Argh - Rectoverb 25 buzzing

Vincet68 · Oct 27, 2015

Was playing for about 10 minutes today on my Rectoverb 25 when, on a not particularly percussive bass note (Strat tuned standard), the amp started to crackle loudly (like arcing) then developed a steady buzz, which went away on standby but was still there when turning back on. Powered amp down, let it cool, turned it back on and the buzz developed over time.

Here's a short YouTube clip (careful your speakers aren't at full volume) https://www.youtube.com/watch?v=jsp4oGYglJ4

Any ideas about checking things before I head off to my amp tech?

Vince

elvis · Oct 27, 2015

Preamp tubes.

Vincet68 · Oct 27, 2015

Thanks, man - it was user error! Last gig, I ran an extension speaker, so the internal (8ohm) speaker was getting signal from one of the 4ohm outs, and the other 4ohm out wasn't connected to anything. I'm not sure of specifics, but something overheated and crapped out - when I got the internal back on the 8ohm out and let things cool down, I was able to play long and hard, right into cranked Modern mode on Channel 2. Sometimes, all it takes is "some stupid" :lol:

elvis · Oct 28, 2015

Glad the issue went away. But it doesn't make sense to me. The 4 Ohm out can easily drive an 8 Ohm speaker with no problems.

Speaker outputs:
1. 8 Ohm. This can drive 8 Ohms, 4 Ohms or 16 Ohms without trouble. Best for 8 Ohms.
2. 4 Ohm. These two are wired in parallel to make it easy to connect two 8-Ohm speakers in parallel. Can drive 8 Ohms, 4 Ohms and 2 Ohms without trouble. Best for 4 Ohms.

Could have just been a bad connection to the speaker cable.

cyber104 · Oct 29, 2015

Elvis is right - that impenance mismatch wasn't the issue

Authorized Boogie · Oct 29, 2015

elvis said:
Glad the issue went away. But it doesn't make sense to me. The 4 Ohm out can easily drive an 8 Ohm speaker with no problems.

Speaker outputs:
1. 8 Ohm. This can drive 8 Ohms, 4 Ohms or 16 Ohms without trouble. Best for 8 Ohms.
2. 4 Ohm. These two are wired in parallel to make it easy to connect two 8-Ohm speakers in parallel. Can drive 8 Ohms, 4 Ohms and 2 Ohms without trouble. Best for 4 Ohms.

Could have just been a bad connection to the speaker cable.

2 ohms may cause trouble.... : )