A-B-Y Box Noise:

[Thatbastarddon]

And the Ccol Switch Pro also has an isolation transformer....

Only one isolation transformer, on one output…same as the entry level Radial ABY(I forget the model name-the light blue one).

The box that solved your issue has one on each output.

 

[Inspector #20]

Only one isolation transformer…same as the entry level Radial ABY(I forget the model name-the light blue one).

The box that solved your issue has one on each output.

Ahhhh....Ok...that explains it. I'm new to running double amps.

 

[Thatbastarddon]

Ahhhh....Ok...that explains it. I'm new to running double amps.

I am familiar with the transformer phase consideration within a circuit. I’d never thought to apply it to multiple amp’s. It makes sense though, as they are part of the same circuit in this application.

 

[Inspector #20]

I am familiar with the transformer phase consideration within a circuit. I’d never thought to apply it to multiple amp’s. It makes sense though, as they are part of the same circuit in this application.

I'm real happy with the rig! Thanks for you and everyone else's input!

 

[Thatbastarddon]

Don’t forget to verify that your speakers are all in phase too. This will really only be necessary if you ever want to run the two amps at the same time.

 

[Inspector #20]

Don’t forget to verify that your speakers are all in phase too. This will really only be necessary if you ever want to run the two amps at the same time.

Right!!! We have actually had clients ask us to reverse speaker polarity on one cabinet in a stereo setup.

 

[Inspector #20]

 

[Amp Mad Scientist]

Even with the One Spot and all FX disconnected the noise was still present.

I don't usually use isolation transformers because to me they kill the audio quality.
I hear the frequency response disappear. To my ears, it dulls the sound.
Really good transformers (as good as it gets) cost a lot.

No matter what type system, it always sounds better to me without the transformers.
I have tested this many times.
Granted, based on my own hearing. There is no meter that tells you or me what sounds good.

I have always been able to solve ground loop hum without using transformers. I can't think of a single system that wasn't solvable, and I have worked on a lot of systems.

But there are a couple exceptions where transformers will benefit:

A. Long mic snakes / large venues (a lot longer cable than a guitar rig would require...)
There is definitely an advantage to using (really good) transformers for systems that have long snakes between the stage / monitor mix and the FOH mixer.
But not because of ground loops.
Because that's so much loss in the long snake wires, that a transformer actually becomes useful.
Particularly for low frequencies / sub woofer.

B. Cable TV ground loop. Cable TV would include internet...
But Cable TV can cause horrendous ground loops in audio systems .
In which case a cable TV isolation transformer becomes very useful.

To me, the concept of audio transformers is outdated for connecting sound systems.
I don't like the way transformers sound.
There is always a way for me without the transformer.

 

[Amp Mad Scientist]

I’m glad you have it solved. I was suspicious of a switching power supply transformer(your 1Spot) contributing to the issue. They’ve been known to cause zero problems…until they suddenly don’t. Usually stemming from that one additional/changed out pedal….then hummmmmmmmmm’s-your-uncle. I was curious if @67plexi had a similar suspicion.

Switching power supplies can create all sorts of irritating noise and power harmonics.
Solar energy power inverters...
There certainly are a growing number of noise sources I don't doubt that.