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samal50

Isn't an AB/Y switch pedal similar to a summing amp pedal?

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JHS Pedals Summing Amp

 

https://www.musiciansfriend.com/amplifiers-effects/jhs-pedals-summing-amp/l51834000000000

 

Old Blood Noise Endeavors AB/Y Switcher Pedal

 

https://www.musiciansfriend.com/amplifiers-effects/old-blood-noise-endeavors-ab-y-switcher-pedal/l53298000000000

 

An AB/Y switcher pedal could be a summing amp too like the JHS Pedal linked above, right?

 

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JHS Pedals Summing Amp

 

https://www.musiciansfriend.com/amplifiers-effects/jhs-pedals-summing-amp/l51834000000000

 

Old Blood Noise Endeavors AB/Y Switcher Pedal

 

https://www.musiciansfriend.com/amplifiers-effects/old-blood-noise-endeavors-ab-y-switcher-pedal/l53298000000000

 

An AB/Y switcher pedal could be a summing amp too like the JHS Pedal linked above, right?

 

I'd need to see the schematic (or a gut shot) of each pedal to say for certain, but technically an active summing amp isn't the same thing as a passive AB/Y switching pedal, although if it has the right resistors, an AB/Y can be used "in reverse" and act as a resistive mixer and sum two signals, although with some signal loss; an active summing amplifier also combines or sums two signals, but can be designed and wired in such a way as to do so without a voltage drop since they include an operational amplifier (opamp) as part of their circuit.

 

 

 

 

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yeah' date=' except most a/b-Y pedals can go two to one, or one to two...[/quote']

 

A Summing Amp is just 2 to one, NOT one to two then?

 

I would assume an A/B Y Pedal would be more advantageous than a summing amp because I think it can be a summing amp as well, technically? 2 to one IS "summing", right? So is an A/B Y Pedal a summing amp in disguise that's more versatile?

 

Here's an overview of the summing amp:

 

OVERVIEW

 

Mix two sources into one to create a tone bigger than both.

 

The JHS Pedals Summing Amp gives you the ability to take two inputs and blend them into one output. Simply plug into the two marked inputs and then plug in your single output and you’re ready to go. From two signals, the Summing Amp creates one mono signal.

 

This is perfect for putting effects in parallel so that they are not affected by one another. The Edge used this technique in the '80s with his delays. When you have a quarter-note delay and a dotted eighth delay, and you place them in parallel, then sum them back together, the effect is that both delays come through more clearly and are not “delaying the delays." This can also be used with overdrives so that they are not pushing each other as in series, but sit atop one another in parallel. Another use is combining fuzz and compression in parallel so the fuzz isn’t getting choked by the compression.

 

The Summing Amp gives you the ability to use effects together in completely new ways that you may never have imagined and can open up new and inspiring sounds with your old effects. This simple little box takes two inputs and creates one output but it adds up to a whole lot more!

Edited by samal50

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like Phil mentioned, the Summing Amp has an op amp to prevent signal degradation and balances both channels to an equal 'summed' signal, whereas the A/B-Y combines the two without any boost or cut. I have used my A/B-Y both ways over the years: combining two signal chains [one dry, one with effects] and as a signal splitter to drive two amps from a single source [good on large stages for monitoring purposes with small amps], which also allowed me to try a dry vs effects laden signal chain to separate amps.

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the A/B portion simply lets you select between two inputs or connected in reverse, splits a signal to one output or the other.

The Y portion you have to be careful. If you used a mono in then used the A/B portion to select one amp or another, then select both in a Y configuration, you'd probably be OK because you're only connecting the amp inputs.

 

If you try and combine active signals from pedal outs in a Y configuration then there would be any buffering. The pedals wouldn't simply combine, the output of one pedals can feed into the output of another pedal in the wrong direction. Getting a balance between the two pedals running in parallel may not be possible without buffers.

 

An ABY is often used for a player who switches instruments regularly. he can leave both instruments connected then simply switch between one or the other. The Y portion wouldn't be of much use however. if you turned the volume off on one instrument you'd attenuate both because the pots are in parallel to each other.

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On 5/9/2019 at 1:36 PM, Phil O'Keefe said:

 

I'd need to see the schematic (or a gut shot) of each pedal to say for certain, but technically an active summing amp isn't the same thing as a passive AB/Y switching pedal, although if it has the right resistors, an AB/Y can be used "in reverse" and act as a resistive mixer and sum two signals, although with some signal loss; an active summing amplifier also combines or sums two signals, but can be designed and wired in such a way as to do so without a voltage drop since they include an operational amplifier (opamp) as part of their circuit.

 

 

 

 

I'm not sure if the summing amp I speak of are even active. This one from Radial Engineering sure isn't:

https://www.sweetwater.com/store/detail/Mix21--radial-mix-21

From what I understand an AB/Y pedal allows 2 guitars to plug into a single amp, or 1 guitar into 2 amps (this might come across like it's similar to what a summing amp is then?).

Edited by samal50

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the Radial unit you linked to is a 2 channel mixer, not exactly a summing amp. It will take two discreet inputs and allow you to balance them, correct for phase cancellation issues [a nice feature] and send both channels as one output.

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I have a Livewire A/B Y pedal.  I can send one signal in and two out or two signals in and one out.  It uses one battery but the only thing the battery does is operate the led lights telling me what's on.  Since I use it to send the signal from my pedal board out two amps I don't even use the battery.  I just make sure they're both on.  I guess the JHS must PROCESS the signal.  

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Most ABY pedals contain no buffering at all. Its just a straight switch with direct connectivity, same as using a Y jack.

This does mean the impedances of a single output can be loaded down by having two loads instead of one, or vice versa. 

I wouldn't try to feed two inputs into a single output with one of these.  The pedal does not act like a mixer and there is nothing separating the two inputs from pone another. You risk damaging one piece of gear when you Y jack two together and feed the output of one device into the output of another. 

This is why they make Mixers, Line and leveling amps.  A/B/Y boxes are normally used for Passive circuits, like connecting two guitars to one amp or switching one guitar to two amps. When combining active signals, you need to buffer and match impedances so you want to use the proper active or transformer based devices for those applications. 

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I see. So an AB/Y pedal is not processing any effect signal? I'm not sure which product it was that I read about that mentioned that it can turn on an effect or amp during chorus and can turn it off during verse. Sounded like it was an AB/Y pedal. 

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