Getting hum from my reverb tank. Fixes?

[Dave Locher]

I made a smaller/lighter housing for my old Randall RG head a year or two ago. Doing so meant moving the reverb tank a lot closer to the transformer. Now I get hum when I use the reverb, and the hum volume increases as I turn up the reverb.

It is not terrible, and it doesn't really get louder as I turn up the amp so not a big problem, but at bedroom volume the amp is totally silent with the reverb off and has this annoying hum with reverb on. Again, even with the amp volume way down the hum is not loud enough to hear while playing but I really like quiet stuff with minimal hiss or hum. Is there anything I can do to reduce the background hum from my reverb?

EDIT: it was just the @#$! RCA connectors. One wasn't making good contact.

 

[Mincer]

Re: Getting hum from my reverb tank. Fixes?

You could try shielding the tank, or enclosing it in something that will isolate it more from the transformer. Is there any other place you can put the tank in the new enclosure? How about using a reverb pedal instead?

 

[Dave Locher]

Re: Getting hum from my reverb tank. Fixes?

Reverb pedal is my last resort. Nowhere else to move it within the head.

I can probably add shielding, I will have to Google how to accomplish that.

 

[ehdwuld]

Re: Getting hum from my reverb tank. Fixes?

wrap it in tin foil
like a hat

 

[Dave Locher]

Re: Getting hum from my reverb tank. Fixes?

It seems to work better if the foil is around my head though??

 

[FuseG4]

Re: Getting hum from my reverb tank. Fixes?

I've heard that sometimes turning the tank around so the input or output is further from the transformer it can help a little, but can't remember if it's supposed to be tank input away from the transformer or not. It might be the tank output it best further from it, if you have enough cord try rotating the sucker maybe it will help?

 

[ehdwuld]

Re: Getting hum from my reverb tank. Fixes?

a bit of metal screen from the hardware store should create a Faraday cage

 

[Dave Locher]

Re: Getting hum from my reverb tank. Fixes?

I did some googling, just haven't had time to mess with it. First attempt will be moving it around, phase 2 will be the cords (cables? Wires?). If those fail then I'll try shielding the whole thing. Those seem to be the three things that someone or other claims worked for them.
Thanks, everyone!

 

[Mincer]

Re: Getting hum from my reverb tank. Fixes?

Had you tried to use a long cable to see what distance the reverb tank would have to be to make the noise go away?

 

[Dave Locher]

Re: Getting hum from my reverb tank. Fixes?

Had you tried to use a long cable to see what distance the reverb tank would have to be to make the noise go away?

Haven't tried anything yet. I was jus researching possibilities and likelihoods so I know what to look for when I do go poking around in there. At the time I built the new housing it never occurred to me that I could just use longer wires. I think I remember they had rca jacks?
Once I finally get to poke around in there I will report back.
It's not a ton of noise, but without it the amp is nearly silent at volume, which I love.

Amusing p.s.: autocorrect on my tablet changed "rca jacks" to "rice Jack's" THREE TIMES.

 

[BenPerkins]

Getting hum from my reverb tank. Fixes?

I had a similar issue (different amp) and bought a reverb tank bag, which shielded the tank. They cost about $15.

I was told (a few years back, don’t remember exact verbiage) that the springs weren’t shielded, hence the hum as reverb was turned up.

 

[Dave Locher]

Re: Getting hum from my reverb tank. Fixes?

This is so stupid I hate to admit it, but hope the info may be useful to someone else some day: one of the frickin' RCA jacks was not making good contact! Giving a good twist and push solved the problem.

Today I finally got around to pulling the face off my head for a looksee. I started moving the reverb cables around and one crackled. So I gave the plug on the tank a good twist and push and...the annoying hum went away!

I can't believe how much I overthought this and how quickly and easily I could have fixed it months ago.

So that's how I spent 3 minutes of my afternoon.

 

[Mincer]

Re: Getting hum from my reverb tank. Fixes?

Wow, I am happy that it was that simple. I am sure the solution will help others, too, so thanks for the update.