Archon Effect Loop Hum Fixed!

[Ben]

I finally got my effect loop to stop humming.

I had my pedals and the power supply far away from the amp, and that seemed to help. If I put either the power supply or the pedals or the cables too close to the amp, it would start humming.

I tried a new power supply. It's called a "pig hog." And that took care of the power supply problem. But the cables and the pedal still hummed.

I tried spending some money on nice, well shielded cables. But that barely had any effect.

The pedal I'm using is an EH Nano Reverb. I thought a different pedal might work, but I don't know of one that doesn't hum with the Archon, and I don't want to keep buying pedals until I find out.

I tried an Ebtech Line Level shifter. That actually cured the hum completely. But it also seemed to reduce the volume. I couldn't find directions for the Ebtech anywhere, and I couldn't figure out how to reduce the hum without also dropping the volume.

Then I stumbled up on something. I plugged the pedal into the effect loop using two really short, right angled patch cables. And either I've gone deaf or the hum is gone.

I have the reverb pedal sitting on top of the amp, right above the effect loop, attached with two shorty patch cables made by Planet Waves. And I swear it's not humming.

 

[bodia]

I've heard of this before. Somewhere on this forum is a picture (if it's not Photobucket broken) of a right angle plugged into the effects loops, and then doubled back over the top of plug, or something like that. Problem was solved in that case as well. Not sure it was an Archon. May have been a Custom 50.

 

[Deleted member 5962]

That loop trick was for an H or Custom. I remember, because I tried it on my Custom and it didn't work. My Custom has a noisy loop. My Archon loop is not noisy at all. However, thanks OP for what you just said. My pedalboard sits right in front of the amps, and it has a power strip. Some pedals powered by the board and some buy things plugged into it's power strip. I keep saying I was going to try a new power supply for the pedals. Never tried just moving it away from the amp. Will try that on my Custom 50. Archon is fine with it right in front of the cab.

 

[jmp22684]

Ive only had the custom 50 for a couple weeks now. Effects loop noise was unbearable when running 4cm with a Helix, to the point that it wasn't going to get taken out live like that at all.

Ebtech hum eliminator in the loop worked flawlessly.

 

[Ben]

How do you hook up the Ebtech?

I ran the effects send to the Ebtech Channel 1 +4 dBu.
Ebtech Channel 1 -10 dBu to the pedal input.
The pedal output to Ebtech Channel 2 -10 dBu.
Then Channel 2 +4 dBu to the effects return.

What did I do wrong?

 

[jmp22684]

You and I are working with two different units. You have the line level shifter, I grabbed the hum eliminator.

This is the unit I bought:
https://www.sweetwater.com/store/de...5hLvlk1YaViaFRmz6SnhcSBnJJkeTV0EaAgeKEALw_wcB

 

[jmp22684]

I just took a look at the unit you bought. That is designed to convert line level to mic/instrument level.

I would exchange that.

 

[László]

Clearly, what the OP had, and may still have, was a ground loop; there were two paths to ground, which causes hums and buzzes, and makes cable runs pick up EMI and RFI. The short cables worked because they were picking up less noise simply by virtue of their length.

The power supply problem of course added noise as well.

The Ebtech isolates the signal ground, and there are other units on the market that do similar things.

There's a lot of good info on ground loops on the web.

Players sometimes blame the amp, when the problem lies elsewhere. Ground loops are the devil in the studio, and they're often hard to track down when lots of equipment gets connected.

I've torn my hair out often trying to find the source of ground loops!

 

[Ben]

I thought the problem was the mismatch between the line level effects loop and the instrument level pedal. But I guess that isn't it. It's a ground loop problem.

I also tried longer patch cables (2' each) with right angle connectors, but they hummed too. It could be my imagination but I think the reason the really short patch cables don't hum is because - with the pedal(s) on top of the amp - the cables don't dip below the metal back plate. I don't know but maybe the metal chassis helps to shield the cables from the transformer.

Regardless, really short right angle patch cables, with the pedal(s) on top of the amp, seems to work. And I am very happy to have found a solution.

I love the Archon. I don't think there is a better amp out there for the money. But I miss reverb. A decent pedal easily solves the problem. But I want to put it in the loop so it works well on both channels.

I'll probably try a "Hum Eliminator" too. If I do, I'll report back on that as well.

 

[László]

I thought the problem was the mismatch between the line level effects loop and the instrument level pedal. But I guess that isn't it. It's a ground loop problem.

I also tried longer patch cables (2' each) with right angle connectors, but they hummed too. It could be my imagination but I think the reason the really short patch cables don't hum is because - with the pedal(s) on top of the amp - the cables don't dip below the metal back plate. I don't know but maybe the metal chassis helps to shield the cables from the transformer.

Regardless, really short right angle patch cables, with the pedal(s) on top of the amp, seems to work. And I am very happy to have found a solution.

I love the Archon. I don't think there is a better amp out there for the money. But I miss reverb. A decent pedal easily solves the problem. But I want to put it in the loop so it works well on both channels.

I'll probably try a "Hum Eliminator" too. If I do, I'll report back on that as well.

I'd be interested to hear if my theory re: your issue is correct.

If it was a mismatch between levels causing the problem, the cable length wouldn't matter. As to the cables dipping below the metal backplate, gosh, that'd be a reach in my experience; note also that the cables in the front of the amp aren't humming, so if the amp chassis was throwing off so much noise that it induced hum in cables, I'd be hugely surprised.

 

[Fro]

I have one question about your solution of putting your pedal on top of your amp. Were you using a power source for your pedal before and are you powering the pedal with a battery now?
Maybe that was two questions

 

[Ben]

I was using a power source both times. I use those little pedals that don't have batteries.

 

[TroyBaer]

I was using a power source both times. I use those little pedals that don't have batteries.

Do you have other pedals? And which kind of power supply were you using?

One of the things I've found with my Archon 50 is that having a bunch of pedals daisy-chained off a non-isolated power supply (particularly a One-Spot) can be a recipe for strange noises. Most of my Archon-specific noise issues were solved when I moved to using a pedal power supply with isolated outputs.

 

[Ben]

I've tried three pedals through the loop: EHX Nano Reverb, TC Electronic Tuner, and MXR Smart Gate. I don't use any pedals out front. The original power supply was the wall wart that came with the EHX Reverb. All of that hummed (and the cables hummed too).

Now I have the same the same pedals with a "Pig Hog" power supply. Everything is attached with 6" right angled patch cables. The pedals are on top of the amp. And the hum is gone!

I also bought an Ebtech Hum Eliminator, and that works too. If I use the Ebtech there is no hum, even if I use long cables.

So I guess it is a ground loop issue. If you have that issue and use a lot of pedals, it will help if you put them as far away from the amp as possible. If you just use a couple pedals in the loop, a much better solution is to attach the pedals with really short patch cable.

But I think the best option is to get a Hum Eliminator. Put that in the loop and you can put things wherever you want!

 

[László]

Sounds like you've got the problem figured out and solved, Ben!

 

[boardn10]

I thought the problem was the mismatch between the line level effects loop and the instrument level pedal. But I guess that isn't it. It's a ground loop problem.

I also tried longer patch cables (2' each) with right angle connectors, but they hummed too. It could be my imagination but I think the reason the really short patch cables don't hum is because - with the pedal(s) on top of the amp - the cables don't dip below the metal back plate. I don't know but maybe the metal chassis helps to shield the cables from the transformer.

Regardless, really short right angle patch cables, with the pedal(s) on top of the amp, seems to work. And I am very happy to have found a solution.

I love the Archon. I don't think there is a better amp out there for the money. But I miss reverb. A decent pedal easily solves the problem. But I want to put it in the loop so it works well on both channels.

I'll probably try a "Hum Eliminator" too. If I do, I'll report back on that as well.

The loop is Instrument level, not line level, according to PRS.

 

[Deleted member 5962]

Do you have other pedals? And which kind of power supply were you using?

One of the things I've found with my Archon 50 is that having a bunch of pedals daisy-chained off a non-isolated power supply (particularly a One-Spot) can be a recipe for strange noises. Most of my Archon-specific noise issues were solved when I moved to using a pedal power supply with isolated outputs.

One Spots are better used for a few OD pedals in front, than anything in a loop. They are switching power supplies and may amps loops will pick up the switching noise. Some pedals will pick it up as well, even if in front. So as you discovered, a quality iso supply is critical for the loop. (And just a general good idea anyway...)