[sydneyaudio]

I have changed the opamps in my Lite Dac to HDAMs with a great improvement in sound quality. Occasionaly I am still bothered by the graininess common to these DACs. I have heard that replacing the electrolytic caps can eliminate the graininess. Can somone point out to me which caps I should change, and what caps I should replace them with.
Thanks in advance!

 

[TheMarsVolta]

Some great discussion on capacitor upgrades here:

http://www5.head-fi.org/forums/showthread.php?t=166545

 

[sydneyaudio]

Quote:

Originally Posted by TheMarsVolta Some great discussion on capacitor upgrades here: http://www5.head-fi.org/forums/showthread.php?t=166545

Thanks, a great thread!
Not looking to do the passive output mod at this stage.
I think its C35 and C36 I need to change. The current caps are 22uM/40V. Still not sure what I should change them to??

 

[TheMarsVolta]

Quote:

Originally Posted by sydneyaudio Thanks, a great thread! Not looking to do the passive output mod at this stage. I think its C35 and C36 I need to change. The current caps are 22uM/40V. Still not sure what I should change them to??

Ok, I found this pic in another thread:
The guy substituted a polypropylene film cap in the same spot as the stock caps.

 

[lan]

Opening this unit up is annoying. I recommend just changing everything at once

 

[sydneyaudio]

Ok, I found this pic in another thread:
The guy substituted a polypropylene film cap in the same spot as the stock caps.

Looks nice. Will see if I can find something similar.
Is 1.0uF the best option?
Iam still trying to understand the different types of caps.


Opening this unit up is annoying. I recommend just changing everything at once

R U suggesting I just move on, spend more money, and try another DAC?

 

[izquierdaste]

I saw that picture on audio asylum. If I remember correctly that is the modded dac-ah from diykits, I think it goes for $235 + shipping. I thought the 1uf caps mundorf silver in oil were stacked with another cap as well. However, I honestly don't know much about modding myself. As for other mods, it seems like some will recommend changing just about everything in the dac. NOt that it is a bad thing, but tough for a beginner like me.

Quote:

Originally Posted by TheMarsVolta Ok, I found this pic in another thread: The guy substituted a polypropylene film cap in the same spot as the stock caps.

 

[regal]

I am also NOT going with the passive mod, less bass is just bad if you ask me. I am going to put in 7uF paper and oil caps on the output. What is the input impedence of your amp? That determines how big your caps should be

 

[dsavitsk]

Quote:

Originally Posted by regal I am also NOT going with the passive mod, less bass is just bad if you ask me. I am going to put in 7uF paper and oil caps on the output. What is the input impedence of your amp? That determines how big your caps should be

This DAC has a passive I/V and then opamps to lower the output impedence (they provide a tiny bit of gain, but not much.) This is different from the normal DAC setup where there are opamps for the I/V. When you do the "passive mod", all you are really doing is removing the extra piece (the opamps) from the chain.

The TDA1543 generally has a highish output impedence, but in this case since there are 8 in parallel, the output impedence is around 270R. The opamps lower this to the single digits and perhaps help drive long cables, but really don't do much for you, and arguably detract from the sound. You should not get less bass without them. If anything, you should get more.

As for the caps, 7uF is way larger than you need. This (http://www.ecp.cc/cap-notes.html) will help you figure out what size caps you might want. And I wouldn't use multicaps for coupling. The are much better for decoupling purposes.

 

[regal]

7uF is just the size I can get surplus p-i-o caps for cheap. Smaller would work but how small depend on your amp.

 

[lan]

Quote:

Originally Posted by sydneyaudio R U suggesting I just move on, spend more money, and try another DAC?

No I'm just saying, doing only part of what can be done doesn't make sense. You'll always wonder if you can do more and opening it for further rounds is sucha chore.

 

[sydneyaudio]

Came across these: Elna Silmic 4.7uf 50v. Would they be an improvement?

 

[quicksilver96]

Silmic IIs are the top of the line Elna caps and are really reasonably priced. They are most definitely better than what is in there stock. I personally like the sound of the Nichicon ES series for something in that price range. Of course you can always spend more for Blackgates, PIOs, or Film and Foil. Most of these are much bigger than Al e-lytics in the capacitance you need. 4.7 uf should be plenty good for an amp with 10k input impedance. If you want to check other values the formula for the high pass filter you end up making is: f=1/(2piRC) Where C is capacitance and R is input impedance.

 

[t52]

add one more piece of info to that formula to make it more "useable":
you'll want f to be about one fifth of the lowest used frequency to avoid phase distortion to be to heavy, an example says more than a thousand words:

lowest used frequency: 20hz -> f = 20hz/5 = 4hz

given an amp input impedance of 10k that makes:
C = 1 / (2 * pi * R * f) = 1 / (2 * 3.14 * 10000ohms * 4hz) = 4uF