The output of my EMU-o404 USB distorts. I would appreciate if someone can provide the schematics of the output section.
There is an old wiki here but the links and images don't work
https://www.diyaudio.com/community/threads/e-mu-0404-usb-mod-wiki.162512/post-2106042
Regards
George
There is an old wiki here but the links and images don't work
https://www.diyaudio.com/community/threads/e-mu-0404-usb-mod-wiki.162512/post-2106042
Regards
George
Hey George,
Here's one for the PCI card:
https://pages.cs.wisc.edu/~timc/e/emu.html
My experience is that the scratchiness comes from cold solders and from dried-out output caps. There should be 4 of them, right between the DAC and the opamps. I had also removed the muting transistors from my 1212m.
There's what looks like the USB version, but I wouldn't know for sure. I pulled it out of a Russian (?) forum, unfortunately the script causes links to totally break when I paste them. The caps are the 47u units C80 and C81.
Here's one for the PCI card:
https://pages.cs.wisc.edu/~timc/e/emu.html
My experience is that the scratchiness comes from cold solders and from dried-out output caps. There should be 4 of them, right between the DAC and the opamps. I had also removed the muting transistors from my 1212m.
There's what looks like the USB version, but I wouldn't know for sure. I pulled it out of a Russian (?) forum, unfortunately the script causes links to totally break when I paste them. The caps are the 47u units C80 and C81.
Thank you Sangram for the treat !
The distortion is not low. It's some 0.1%. Plus the headphone out started clipping (1st attachment).
Yesterday I replaced four dual OPamps, two at line out and two at headphone out. No change.
PSU is OK. I guess it's either the diodes or the FEts.
There are many of these 3 legs. 11 at line out, 7 at headphone out. Marking 10XUJ and 15Du
The distortion as probed on main level pot is on 2nd attachment.
I don't know what has happened. The output distortion was normally at the third decimal place. In general the EMU was a slightly better performer than a new Motu M2 which I have borrowed from a friend.
George
The distortion is not low. It's some 0.1%. Plus the headphone out started clipping (1st attachment).
Yesterday I replaced four dual OPamps, two at line out and two at headphone out. No change.
PSU is OK. I guess it's either the diodes or the FEts.
There are many of these 3 legs. 11 at line out, 7 at headphone out. Marking 10XUJ and 15Du
The distortion as probed on main level pot is on 2nd attachment.
I don't know what has happened. The output distortion was normally at the third decimal place. In general the EMU was a slightly better performer than a new Motu M2 which I have borrowed from a friend.
George
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