# EMU 0404 USB Modding FINISHED!



## foreverzer0

I want to mod the 0404 USB like they have been doing for x-fi's and the PCI EMU boards for years. There's pictures in the computer source thread of the internals. I have 12 ad8599's coming as samples from Analog Devices as I'm in university still. From the look of it, this thing has 11 opamps, not sure if I need to even replace all of them but I'm getting 12 just to be safe. I also want to replace capacitors, this is where I need the most help. I'm not sure which ones to replace, and if all of them (I think theres about 16 of them), I'm not quite sure which types to use (same specs or higher?) and whether to use different ones for the power stage (not quite sure how to identify which caps are for audio or power at this point, either).

 So far, I've found a fairly easy mod that I did today that noticeable improves the sound, it's smoother and dare I say a bit more fast and dynamic and even removes most of my background noise. I replaced the wall wart power supply with a linear regulated, higher power one:

Jameco Electronics Power Supplies & Wall Adapters: VARIOUS : DV51AAT

 the plug needs to be replaced with another size though (1.7mm ID x 4mm OD):

DC Conn 1.7mm X 4.0mm R/A power cord - Ace Electronics

 Thanks for all your help!


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## foreverzer0

BUMP!


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## senns&nonsense

Bump to see if anyone else has done this and had similar results....

 Any other specific ideas about alternate power (preferably right off the shelf and not involving soldering?)


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## foreverzer0

DONE:

 -Replaced PSU with linear regulated version [stated from 1st post]

 -Op-amp rolled 3x AD8599's for headphone and line-out stage, I accidentally ripped out a few legs so I bypassed them with solid silver wire outfitted with teflon tubing

 -Replaced analog capacitors with Blackgate FK Series (2x 22uF/16V) for headphone and C series (5x 47uF/50V + 2x 10uF/50V) for line-out

 -Replaced power capacitor with large FK series 220uF/100V

 the caps were so large it had to be put it in like so (looks like a bouquet of capacitors; nerd romance lol), but it still sounds awesome:


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## d-cee

my goodness i'm somewhat shocked and amazed at the same time


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## infinitesymphony

Hahah, I like the bouquet. So many questions:

 Does the top fit back on?

 How did you choose the capacitor values (are they direct replacements)?

 What's going on with the jumper wires?

 Do you have a picture of the new power supply?

 Did you do any SQ comparisons along the way, or was it one big upgrade?

 Do you have any pre/post SQ comparisons to share yet?


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## foreverzer0

Quote:


  Originally Posted by *infinitesymphony* /img/forum/go_quote.gif 
_Hahah, I like the bouquet. So many questions:

 Does the top fit back on?

 How did you choose the capacitor values (are they direct replacements)?

 What's going on with the jumper wires?

 Do you have a picture of the new power supply?

 Did you do any SQ comparisons along the way, or was it one big upgrade?

 Do you have any pre/post SQ comparisons to share yet? 
	

	
	
		
		

		
		
	


	


_

 


 lol yeah the top fits back on, with exactly enough room!

 for the large cap I used the largest capacity I could fit from the FK series, the headphones caps (2) were direct replacements, the line-out caps were C series for decoupling and are the same values except the V are much higher (which doesn't harm it in anyway).

 the jumper wires are because I ripped some pads out while trying to remove the old op-amps (they op amp legs so small and hard to cut).

 I did the power supply upgrade first, then everything else at the same time later in one large soldering job. I did use higher uF blackgate FK series on the line-out's at first but it sounded too dark (although very rich) so I opted for the stock values. I no longer hear any noise in the background either, like when nothing is playing there is no sound at all anymore.

 after about 24 hrs of playback, there were a few differences in RMAA graphs but not much as the EMU 0404 USB already had excellent characteristics from stock, however the sound is quite the improvement!! the head-phone out sounds really nice now (instantly notice the improvement) to the point where I find myself using headphones more and more (which also has to do with me liking to hear music at louder volumes which isn't always a good idea with speakers).

 You can definitely hear the characteristics described for the AD8599, as in it brings the sound forward, including those subtle sounds with great detail; definitely smoother and warmer than the stock nj2068's. How much warmth I couldn't tell you as I put the blackgates in at the same time.

 As for a picture of the power supply, it's not that appealing, it's just looks like a shrink wrapped connection of the two cables, the rest is identical to the pictures from the websites I linked on the first post:






 Oh, and btw, what is listening fatigue?


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## amb

If anyone is interested in the RMAA loopback test results of the E-MU 0404 USB, M-Audio Firewire Audiophile and M-Audio Transit USB sound interfaces (and a few headphone amps and other devices), you can find them here:

RMAA Results

 The sound cards are all in stock, unmodified condition. The E-MU 0404 USB does indeed measure very, very well, with the exception of its headphone output. It's fine with high-impedance loads, but suffers significantly when faced with a low-Z load. Its output level dropped 0.7dB going from unloaded to 330Ω load, and drops 5.5dB more when loaded with 33Ω. The RMAA graphs don't show this because they are "normalized", but you do see a significant increase of THD, IMD and stereo crosstalk. This is indicative of high output impedance and lack of adequate current drive capability.


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## infinitesymphony

Listening fatigue happens when you listen to music for too long. Basically, when your ears start to get sore and stuff starts to sound the same. Sound signatures that emphasize treble brightness tend to cause fatigue faster than others.

 amb, what's your opinion of the 0404 USB's SQ and design?


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## foreverzer0

Quote:


  Originally Posted by *infinitesymphony* /img/forum/go_quote.gif 
_Listening fatigue happens when you listen to music for too long. Basically, when your ears start to get sore and stuff starts to sound the same. Sound signatures that emphasize treble brightness tend to cause fatigue faster than others.

 amb, what's your opinion of the 0404 USB's SQ and design?_

 

LOOOL yeah I know, I was just being sarcastic because I don't recall getting it anymore


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## infinitesymphony

Gooootcha.


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## amb

Quote:


  Originally Posted by *infinitesymphony* /img/forum/go_quote.gif 
_amb, what's your opinion of the 0404 USB's SQ and design?_

 

My 0404 USB is brand new and I haven't really spent enough time listening to it yet to form an opinion, but it does measure superbly as a DAC, ADC and external sound card. Actually, for its price it's beyond reproach. It is amongst the best measurements I've seen, at least as far as RMAA goes.

 The balanced input/output capability is also very nice (which, is the primary reason why I bought one). The internal headphone amp section is good, but probably no match for a standalone hgh-quality headphone amp. It appears that it doesn't have the "guts" of the better headphone amps in terms of output current and voltage swing. With less demanding headphones it should be just fine, however.

 There is limited mixing/routing capability available, unlike the M-Audio Firewire Audiophile which I also have. However the real knobs and buttons on the unit are a welcome feature, even though it is ultimately limited by them in terms of flexibility. One nice thing is the "Direct Monitor" feature which lets you use it as a standalone preamp/headphone amp without even connecting the USB cable to a computer.

 The S/PDIF input and output requires a ASIO driver in Windows, but E-MU's own driver does not appear to be ASIO (they show up as DirectSound for playback and MME for recording in RMAA and other audio apps, with no ASIO option available), or at least I haven't figured out how to make the S/PDIF work. I have ASIO4ALL installed but it doesn't seem to do anything for the 0404 USB.


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## ephrank

foreverzer0, have you compared the sound quality of using the stock wall wart and the linear regulated? How big is the improvement upgrading the wall wart alone?


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## senns&nonsense

AMB - thanks so much for the technical info that confirms what so many have assumed by listening. I have an additional tech question.....

 Is there a difference in quality/specs between the 2 outputs available on the back assuming the use of the balanced out with unbalanced plugs in a an unbalanced set-up? Is it still preferable to use the plugs or is the mini out just as good?

 Thanks!


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## amb

Quote:


  Originally Posted by *senns&nonsense* /img/forum/go_quote.gif 
_Is there a difference in quality/specs between the 2 outputs available on the back assuming the use of the balanced out with unbalanced plugs in a an unbalanced set-up? Is it still preferable to use the plugs or is the mini out just as good?_

 

I did not test the mini jack output so I don't know if there is a difference. According to the E-MU docs it would seem that the mini jack is just parallel-connected to the 1/4" phone jack outputs (albeit only in unbalanced), so it should be the same as using a pair of TS 1/4" plugs.


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## grenert

Quote:


  Originally Posted by *foreverzer0* /img/forum/go_quote.gif 
_for the large cap I used the largest capacity I could fit from the FK series, the headphones caps (2) were direct replacements, the line-out caps were C series for decoupling and are the same values except the V are much higher (which doesn't harm it in anyway)._

 

Well, I'm glad you like the end result, but I've opened up my own 0404 USB, and what I believe to be the stock headphone caps (the ones closest to the headphone out) are 220uF, not 22uF. 22uF is pretty small for headphone out decoupling, considering the relatively low impedance of most headphones.

 Also, I think those five 47uF capacitors near the line out section serve as local power supply caps (someone who knows more about this stuff than I should probably confirm this). You'd probably do better with larger capacitance, low impedance caps like Panasonic FM/FC or Nichicon UHE/PW, rather than those gigantic Blackgates (although given their higher voltage, they probably have less impedance than the stock caps).

 I completely agree that the stock wall wart is a joke (basically a cell phone charger), and replacement is definitely a great idea.


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## amb

To follow up on my post above, I measured the resistance between the 3.5" mini output jack and the 1/4" TRS output jacks with a DMM, and found unexpected results. The sleeves all have zero ohms across them, so the grounds are all connected together as expected. However, there is 24.8 ohms between the left channel 1/4" jack's tip and the 3.5mm mini jack's tip (I expected it to be zero ohms). The right channel 1/4" jack's tip to the mini jack's ring is 22.8 ohms. So there is some asymmetry.

 What even stranger is that the left channel 1/4" jack's tip to the 3.5mm jack's ring is 21.4 ohms, and the right channel 1/4" jack's tip to the mini jack's tip is 26.1 ohms (I expected both of these to be infinity, because these are across the two channels). I then tested each of the 1/4" jack's tip to sleeve (ground), and got 11.4 ohms and 12.2 ohms, respectively.

 Ah hah. Not having opened up the box to look, I think I understand what might be happening. The 1/4" outputs are probably coupled through an unbalanced-to-balanced conversion transformer and I am measuring the winding resistance. The mini jack output is probably before the transformer. So my resistance readings are a bit bogus because it includes connectivity through ground. But it does show that the two sets of outputs are not exactly the same.

 Here is a diagram of what I think is at the 0404 USB's outputs:






 The measurements show that the transformer winding resistance is around 10-12 ohms per section, which is a really low impedance load for an active stage to drive. It would need to have a fairly stout output current capability and low output impedance.

 If my guess is correct about the presence of the transformers, then for unbalanced output, theoretically the mini jack may actually be better because it skips the transformer. But, my RMAA tests of the 1/4" outputs in unbalanced mode shows excellent results anyway, and it's hard to imagine that the transformer is hurting performance, at least for those metrics that RMAA measures. It would be interesting to do an RMAA loopback run through the mini jack outputs and see what the results look like. I'll do that some time soon.


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## amb

Quote:


  Originally Posted by *grenert* /img/forum/go_quote.gif 
_I completely agree that the stock wall wart is a joke (basically a cell phone charger), and replacement is definitely a great idea._

 

The little wallwart is a 5V switching supply. The digital stuff in the 0404 USB shouldn't be affected by the noise/quality of the power, and I am sure there is internal regulation for the analog stages (or the measured noise performance wouldn't be as good as it is). Nevertheless, it would be interesting to substitute the wallwart with a good, clean linear regulated supply. I had planned to build a σ11 PSU configured to 5V output as an upgrade for my Squeezebox 3 anyway, so this should be an good experiment.


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## Budgie

Anybody have a "tops off" picture?


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## grenert

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_The little wallwart is a 5V switching supply. The digital stuff in the 0404 USB shouldn't be affected by the noise/quality of the power, and I am sure there is internal regulation for the analog stages (or the measured noise performance wouldn't be as good as it is)._

 

You know, based on your testing this makes sense, but I cannot recognize anything in the soundcard that looks like a voltage regulator. This is perhaps not saying much, given my inexperience. However, I definitely don't see anything that looks like voltage regulators I've seen in other equipment. Additionally, there is no capacitor larger than 220uF inside.


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## infinitesymphony

Quote:


  Originally Posted by *Budgie* /img/forum/go_quote.gif 
_Anybody have a "tops off" picture?_

 

Page 1 of this thread, and here.


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## d-cee

Some more here too: E-MU 0404 USB


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## foreverzer0

Quote:


  Originally Posted by *ephrank* /img/forum/go_quote.gif 
_foreverzer0, have you compared the sound quality of using the stock wall wart and the linear regulated? How big is the improvement upgrading the wall wart alone?_

 

I don't know whether it's placebo or not, but to me it was rather subtle but it does seem smoother and faster, if not anything else. It's rather inexpensive and easy to implement anyhow.


  Quote:


  Originally Posted by *grenert* /img/forum/go_quote.gif 
_Well, I'm glad you like the end result, but I've opened up my own 0404 USB, and what I believe to be the stock headphone caps (the ones closest to the headphone out) are 220uF, not 22uF. 22uF is pretty small for headphone out decoupling, considering the relatively low impedance of most headphones.

 Also, I think those five 47uF capacitors near the line out section serve as local power supply caps (someone who knows more about this stuff than I should probably confirm this). You'd probably do better with larger capacitance, low impedance caps like Panasonic FM/FC or Nichicon UHE/PW, rather than those gigantic Blackgates (although given their higher voltage, they probably have less impedance than the stock caps).

 I completely agree that the stock wall wart is a joke (basically a cell phone charger), and replacement is definitely a great idea._

 

Sorry, I believe that was a typo if I said 22uF, the ones I have installed are direct replacement values so 220uF is right. If they were 22uF, those would be some rather huge 22uF caps!


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## foreverzer0

Double post, please delete. My apologies.


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## amb

I ran RMAA loopback test of the 3.5mm mini jack output and added it to my RMAA results web page. It basically measured similarly to the main 1/4" phone jack outputs in unbalanced mode, except that the distortions are _slightly_ higher, but the big loser is stereo crosstalk. I don't know why, but it might have something to do with the less robust 3.5mm connections.

 Btw the internal photos don't seem to show any transformers, so my theory posted previously might be wrong. If I get a chance sometime in the future I'll open it up to have a good look.


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## foreverzer0

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I ran RMAA loopback test of the 3.5mm mini jack output and added it to my RMAA results web page. It basically measured similarly to the main 1/4" phone jack outputs in unbalanced mode, except that the distortions are slightly higher, but the big loser is stereo crosstalk. I don't know why, but it might have something to do with the less robust 3.5mm connections.

 Btw the internal photos don't seem to show any transformers, so my theory posted previously might be wrong. If I get a chance sometime in the future I'll open it up to have a good look._

 

They don't have transformers, but I hear they have multiplier circuits in the design, I don't know if that has anything to do it with it or not...


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## PDOT

I modded my E-MU0404Usb-LM4562MA-line out, LM4562MA+AD8066AR-headphones out. All the caps are Black Gates. The sound card sounds much more interesting: rich, detailed, not so sharp as it was. Bass response became much better. Thanks to foreverzer0.


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## foreverzer0

Quote:


  Originally Posted by *PDOT* /img/forum/go_quote.gif 
_I modded my E-MU0404Usb-LM4562MA-line out, LM4562MA+AD8066AR-headphones out. All the caps are Black Gates. The sound card sounds much more interesting: rich, detailed, not so sharp as it was. Bass response became much better._

 

I was wondering which types and specification black gates did you use? and how did you use two different opamps for the headphones?


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## foreverzer0

Quote:


  Originally Posted by *grenert* /img/forum/go_quote.gif 
_Well, I'm glad you like the end result, but I've opened up my own 0404 USB, and what I believe to be the stock headphone caps (the ones closest to the headphone out) are 220uF, not 22uF. 22uF is pretty small for headphone out decoupling, considering the relatively low impedance of most headphones.

 Also, I think those five 47uF capacitors near the line out section serve as local power supply caps (someone who knows more about this stuff than I should probably confirm this). You'd probably do better with larger capacitance, low impedance caps like Panasonic FM/FC or Nichicon UHE/PW, rather than those gigantic Blackgates (although given their higher voltage, they probably have less impedance than the stock caps).

 I completely agree that the stock wall wart is a joke (basically a cell phone charger), and replacement is definitely a great idea._

 

What capacitance are we talking about? I tried using 100uf types for those but they made it rather dark sounding... Are those Panny's or Nichicon's better spec'd than black gates?


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## PDOT

*foreverzer0*,
 I use STD and PK series.
 STD 16V 10uf
 STD 50V 220uf (as a power cap and headphones out)
 PK 25V 47uf


 2*LM4562+ad8066 just a good variant.


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## PDOT




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## henrylar

I am going do mod my 0404 usb. I am not using the headphone output, so I would not be modding that. Having read this thread I am considering to change the two lineout opamps to lm4562, the five 47uf, the two 10uf and the one 220uf power cap, using black gate caps for all.

 Any comments or suggestions to that?


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## henrylar

I now realize that black gates is not to achieve any more.

 Which caps would be recommended then?


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## espressogeek

"I now realize that black gates is not to achieve any more."

 Are you saying they are not being made anymore? Cerafines are supposed to sound really similar and they are available , no? Muze KZ caps (I think that is the name) are supposed to be good to.

 How long can you make those leads on the caps before they become antennas for noise?

 Cheers


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## henrylar

Thank you for this inf. Black gates are not produced any more, and I have been told that there is a lot of fakes out there. I did a research and found the Black gates I need from a supplier I think I can trust.

 To the second part of your Q. Does any of you who has done these mods have any exp. about drawbacks with the longer leads/ or other drawbacks that would be worth knowing ( of course we all like to present the positive results


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## manaox2

Once a year, Blackgates "stop" being made anymore. Its getting tired. I sincerely doubt its true this time either.


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## henrylar

Pls help: I have run into a problem with my modding. I have changed the two line out opamps (U16 and U22) to lm4562ma. One channel works fine, the other gives a signal, but with low gain. I have checked that there are 12V between leg 4 and 8 on both, so it is not that easy. Can anybody help with a diagram or on other ways give me a clue about how I can find the fault?


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## vagii

has anyone tried LT1364 as headphone opamp?


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## KevM2

Interesting thread. I'll have to look into modding mine some time.


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## luvdunhill

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_My 0404 USB is brand new and I haven't really spent enough time listening to it yet to form an opinion, but it does measure superbly as a DAC, ADC and external sound card. Actually, for its price it's beyond reproach. It is amongst the best measurements I've seen, at least as far as RMAA goes.

 The balanced input/output capability is also very nice (which, is the primary reason why I bought one)._

 

Ti:

 Have you a preference between the M-Audio Firewire and the 0404 USB these days? I notice most your measurements are with the M-Audio Firewire, but the 0404 seems to measure slightly better in many of your tests.


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## amb

luvdunhill, I primarily use these as RMAA test instruments. I use the M-Audio Firewire Audiophile more because it's what a lot of my tests were done on, so it makes sense to use the same instrument for consistency. I use the 0404 USB when I need the balanced input/output capability.


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## amb

BTW, I am on my 3rd 0404 USB. The first two died mysteriously with similar symptoms -- one day it was working fine, the next day it would be dead as a doornail. I am wondering if there is a intrinsic problem with the design. Fortunately both times it was replaced under warranty, now I have one of the white ones 
	

	
	
		
		

		
		
	


	




.


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## mfaughn

resurrecting this thread because I modded mine and it has problems. maybe somewhat can offer help/suggestions/opinions...or a round thump on the ear for buggering up my gear.

 I recapped with silmics (the 47uf and 10uf caps), cerafines (220uf for phones out) and muse for PS cap. I now have uneven output between right and left channels on both the headphones and line-out. Can anyone explain that?

 At the moment I'm going balanced from the 0404 directly into my amp (Ashly FET-500). The amp has attenuators for each channel so I can fix it there but the headphone out is a bust as would be using it with any of my other amps.

 Thanks,
 Michael


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## mfaughn

...and I screwed up some more. lifted a pad while swapping in a new opamp. Now I don't know where to jumper the pin to. Anyone got a schematic?...probably not. 

 So, even if you read this a year or two after I posted it and you can help out please do so because this will just be hanging around on the shelf until then.

 Also, if you think you might be able to fix it yourself and either might be interested in buying it cheap or getting paid to fix it for me I'd be interested.

 -Michael


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## diditmyself

Quote:


  Originally Posted by *mfaughn* /img/forum/go_quote.gif 
_...and I screwed up some more. lifted a pad while swapping in a new opamp. Now I don't know where to jumper the pin to. Anyone got a schematic?...probably not. 

 So, even if you read this a year or two after I posted it and you can help out please do so because this will just be hanging around on the shelf until then.

 Also, if you think you might be able to fix it yourself and either might be interested in buying it cheap or getting paid to fix it for me I'd be interested.

 -Michael_

 

I have a fried E-mu 0404 pci lying here. If you take a picture of your destroyed pin, maybe I can help you measure where it goes.


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## mfaughn

Quote:


  Originally Posted by *diditmyself* /img/forum/go_quote.gif 
_I have a fried E-mu 0404 pci lying here. If you take a picture of your destroyed pin, maybe I can help you measure where it goes._

 

Thanks very much. I don't know if the USB and PCI version are very similar but its worth a shot. Post #4 in this thread shows what we would need to see. My problem is (at least) on U22, which is the same one that the OP has jumpers on. I know that I at least totally mangled the pad for pin 8 (V+), which is closest to the cluster of caps and on the right hand side in the picture. I've tried just jumpering from the same pin on U16 thinking that all I needed to do what get voltage to the thing from somewhere. No dice. I might have buggered something else up as well. Don't know. I'd really like to have a second (working) on to go from so I could at least trace what ought to be connected where.

 -Michael


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## diditmyself

Sorry, I didn't notice it was about the USB version. They are completely different circuits. I hope there's someone who can help you.


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## elingeniero

Maybe this can help: http://www.a-chau.net/gallery2/v/mambo-articles/0404USB/


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## mfaughn

Aha...there is new interest in modding this thing.
   
  See here and here and here!!


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## hallom

Hey Guys,
   
  I bought an E-MU 0404 usb, and I want to mod it, but, I I'm not an electrician kinda person, let's say total lame, don't have the knowledge for it. So, is there anyone, who would do that for me for some bucks? I live in London by the way.
   
  Thanks in advance,
   
  Zoltan
   
  neoyoli at gmail dot com


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