[Eboz]

I've been working on a large project for about a year now. I now have the first section of it ready to go. This first section is a USB interface, powered by either USB or +5V external. It has two separate regulated (local) power supplies that are also powered by either the bus power or external power. One for digital and one for analog, with USB differential signals and ground passed through a pulse transformer and bus power through ferrite beads. It's output is both analog and digital, with crossfeed on the analog headphone output and either SPDIF or I2S for digital output. Basically this board can either be USB-powered in a small enclosure for use at work, or it can be upgraded to external power and external DAC via I2S for an ultimate source to your preamp. I plan on designing more modules for these upgrade options during this year. Here is a picture of the prototype board. The production board will have a type B USB connector instead of the A, surface mount main chip instead of the adapter, and also a connection for an LED power indicator. The adapter is from aprilog.com. It also only uses a few surface mount parts, which also could change. My only hold up now, is finding a way to make orders to thlaudio. I've sent them a request for a quote on enclosures, RCA connector, BG caps, Neutrik 1/4" connector, etc. and I've not heard back from them on waiting four days now. Anyone know if this is a good company to work with? I was going to do laser cuts on their blank enclosures and it would look amazing... Anyway.. here is the board.
http://www.wsu.edu/~woods1/ebozdac-0.9.jpg

 

[KARMAZ]

Great project Eboz !
Is it possible to have a complete interface with input/output ?

 

[Eboz]

I forgot to menton that it does also have mute and volume. As far as interfaces: It is USB input, analog output, digital SPDIF and I2S output. It is not an ADC. The next module with external TDA1541A (at least testing this one) DAC would also include SPDIF input and you'd select btw. USB and SPDIF inputs...

 

[RioTubes]

Hi Eboz, can we get more info on this 2706 usb interface? Link to photos is dead. I'm at the beginning stages of researching this exact interface, but for use as a daughterboard so that I can install it into my twin 1541a dac. I am a novice diy and am looking for any help on this subject...parts list, schematic, end-product, anything.