[izquierdaste]

Question moved to new thread.

 

[Halide]

Hi guys... I'm interested in doing the passive mod + 8v mod.

First of all, I need about all the output I can get because I like to listen to music relatively loud and I am using bookshelf type speakers with a 70 watt per channel power amp (which needs a good signal to get loud). So, I'm wondering, if I do the passive mod, will it even have enough signal to "get loud" anymore? Also, how much more output signal will the 8 volt mod give?

Thanks in advance for your help.

Also, what are some good capacitors for the passive mod that would cost less than ~$50 (for both), preferably less?

 

[blah1134]

can i use 1uf or lower for the bypass caps ?

 

[Samgotit]

Quote:

Originally Posted by blah1134 /img/forum/go_quote.gif can i use 1uf or lower for the bypass caps ?

Try these articles:

http://www.ecp.cc/cap-notes.html
http://tangentsoft.net/audio/input-cap.html

 

[Halide]

Ok, I ordered microsinks for the dac chips and 2x 3.3uF Auricaps for the bypass. If I don't get enough output voltage I'll change the voltage regulators to 8v.

Can someone tell me if the 100k resistor from the RCA out to ground needs to be high quality or can I just use the 5% radio shack resistors?

Also, what exactly does that resistor do? (I'm an electronics newbie)

 

[Halide]

I did the passive mod

and the good news is... my dac still works!

 

[Halide]

I just ordered LM7808s, going to do that next

 

[Halide]

i should have thought twice about changing out the voltage regulators. that was SO hard to desolder... especially with the crappy solder sucker i had.

i just unscrewed the ones that were there and basically ripped them off with some needle nose pliers. then pulled each leg out one by one. i lost 2 solder rings (on the bottom of the pcb) and amazingly after putting in the new regulators it still plays music. maybe i am lucky?...

 

[MCC]

I'm considering acquiring a DAC-AH and am planning on doing all of these mods. Since this DAC is so cheap I can afford to go all-out (well, to a certain extent...) I'm planning on using 275ohm Vishays for I/V (VISHAY-50437 @ partsconnexion) and 3uf Auricaps for the bypass (AURICAP-63054). Are these suitable for this mod? I'd really hate to waste $45 USD on a couple resistors and capacitors if they won't be optimal.

It is my understanding that high-end resistors aren't needed @ the RCAs (100ohm). Would old generic electronics kit resistors work here, or are those too cheap?

Finally, are the Auricaps polar? If so, which color wire goes where?

And the thread lives again...

 

[shlomomofo]

i think i used 4.7uf auricaps and 270ohm rikens. also swapped in 8v regulators.... essential reading here

 

[regal]

Quote:

Originally Posted by shlomomofo /img/forum/go_quote.gif i think i used 4.7uf auricaps and 270ohm rikens. also swapped in 8v regulators.... essential reading here

You don't want to do the resistor and the 8v regulator, this will just send the DAC-AH back into outputing a clipped signal. Do one or the other not both!

 

[MCC]

Quote:

Originally Posted by regal /img/forum/go_quote.gif You don't want to do the resistor and the 8v regulator, this will just send the DAC-AH back into outputing a clipped signal. Do one or the other not both!

Are you sure? From what I can tell from looking at the schematic, a 270ohm resistor in R35/36 is actually the correct value for an 8v source, not 6v. That makes the unmodded value incorrect, right? I might be missing something though, my knowledge of electronic engineering is rather slim.

shlomomofo, thanks for the link.

Edit: That link seems to confirm my conclusions. Hmm. Yo soy confused.

 

[regal]

Quote:

Originally Posted by MCC /img/forum/go_quote.gif Are you sure? From what I can tell from looking at the schematic, a 270ohm resistor in R35/36 is actually the correct value for an 8v source, not 6v. That makes the unmodded value incorrect, right? I might be missing something though, my knowledge of electronic engineering is rather slim. shlomomofo, thanks for the link. Edit: That link seems to confirm my conclusions. Hmm. Yo soy confused.

The original value 270 ohm is correct for 8V. You don't need to change it unless you want a boutique resistor. The original is fine for 8V regs.

 

[shlomomofo]

and the newer stock units come with 6v regs... so you need to change the regs or the resistors. or both if you want boutique resistors.

read through this thread and the thread i referenced and you'll be set as far as mods go.

edit: typos... too much scotch

 

[MCC]

Sounds great! One final question though. I already have a very nice Zu Pivot mini 1/8"-stereo RCA cable. To use it I'd like to install a 1/8" jack in the DAC but I can't seem to find a suitable quality component anywhere. At all. Everything I can find is either not gold plated or incredibly cheap looking. Suggestions?

Edit: Ignore this, it really seems that such a thing doesn't exist. My dad has some decent RCA cables I can "borrow", and I can sell the Zu Pivot to help pay for the DAC. Problem solved.