[choariwap]

hi diy guys

i've got an m-audio audiophile usb and am using it as my dac while i scrape some money together.

anyway, i've read a lot of mods to dacs in here and was wondering if any of those mods can be done to this thing (ie bypass output caps and opamps etc)

i think it would be good to take the volume pot out of the signal path as well as any caps. my head amp has input caps to take care of any dc offset and it has a volume control of its own.

i've taken a pic of the output jack area:


i've also taken a pic of the whole thing:

so you guys see anything to mod here?

thanks!

 

[ironbut]

I've had this on my desktop forever but still haven't done any yet. Do a search there and you'll get tons of other stuff ( wall wart replacement is supposed to be good ) so here it is;hat worked well and here they are:

1. The mroe subtle stuff, these will help the subsequence ones bylowering noise floor but are themselves mild in terms of improvements. All except the 1st one are to be done on the back of the PCB
- ferrite beads in power supply line
- take out the
- ceremic capacitors to AC input, output of all 3 voltage regulators

2. This is the big single jackpot.
- get really good caps (cross over quality MKP, etc) for the +5v output of the regulator (so that the digital part and DAC part gets a more responsive power. I used 2 X 10uf tantalum + around 0.4 worth of MKT caps. You may get better results by putting in say a few uf of MKP of 400V or so.

At this stage the high opens up and the lows are more understandable.

3. Add low ESR caps to the 15 volt regulator outputs. This cures the lower spectrum of the sound stage and stability. Be warned that the 78 and 79 series has DIFFERENT pin assignments !! Use your multimeter to reconfirm.

4. I don't want to change the SMT chips. The 7 5532 are a bit of an eyesore but so far it is good enough.

5. If you use the headphone (or other 1/4 inch plugs), beware that if the unit falls down with the plug, the socket breaks easily because it is very flimsy. Use a black document clip that comes with removeable crome wire handles to envelope the socket and then remove the wires to mechanically strengthen it. This can also fix a cracked socket (needless to say I've broken mine !)

6. A blob of blutak on the quartze is the finishing touch
Let us know if you have any luck with any of these that you try.

 

[choariwap]

thanks

I'm interested in doing the following:

2. This is the big single jackpot.
- get really good caps (cross over quality MKP, etc) for the +5v output of the regulator (so that the digital part and DAC part gets a more responsive power. I used 2 X 10uf tantalum + around 0.4 worth of MKT caps. You may get better results by putting in say a few uf of MKP of 400V or so.

- Where is this on the PCB? do i run the MKT and MKP in parallel? if it's MKP @ 10uF, that would be too big for the case right?


3. Add low ESR caps to the 15 volt regulator outputs. This cures the lower spectrum of the sound stage and stability. Be warned that the 78 and 79 series has DIFFERENT pin assignments !! Use your multimeter to reconfirm.

- Where is this on the PCB? do you mean here the larger caps? what value to use and type?

part of me just says damn it all and just get a dac1

but i want to practice some more soldering

Thanks again!

 

[ironbut]

You're probably right. Getting a good DAC and using the audiophile usb as a usb to spdif seems to be the best idea. Used in this way, it sounds like there are only a couple of mods that really are worth the time and money. I've used mine for about 4 years and feel like I've outgrown it and considering how cheap it was and the MIDI functionality that I've been able to use a few times, I'm glad to have it. But, if you do a search over at the Audio Asylum on the digital/pc forum for audiophile usb, you'll get tons of info and the post that I quoted above is pretty close to the top of the results you'll get.There is an attachment for the above "original post" and discussion of the opinions of other posters about the worth of these mods. Hope this helps but personally, I'm on the lookout for a cheap used DAC-1 to mod.

 

[granodemostasa]

Hello.
i'm currently using this unit as my transport. are any of these modds capable of improving the digital out?
Thanks

 

[ironbut]

Like I said, I haven't tried any of these myself but check out audio asylum's digital/pc forum. You'll find lots of info from folks that have modded the usb.

 

[choariwap]

alright... i caved

best mod to an audiophile usb is.... get a dac1. hahaha!

just got one and improved the highs and details... very cool.

interestingly RMAA measured excellent in all for the audiophile usb but only very goods and good for the dac1... whatever, sounds good to me

 

[Francis_Vaughan]

Overall I quite like my Audiophile USB.

There is one almost unbeatable advantage that this particular unit can potentially be used for in a high end setting. The TUSB3200 supports Isochronous in Asynchronous mode USB audio protocol. If you set the controls to accept S/PDIF input on the unit it will sync the S/PDIF output to the input clock. No matter what the output is sourced from. (Note that if you enable the input with no digital input stream the unit simply stops - which is really what you should expect.)

Thus if you have a DAC with a high stability internal clock, in principle you can create a perfect USB source for that DAC with one of these little devices.

 

[Spasticteapot]

Looking at some pictures, it seems the whole thing is stuffed with 5532s.

I'll see about adding some caps to various places - goodness knows I've got quite a few. That said, with the compact circuit boards, wiring could be...interesting.