Passive or Active A/B box?

[funky-one]

Hi!

I am trying to decide whether a passive or active AB box would work better for me.

This is my set-up:
1) 2 amps. 1 for clean tones and looping, the other one for dirty tones, lead and everything else.

2) Guitar with passive pickups

3) My proposed signal chain is this:

Guitar out -> Korg DT-10 tuner -> TS808 -> Plextortion -> AMT E1 -> Phase 90 -> AB switcher

For A: -> DD-7 (used as a looper) -> clean amp
For B: -> DD-6 -> dirty amp or efx return on amp head

I think that an active AB box would be the best option to minimize signal loss. Radial Bones Twin-City seems like a good choice or sth made my TYMC.

I am especially confused with the issue of ground hum and amps being out of phase that I have read online.

Any thoughts/explanations would be much appreciated!

Thank you!

 

[tyzjames]

Hi funky-one,

I took this off the fulltone site, hope it helps.

"First, let's mull over the problem with ABY boxes!

There are 2 types of A/B boxes out there:

Passive A/B boxes

These are simple, inexpensive units using a footswitch to toggle between two outputs... some adding a second footswitch to combine the ouputs for the "Y" function. (both amps on) This can work fine when the AB box is placed AT THE END of a chain of various effects pedals, right before the amps.

The first problem arises when (like me) you use a separate effects setup for each amp, placing the A/B Box BEFORE all the effects. THIS is when you will experience horrendous POPPING sound while switching between amps.
The second problem (if you use fuzzes or hi-gain pedals) being a very loud white-water sounding HISS should you ( for example; have a fuzz on side "A") then switch to side "B" without turning off said Fuzz.
The third problem is that you will get "loading" between the amps when running in "Y" mode where both amps are on at the same time, taking away highs and muddying up your sound.
The fourth problem can be "phase issues" when running both amps in "Y" mode. When 2 amps are out-of-phase it can be very odd sounding, with an apparent loss in volume instead of the expected increase and a very strange EQ, like a wah-wah being on in a fixed position.
The fifth problem can be dangerous as well as noisy; when a "ground loop" happens while connecting two amps via an A/B pedal, the result can be a constant loud HUM and could result in a nasty shock, especially hazardous when stepping up to a vocal mcirophone!
Active A/B boxes

Some active boxes can alleviate the loud popping sound, but do nothing for the other problems common to Passive A/B/Y boxes. And they introduce a new problem; They convert your guitar's native Hi-Impedance signal to Lo-Impedance. And most great distortions and Fuzzes simply do not like to see Lo-Impedance signal! They lose volume, dynamics, become trebly sounding... it just changes everything for the worse."

 

[funky-one]

Hi tyzjames!

That's a really good summary of the things I need to know! Thank you for sharing!

So it looks like a passive one would work for me

 

[carboxymoron]

I've had decent results with the Radial BigShot ABY. It's passive but includes the same isolation transformer, ground lift and phase switch in their active products, and overall seems a much more solid pedal than most simple passive switchers. Also seen it on quite a few other boards locally (at least, some years ago).

The drawback as pointed out is the load which may be noticeable as reduced treble, but that can usually be compensated for by tweaking your amps.

 

[mightyboy88]

i would think that the radial bones twin cities could be a worthy investment, especially for splitting two signals out to two amps, where ground loops could be a big issue. The twin cities has got an isolation transformer on one of its outputs so i guess the grounding of both loops will be isolated from each other and hence eliminate issues of ground loops

The twin cities also has a phase reverse switch which could be useful in future if you are adding pedals after the signal is split, you never know which pedal will require phase inversion so it is always good to have a phase reverse at hand

 

[funky-one]

The drawback as pointed out is the load which may be noticeable as reduced treble, but that can usually be compensated for by tweaking your amps.

Hi carboxymoron!

Regarding the reduced treble you mentioned, does it occur when you engage both amps at the same time aka Y or is it because you the the Bigshot ABY at the start of your signal chain before your effects?

I am actually considering to the the Radial Bigshot ABY too! hehe

 

[carboxymoron]

I can't remember exactly as it was quite a while ago, but I think there might be some effect even without both outputs engaged. Slightly more if you also connect the always-on Tuner Out.

 

[simplecomplexity]

i use a T-rex polyswitch. so far so good.

 

[funky-one]

I just got my hands on DOD 270 A-B box. I am loving it.

Silent switching and doesn't suck tone! YAY!

Even though it does not have a Y function, it will do for now.