Can anyone explain why I need more than a Morley ABY?

[Pale Rider]

All I want to do is be able to switch between amps and combine them -another loop is cool, but why would I need a lift, etc

Apologies for the stupidity-plus we can't search for "aby" as it's too short
Thanks

[stinkfoot]

It depends. The Morley (and others like it) is passive and non-isolated. Passive means it has no buffer stage, which can be a problem if you plug the guitar straight into it and hit the "Y" mode (running the amps' input impedances in parallel can make the total too low for a passive guitar). That problem is easily solved by keeping a buffered pedal (Boss-type or other pedal left on) in front of the ABY - something most players will do by default.

The other main problem that may occur has to do with ground loops - combining two amps can cause ground loop hum (you'll know instantly if you get it), due to the dual ground connections (both through the safety ground system and through the signal cables). A properly isolated ABY will prevent ground loops, as one or both outputs are transformer isolated (breaking the signal ground connection between the amps).

A third problem (far more uncommon than the other two) is phase issues. Some amps run their inputs in reverse phase - some older Fenders even have the normal and vibrato/reverb channels out of phase with each other - which normally isn't a poblem. But when combining amps, both have to be in phase, or you'll end up with a hollow, thin sound. It's not a very common problem (compared to the other two), but if you encounter it, the signal to one of the amps has to be phase-reversed.

So, while a Morley (or any other type of passive, non-isolated ABY) can work great for you, you will need more if you experience any of the above problems.

[Pale Rider]

Thanks for putting that in almost pure idiot-proof terms-very helpful-
anyone care to make a suggestion of a great ABY box that will take care of any problems possible?
switchhazel? radial?
Thanks again

[stinkfoot]

I usually suggest Lehle, but if you also need a phase switch, Radial has those. The Framptone Amp Switcher is very good, but at a price... :D

[Pale Rider]

sTNKFOOT-
there's no real way to know until you plug in right?
it would be between a VOX AC30 and Victoria Regal II and eventually a 5E3 clone

[Pale Rider]

So now that I pretty much understand why about this, I need a good recommendation that won't have a ny tone suckage and has a buffer-polarity switch and these bells and whistles-
is this my best option:
http://www.tonebone.com/bones-twincity.htm
http://www.radialeng.com/images/Bones-TwinCity-34-dds-540.jpg

[Bo Faulkner]

I use the Radial Switchbone (which appears to be the twin city with added boost ability and tuner out) If the twin city is as good as the switch bone and you dont need the features I'd highly recommend it

[lord preset]

This works too and is cheaper if you don't need a buffer.

http://www.tonebone.com/images/bigshot-aby-slice.jpg

[stinkfoot]

sTNKFOOT-
there's no real way to know until you plug in right?
it would be between a VOX AC30 and Victoria Regal II and eventually a 5E3 cloneNope. The Twin City looks interesting - could be worth a try.

[aziltz]

+2 for Big Shot and/or Twin-City

[frisco]

+1 Radial Bigshot. No noise issues.

[glennc100]

I recently needed an ABY and was in same situation. I ended up with the radial switchbone off ebay for 200 in excellent condition. When I hooked it all up it sounded fine, but when I switched the phase reveral--BAM! my amps sang in true unison, it was amazing. I highly recommend the switchbone because of the above and it truly did eliminate the hum, it was an astonishing improvement. I implore you to get this pedal or something with phase reveral and ground loop elimination. The booster also is a tremendous difference. It's a fantastic piece of equipment.

[mix2much]

I recently used a Radial Big Shot and it was great. It's non powered which means no LED indicator but you can tell which amp is on right?

[Pale Rider]

Thanks for all the help here-
so the only real difference between the Radial Switchbone and Twin City beside size is the boost and tuner out it seems-
correct?
the Twin City has the phase reversal and ground loop elimination. plus it's small

Thanks!

[michael.e]

I have the bigshot and it does have both the phase reversal and the lift.

I have run through the gamut of switchers and for my purposes, the Bigshot makes the most sense and I am totally happy with my tone.

[Realfi]

I usually suggest Lehle, but if you also need a phase switch, Radial has those. The Framptone Amp Switcher is very good, but at a price... :D

Lehle dual and little dual have these features.

[Guitar Dave T]

It depends. The Morley (and others like it) is passive and non-isolated. Passive means it has no buffer stage, which can be a problem if you plug the guitar straight into it and hit the "Y" mode (running the amps' input impedances in parallel can make the total too low for a passive guitar). That problem is easily solved by keeping a buffered pedal (Boss-type or other pedal left on) in front of the ABY - something most players will do by default.

The other main problem that may occur has to do with ground loops - combining two amps can cause ground loop hum (you'll know instantly if you get it), due to the dual ground connections (both through the safety ground system and through the signal cables). A properly isolated ABY will prevent ground loops, as one or both outputs are transformer isolated (breaking the signal ground connection between the amps).

A third problem (far more uncommon than the other two) is phase issues. Some amps run their inputs in reverse phase - some older Fenders even have the normal and vibrato/reverb channels out of phase with each other - which normally isn't a poblem. But when combining amps, both have to be in phase, or you'll end up with a hollow, thin sound. It's not a very common problem (compared to the other two), but if you encounter it, the signal to one of the amps has to be phase-reversed.

So, while a Morley (or any other type of passive, non-isolated ABY) can work great for you, you will need more if you experience any of the above problems.

A forth problem with basic a/b/y switches is you're splitting and weakening the signal to each individual amp in "y" mode. A good Lehle, Radial or even Voodoo Labs amp switcher eliminates the problem.

[stinkfoot]

Lehle dual and little dual have these features.

Indeed they do - I took a quick peek at their website and didn't see it. It's mentioned in the manual, though. Even better :AOK

[stinkfoot]

A forth problem with basic a/b/y switches is you're splitting and weakening the signal to each individual amp in "y" mode. A good Lehle, Radial or even Voodoo Labs amp switcher eliminates the problem.That's actually the first problem I mentioned. :D

The signal isn't weakened by the splitting (like splitting a water pipe into two hoses does), but the combined input impedance of the two amplifiers can get too low for the guitar pickups to drive. A buffer in front of the split (either in the ABY itself, or right in front of it) will take care of that problem.

[Guitar Dave T]

That's actually the first problem I mentioned. :D

The signal isn't weakened by the splitting (like splitting a water pipe into two hoses does), but the combined input impedance of the two amplifiers can get too low for the guitar pickups to drive. A buffer in front of the split (either in the ABY itself, or right in front of it) will take care of that problem.


Thank you for explaining that.

I ran a Morley a/b/y switch a few years ago for a medium-large club where the sound man was just awful, and could not be trusted to mic and mix a single, small guitar amp, so I ran two small amps in order to rely solely on amp volume.

Problem was the weakness of signal you illustrated was readily apparent in the tone of the amp, especially when we mic'd it one show for recording.

Meanwhile, I had a buffered amp switcher built for me in the 80's before you could buy Radials and Lehles off the shelf, that had been retired for over a decade.

Then I 'rediscovered' it when cleaning out the garage, where it had sat since the days of multi-big-amp rigs in large hotel ballrooms (I retired it because I finally wised up to the fact that our sound man had a talent for micing and mixing a single small amp to FOH nicely, and he could even make it sound 'big' on stage through the monitor mix).

Since rediscovering it, I now use it for micing a couple small amps in clubs, not to be loud, but to comliment each other's tones. Works like a charm. I even use the third, unused circuit, to bypass straight to the tuner.

[Pale Rider]

JUst an update, in case anyone ever reads this:
I bought a Radial Twin City ABY and it is great-it's the only unit I've ever used like this but it does exactly what I need it to -the LED lights are great for switching-all the bells and whistles of this unit are great
stereo never sounded so good

[fendergeek]

+1 Radial Bigshot. No noise issues.
:agree

[methenyesque]

Just as a general question, how does running an ABY box compare sound-wise to using a stereo effect pedal (chorus, delay, etc.) to split the signal? Obviously, one is stereo and the other is mono...but which way will generally give you the best overall tone?

I suppose utilizing effects loops or not also factors into the equation.

[krisharmony]

I'm wondering what kindof power supply the Bones series Twin-City runs off of, can one use a Pedal Power 2 or does it require its own wall wart?

[stinkfoot]

The website says standard 9vDC (Boss-style plug), 100mA. So it should work from a Pedal Power 2+.