Help with Theta Ds Pro Gen V

I would try Theta. Otherwise, if you do a google search for the unit, click on images link once the search is complete. Sometimes you can get lucky and find that someone has posted schematics as an image file.

I would Email theta. Diy forums have very few info about their products and how to service/repair them.

I wouldn't count on Theta.

Theta stopped supporting all legacy products after the company was sold several years ago. I am the original owner of a Gen Va DAC that fortunately still works.

Bummer. I had some weird distortion with my Gen V as well that I eventually traced to my power cord not making a great connection with the ground. Once I was able to insert it flatter into the IEC socket, my problem went away, knock on wood :)

I won't be able to look inside to check transistor specs for another few weeks. How can you tell the transistors were changed, is it due to the soldering? Does your DAC have the "A" upgrade?