USB DAC advice (build into preamp)
 

I'm looking to build a tube preamp (circuit from here) with both analog and USB inputs (PC source). I don't have experience in building DACs so I'm looking for a module or kit to graft into the preamp (SMD kits are no problem).

The custom transformer that I had made for the tube pre has an extra 9-0-9V secondary at 2A (18VCT) so I can supply isolated power to the DAC via a separate rectifier + regulator.

The DAC board will be built into the preamp enclosure so the DAC preferably has the connectors (coax/usb) on one side so it can be mounted on the rear with connectors accessible.

Reading around, the Muse DACs seem to have decent reviews so I narrowed my choice to these:
MUSE-Mini-24Bit-192Khz-Coaxial-Optical-USB-Input-DAC-Headphone-Out-66-60m
or
MUSE-HIFI-USB-to-S-PDIF-Converter-USB-DAC-PCM2704-Sound-card-BOARD

I have seen other DACs out there but they need another secondary so they're out.

I don't need extreme hardcore SQ, just something of decent quality and doesn't cost an arm and a leg. :p This preamp will be paired to my recently built P101 amp.

Are these a good choice? If you guys could give other suggestions for better DACs out there, it would be much appreciated. (preferably ebay since I'll have a friend buy it for me) :)

You didn't give a cost budget figure, but the well reviewed JKDAC32 seems like an interesting alternative to consider. It features asynchronous USB, and the PCM5102 DAC with minimum pahse (apodizing) digital filter.

JKDAC32 - Hiface Modifications & Ancillaries

I forgot about the budget. I would like something under US$100.

I think the JKDAC32 is a little out of budget. :p

Also looking for something in bare PCB form since I will be integrating this into the preamp.

up :)

no other comments? I guess I'll just have to bite and see. It looks like they used decent quality parts so it shouldn't be that bad.

I'll post how it turns out.

George at Yoyodyne has an Audio Widget based kit for $96.. Async USB driverless.. Yoyodyne Consulting//Audio Hardware/USB5102

Check out the Audio Widget thread here: http://www.diyaudio.com/forums/digit...io-widget.html

So I bought the two Muse ebay dacs in the first post. And compared it to a Schiit Bifrost and then ended up buying the (very slightly) used Schiit Bifrost which I then modified. :D

Since the Bifrost that I bought did not have the USB option, we tried the second ebay dac in my first post and used its SPDIF out (this device has optical output on its 3.5mm jack! - which, for some reason, wasn't in the product description) and the sound quality is much better than we expected.

The first one has coax SPDIF out and using the Cmedia CM108 USB chip and CS8416+CS4398 receiver/dac combo. This thing is funny. It was listed as having ELNA/NICHICON/ NIPPON-CHEMI and EVOX audiophile grade capacitors and LM317 high precision regulator from ON-semiconductor but They appear to be counterfeits. :p The "EVOX" film cap markings rub off when I had to remove flux using IPA after resoldering the poorly wetted SMD pads. The caps I'm not too sure. The gold ones are Nichicon FW in my unit, others are Elna RJJ series if those even exist. The On semi 317 regulator seems to have a rough sanded face which appears to be a restamped device. :D But it does work and even without external power when used with USB. external power is only needed when using only as DAC mode with SPDIF input.

But both do well as a USB to SPDIF converter. One uses a PCM2704 and the other uses a CM108. Which one sounds better? I can't distinguish with my tin ears. :rolleyes:

I plan to make a preamp and build in the CM108 based one and add the external power so I can use it as an onboard DAC or as USB to SPDIF converter then loop out to the Schiit then back to the preamp. Any reason to use the PCM2704 instead? I do like the optical output though due to the galvanic isolation. ;)

Nobody else wants to share their expertise? I'm looking for a dac also...
I'm hoping to drive it from a fanless PC that I have.

Try the many DAC kit/assembled on eBay... the ones with discrete parts and try the one with DAC made by Analog Devices -- AD1955, I think it is.

Thx-RNMarsh

I have a Nuforce Dac NuForce uDAC-2 (Black) USB digital-to-analog converter/headphone amplifier at Crutchfield.com

I like it a lot.