Is reverb hum "normal"

[Scatterwound]

I have noticed on a few amps I have tried in the past weeks.....The amps produce a hum when turning up the reverb full blast....When the reverb is around half or so the hum is not so bad....Turn it up to full and a hum happens....This hum has some unique properties:

- It is at a constant volume - not ifluenced by the amps volume or gain settings
- Happens even when no guitar/cable is plugged in

One guy in a store told me that this reverb hum is 'inherent' to some amps...

I never really noticed it before as I never really turn the reverb up to 10 on any amps (dont play surf music too much)...


Any thoughts? Experience?

[Chickenwings]

Re: Is reverb hum "normal"

is it a tube driven reverb? I've found that EH tubes seem to hum less than other brands in the reverb send spot. Reverbs do hum a bit tho cos they are their own little amplification circuit running thru some long wires out to some springs and back thru another long wire

[Scatterwound]

Re: Is reverb hum "normal"

is it a tube driven reverb? I've found that EH tubes seem to hum less than other brands in the reverb send spot. Reverbs do hum a bit tho cos they are their own little amplification circuit running thru some long wires out to some springs and back thru another long wire

Thanks for the reply....I am not sure if the amp was tube driven or not....One of the amps was a Fender Super 60 112 combo....

[Chickenwings]

Re: Is reverb hum "normal"

according to google the super 60 has a valve driven reverb (12aT7).

[Mr 9finger]

Re: Is reverb hum "normal"

Like Gibson said, it's not uncommon for tube driven reverb circuits to hum or hiss a little bit. Trying different tubes in the reverb driver slot usually helps, but you'll never get rid of it completely. It's the nature of the beast unless you have the reverb disconnected and that's a pain. Simply unplugging from the spring tank doesn't do it. Has to be done in the amp. Me personally, I'll take tube driven reverb over some digital box any day.

[Bludave]

Re: Is reverb hum "normal"

I have a 67 Deluxe Reverb & a 68 Super Reverb. Now I really don't turn the Reverb up all the way so I can't really say, but I have no hum to speak of out of my amps.

[Scatterwound]

Re: Is reverb hum "normal"

Just found something out...At least for one of the amps....Got back to a buddy of mine....He has a Peavey Delta Blues.....Now I am sure this is common knowledge for others but new to me...Plugging in the amp into a power bar with the reverb up full gives the hum....


Plugging the amp directly into the wall no hum with the reverb up fulll...

Therefore the hum is coming from the power bar? Not the amp itself?

[Rockstar216]

Re: Is reverb hum "normal"

Thats possible too has to do with the electrical currents and being grounded well. You particularly notice it with single coils in certain venues that you get more hum then usual or that the amp doesn't respond like it normally would.