Setting up dual amps

Discussion in 'Amps & Cabs' started by living room rocker, Aug 12, 2019.

  1. living room rocker

    living room rocker Member

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    Complete ignorance here. I'll soon own a second amp and am thinking what to do with my original cheapo......mothball it, sell it, or? Does an ABY switch allow a guitarist to switch between amps via a foot switch? Will this same ABY switch allow for feeding both amps simultaneously providing a stereo effect? Does feeding (splitting) one's guitar signal into two different amps simultaneously affect the power and tone shaping aspects at each amp? Or is one better off using an ABY switch primarily to access each amp independently?
     
  2. Bob Womack

    Bob Womack Active Member

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    A simple ABY such as the classic Morely does, in fact, allow you to switch between amps and use dual amps. There are a couple of "BUTs" in the situation, however: It works as long as the two amps are in-phase with each other and their grounds are in sync. You'll instantly know if there are problems. With phase, the two amps combined will cause a thinned-out sound. With the ground issue, there will be a terrible hum. In either case you need to go with a slightly more complicated ABY that allows phase to be shifted and ground isolate with a transformer.

    Hope that helps,

    bob
     
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  3. living room rocker

    living room rocker Member

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    It does help Bob, thank you. Is a stereo setup even a worthwhile pursuit given my gear. Would be pairing a Roland JC40 with a cheap Fender Champion 20 modeler. How important is amp pairing in getting a good quality stereo sound. Is stereo typically achieved by pairing identical amps?
     
  4. plankton

    plankton Well-Known Member

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  5. GrumpyOldDBA

    GrumpyOldDBA Well-Known Member

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    Ummm your guitar is probably not putting out a stereo signal.

    There are a few ones that do but very limited.

    So trying to do multiple amps is something that does not need done for most of us.

    Just hide the old amp somewhere thats the typical solution?
     
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  6. Clifdawg

    Clifdawg Well-Known Member

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    As plankton mentioned, your JC-40 already has stereo inputs and will send left and right signals to each speaker. No need to set it up with the Fender Champion.

    My suggestion - get a Boss GT-1. It's 200 bucks. I love mine, has some great modeling capabilities (it's what the Boss Katana is based on), but in your case the important features are that 1. It's designed to specifically work best with the JC series of amps, and 2. It outputs in stereo, and the effects will be in stereo.

    I can only imagine what the Marshall 1959 I+II model would sound like with the stereo reverb and chorus of a JC-40... :naughty:
     
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  7. living room rocker

    living room rocker Member

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    This underscores my ignorance of what stereo actually is. I've always assumed two amp combos received the same exact guitar input. Henceforth, placing one amp combo in one corner of a room and placing another amp combo in the opposite corner of the room would provide a stereo effect. Apparently that's not technically correct?
     
  8. Bob Womack

    Bob Womack Active Member

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    The technical definition of "stereo," ie. stereophonic reproduction, includes having two sources picked up by two mics and played back with two channels and speakers. Of course, we aren't talking about reproduction but instead about production of the initial sound. In that context, a defining criterion seems to be two sources with some difference between them. That could include level, timbre, or some form of modulation.

    If the two amps are different enough, any distance between them will contribute to a "spreading" effect. If they have different-sounding reverbs, that will add to it. If you have a true stereo pedal board with stereo effects and send the left and right outputs to separate amps, you've got stereo.

    Most people I know who have connected to two amps have experienced an interesting stereo effect just because the two amps perform differently. Frequencies missing from one my be supplied by the other. Distortion may occur earlier with one amp. In my stereo rig I take it a step further and make one of my two amps a rotary speaker amp such as a Motion Sound Sidewinder or a Leslie. When I put the rotary amp in "chorale" (slow) mode, it swirls the whole thing around the room luxuriously. Yummy.

    Bob
     
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  9. cerebral gasket

    cerebral gasket Well-Known Member

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    Replace the TS (mono) output jack on guitar with TRS (stereo) output jack so that the neck pickup goes to the first amp and the bridge pickup goes to the second amp.

    [​IMG]

    Just kidding.
     
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  10. plankton

    plankton Well-Known Member

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    The guitar doesn't need to put out a stereo signal, as Bob so eloquently explained above. One of the great things about a two amp setup is that it can become more than the sum of its parts. Often people will use two amps with an A/B switch using one for clean and the other dirty. Before more modern amps it was a good way to get Fender cleans and Marshall dirt, by using those actual amps.

    The really nice thing can be using both together with an ABY switch. The two amps can be setup to really complement each other, and if they have some separation in the room you get that stereo effect and everything just sounds bigger.

    But personally, with the OP's options, I would use the JC-40 as my main amp and the Champ 20 as a backup (or just sell it).
     
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  11. the jaywalker

    the jaywalker New Member

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    The Radial "Twin City" Bones does a good job of amp switching A or B or A&B. It also has a slide switch to reverse phase on one amp (or channel). The phase switch also does the job for correcting phase between the Trem circuit and the Normal channel in my BFed Fender Super Reverb so yes you can run and blend both channels (at least on mine. Should do the same for any of the two channel Vintage Fender amps with rev and trem). I also TweedyFied my Normal channel for more variety.
     
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  12. Bad Penguin

    Bad Penguin Active Member

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    I use a two amp system when playing live, a Roland Bolt 60 and a Roland Blues cube (the original one.) Generally, any true "stereo" effect I use is a delay pedal. (short ping pong, or modulation. ) Sometimes an EH Mel9 on one amp, clean on the other, or I have a guitar that actually is stereo. (A modified Ibanez Artist.)
     
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