2. amps-preamps
  3. 1423424336

Motorboating after tube change

I posted this on Audioasylum tubes, but I'd like to increase the knowledge base, so here I am.

I own an Aikido preamp that was built for me in 2007. Since I don't use it that much, I haven't replace the tubes till now. After I changed them out, there was clearly audible motorboating emanating from both speakers. I returned each old tube to the unit but the motorboating didn't stop. The only screwup was that when initially replacing the tubes, I accidentally installed a 5751 into the spot for a 5755.

Any ideas?

Thx,

GP
garibaldi

Showing 1 response by atmasphere

atmasphere's avatar
atmasphere
12,088 posts
 
Motorboating is an indication of a power supply problem.

My theory is that the different tube somehow was able to do some damage, but it is not obvious how upon looking up the two different tubes. So it could be coincidence, but at any rate you are experiencing a power supply problem.
More to discover