Running 2 amps....hum :(

Slowclimb

I’ve now managed to build a pedal board I’m happy with, it’s then running into my trusty old Alesis Microverb and then into 2 amps. But I get a terrible earth mains hum, the only old school way I know to fix it is to remove the earth wire on one of the amps plugs...but I know that is about as safe as a very unsafe thing
what does anybody else do? Plenty of people run 2 amps and I’m sure they get rid of this annoying hum!

mrkb

You need an isolation transformer on one of the amp audio feeds to prevent an earth loop. Gig rig do a hum buster and I think lehle do one as well.

ICBM

You need to break the ground connection on one of the signal cables to the amps.

The proper way to do it is with a transformer-isolated 'through' box, but often simply cutting the shield connection in one of the plugs works fine. If that increases noise, try putting a 100-ohm resistor in the gap.

SRich

Lehle and other assorted love songs

ICBM

SRich said:

Lehle and other assorted love songs

Glass Bright Onion

ecc83

https://www.rapidonline.com/AV-Link-201-086UK-High-Quality-Ground-Loop-Isolator-35-4561?IncVat=1&pdg=pla-294357559827:kwd-294357559827:cmp-757438067:adg-44804851896:crv-207912323492:pid-35-4561:dev-c&gclid=CjwKCAjwzenbBRB3EiwAItS-u5o6OpkSblD1RLQ801uUQYxWMcYgwiMH_RMBwyc4suFiqhIB0PfVWRoCkNoQAvD_BwE

Yes, I know it is 2 channels and yes, you have some cable swapping/adapting to do but at that price?

They work fine. MORE than good enough for geetar!

Dave.

Slowclimb

Thanks for the replies chaps, some great advice there!
That thing looks spot on ecc83, I'm guessing I would just need a couple of 1/4 in to RCA adaptors and just run it through one of the channels you reckon?

thermionic

It would be cool to mount one of those in a diecast box with proper jack sockets. Give it a snazzy paintjob and a boutiquey name!

Rowby1

+1 Bright Onion. Half the price of the Gigrig version.

The phase switch is very useful if you have three different amps that you pair up in different combinations and one operates out of phase from the other two.

steamabacus

The Orchid transformer isolator doesn't cost an awful lot more than that one ECC83 linked to and is top quality (and no faff with connectors). Every gigging/recording guitarist should have one (or two)...

http://orchid-electronics.co.uk/trans.htm

ecc83

steamabacus said:

The Orchid transformer isolator doesn't cost an awful lot more than that one ECC83 linked to and is top quality (and no faff with connectors). Every gigging/recording guitarist should have one (or two)...

http://orchid-electronics.co.uk/trans.htm

Cannot argue with that.

Dave.

digitalscream

Another +1 to the Orchid units. I've got two (a single and a double), and I always have them in the gig bag for problem-solving hum issues at a gig or recording session.

Sporky

Or the Behringer.

https://www.gear4music.com/Recording-and-Computers/Behringer-MICROHD-HD400-Hum-Destroyer/6RR

Slowclimb

They both look ideal, thanks again