Brown-Burr/Texas Instruments USB DAC

zingo

I just received a Brown-Burr/Texas Instruments USB DAC from Fred (GV#27). It looks like a fun little unit that was designed for headphones, and I plan on converting it to RCA. I'll be updating it as I make progress.

zingo

http://focus.ti.com.cn/cn/lit/ug/sleu049a/sleu049a.pdf

Systems

Glad it made it there safely.I see someone is selling a similar item on Ebay.Im betting it also uses the PCM2704.http://cgi.ebay.ca/HOTAUDIO-MARK-IV-USB-HEADPHONE-AMP-AMPLIFIER_W0QQitemZ280324337357QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item280324337357&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A1%7C39%3A1%7C240%3A1318

Ender

In case you're interested... loooong thread about hotaudio and how awesome he is: http://www.head-fi.org/forums/f5/hotaudio40-s-amps-242880/

Systems

Ender wrote: »

In case you're interested... loooong thread about hotaudio and how awesome he is: http://www.head-fi.org/forums/f5/hotaudio40-s-amps-242880/

Thanks for posting that link ,I just skimmed through for now but it looks interesting.It appears like he uses the near identical PCM2705 and adds an opamp to buffer the output.I think this is exactly what Zingo is looking at doing.

zingo

Thanks again for the board Fred! Since I'm not much of a headphones guy, I installed a pair of RCA outs for the board. It works well and I was suprised but the sound. Maybe that's because I am currrently using an AMC 8 DAC... I was thinking it would be fun to couple this to a little chip amp and house it all in one chassis. It would be great for a computer as it would be small, make decent power, and only have USB in, power in for the chip amp, and speaker outs.

Systems

zingo wrote: »

... I was thinking it would be fun to couple this to a little chip amp and house it all in one chassis. It would be great for a computer as it would be small, make decent power, and only have USB in, power in for the chip amp, and speaker outs.

Add in a pair of speakers like the little Vifa recession busters kit from Madisound,and you would have the making's of a good PC rig.

engtaz

Fred is awesome. Super guy.

zingo

Any suggestions or sources for a good chip amp and power supply?

Systems

Here http://www.chipamp.com/ and here http://www.audiosector.com/


Or you can get the Chips directly from Digi Key for $5 ish each and just use point to point wiring.

I believe PE also sells the LM3875/3886 chips and have some suitable toroidal xformers.

zingo

My newest consideration is to integrate the DAC into my K16LS amp. It would have the ability to accept RCA or USB input depending on what was wanted/needed. I'm still working on the details...

zingo

I just finished installing the board into my K16LS and it now allows the amp to accept unbalanced cables or USB. The sound is great and as good as my AMC DAC 8. Plus, the internal DAC works pretty well for this amp because it has pre section with a pot that I already bypassed. So using the USB in, the signal goes USB>DAC>Pre>Amp, all with the volume being controlled with the computer since this is my PC rig. I'll post pictures later after a few more tweaks.

Systems

zingo wrote: »

I just finished installing the board into my K16LS and it now allows the amp to accept unbalanced cables or USB. The sound is great and as good as my AMC DAC 8. Plus, the internal DAC works pretty well for this amp because it has pre section with a pot that I already bypassed. So using the USB in, the signal goes USB>DAC>Pre>Amp, all with the volume being controlled with the computer since this is my PC rig. I'll post pictures later after a few more tweaks.

A USB dac /tube amp,now thats cool.

zingo

Well thanks! I was inspired by the Peachtree Audio Decco. They claim that a DAC followed by a tube pre section really tames down the "digital" sound. I looked at my amp below my desk and said, "I can do one better."

zingo

I was listening to my new "super amp" last night when I heard a weird pop or such noise come out of the speakers and the music stopped. I did the simple checks and everything seemed to be fine, except that the computer no longer saw the USB DAC, or any other USB devices for that matter. I restarted the computer and upon loading Windows, received a USB Overvoltage error and it would not allow start-up with the DAC plugged in. I unplugged the DAC, started the computer fine, tested the amp and it works great. I have scoured the DAC board and find no burnt components or anything the looks suspicious. The only thing I can think of is that I never grounded the USB terminal to the board after I moved it, but I'm not sure if that would cause an overvoltage anyway. Has anyone see this problem before or know anything about "USB overvoltage"?

Systems

Is the DAC being powered via the USB port or did you give it a separate supply?

zingo

It's being powered via the USB.

Systems

zingo wrote: »

It's being powered via the USB.

Huumm

Systems

Not sure if it will work but there are 2 or 3 jumpers marked self and bus.Place the jumpers in the self position then you can use a 9volt battery to power the unit.Ofcourse be sure to hook it up with the correct polarity.

zingo

I played around with the jumpers and got the unit so that when I plug in the USB, the unit powers up and registers with the computer, than a second later shuts off and disengages all USB ports on the computer. Unplug it and all the USB ports work instantly.

Systems

Something on the DAC board must have failed.

Systems

Try this.If you are operating it from the battery (with USB disconected)you can check the voltage at the self pins with your multimeter.You should get 3.3 volts.

zingo

I'll have to find a 9v battery and I'll look over the board again.

zingo

As I just told Fred, I got the unit working again (I think two of the USB wires were touching) and I will try to post pictures of the completed unit tonight; DAC installed in amplifier.

zingo

Part One

zingo

Part Two

Systems

Very cool.I bet the tubes add some body to neutered MP3 files.What are you using for speakers?

zingo

Don't worry, there aren't any MP3s running through that amp.

I am currently powering my CRS+ and they sound really good except for being a little bass shy. This amp also sound fantastic with my old Monitor 5Jrs.