Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Comments for my PCM2702 DAC layout?
New Posts  All Forums:Forum Nav:

Comments for my PCM2702 DAC layout? - Page 9

post #121 of 613
10/12/08 at 9:30pm
Quote:
Originally Posted by tomb View Post
It's fairly easy to game certain aspects of RMAA, IMHO, too - which is why I felt that comparisons are what's important.
For sure... I always wondered how long the engineers at TI had worked to get the -100dB measurements they claim for the pcm2702.

Good work on this pcb anyway. It looks really clean (certainly cleaner than the USB DAC sitting in a tin on my desk).
Reply
post #122 of 613
10/13/08 at 7:40am
How feasible do you think it'd be to use the Box Enclosures case with a 'standard' non-Cable DAC?
Reply
post #123 of 613
10/13/08 at 8:35am
Quote:
Originally Posted by error401 View Post
How feasible do you think it'd be to use the Box Enclosures case with a 'standard' non-Cable DAC?
Completely feasible. That's the regular case option, too - just haven't documented that one, yet. Essentially, one just needs to take a razor saw to the plastic to cut out a notch for the USB jack.
Reply
post #124 of 613
10/13/08 at 9:05am
Quote:
Originally Posted by tomb View Post
Completely feasible. That's the regular case option, too - just haven't documented that one, that. Essentially, one just needs to take a razor saw to the plastic to cut out a notch for the USB jack.
Excellent! Awaiting the arrival of the Box Enclosures on Beezar
Reply
post #125 of 613
10/13/08 at 11:55pm
Still quite a few pages left to do, but I've added some extensive Step-by-Step Construction and Preparation pages on the website - under "Construction".

http://www.diyforums.org/BantamDAC

Reply
post #126 of 613
10/14/08 at 1:21pm
Jantzen 4.7uF 400V Crosscap Capacitor fits the hammond case.

TPA used this brand of capacitor in their kokaburra pre amps just as a pointer and brian recomended me these as output caps for an opus dac, anyone want's to give them a try?
Reply
post #127 of 613
10/14/08 at 5:18pm
Quote:
Originally Posted by MASantos View Post
Jantzen 4.7uF 400V Crosscap Capacitor fits the hammond case.

TPA used this brand of capacitor in their kokaburra pre amps just as a pointer and brian recomended me these as output caps for an opus dac, anyone want's to give them a try?
They look like they might be re-branded Solen's - the physical size is similar, too. If that's the case (not saying for sure that it is), then there are better caps to pick from.

Honestly, I can't imagine a PCM2702 DAC with direct output capacitor coupling sounding better than with VitaminQ's. I have that one Alien DAC with 6 x 0.22uf on each channel (it died I thought, but miraculously came back to life). That's 0.66uf and there's no loss of bass, while the sound is great. Maybe a Mundorf would sound better, but those are out of my price range.

EDIT: This is of course, if we are talking about something advanced. The BG's and film caps sound just great within the footprint of the BantamDAC board. What we're talking about with Jantzens, VitQ's and Mundorf's is an extreme build.
Reply
post #128 of 613
10/14/08 at 6:05pm
Quote:
Originally Posted by tomb View Post
....What we're talking about with Jantzens, VitQ's and Mundorf's is an extreme build.

yada yada blackgates yada yada wimas....

tomb, what would head-fi be without a few momentary insanity moments where you spend more on the output caps that the rest of the parts???
Reply
post #129 of 613
10/14/08 at 7:09pm
Quote:
Originally Posted by MASantos View Post
yada yada blackgates yada yada wimas....

tomb, what would head-fi be without a few momentary insanity moments where you spend more on the output caps that the rest of the parts???
True.
Reply
post #130 of 613
10/14/08 at 7:16pm
That's why you buy some 1uF VitaminQ of ebay and use the DAC with 50k impedance amps
Reply
post #131 of 613
10/15/08 at 7:51pm
I've now built two BantamDACs, having received the bits last week; the working one is, as has been said before, very much like an Alien (of which I've built two), only much smaller. Thanks for making an alternative DAC that's easier to integrate with DIY amplifiers!

The non-functioning one, incidentally, is a classic example of the risks of being an 'early adopter' of new technology: when I built it last Friday, the construction pages for the Bantam hadn't been created yet, so - silly me - I put c16 in the obvious position. Doh! Now, having rectified that - and having figured out why the 4.75v regulator went "poof" - as soon as Mouser delivers a new regulator, I should have *two* working Bantams, bwahahahaha...

One will wind up feeding an "original SOHA", I'm not sure about the other. Maybe I'll put it - and some enormous 4uf KGB PIO caps - in a case with a spare Pimeta, or something...
Reply
post #132 of 613
10/15/08 at 8:00pm
Quote:
Originally Posted by Nemo de Monet View Post
I've now built two BantamDACs, having received the bits last week; the working one is, as has been said before, very much like an Alien (of which I've built two), only much smaller. Thanks for making an alternative DAC that's easier to integrate with DIY amplifiers!

The non-functioning one, incidentally, is a classic example of the risks of being an 'early adopter' of new technology: when I built it last Friday, the construction pages for the Bantam hadn't been created yet, so - silly me - I put c16 in the obvious position. Doh! Now, having rectified that - and having figured out why the 4.75v regulator went "poof" - as soon as Mouser delivers a new regulator, I should have *two* working Bantams, bwahahahaha...

One will wind up feeding an "original SOHA", I'm not sure about the other. Maybe I'll put it - and some enormous 4uf KGB PIO caps - in a case with a spare Pimeta, or something...
Glad to hear that at least one went together well.

On the other hand, I am so sorry that the C16 tripped you up. I made a post in this thread in BOLD about that, but we can't expect that everyone will read all of these posts, either. I will try to emphasize it everywhere I can - even putting it on Beezar on the catalog page.

Colin and I debated the silkscreen before ordering the production boards. However, we felt the dual-compatibility with the REG101's was important. The prospect of labeling that one pad with C16 and making alternate silkscreen labels for three pads was daunting. So, we decided to leave it as is. My fault for not making the change clear enough.
Reply
post #133 of 613
10/15/08 at 8:17pm
Yeah, and I *read* that post, too - I've been following this thread pretty closely for a few weeks, had my parts ordered back before the "final" BOM was out (oops!), and was one of the many who kept re-visiting Beezar looking for the boards that joyous weekend - but it was late at night/very early in the morning, and I kind of saw "REG101" and didn't really pay any attention, as I didn't think it was relevant. I'm not blaming you; I jumped the gun, and the time I spend wondering "but *why* did IC2 go kerplooey?" is entirely my own fault...
Reply
post #134 of 613
10/15/08 at 9:07pm
hey you learned what (not) to do next time!
we've all somehow been there abouts...
Reply
post #135 of 613
10/16/08 at 7:47pm
I hope to make my order before the end of the day at Digikey (for that oh, so sweet next-day shipping), but it seems R4's 541-1.00MCCT-ND and C7's P12340-ND from the BOM are backordered. Just thought at least one person might like to know. I switched to Nichicon PW (493-1707-ND) for C7 and Panny for R4 (P1.00MCCT-ND).
Reply
New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Comments for my PCM2702 DAC layout?