[Alf]

Quote:

Originally Posted by whiz i have a problem too... i'm going to use high quality components like os-con for the C23-C33 and panasonic FC for the C2 and i can't find not even one brand of the capacitors specified for the output......i could use whatever i have! but i don't think it's wise... i either make it "cheap" or high-tech...is there anyone can suply me Cilmic II? or has any idea what to put for output capling?!?! the components were real pain to collect them! from local stores/sites!!!

http://www.audio-cube.nl/elna.htm

 

[whiz]

Quote:

Originally Posted by Alf http://www.audio-cube.nl/elna.htm

Thank you alf!

but i know this site...it's probably the only way
to get elna capacitors without paying a fortune...but still the
value for money of elna capacitors goes wasted because of the 9E
for transportation cost...i only want to buy 6 capacitors and they
only cost ~2.50E. I believe most of the online shop are effective only
if you need to go on with a big order.

splaz tryed to help me by puting my order in his list...but i saw his
PM too late...

anyway...THANKS splaz!

 

[splaz]

Well like I said I don't expect someone to check in here 24/7 but you did take 3 or 4 days I think it was to get back to me and those cases weren't going to wait. :|

Yeah well check your pms just now, I may have some extras of a different value if you're interested.

 

[whiz]

Quote:

Originally Posted by splaz Well like I said I don't expect someone to check in here 24/7 but you did take 3 or 4 days I think it was to get back to me and those cases weren't going to wait. :| Yeah well check your pms just now, I may some extras of a different value if you're interested.

You have PM!

(i always wondered why we notify someone for his PM...but from my recent experience, it is very effective!)

 

[kennylee]

Quote:

Originally Posted by Buzzerbro Regarding the CL and CR capacitor positions, what would be better, the 47uF/16vdc Nichicon Muse ES or 47uF/25vdc Nichicon Muse KZ ? Size nor cost is an issue for me.

Where can I get the "Nichicon Muse series Caps"? Thanks!

 

[mikemacwillie]

Quote:

Originally Posted by rreynol Yeah, it is a pain. I've got 3 more untouched boards that maybe I'll revisit someday. I tried a big tip (which some said they preferred) as well as a tiny conical tip. I've got a weller soldering iron and I've used plenty of flux trying to fix it. I'm constantly cleaning the tip. Best I can guess is that somehow its not exactly straight (it was when i tacked it down). /Shrugs. At nearly 10 bucks per PCM2702 chip, it's frustrating enough to put down for a while.

If you would like, I could solder your PCM2707 chips for you for the cost of shipping..


Mike.

 

[tomb]

Quote:

Originally Posted by kennylee Where can I get the "Nichicon Muse series Caps"? Thanks!

Handmade Electronics Unlike some other suppliers that may get mentioned, they are straightforward, fast, and dependable. Same for PartsConnexion if you are interested in Black Gates. I got some of both.

 

[Seaside]

I made Alien DAC yesterday.
Sounds great and everything is fine except one glitch.

There's a severe distortion when directly connect earphones(Senn MX-500 and MX-510) to the dac and max up the volume. No distortion under about 75% volume, but it gets real ugly when I pump up the volume more than that. I can not hear any distortion when i hooked the dac to my amp. In short, distortion w/o amp, no distortion w/ amp. I think this might be an impediance issue, but not sure what the heck is the cause.

Parts I used are the same or within the range with what Alf specified at his website.
REG101UA-A, regulated down to 4.71V. Regulation is very stable. Pana and Elna electrolytics C2 470uf, C13,23,33 47uF, CL CR 22uF, 600ohm murata Ferrites, AVX 1uF C1, etc. Triple checked for soldering brigde and flux residue. There's no problem with them.

Anyone has the same problem with me? Any fix?
Thanks.

 

[mikemacwillie]

Quote:

Originally Posted by Seaside I made Alien DAC yesterday. Sounds great and everything is fine except one glitch. There's a severe distortion when directly connect earphones(Senn MX-500 and MX-510) to the dac and max up the volume. No distortion under about 75% volume, but it gets real ugly when I pump up the volume more than that. I can not hear any distortion when i hooked the dac to my amp. In short, distortion w/o amp, no distortion w/ amp. I think this might be an impediance issue, but not sure what the heck is the cause. Parts I used are the same or within the range with what Alf specified at his website. REG101UA-A, regulated down to 4.71V. Regulation is very stable. Pana and Elna electrolytics C2 470uf, C13,23,33 47uF, CL CR 22uF, 600ohm murata Ferrites, AVX 1uF C1, etc. Triple checked for soldering brigde and flux residue. There's no problem with them. Anyone has the same problem with me? Any fix? Thanks.

The problem is that you're not supposed to use it to directly drive headphones!

 

[doobooloo]

Quote:

Originally Posted by mikemacwillie The problem is that you're not supposed to use it to directly drive headphones!

Exactly!

 

[robzy]

Quote:

Originally Posted by mikemacwillie The problem is that you're not supposed to use it to directly drive headphones!

As above, the DAC is not made to drive headphones.

Rob.

 

[Seaside]

Dac is not made to drive earphone... yeah... that's right.
But that does not neccessarily means that the sound of DAC automatically will be distorted at higher volume when you plug earphones into the dac.
In fact I have another dac that uses PCM2704 doesn't have this kind of distortion at all, and that dac is intended to use with amps too.

So, all of you have the same distortion experience?
If you didn't please do so just for testing purpose and tell me what happened.
In this way, I can figure out if my dac is normal or not.
If all of you had the same distortion, it will be a normal characteristic of this dac. Or else, my dac has some problems to fix.

 

[robzy]

Quote:

Originally Posted by Seaside Dac is not made to drive earphone... yeah... that's right. But that does not neccessarily means that the sound of DAC automatically will be distorted at higher volume when you plug earphones into the dac.

You make a good point. However, it does mean that if the sound is distorted the reasons should be pretty obvious.

As you increase the volume you increase the voltage supplied, because V=IR and the resistance of your phones is pretty much fixed this means that the current would increase. The outputs of the PCM2702 are designed for low current.

Can't hurt looking into it i guess though.

Im not willing to try headphones with my DAC with my current knowledge though. The output stage is made to drive high impedance load and has probably been specifically designed that way.

Rob.

 

[tomb]

Quote:

I can not hear any distortion when i hooked the dac to my amp. In short, distortion w/o amp, no distortion w/ amp.

I think it could hurt to look into it. No offense, but why look for problems in an incorrect configuration when there are none without it?

This is similar to some of the tube DIY amps lately when people take measurements without the pot in the circuit and then spend days asking what's wrong. One thing is certain: under limited power and current, a headphone will distort as the volume is turned up. That's the whole reason we build headphone amps, anyway.

If everything sounds good with an amp, I'd chill out and enjoy my results.

 

[whiz]

I have the same problem with an other project (PCM2902)
i don't understand it too...i thought the outpout impedance was 32Ω
and can drive 32Ω headphones....