Vegas 400- hum in reverb? best speaker? 4 or 8 ohm? Neo?

[Lynn Kasdorf]

I'm getting this old Vegas 400 back into rotation since I figured out what was causing the intermittent low volume (it is the switching jack for power amp in- I just bypassed it).

First, this amp has always had an annoying hum when you turn up the reverb. Reverb off, no hum. Is this a known issue?

Second, I need a speaker for it. I think I have a working black widow kicking around, but I'd like to get a neo for the light weight. Suggestions?

Do I need to run a 4 ohm, or will 8 ohm be ok, albeit at reduced power output?

[Fred Hedgecoth]

Lynn, my Vegas also hums at about mid-level up. I've cleaned the pots but still get the hum. Don't know if that's typical for this amp but boy is it annoying!

[Jack Stoner]

Many times reverb hum is caused by the "Molex" connector.

I had the hum in a Nashville 400 and went thru the usual cleaning contacts on the Molex connector, reforming the female pins in the Molex connector, etc and it still had hum. It developed an output problem and Peavey repaired it under warranty (including a blown speaker). I told Mike Brown about the hum when I was making arrangements with him for the warranty repair. It came back repaired but the hum was still there. Being I'm an ex amp tech I got into it further and found a hairline crack (open) in one printed circuit lead from one of the Molex pins on the main circuit board. I fixed the "crack" (soldered across it) and finally tamed the hum. This may not be a common cause but something to consider.

[Fred Hedgecoth]

Apparently I had the Molex connector reversed. Flipped it and reverb hum disappeared. Must admit to feeling a bit stupid right now...

[Foster Haney]

In my old Vegas, and now all my amps. I take the reverb tank out and mount it to a piece of cardboard with some copper shielding tape. This reduced the hum in my Vegas a reasonable amount.