That was one of the versions that I had contemplated last year…never took the plunge.
A-B-Y Box Noise:
- Thread starter Inspector #20
- Start date
Ok,
The noise from running two amps is overwhelming. I'm using the Cool Switch Pro Passive A-B-Y box that has a ground lift Switch, a phase switch and a transformer isolate switch.
Both my Blackstar ID-Core 100watt and my 1999 Marshall MG50 Solid State behave in exactly the same manner.
Both amps are powered from a Fuhrman SS-6B power strip.
Using a modified ground lift cable makes the noise even worse.
Here's a short video I shot today:
Noise From Two Amps Through Cool Switch Pro A-B-Y Box:
Ground lift feature doesn't cut the noise. I've used both a Blackstar ID-Core 100watt solid state and a Marshall MG50 Solid State with identical results. A g...youtube.com
Robert,
You say both amps are "powered from a Fuhrman [sic] SS-6B power strip."
Does this mean both amps are plugged into the same strip, or are you using a separate strip for each of them?
Also, if you are using a box with an isolation transformer, you don't need the modified guitar cable.
How do you actually have everything connected?
BTW, is this the unit you're using?
syscokid
Ambassador of War & Peace
I didn't catch that. A power strip is not the same as a power supply conditioner with isolated AC outlets. The power strip with two amps plugged into it could be a problem?
Jethro Rocker
Ambassador of Live & Loud Action
My Radial ABY seems to work great w the iso and geound lift switches. I wonder... to get to LEDs one powers it and I wonder whether an active powered box worrks better?
OP
I wonder if Robert's ART amp switcher pedal is defective...
Radial Engineering (Canada) products must be good stuff. Excellent reviews on any of their stuff that I have looked into. The Radial Switchbone V2 is loaded with extra features. Maybe (@Robert Herndon) can consider the simpler and less expensive Radial Twin City as an alternative:
Could be a defect I suppose. It's new and under warranty.
OP
Hmmmmm....
So, you have both amps plugged into the one strip?
Incidentally, that is what you should do. It is less preferable to use a different strip for each amp.
OP
Yes Sir...
OP
Maybe i could figure out what's wrong with my setup via testing????
Remove all other pedals from the equation. See if it still makes noise with standard cabling.
Amp Mad Scientist
Ambassador of Heresy
If you turn down the volume of the slave amp does the hum go away?
Does the slave amp hum after you un-plug it from the A/B switch cable? Or does the hum stop?
If you touch just the ground of the cable (from A/B switch) to the metal part of the amp chassis without plugging the cable in to the amp, does it make the amp hum?
OP
I will have to check this behavior exactly as you have written it...
How do you have everything connected in the A/B switch?
OP
Tonight, I bypassed all the FX and just hooked the origin 50 to 'Output A' of the ABY box (Origin Input cable to ABY Box Output A) and I plugged the Blackstar into the 'Output B' of the ABY box. (This is how the instructions say to connect two amps.)
I get really loud 60 cycle hum. Activating the ground lift, transformer isolation and/or phase switch on the ABY box does not stop the noise, but it does change the frequency, as I posted in the video link above.
If I unplug the slave amp from the A-B-Y box, the hum stops, even with the slave amp's volume up
I can turn the Blackstar down enough that the volume drops to zero.
OP
Guitar into ABY "Input"
Output A to Origin Input Jack
Output B to Blackstar or Marshall MG50
Same behavior on both amps.
Same behavior when taking power for each amp from a different location in the house.
Okay…and setting the Transformer Isolate switch to “Isolate” doesn’t help?
OP
Nope. I am stumped.
Noise From Two Amps Through Cool Switch Pro A-B-Y Box:
Ground lift feature doesn't cut the noise. I've used both a Blackstar ID-Core 100watt solid state and a Marshall MG50 Solid State with identical results. A g...
youtube.com
OP
Yep.