syscokid
Ambassador of War & Peace
A-B-Y Box Noise:
- Thread starter Inspector #20
- Start date
OP
More testing....
OP
Ok!!!!
So, I was discussing this anomaly with a producer friend and he said, "Dude, I got a brand new Lehle ABY. Just swing by my pad and grab it."
He just so happened to be spending a week at his cabin in Big Bear, so it was just a 20 minute drive for me.
This is a powered ABY with an 'Eprom,' so the proximity switch functions are fully programmable.
The A & B sections are electronically isolated and It also has an audio ground lift feature.
The 3 switches have a bright light next to them. Channel A is Green, Channel B is Yellow and Channel C is Red.
I programmed it to "Mode 1" where it functions as a standard A-B switcher.
Get this...
It's dead quiet. No noise when switching. No noise at idle. No need to lift the AC Mains ground or use a modified ground-lift cable.
(Testing was conducted with amps plugged into different power strips/outlets in the same room)
Really impressed. I've never used one of these Lehle products before. They are top notch.
The only downside was I had to rearrange my board... :-(
Will need further testing at the rehearsal studio on Saturday.
So, I was discussing this anomaly with a producer friend and he said, "Dude, I got a brand new Lehle ABY. Just swing by my pad and grab it."
He just so happened to be spending a week at his cabin in Big Bear, so it was just a 20 minute drive for me.
This is a powered ABY with an 'Eprom,' so the proximity switch functions are fully programmable.
The A & B sections are electronically isolated and It also has an audio ground lift feature.
The 3 switches have a bright light next to them. Channel A is Green, Channel B is Yellow and Channel C is Red.
I programmed it to "Mode 1" where it functions as a standard A-B switcher.
Get this...
It's dead quiet. No noise when switching. No noise at idle. No need to lift the AC Mains ground or use a modified ground-lift cable.
(Testing was conducted with amps plugged into different power strips/outlets in the same room)
Really impressed. I've never used one of these Lehle products before. They are top notch.
The only downside was I had to rearrange my board... :-(
Will need further testing at the rehearsal studio on Saturday.
OP
Well, I could totally eliminate it by lifting the AC plug ground on the slave amp, so whatever it was, it was related to the ground circuit.
Curious as to your thoughts on what it was...as I have my own.
Excellent news, Robert!
This is the right way to deal with your ground loop issue. The Lehle products are really good.
OP
I'm totally open to discussion on this.
A modified 'ground lift' audio cable between slave amp and ABY Box had no effect whatsoever on the noise.
I moved this modded cable between primary amp and ABY and also used it between the guitar and the ABY input with no change in the noise.
I got this same noise with 3 different amplifiers and the noise was consistent at my home studio and at the music academy where I teach.
The Cool Switch Pro Passive ABY Box has an isolation transformer, phase switch and audio ground lift. As you can see in the videos posted, none of those features eliminated the noise.
The ONLY thing that killed the noise was using an adapter plug to lift the AC Mains Safety Ground.
OP
Agreed. This is my first experience with these Lehle products. It's very, very well made and works perfectly.
With the Ivanberg Modded ORI50, a clean amp is an absolute necessity.
OP
Here's how the board looks now...the cable to the wah is tethered to keep it from raising up and getting caught in the pedal mechanism.
Cable paths under the board...
The left side of the board.
I added a second One Spot dedicated to just the Lehle SGos A-B-Y Box. However, I have at least one insulated tap under the board that could be used to power it.
Thus far, there have been no noise issues with the second One Spot.
Cable paths under the board...
The left side of the board.
I added a second One Spot dedicated to just the Lehle SGos A-B-Y Box. However, I have at least one insulated tap under the board that could be used to power it.
Thus far, there have been no noise issues with the second One Spot.
OP
I wonder if Robert's ART amp switcher pedal is defective...
I thought so too, but I'm not certain.
OP
@smitty_p - Just for fun, the signal chain is:
Tuner ---> Wah ---> ABY Box Input ---> ABY Box Output 'A' ---> TS-9---> Primary EQ ---> Compressor ---> Noise Gate ---> Front (input) of Ivanberg Modded Marshall Origin 50
Boss FV30L----> FX Loop Send ---> Chorus ----> Secondary (Solo Boost) EQ ---> Delay ---> Reverb Pedal ---> FX Return of Ivanberg Modded Origin 50
ABY Output 'B' to Blackstar ID-Core 100watt Solid State Amplifier for "Cleans Only."
This is my teaching platform, so I want to control the noise and have a reliable unit.
Tuner ---> Wah ---> ABY Box Input ---> ABY Box Output 'A' ---> TS-9---> Primary EQ ---> Compressor ---> Noise Gate ---> Front (input) of Ivanberg Modded Marshall Origin 50
Boss FV30L----> FX Loop Send ---> Chorus ----> Secondary (Solo Boost) EQ ---> Delay ---> Reverb Pedal ---> FX Return of Ivanberg Modded Origin 50
ABY Output 'B' to Blackstar ID-Core 100watt Solid State Amplifier for "Cleans Only."
This is my teaching platform, so I want to control the noise and have a reliable unit.
syscokid
Ambassador of War & Peace
Glad that a quiet path has been achieved with the Lehle "1 at 3" amp switcher (New @ $300).
And now, to muddy-up this thread...
Since I'm a big fan of Fulltone products, may I suggest a look at their amp switcher: the
True-Path CS-ABY-ST V2 @ $213 new.
And now, to muddy-up this thread...
Since I'm a big fan of Fulltone products, may I suggest a look at their amp switcher: the
True-Path CS-ABY-ST V2 @ $213 new.
Custom Shop True-Path CS-ABY-ST V2
The CS-ABY-STv2," is the best ABY switcher in the world. It has silent soft switches with no pops, no ticks, and no electrocutions, thanks to a Nickel core custom-wound 1:1 transformer that doesn't boost the treble frequencies like the "industry standard" Jensen transformer does, so fuzzes...
store.fulltone.com
Amp Mad Scientist
Ambassador of Heresy
That's good news got rid of the noise...
"The ONLY thing that killed the noise was using an adapter plug to lift the AC Mains Safety Ground. "
OK That is telling you something.
So...it "is" a ground loop...
2. or there is something (possible) wrong with the power ground itself.
Do you have a receptacle tester?
This is a cheap little didy that tells you if the power is wired correctly, and that there "is" a ground.
You can buy one at the hardware store etc...
I would rather carry one in my guitar case to test at any place / venue for safety before using the power.
If there is any wiring error the lights tell you. If there is no ground you will know...But I'm starting to think it's some noise from somewhere...
and the ground loop may be inside the first A/B switch according to some design error?
But what I don't understand is
why does lifting the power ground stop the noise?....
.......................................but still there is noise after lifting the signal ground?
It should work either way.
It should stop the noise too when the signal ground is lifted. That's what I don't get.
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OP
I'm gonna get a signal tester as you described. But, the noise was the same both at my home and two studios!!!
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.
OP
And the Ccol Switch Pro also has an isolation transformer....but it didn't make a difference.
OP
Even with the One Spot and all FX disconnected the noise was still present.