ones were cssarrow's. 

cssarrow:

replacing them would be more than a waste of money for most people, replacing them in the way you describe is destructive, it doesnt just do no good, it does evil. Replacing caps because you dont like the colour and posting it on your blog? wow

I wasnt aware I had to read the entire thread when replying to a specific post asking for opinion..... out of due diligence I read back a couple of pages and edited my post.


----------



## cssarrow

Quote: 





qusp said:


> Handy Ray, I was commenting on the photos posted recently, since they were posted several times and people were talking about following recommendations and buying bunches of Elnas, I made the fairly reasonable deduction people would be replacing the 'crappy ceramics and SMD polymers' as is the current mode.
> 
> oscon has become the generic name for polymers it seems, I dont use it and I agree with you, terrible signal coupling caps and DC leakage is an issue, but myself I try first to build DC coupled, then film if I have to, I wouldnt use an electrolytic ever. I build from scratch mostly these days or with designs ive chosen, so I dont have to put up with bad decisions
> 
> ...


 
  Replacing it was my choice, and there's no negatives to this, i followed specs and only went a little higher. Even though this yields no benefits, it put on my blog, because after all, this is MY MOD, and i decided to share everything that i did.
   
  To let people understand, i added the _(Not Required)_ tag, so people would understand it's not needed and outputs ZERO gains.
   
  Changing caps due to color approval is strange isn't it? Color choice man, color choice. Applies to cables too.
   
  You were just trying to be helpful, and i appreciate that.
   
_Best Regards,_
   
*Tim*


----------



## Handy Ray

Cheers mate! 
   
  What type of SMDs are you referring to that are coming out these days ?  I'm going to evaluate some PPS caps against MKPs or PPs (non-metalized polypropylene) for signal coupling when possible in the future.  I have only used PPS film caps for compensation and filters, and seen them once (assuming they are PPS) in a Pedja Rogic built Aya II dac for the resistor-ladder DAC chip.  Or are you referring to some other technologies ?  I have once heard that niobium oxide caps are supposed to be great with the pros of tantalums, but none of the drawbacks, but then haven't heard anything on them since. 
   
   
  Quote: 





qusp said:


> Handy Ray, I was commenting on the photos posted recently, since they were posted several times and people were talking about following recommendations and buying bunches of Elnas, I made the fairly reasonable deduction people would be replacing the 'crappy ceramics and SMD polymers' as is the current mode.
> 
> oscon has become the generic name for polymers it seems, I dont use it and I agree with you, terrible signal coupling caps and DC leakage is an issue, but myself I try first to build DC coupled, then film if I have to, I wouldnt use an electrolytic ever. I build from scratch mostly these days or with designs ive chosen, so I dont have to put up with bad decisions (of course I sometimes _make_ them)
> 
> ...


----------



## qusp

cssarrow said:


> Replacing it was my choice, and there's no negatives to this, i followed specs and only went a little higher. Even though this yields no benefits, it put on my blog, because after all, this is MY MOD, and i decided to share everything that i did.
> 
> To let people understand, i added the
> _(Not Required)_
> ...




I speak mainly of the ceramics, there is more to specs than voltage and capacity. replacing them how you described will make the circuit performance worse. even replacing with the same type and increasing the capacitance may be worse by setting up resonances. as HF decoupling/bypass caps, the silmics (especially with long inductive leads like that) are completely useless, this isnt a subjective matter. 

SMD ceramics have low impedance at high frequency and the fact they have no leads means they are very low inductance. the 'bipolar silmic' is practically the opposite of this and at high frequency they look almost like no caps at all, mostly inductive. genuinely high frequencies will simply pass them by, taking a short while to radiate RFI from the leads as they go. it looks a bit like a dipole antenna.

of course this isnt terrorism, but I do think people who illustrate technical mods on their blog have at least a small amount of due diligence to follow. realize that people less informed than you will look at your blog and perhaps incorporate another round of misinformation into it. its very easy to appear an expert online (even if you dont intend to present that way), even myself (I have no blog) I get messages all the time that assign me more depth of understanding than I have and as a publisher you should keep this in mind. otherwise real knowledge will become more and more diluted.

now of course we cant protect people from themselves....

Mr Jung most likely did not have point to point wiring in mind when suggesting this technique. Analogue circuitry was also not so full of VHF as it is today.


----------



## cssarrow

Quote: 





qusp said:


> I speak mainly of the ceramics, there is more to specs than voltage and capacity. replacing them how you described will make the circuit performance worse. even replacing with the same type and increasing the capacitance may be worse by setting up resonances. as HF decoupling/bypass caps, the silmics (especially with long inductive leads like that) are completely useless, this isnt a subjective matter.
> 
> SMD ceramics have low impedance at high frequency and the fact they have no leads means they are very low inductance. the 'bipolar silmic' is practically the opposite of this and at high frequency they look almost like no caps at all, mostly inductive. genuinely high frequencies will simply pass them by, taking a short while to radiate RFI from the leads as they go. it looks a bit like a dipole antenna.
> 
> ...


 
  I understand.
   
  As for the ceramics that i replaced with film, Audioengine designed this circuit, so it had to have served some kind of purpose for the ceramics to be there. in which i have already gotten some TDK as a replacement and will be removing those MKP2's soon. For the Silmic's, i'll make their leads as short as possible so it wouldn't act much like an antenna.
   
  You're right about that. 
  A person who randomly googles ebay may mistaken me for being some sort of expert, so i'll do them a favor and remove the the film cap change section since most people (cough* TE HE 
	

	
	
		
		

		
			





), does not read all pages.
   
_Best Regards,_
   
*Tim*


----------



## Handy Ray

Quote: 





qusp said:


> I speak mainly of the ceramics, there is more to specs than voltage and capacity. replacing them how you described will make the circuit performance worse. even replacing with the same type and increasing the capacitance may be worse by setting up resonances. as HF decoupling/bypass caps, the silmics (especially with long inductive leads like that) are completely useless, this isnt a subjective matter.
> 
> SMD ceramics have low impedance at high frequency and the fact they have no leads means they are very low inductance. the 'bipolar silmic' is practically the opposite of this and at high frequency they look almost like no caps at all, mostly inductive. genuinely high frequencies will simply pass them by, taking a short while to radiate RFI from the leads as they go. it looks a bit like a dipole antenna.
> 
> ...


 
  These are some of the more representative pictures I took of the stock amp plate.  Based on what the OP's mods look like, it appears (to me) that the OP installed the Wima caps in place of some existing polyester caps (in yellow in the pictures) and through-hole ceramics.  There were also some through-hole ceramics that you can't see in my pictures, but do see in OP's pictures from a different angle.  I am not convinced that these PARTICULAR ceramics that are through-hole should have been replaced by films (mainly because I can't remember their function in their circuits, my current guess is that they are NOT rail bypass/decoupling caps, as all existing rail bypass/decoupling caps are polyester films).  The other green ones (seen clearly in OP's pictures) are fine with either the stock polyesters or polypropylenes.  The other through-hole electrolytics around this area (the chip-amps section) are for boot-strapping the amp chip and AC coupled-feedback.  The boot-strapping capacitors are absolutely irrelevant to the sound quality (one set of 22uf caps, if I remember their values), and the other set of AC-coupled feedback can be changed in theory for something more audio-suitable.  Based on what the OP said, it was wise to replace them anyway, as the stock caps suffer from "bad caps" symptom and will eventually vent and become unusable (as per experience with AudioEngine A5's).  Replacing the polyesters that were stock with the polypropylenes MIGHT yield a small improvement in theory, but who knows if this is big enough to be noticed. 
   
   
   
  The ceramics you see in OP's and my pictures that are at the lower bottom of the PCB and are surface mount are responsible for 3 duties, there was a ton of power rail bypassing/decoupling for each op-amp, and I think some for compensation of the op-amps (can't remember this one), and the larger ones that are 10uf each are for signal coupling.  I would advise to shunt the signal coupling caps here (SMD ceramics) as part of my mod.  Equivalently, at the right most side near the jumper connector, there are those polymers for signal coupling, that I advised to replace with some Silmics.  Since there wasn't a bias voltage on these caps, I would recommend as I did, a set of these Silmics in back to back forming a bipolar capacitor.
   
  There were NO SMD ceramics that were either replaced with Wimas, or replaced with Silmics.  The relevant SMD ceramics that are signal coupling are shunted to allow DC-coupling between stages of the pre-amp.  All rail bypass capacitors (such as the 4 polymers you see around the NJW volume control chip) are left alone in my mod, and are suitable in their applications.
   
   
  OP's amp plate showing where the red Wimas were installed:


  
  Pictures of the Stock Amplifier plate from my images collection:

   

   

   
   
  I hope this clears up everything that's been discussed thus far...


----------



## cssarrow

Thank you for clarifying for the readers Steve.
   
  In your last picture, with the two yellow film caps.
  They gave me a gray one and a yellow one instead.. bo hoo.. 
	

	
	
		
		

		
			





 I'm surprised you still have some of your old pictures. 
	

	
	
		
		

		
		
	


	



   
*Tim*


----------



## cssarrow

Section 3 Completed.


----------



## cssarrow

Section 4 Completed.


----------



## Scallywag

Any updates??? I'm really curious as to how the speakers sounds after these mods. Thanks.


----------



## cssarrow

scallywag said:


> Any updates??? I'm really curious as to how the speakers sounds after these mods. Thanks.




Hello,

Upgrades costed around $100-150 and valuable time.
I painted the the rings/tweeter cup, so during the process of removing the cup, i opened the tweeter magnets and let too much ferro fluid leak out.
Its important to have them as it needed for their intended purpose, the higher frequencies.

Waiting 100uL of ferro fluid i bought from parts express to reapply, so i'll give you impressions real soon.

From what i can tell with one of them hooked up, was the detail was soooooo much better. I heard sound from one side multiple times in the past, and it would always sound like what it was, one speaker. Now it sounded more lively, like one and a half.

I'll review the sound quality within the week.
Thanks for checking up on the thread


----------



## Scallywag

Looking forward to it.


----------



## cssarrow

Quote: 





scallywag said:


> Looking forward to it.


 
  I'm done.
   
  Added the picture for finished model, and will do a Sound Quality Review soon enough.
  As of now, what i can tell you is that it sounds much closer to neutral studio monitors.
  + Detail
  + Sound Stage (a tad)
  + Separation
  + Vocal Definition/Veil
  + Bass Impact
   
  Was going to replace these speakers, but looks like now i'll keep them for another few years as they're now able to give me what i was searching for.
  The other side of the picture i never got to see, now, i'm getting the entire image from these set of speakers.
   
*Tim*


----------



## Scallywag

Question... I'm sourcing caps right now and I'm having trouble finding the Nichicon KG 4700uf 35V caps that will fit OK on the amp board. I'm wondering... can I use 50V caps instead of 35V as long as they fit?? I think using a higher voltage is OK in general but I wanted to make sure. Here's a link to the cap I'm asking about. Thanks!!
   
http://www.mouser.com/ProductDetail/Nichicon/LKG1H472MESBBK/?qs=sGAEpiMZZMtZ1n0r9vR22d%252blFeYd%252bH4E4y%252blePlNK%2fk%3d


----------



## cssarrow

50V will work fine, it should have even better ripple current actually.
   
  Just make sure you don't go over 30mm diameter, otherwise it will hit nearby film capacitors.
   
  If you plan on upgrading the inside wire, 18AWG is the largest size that will fit in the hole. (16AWG it too large).
  Personally, i ended up using 20AWG, as i didn't have enough 18AWG wires.
   
  Ask any question you require, i'm here to help.
   
*Tim*


----------



## cssarrow

Review completed.
   
  End of Mod.


----------



## Scallywag

How many feet of hookup wire do you recommend I purchase for this project? Thanks for your help.


----------



## cssarrow

I would say that you'd be safe with using under 15FT, but if i were you, i'd grab a 25FT bundle just in case (ease of mind).
   
  http://www.ebay.com/itm/25-feet-18-AWG-Silver-Teflon-Wire-White-19-strand-/230950852679?pt=US_Audio_Cables_Adapters&hash=item35c5be5847
   
  The silver plating on the wire decreases the resistance for AC signals, and the PTFE insulation doesn't melt under a soldering iron which also has excellent dielectric strength.
  Lower resistance for AC signal = more micro-detail.
  If you want an even better upgrade (wire wise) than what i had done, you can use some silver plated OCC wire.
  The OCC should help it sound a little better than the regular, but for speakers, it's harder to tell when compared to headphones.
   
*Tim*


----------



## Scallywag

OK, I have all the parts and I'm about to start this mod. 
   
  Question... I'm wondering about the poly caps to be replaced at C21 & C22 (pre-out coupling.) Is there any benefit to using polar caps (Elna's) there are opposed to bypassing with a wire, as you did?? I use the pre-outs only for subwoofer usage. Will subwoofer performance be affected either way?? I suspect not but I figured I'd ask. Everything else in that section, including making the bi-polar caps, is clear. It's only C21 &C22 that I'm wondering about. 
   
  I'll post some pictures of my progress...should be fun. Thanks again!


----------



## cssarrow

Quote: 





scallywag said:


> OK, I have all the parts and I'm about to start this mod.
> 
> Question... I'm wondering about the poly caps to be replaced at C21 & C22 (pre-out coupling.) Is there any benefit to using polar caps (Elna's) there are opposed to bypassing with a wire, as you did?? I use the pre-outs only for subwoofer usage. Will subwoofer performance be affected either way?? I suspect not but I figured I'd ask. Everything else in that section, including making the bi-polar caps, is clear. It's only C21 &C22 that I'm wondering about.
> 
> I'll post some pictures of my progress...should be fun. Thanks again!


 
  Signal will be better without polymer/polar caps.
   
  Steve told me that its only there to make sure no dc line is going through.
  I've already measured it, and it's in the  millivolts, which is close to none, so having it bypassed (jumper), better sonic's is achieved.
  I'm using the pre-out to a powered subwoofer (Polkaudio/Audioengine S8) and everything checks out fine.
   
  The C3 & C4 will need the bipolar though, however, it would still work with it bypassed.
   
*Tim*


----------



## Scallywag

Was I a fool to buy lead-free solder??? It's the Cardas brand. Some opinions online have left me worried and considering buying the leaded stuff. My iron certainly gets hot enough to use it. Any experience with lead-free solder? Thanks again.


----------



## Scallywag

OK, another question... is the 18 AWG wire I purchased (from navships, via your link) too big for shunting/bypass purposes??? It is stranded so if it's too big perhaps I could remove some strands?? Sounds like a pain...
   
  Have you done any mods to the S8 sub? I use an S8 with the A5+'s so I'm curious.
   
  Wouldn't be trying this mod if you hadn't made this thread so thanks again!


----------



## cssarrow

I use lead-free solder.
  Less poisonous and the smell is a lot more bearable.
  I used Kester 5% Silver Solder for my mod, anything should work though. (recommend 63/37)
   
  For shunting/bypass, 18AWG should do, but if you think it's still too large, remove 3-6 strands, twist the leftover strands, and continue to the tinning process using solder & soldering iron.
  What mainly matters with this mod, is for you to use a good soldering iron (sharp tip).
  Something similar to the Weller or Hakko should work.
   
  For the Subwoofer, i'm thinking about just replacing some capacitors for longevity.
  After your A5+ mod though, you should know how to do this yourself with the S8.
  You'll pick things up quick, trust me.
  I don't bother on modding subwoofers, as it's way harder to hear the difference in sound compared to speakers, so doing so would just be a time consuming waste.
   


> Wouldn't be trying this mod if you hadn't made this thread so thanks again!


 
  No problem buddy!
  You'll be sure to notice better sonics, especially for FLAC music files after your mods.
  Make sure to dampen the speakers nicely, as that's one of the main phases to not color your sound (more neutral).
   
  After you're almost done, i recommend using something like 100% silicone caulk to put the speaker ring & tweeter cup back in.
  It's very flexible, and does a great job dampening the cup and ring. (won't crack over time, great stuff).
   
  Feel free to ask questions when you're stuck.
   
*Tim*


----------



## Scallywag

Great, very helpful. I felt better about the solder being lead-free, for environment reasons, but there are some scathing opinions online regarding it's workability. Amazing how the internet can compound paranoia to those who go looking for problems!
   
  I use a Hakko and I bought a conical .05mm tip so I'm all set there. I've replaced plenty of caps (the shabby power supply caps in Samsung LCD TVs belonging to myself and friends kept me busy.) It's the shunting, etc., that's new to me. I don't expect any issues though. Yes I have plenty of foam and silicon caulk. The rowdy mid-bass in these speakers has always bugged me so I'm hoping this tames the issue a bit. 
   
  Most of my music is lossless/FLAC so I'm curious to hear the results. OK, enough for now...
   
  -Matt


----------



## cssarrow

Actually, lead might be easier to work with and be better for joint stress.
   
  There was an article regarding lead-free solder uses, in which the joints would degrade over time.
  This was regarding somewhere in Europe where Lead Solder was banned, and i think it mainly involved technologies that were made to orbit earth, not entirely sure, but yeah, lead-free shouldn't have issues for audio electronics.
  Perhaps more regarding electronics that are likely under more stress.
   
  Hakko's are nice, you should use the 599B instead of wet sponge.
  Helps prolong tip life, and seems to remove solder from the tip better for me.
  Very happy to hear you have experience in soldering.
  So this wouldn't be a blind application, which is great.
   
  Ah! so you also experienced that annoying mid-bass.
  Yes! The mod will fix your issue.
   
  FLAC FTW.
   
*Good luck!*


----------



## Scallywag

So I accidentally removed a couple of solder pads from the board while using the desolder wick. Growing pains. Yikes. Going to have to get creative...
   
http://www.audiokarma.org/forums/showthread.php?t=483358


----------



## Scallywag

Actually it looks everything is OK except for two pads that are still partially there. I'll use a multi meter and see if everything checks out. Lesson learned.


----------



## cssarrow

Which solder pads?
   
  You mean the ones for the resistor or polymer capacitor?
  Just follow the lead (the line of copper that connects to that area) and solder it to there instead, you might need to scratch the top part a bit to show the copper.
  Or you can just solder it to where that lead line ends (usually at one side of a resistor).
   
  A detailed picture would help, let me know if you are able to fix it, don't want you breaking your speaker haha.
   
  To be real honest, i didn't use a desoldering wick.
  For capacitors, i simply used a heat gun at the appropriate temperature underneath the the pcb (where soldering), once it's heated, you can remove the capacitor and put a new one in right away, simple stuff.
  Or the soldering iron method where you un-solder each side and pull it slowly until it slides off, then do the same when installing the new one.
   
  For the polymers, it's really easy to have the pads rip.
  Just make sure you add solder to each side of the pad (while the polymer is still there) before heating it up for removal.
  This gives you more mass to touch with the soldering tip, to flow it for easy removal.
   
*Tim*


----------



## Scallywag

Pads on the amp board for the electrolytic caps. Looks like everything is OK however. I'll keep checking terminations as I go. It's the solder removal that's proving to be a pain in the rear. The wick method is clumsy. I'm just over-thinking it, trying to do more than is needed for everything to function. Plus, I needed to get some sleep!! Thanks for the help.


----------



## Scallywag

Here's a quick progress update/photo of the board thus far. Mostly done here so its on to the crossovers tomorrow. I'm a bit confused buy the hook-up wires- specifically, where does each wire from the board connect to?? I should have mapped it out or something. I thought the board indicate which wire goes where but I don't see anything of that nature. Maybe I'm missing something??


----------



## cssarrow

Very good job, im thoroughly impressed.
   
  Nice job shunting the old ceramic's.
  You might want to do a bypass wire for the C21 & C22 area. (pre-out) or using polar Elna Silmic II 22uF works too.
  Looks like you went with a higher end upgrade than me, and you managed to fit the 100uF near the heatsink, be careful with that one as space is tight.
   
  Bipolar coupling caps are negative leg to negative leg or positive to positive right?
   
  If you're taking about the wire that goes to the Crossover, near the large 4700uF caps, there should be labels of L-, R-, L+, and R+.
  L- and R- is just ground, so you can even have it soldered to the same area, doesn't really matter.
  The R- and R+ connects to the gold plated brass outpost, R+ to the Red, R- to the black (it then goes through the speaker wire and connectors to right speaker crossover).
  The L- and L+ you solder to the crossover for the left side speaker, TW = Tweeter, W = Woofer, the positives and negative should be labeled on the crossover pcb.
   
   
  When using a wire to connect the amp board to the crossover or crossover to woofer/tweeter, try and twist it, as this helps the wire act less of an antenna, which will help sound quality further.
  make sure to use different color wires to know which is positive/negative, otherwise you can just use the same color wire but with a multimeter to check for continuity.
   
*Tim*


----------



## Scallywag

Oh yes I see some markings on the there. I need to remove more of that nasty black epoxy. Any tips on removing it?? Using the iron is messy.
   
  Yes, the coupling caps are both negative to negative. I'll use polar Elna's for C21 &C22. Then lots of hot glue. 
   
  The cap near the heat sink leaves enough clearance, I checked and the board fits fine.
   
  Doing the crossovers today, then I'll deal with the hookup wires.


----------



## cssarrow

Black Epoxy, i used a mini clamp to feel it off.
  First i i would scratch one side up with a flathead screwdriver, then clamp it and peel it upward.
  Yes, you can use the Elna's for C21 & C22 just to be sure, but it will be sonically better IMO with a bypass wire.
  Shouldn't be that audible as it's going to a subwoofer anyway.
   
  Lucky you had clearance, i don't know why, but when i was sourcing parts, i thought 2.5mm more was too significant so i didn't get the Elna's, haha.
   
  Good luck doing the crossover, it's easier to do, but kills a lot of time.
  When soldering the resistor on the bottom side of the pcb, lean it so it would have clearance when being pushed back into the speaker.
  Mine was like 1mm away from hitting.
   
  I wish i had put Elna Silmics & Silver Plated OCC instead of my regular Nichicon KZ & Silver Plated OFC wires.
  Oh well! Too late now.
   
*Tim*


----------



## Scallywag

Crossovers are done, started cutting the dampening foam pieces. Should be all done tomorrow! 
   
  Regarding the hookup wires, everything you said makes sense as far as where each wire leads to... but I want to make sure I've done it right. Picture below. That center ground hole ("GND")... there doesn't need to be a wire or anything there??
   

   
  Regarding C21 & C22... can I just shunt those like I did the old ceramics?? Or do I need to use a wire?? I don't think there is a difference but I want to check. Almost done and learning a ton as I go!!


----------



## cssarrow

The GND does not have anything going to it except the L- and R- since they are connected underneath anyhow.
  To tell you the truth, i wasn't even aware that there was a hole at the center of GND, probably because i didn't use a soldering wick 99% of the time.
   
  I see you went with a 18AWG.
  i had 16, but it didn't fit, so i went with 20 and knew there was room leftover to squeeze in 18AWG.
   
  You should just shunt C21 & C22 like you did with the ceramics.
  The only reason why i had a wire in my picture was because my solder pads ripped off, so i had to trace the lines to the next available solderable area.
   
  Whatever you do, there are two things you need to be careful about.
  The first is not losing the white washer where you screw in the amplifier chip to the heatsink.
  The other is not accidentally touching the bipolar capacitors.
  Once they lean a bit, the pad will surely rip off.
  My C3, C4, C21, and C22 all ripped off, but i fixed it.
   
  I wonder, are you going to replace the wires connecting your Input/Output board to the Amp Board?
  If you are, i don't recommend replacing the 5V (2 wire) cable, it will do nothing to sound improvement, i did it by accident.
   
  Everything looks good though, make sure to test before hot gluing all the capacitors down (partially for polars).
   
*Tim*


----------



## Scallywag

Yes, I have the other white washer. 
  I will be very careful with the coupling elna's, thanks for the heads-up.
   
  Wait, which one is the 5V cable? Can it be seen in any of the photos on this thread? I may replace the wire connecting in input/output to the board but I haven't decided yet. I've come this far so... Is it worth the time to replace them in your opinion?
   
  Damping is basically done, messy job. I'll let the silicon cure overnight while I finish the wiring this evening. 
   
  Man you weren't kidding about this mod being time consuming..


----------



## cssarrow

Good! Dont lose those washers, i almost lost one.

The 5V is only a 2 wire so you'll know which one it is right away.
It connects to the middle right side of the amp board.

The cables with 5-6 wires, i replaced all with silver plated copper 24AWG, as those are the ones carrying signal from the input RCA, 3.5mm, and output RCA.
Shouldn't be hard.
They're connected in order from left to right.
I felt as if i didn't do it, it would be a bottleneck, so i had it done.
I can't tell if it was worth it, as i did the mods all at one time.

I let the silicone cure for 2 days before playing loud music.

Yes, its very very time consuming, but the journey is a fun one, you learn lots, and at the end of it all you have improved sounding speakers which is great.
How long have you had your A5's?
If its quite awhile, you should be able to hear the differences instantly.


----------



## Scallywag

Yes I see the wire you're referring to. I'll leave it be. Might as well replace the others being that they are part of the signal path. 
   
  Question. The leads on the tweeters... I think I see a faint red mark on one of the two leads on each tweeter. I assume this indicates the + lead?? I ask because the red color looks like a faded marker or something.. not really obvious. Did you see this also?
   
  I've owned these A5+'s for 2+ years now so yes, I'm very familiar with the sound. It seemed to me that the drivers and tweeters themselves are of a high enough quality to reflect the desired results from these mods. They're perfect for the small den they reside in. I use them with the aforementioned S8 along with a Schiit Bifrost. These speakers also handle home theatre duties so, being that I use them so much, I figured the mod was worth doing. Already upgraded the power cord (for DAC also... really made a difference to my ears) and I use quality cables (nothing too exotic.) I've beed using a Furman power conditioner as well (also used for guitar amp purposes and surge protection) so this seemed like a good next step.  
   
  I'm learning as I go. I guess after all these "how" projects I may need to further educate myself in the "why" aspect. I know that the amp works but I don't know why, electrically speaking. Recommend any books/resources to better understand what the heck I am actually doing?


----------



## cssarrow

Yes, leave that 5V alone, it's for the USB 5V charging dock.
   
  Before removing the crimps on my tweeter, i used a sharpie to mark which was + and - so i could come back to it later.
   
  I remember i checked with my multimeter before and the two spots seem to be bipolar (touch each other).
  It should be safe to solder to whichever lead.
  You can double check it just to be sure once you've semi-completed your mods.
  Simply touch the wires onto the tweeter leads, and see which would make sound.
   
  The silk dome is good stuff and so is the kevlar speakers.
  Just like what Steve said before, it goes through a long process in which the parts become replace with cheaper parts in order for them to be able to market it at the price that they do, otherwise it would be very expensive.
  Air Motiv's use high quality parts, and prices remain low, that's why it's popular nowadays.
  Also their planar magnetic tweeter is great.
   
  Ah, so you believe in cable differences.
  I too change out my wall outlet and power strip with pure copper with a silver plating.
  I use a custom cable on my A5+, it's shielded since i used a 3 Socket Mains Plug unlike the stock cable.
  It took me awhile to look for a affordable C7 plug, and ended up getting one from Alibaba.
  The Furutech ones are way expensive, i think $50+.
   
  Here are a few links i like to help you understand more of DIY.
  Parts and Components: http://www.sg-acoustics.ch/analogue_audio/parts/index.html
  DIY: http://www.diyaudioblog.com/2011/08/custom-right-angle-double-shielded-iec.html
  And once i've completed my website, you can drop by and there's some DIY Sections on there that can help you.
http://www.artemiscables.com/
  I should have one soon for a DIY Sigma 11 power supply.
   
*Tim*


----------



## Scallywag

So Im just about done. Before I start putting things back together I'd like to see the the amp is functional. How to I go about this with the multimeter?? I've check for continuity from the inputs to the crossover outputs and signal is going all the way though. But when I connected the left speaker to the crossover and powered up the amp I wasn't getting any sound. Power is being supplied, so far as i can tell, because the LED light comes up and it blinks when I turn the volume pot. I connected an iphone via both 1/8" and RCA to test but again, no music. But I was hearing some slight static when brushing the wires to the terminals on the driver.   
   
  Do both speakers/crossovers need to be connected for everything to work?? I've checked for continuity in every place I could on the board... so I'm kinda stumped. What do I need to do to figure out what the problem is, if there even is one??? I'm at a loss.


----------



## cssarrow

Quote: 





scallywag said:


> So Im just about done. Before I start putting things back together I'd like to see the the amp is functional. How to I go about this with the multimeter?? I've check for continuity from the inputs to the crossover outputs and signal is going all the way though. But when I connected the left speaker to the crossover and powered up the amp I wasn't getting any sound. Power is being supplied, so far as i can tell, because the LED light comes up and it blinks when I turn the volume pot. I connected an iphone via both 1/8" and RCA to test but again, no music. But I was hearing some slight static when brushing the wires to the terminals on the driver.
> 
> Do both speakers/crossovers need to be connected for everything to work?? I've checked for continuity in every place I could on the board... so I'm kinda stumped. What do I need to do to figure out what the problem is, if there even is one??? I'm at a loss.


 
   
  Take the following pictures in birds eye view:
   

 Where L- / L+ & R- / R+ is soldered.
 Top left side of amp board where the large 3 pin from torroidal is plugged in.
 Ceramic capacitor bypass solder (each one)
 Panasonic FC/FR Area (to make sure their legs aren't touching anything metal)
 Bipolar Capacitor area
   
  I had that popping noise before.
  You do not need both crossovers to be plugged in at the same time.
  Make sure you distinguish your positive from your negative leads.
   
  Also, for the cable that controls the LED and Volume, make sure if any wire ripped on inside of the speaker.
  I had the issue where one wire ripped and the volume started at 1%, so turning up the volume, turns off the sound completely.
   

   
   
  That's what im talking about.
  That might be an issue.
   
  What i did was:
   

   

   
  If this isn't the case, Steve and i will help you find out whats wrong.
   
*Tim*


----------



## Scallywag

Photos coming soon. In the mean time I think I found a problem. One of the tiny resistors ( I assume, labeled with "R") just next to the upper-most cap on the left side of the board is very loose and kind of burned. My own fault. I was impatient while desoldering in that area and I almost lost a soldering pad, was running on too-little sleep. Can I just bypass that tiny (and I mean tiny) resistor with a wire?? I'll upload a picture shortly.


----------



## cssarrow

Quote: 





scallywag said:


> Photos coming soon. In the mean time I think I found a problem. One of the tiny resistors ( I assume, labeled with "R") just next to the upper-most cap on the left side of the board is very loose and kind of burned. My own fault. I was impatient while desoldering in that area and I almost lost a soldering pad, was running on too-little sleep. Can I just bypass that tiny (and I mean tiny) resistor with a wire?? I'll upload a picture shortly.


 
  Doesn't matter how tiny they are, their values can be very high, and that's what counts.
   
  Use your multi-meter and measure in ohms each end of the resistor (does not need to be on) to see how much resistance they carry.
   
  Start with 200 on the multimeter ohm scale and slowly go up from there, (2000, 20K, 200K, etc)
  Once you find their value, buy a new one the same size from radio shack or some place online/nearby that sells "smd resistors".
  You can show me a picture, and i'll tell you what size it is.
   
  I melted a corner of a resistor too, but it was just a slight corner, thank god.
   
*Tim*


----------



## Scallywag

multimeter set to 20K gives a reading the hovers between 2.2 and 2.3. So the value is 2.2?? The resistor came off of the board... so lucky to have found it.


----------



## cssarrow

Quote: 





scallywag said:


> multimeter set to 20K gives a reading the hovers between 2.2 and 2.3. So the value is 2.2?? The resistor came off of the board... so lucky to have found it.


 
  20K with a 2.2 or 2.3 reading means 2,200 or 2,300 ohms which is a decent amount, if you had shunted it = not good idea.
  Have you tried doing it on 2K?
  Anything higher than 2K would not be able to get measured, so 20K is the next closest.
  I'm thinking its a 2200 resistor.
   
  Does it have any marking on it?
  If so, you can measure another one that's close to it, in order to find a closer exact value.
  Please take a picture with it on the amp board so i can see what size it is.
  It seems like a size 0805 or possibly 1206.
   
*Tim*


----------



## Scallywag

Well I would except all of the sudden it's disappeared. The marking was gone anyway. It's so small, I don't think I'll be able to find it. Ugh. Anyways, there was no reading on 2K so I think you're right. It was the exact same size as the resistors in this photo, those 4 in a row. Dang, I thought I'd done everything right. Oh well. As long as it's something I can fix/replace then I'll live. Thanks for you help.


----------



## Scallywag

i think the resistor I lost/melted had a 2202 marking on it. It was right next to a 47uf 50v cap, the upper-most of the four on the board. The three other caps with that value also have 2202 marked resistors right next to them. But the ohm readings on those resistors are not all the same, so I'm confused. The board # for it is half melted but I think its R49. Maybe I'll call Audioengine tomorrow and see if they can tell me the correct size and value. I don't know, maybe they will sell me a new un-capped board or something.  I hope I didn't destroy my speakers.
   
  Does the resistor value need to be exact or just close??


----------



## cssarrow

First, i would like for you to calm down.
  It's not the end of the world.
  Losing a resistor would prevent the signal from passing, as there are no jumpers there (wire connecting one side to the other).
   
  Thanks for the picture, but you should of sent me a picture of the actual spot that fell out, that way i can find it on my own speakers, and help you measure the resistance and tell you what to buy.
   
  The reason why your multimeter shows 2,200-2,300 was because your set value was 20K measurement, which was far from the value of that capacitor, so reading was off.
  It could also have been that multimeters generally degrade over time, and would need re-calibration.
   
  Honestly, i think it could of been "2201" and not "2202".
  Reason being, your measurement was 2.2 or 2.3 on a 20K scale which is a 2.2K estimate.
  2201 is the code for a 2.2K resistor.
  2202 is the code for a 22K resistor.
  202 is the code for a 2K resistor.
   
   

   
   
  If the resistor was big enough to fit 4 codes, it would be a 0805 or 1206.
  I say you get a 2.2K resistor in SMD size 0805 and 1206 (just to be sure).
  No need to contact Audioengine, this is a very easy fix my friend.
  Just because it was placed next 22K resistors, doesn't mean it will be a 22K resistor.

 It's ideal to replace it with the exact or near value.
  You shouldn't go wrong with replacing it with 2K or 2.2K, but since you measured it and it proved to be 2.2K, then get a 2.2K resistor.
 If you're still unsure, just tell me where it is, and i'll measure my own and tell you the size and where to buy it online.
   
  Online: http://www.ebay.com/itm/100x-SMD-Chip-Surface-Mount-0805-Resistor-2-2k-ohm-222-/120823595088?pt=LH_DefaultDomain_0&hash=item1c21a5c050
  If you live in the U.S., simple drive down to Radio Shack or anywhere like Fry's Electronics, they should sell resistors.
  Find a 2.2K in the appropriate sizes i said above, or how large you saw it is and buy it.
   
  When you solder it, first place it down where ideal, use a flat head screwdriver to push down on it, that way when the solder gets wet, it doesn't move the resistor.
  Don't flow it for too long, as the metal ends can come out pretty easily if done too long.
   
  After you're done, try it again.
  If you still hear no sound, check for loose capacitor/resistors/ripped wires.
   
*Tim*


----------



## Scallywag

Yes, yes you are right. Cooler heads prevail. I can fix this so no need for me to be freaked out. Thanks, I needed that proverbial slap-in-the-face
   
  Ok, so here are two photos showing the exact location of the missing resistor. I'm pretty sure that it was the same size as the resistor just above the spot where the missing one was in the second photo. The board is pretty mangled right there, that's what I get for trying to force things. For what it's worth the rest of the board is clean, free of char, etc. But that spot has noob written all over it!!
   
  I checked the hookup wire terminations (L+ L- R+ R-), the 3 pin plug for the transformer, ceramic bypass/shunts and the Panasonic cap area and they all look to be OK. No metal touching, no loss connections, no stray jumpers, etc. The polars caps are now sealed in hot glue but I was VERY careful with these, making certain that the solder points were solid, no legs touching anything else etc. Everything else on the board seems to be OK, but I guess I can't be completely sure until the speakers start singing again. One thing at a time..
   
  I can find the parts I need down in Chinatown (I live in NYC) or certainly online if need be.  
   
  Again, thanks. Seriously. 
   
  (FYI, in the first photo you'll see that one of the wires (blue) for the input board connection is loose. This just happened as I was taking these photos. When I was testing the amp it was in place and working fine so that's not the problem.)


----------



## cssarrow

It's most likely a 0805.
Size 1206 i'd expect to be as large as one of those R's on the top right of the pcb, but i could be wrong.

You should first clean up that soldering area with some rubbing alcohol or acetone with a q-tip/cotton swab as the appplicator.
That way its nice and clean, and that you won't mistakenly have the ends touching one another or anything else nearby.
That should be your main focus as of now.
Make sure to push firmly on the resistor when wetting each side using something by all means available.

The wires that you replaced connecting the amp and input/output board, you don't have them braided or twisted? Haha.
I have a picture on the first page showing how mine looks like.
Then again the distance is short anyway, so EMI shouldnt affect it as much.
I hope you checked continuity there before removing the wires for replacement.
If i remember correctly, they should go in order horizontally from left to right.
Double check that area to make sure that none of those soldered areas are touching one another, and you should be good to try firing on the speakers again after getting that resistor replacement.

For a DIY'er, anything is fixable as long as you can source the replacement parts, so don't freak out, its part of the learning curve.
Just think to yourself..."i can fix this $h1t".

The only thing im curious now is how your reaction would be to the new sound after having owned the speakers for nearly as long as i have.
Maybe you'll have the same opinion as i had under my Sound Review on page 1.

Keep up the hard work brother, it pays off in the end.


----------



## Scallywag

OK, I can do that. Question... in the case that my ohm reading was wrong, would having the wrong value resistor there (22K vs. 2.2K) result in serious damage or inability for the amp to function properly?? Perhaps I'm being paranoid here, second guessing my ohm reading because all the other resistors in and around that area are of a much higher value than 2.2K. If I purchase both and end up first installing the wrong value would I know it right away?? This is what I'm considering calling Audioengine about... to see if they can confirm the value of my missing resistor.


----------



## cssarrow

Quote: 





scallywag said:


> OK, I can do that. Question... in the case that my ohm reading was wrong, would having the wrong value resistor there (22K vs. 2.2K) result in serious damage or inability for the amp to function properly?? Perhaps I'm being paranoid here, second guessing my ohm reading because all the other resistors in and around that area are of a much higher value than 2.2K. If I purchase both and end up first installing the wrong value would I know it right away?? This is what I'm considering calling Audioengine about... to see if they can confirm the value of my missing resistor.


 
  Dude, i'll just take my A5+ out today and measure that resistor and tell you what to buy.
   
  Quit being a:
   

  If you didn't know, 22K and 2.2K is off by 20,000 which is pretty significant.
  You could end up hurting another part (due to heat/short) if you use the wrong resistor (or have shunted/jumpered it)
  Audioengine won't tell you crap.
  I asked them about their film caps, and they said they had to call their Chinese department, which the main place is in China anyway, and still, never gotten back to me.
   
  Just let me finish a few cable orders, and i'll have the resistance measured for you.
  Simply just buy a replacement with my given value and solder it there.
  It was probably to lower the voltage that was going to your amp chip (maybe), so that's probably why you weren't getting sound.
   
  As for your picture, the input wire with the blue label, why is it not soldered?
 Whats with the whole yellow/yellow, red/red, blue thing?
   
*Tim*


----------



## Scallywag

The large difference in values is what I'm concerned about. Sorry, just trying to be careful. Too careful I guess. Wow, that's awfully generous of you to check that resistor for me. Man you must be getting sick of dealing with me at this point
	

	
	
		
		

		
			





 I really really appreciate you doing that. Very kind. 
   
  The blue input wire came off while handling the amp board. The wires are (well, were) already soldered to the input board and the stress to that joint from me trying to figure our what was wrong cause it to come loose. It's ok though, I'll reattach it once I get this resistor problem solved. It was soldered and working fine when I powered up the amp to test it.
   
  The colors were just to help me keep the wires in order. I only have white wire so I color coded them on each end with electrical tape to make sure they were installed correctly (they do line up horizontally, as you mentioned.) I did check continuity, they all checked out fine. Colors are doubled up because I attached them in two groups of three. I actually did braid the wires there (see photo) but space was tight on the amp side to I un-did some of the braiding to make it easier to set the wires into place. Looks a bit funny, I know. I may re-do that side before putting everything back together. We'll see. 
   
  Thanks again, man. You are awesome.


----------



## cssarrow

I'll have the value for you by today, still a little busy with some cables.
   
  Just by looking at your wiring, red > yellow > blue + repeat seems pretty darn correct to me.
   
  Only problem seems to be that the one specific resistor came off, which is preventing sound.
  Let me know once you've cleaned that trouble area, it looks like a mess.
   
  What i did with the braid, was do a 3 conductor round braid first, then heat shrinked the ends with some 1/8".
  After that, i soldered it onto the boards while doing some continuity checks.
   
  Check the wire that connects to the LED light and volume knob.
  Make sure no wires are ripped off.
  If it did, fix it and hot glue it.
  If it didn't, hot glue it.
   
  The reason for this, is when you're testing it, pulling that cable in and out for testing will put strain on the wires and cause them to rip.
  The hot glue will be the strain support.
   
*Tim*


----------



## Scallywag

The volume/LED cable is intact and I put some hot glue on there. 
   
  I cleaned up the resistor area with some isopropal and it's now nice and clean. Well, not nice but very clean. It does look a whole lot better than it did in the photo I posted. Should be workable. 
   
  Thank you for checking that resistor. It's a pain to take out your amp board, certainly, so there is no big hurry. I'll have to buy one of your cables to repay you!! I dig your website. Is the business up and running?? I'm serious about checking out your cables.
   
  OK, one quick question... in one of photos of your right crossover, what's the purpose of the wires you soldered on the bottom of the board?? See red lines in the photo below.


----------



## cssarrow

Quote: 





scallywag said:


> The volume/LED cable is intact and I put some hot glue on there.
> 
> I cleaned up the resistor area with some isopropal and it's now nice and clean. Well, not nice but very clean. It does look a whole lot better than it did in the photo I posted. Should be workable.
> 
> ...


 
  Haha, good job gluing the volume knob wires down!
  Hope that wasn't too hard for ya.
   
  Nice and clean will surely make the job more workable.
   
  I'll have the resistance value for you by today along with a link to purchase it online.
  Shouldn't be over $2 for 100 pieces.
   
  I have my speakers mounted to the wall, so i'll have to take down the left one and open the back, shouldn't be a problem.
   
  You might want to get one of these Pinpoint AM-40 wall mounts.
  Having it angled and pointed at your ears improve you so much as an audience.
  It's way better than just having it sitting on a desk and "blowing" music by you, right past the torso.
   

   
  Business is ok, all HTML coding (for the website) was left on a hard drive that then.. err.. kind of died.. so i now have to start from scratch.
  If you're ever need a cable (any kind), do let me know.
   
  To address your question.
  I'm a cable guy, I believe a lot about conductance and impurities (from metals that don't conduct so well).
  The left side speaker crossover is connected by wires, being wires, you can choose the quality.
  It isn't the same for the right as it's connected to the tin plating, that's why i kind of ditched that and went with a straight wire.
  The higher conductance of that wire, should make that pathway more accessible (for signal) than the tin plate with the mounting screw.
   
  I simply soldered a silver plated copper wire to that copper ring, then soldered it onto the brass outpost.
  You might not want to try it, since the solder won't stick to the brass, unless you use like insanely high temperatures.
  It ended up melting the plastic that held it a bit, but didn't really bother me.
  As long as the wire touches or wraps around outpost, then you should be good.
  I say just solder the wire to the copper rings, (but leave a good length) then wrap it around each post (on appropriate size).
   
  I noticed you copied my idea to dampen the crossover pcb, how cute haha.
  Did you source your parts from Parts Connexion? I see the M-Resist.
  When i tried to buy it there, they only had one in stock, so i had to go to Madisound for mine.
   
*Tim*


----------



## Scallywag

I've considered using wall mounts, I'm still considering it. But that would require running all the relevant cables behind the wall in my den. I'm a bit OCD when it comes to equipment and wiring looking clean. Cords and cables hanging all over drives me nuts and my girlfriend doesn't like it, so I'd have to hide everything. It's just drywall so it's not difficult but I'll have to make sure my cables and power cords are long enough to accommodate. Little things like that make my relatively small Manhattan apartment feel much bigger and that's important to me.
   
  Right now my A5's sit atop some grungebuster pads I bought from Herbies Audio Lab to aid in vibration control and decoupling (nice products.) They really made an improvement to the sound, took some of that bass out from the dresser that the speakers sit on. The speakers are about 6' apart, 6'- 7' from the listening position and are at the same height as my head. Unfortunately it's not a solid wood dresser and there is a fair amount of resonance going on in there, easily heard when I put my ear up against it. It does bug me a bit. I understand wall mounting tightens things up so perhaps I'll do it. My A5s are about 6" from the back wall. I found that any less of a distance results in muddier bass with those rear-firing ports, in my room anyways. Again it's a small room so certain bass frequencies can quickly get out of control (hence my previous mid-bass comment.) I wonder if you don't have that problem even with your speakers being so close to the wall they're mounted on? 
   
  My big conundrum is what to do about the subwoofer. It sits in a corner about 2 ft off the ground and 6" from each wall. The bass just goes straight to the wall and floor- an issue sometimes for my downstairs neighbors. I understand the cause of this phenomenon, such is the nature of bass frequencies, but aside from proper acoustic treatments to the room I'm not sure how to remedy the issue. But...that's a problem for another day. 
   
  Yes, I sourced my parts from Mouser and Parts Connexion. I figured dampening as much as possible couldn't hurt and I have lots of foam. So why not?


----------



## cssarrow

All my wires are extremely the "exact" length, so it's not going all over the place.
  That's pretty insane that you need to put it through the wall, never heard that one before.
   
  Pads?
  Haha.
  You know the acoustic foam that you're using to dampen the speakers?
  Well, when i had the speakers on my desk, i would put lay a 2mm silicone piece (cut for desired size) then a 1/2" acoustic foam over.
  The speakers of course, goes on top of the foam.
  Helps stop that wood desk coloration bass you were talking about.
   
  I put a 2mm silicone piece before mounting the metal plate to the wall.
  Screws are all fastened to the 2x4's behind the wall, not to drywall.
  I also put a 2mm silicone piece and foam underneath the speakers before equipping it onto the mount.
  Gets rid of the vibrations that would ultimately end up going into the drywall, wood support, etc.
   
  You're using the S8 right?
  It should have those pointy speaker feets.
  Try putting something soft underneath the feets to dampen it, so it doesn't move the floor.
  That's what i did to mine, but of course, i remove it when i watch Action movies, as i like to have the room shake.
   
*Tim*


----------



## Scallywag

I don't need to, I choose to. i'm not that crazy!! Plus it makes my woman happy (we live together.) It's easy to do with the hollow wall that my TV hangs on. 
  I used to use foam but, with it being so soft, the weight of the cables attached left speaker, along with the heat sink, would cause it to lean back so that driver was pointing above my head while the other one was level. The grungebuster feet work well and they keep that left speaker seated. Honestly I was surprised at how well they absorb vibrations. Even with that the bass is getting into the dresser so I may do the wall mount.
   
  Your wiring is indeed clean. I wasn't implying that it's a mess. Apologies if it sounded that way.


----------



## cssarrow

Oh no man, i wasn't trying to sound mean or anything, didnt even know i made my words like that actually.
  Pinpoint AM-40 wall mounts has clamps, so regardless of cable weight, it will stay there.
   
  To give you an update,
  The resistor code value is 751.
  Which is of 751Ω resistance (R49 on PCB).
   
  I went ahead and measured it anyways using multi-meter set as 2K, which measured .748 = 748Ω.
  So basically you need a replacement 750Ω resistor in either size 0603 or 0805.
  From the looks of it, i would say go with 0805.
  Even if 0603 ends up being too small, as long as you solder it to each end, you're good to go.
http://www.ebay.com/itm/100x-SMD-Chip-Surface-Mount-0805-Resistor-750-ohm-751-/120823591947?pt=LH_DefaultDomain_0&hash=item1c21a5b40b
http://www.ebay.com/itm/100x-SMD-Chip-Surface-Mount-0603-Resistor-750-ohm-751-/120823582356?pt=LH_DefaultDomain_0&hash=item1c21a58e94
   
  While taking out my board, i was able to restock my thermal paste behind the amplifier chips with some Prolimatech PK-3 Nano Aluminum.
  It's one of the top performing thermal paste as of 2013.
  I'm a computer nerd, so i know a lot of stuff when it comes to thermal conductivity.
   
  If you don't like waiting for the item to ship all the way from Macau, what you can do is just go buy a 750Ω Axial Resistor instead of the SMD.
  Just solder each end to where it's suppose to go and you're good.
  Try and keep it +-1% or +-5% Tolerance rating.
  I don't know too much about the wattage rating, but it shouldn't matter much.
   
*Tim*


----------



## Scallywag

Ah, thanks so much. I don't know how I got such an errant reading but I'm glad that you confirmed the value for me. I'm going to order some from mouser and just be done with it. 
   
  Also decided to try the wall mounts. I can also reclaim some surface area on my dresser by mounting the speakers so that's a plus. 
   
  You really helped me with all this and I appreciate it. I'll let you know how everything works out when I'm finished with this project.
   
  Until then take care!


----------



## cssarrow

My Audioengine A5+ modded edition is going for sale.
   
  If anyone is interested, PM me.
   
*Tim*


----------



## Scallywag

Been a while... so finally, after a lengthy shipping ordeal, I received the resistors in the mail. I installed it carefully, tested it and reassembled the amp to see if my problem was solved... but still no good sound. However, this time I could hear music coming through but only with the volume cranked to max and even then it's extremely quiet. I can only hear it when my ear is pressed against the tweeter. I mean whisper quiet. I went back and started checking over everything. In the process I lost a solder pad on the C4 Bipolar. Managed to repair it by pulling up the trace and installing a small jumper wire. I'm not thrilled about the longer unshielded lead but I have no choice.
   
  Anyways, I'm not sure what to do now. All the caps are installed properly. No solder bridges anywhere, no metal parts touching, etc. The volume wire is OK. I'm apprehensive to keep tinkering blindly because each time I do I end up losing another solder pad or something and the board becomes even more shredded.  
   
  The signal is getting through... I can hear music, barely, but it's not being amplified or something. Any ideas?? I've exhausted my limited knowledge in this area and the hope that I'll be able to get my speakers working again is fleeting.  
   
  Help me Obi-Wan...


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## Scallywag

Not sure who's listening, but... progress!! I'm getting clean amplified music. I had to re-do all of my clumsy work on the board but it worked. However the right channel is louder than the left... significantly so. I swapped the drivers and crossovers and I reversed all the external cabling. Got the same result so the problem is with the amp itself and not those external parts. Man... after all this work I was really excited to be done. Alas, work remains. 
   
  So, can anyone out there point in the right direction to troubleshoot this thing?? I have a sneaking suspicion that it's the left amp IC causing the issue. This is based on nothing concrete, as I have no experience here. The last few pages of this thread may shine some light on the issue to those who know better. 
   
  What can cause one channel of this amp to be louder than the other??? There is no internal or external balance pot. I've triple-checked all my wiring, mods, etc. Both sides of the amp are identical, far as I can tell, in terms of components and design. Should I test both amp IC's (TDA7294V) and compare readings?? If so, how would I do this with a multimeter??
   
Any help is appreciated. I WILL get this thing working properly once again!!!


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## Scallywag

Problem solved!!! The amp is working as it should and I'm now almost done reassembling the enclosures. This has been quite the learning experience...
   
  Once I'm completely finished and the speakers are up on my wall I'll perform due diligence and post my impressions. From what I've already heard during testing with an iPhone I can say that the various mods have culminated in a not-so-subtle improvement in SQ.
   
  Tim, if you're out there, thank you again for your guidance and patience.  
   
  More to come.


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## Scallywag

After a couple of weeks burning in the new components and listening to the upgraded A5+'s I figured it's time to offer some impressions and post a brief recap. So, here goes...
   
  Each of the little mods detailed in Tim's directions was implemented on my A5+'s (minus the pure aesthetic changes he made.) Having owned them for some time before beginning this project I was very familiar with the stock sound from the speakers. While I always though they sounded nice to begin with, the various mods have culminated in a rather shocking change to the sonic character of my modest little system. They sound quite different... in a very good way. A few bullets:
   

 Tim wasn't exaggerating about the improved bass response. The speakers are certainly moving more air now and it is impressive to experience. The dampening has successfully tempered the previously bloated mid-bass while the newly-extended low end is now more pronounced, resulting in a more even-sounding bass response. Kick drum thumps are startlingly weighty- a modest source EQ tweak was required. The extension has allowed me to set the crossover on my sub lower, further evening out bass response across my system. 
 The A5+'s are now _far_ more resolved and detailed- imaging is tremendous for speakers of this size. The soundstage extended modestly in all relevant directions, as Tim mentioned, offering a more enveloping character in its presentation. Voices project from somewhere in between the speakers now as opposed to simply coming from both the left and right simultaniously. I find my dog looking all over the place for sounds now when I'm listening to music with him at my side... before he would be looking at one of the two speakers only (he has good ears, right??
 The mids are a tad stronger now. Certainly clearer. I also experienced a slight extension in the highs along with the increased clarity/resolution. The highs also smoothed out nicely. A once-occasionally present edginess in the upper registers has disappeared. 
 As Tim mentioned, the noise floor is now noticeably lower resulting in a better sense of dynamic.
   
  These mods have improved the sound quality of my system rather dramatically- more than I was expecting, honestly. The project was certainly an adventure for me (as my previous posts will attest to.) I admittedly was a tad green when I started. At one point I screwed up and thought I'd ruined my speakers. With Tim's help I realized that nearly anything can be fixed when it comes to circuitry. In the process of fixing my mistakes I learned to bypass damaged traces, run jumper wires, troubleshoot with a multimeter, decipher signal paths, etc.- all useful skills that will serve me well as I undoubtedly take on more projects in the future.
   
  To conclude, I recommend these mods to anyone who may be considering them. It's a time consuming project but you won't be disappointed in the outcome. My A5+'s are very different and much more impressive sounding speakers then they once were. I am very happy with the results. Audioengine could charge a healthy amount of money for these! 
   
  -Matt
   
  P.S. Hats off to the OP, who's direction and patience guided me through this project. Tim, if you're out there reading this, thanks a million.
   
  P.P.S. A few weeks after completing the A5+ mods I purchased and installed the "uber" analog board upgrade for my Schiit Bifrost DAC. I won't go into detail here but I will say that it is a fantastic change. It took an already nice sounding DAC and vaulted it up to a new level of detail and resolve (along with eliminating the last remnants of boomy low end I would occasionally hear.) I was happy to know that my modded speakers would be able to faithfully convey the improved sonics provided by the upgraded analog stage in the DAC, which they did in spades. Should anyone be wondering, they pair very well.


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## Daisho

Anyone know if there would be any benefit in replacing the two 4700uf capacitors with higher capacitance models?  The 35v 10000uf Nichicon KG caps are 30mm in diameter and have 10mm lead spacing, so they should fit at least physically.


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## Eclipse-

how do you position your speakers?


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## wiz2596

I want this mod to mine but I don't know anything about electronics and circuits, what can I do? after watching this mod I feel very jealous


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## canali

just picked up a used pair in great shape for us190...I like
  that they have no
 dac...i can experiment with my own


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## maiieu (Nov 4, 2017)

...


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## mzanlorenzi

I'm considering modding my A5+ because I find them to "boomy". If I'm not wrong, to solve the boomy issue, just dampening the enclosure will suffice? 
I don't have great skills when it comes to soldering and specially desoldering components, so I want to do first the dampening stage and if that doesn't improve bass quality I'll move foward to the other mods.


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