• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Trouble with Pathos Logos amp

dimisaki

New Member
Joined
Mar 5, 2023
Messages
3
Likes
0
Hi everyone!

I am writing to better understand an issue that my amp displayed today.
Specifically, the amp gives a periodic popping sound on the right speaker, even at 0 volume. The amp is question is a Pathos Logos that I recently bought used (worked fine until today!).
Something to note is that even if I remove the right channel tube from the pre-amp stage, the popping sound continues - so it shouldn't be a problem with the tubes or the preamp, right? Other things I tried were disconnecting all sources, changing power cables, and swapping the speakers, nothing made a change (other than the speaker swap, which moved the issue to the other channel:) )

Does anyone have an idea as to what may be causing this? Is it more likely to be an issue with the power supply or the power amp? My main fear is that the problem could be with one of the huge capacitors in the power supply, which would cost quite a bit to repair..

I am attaching the service manual in case useful for anyone who can help on this
I uploaded a video that displays the problem in this link:
Thanks!
 

Attachments

  • Pathos Acoustics Logos Service manual.pdf
    2.8 MB · Views: 138
Last edited:
Top Bottom