Another PCM2702 DAC project.

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi all,

I am planning to make a PCM2702 based USB DAC for my computer. I found a lot of projects on the web. However non of them has high current output or gain for 32/64R headphones..
Then I decided to design my own DAC and use AD8397 opamp for LPF circuit which has rail to rail outputs and capable to drive 32R loads.. Also has really good THD figure.
I was also expecting a simplistic and tiny solution that may placeable in a little hammond enclouse and feedable with a wallwart type PSU (and/or just a trafo).. Because of the limitation the voltage it was not an option to use USBs own power..
And, this is my new USB DAC project;
An externally hosted image should be here but it was not working when we last tested it.

Not yet assembled or tested but in the simulation, the analog part (and also the PSU) looks work..
But I am a bit confused on LPF design.. I have calculated some R and C values for 100Khz corner frequency but they did not work on the simulation! After these modifications it worked like a charm.. I know the values are a bit weird, but it works on the simulation..
So, may I have your comments about my design pls? What do you think about the output stage?
Thx in advance for every kind of advices..
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.