Question about High and Low sensitivity inputs on 2204

Discussion in 'The Workbench' started by Joe Levens, Aug 13, 2020.

  1. Joe Levens

    Joe Levens New Member

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    I have a 2204 (from 1977) which has High and Low sensitivity inputs (one channel, with preamp master volume). I do not use the Low, and would like to have my guitar go into two separate amps simultaneously. I am wondering if I can rewire the Low jack to take the input from the High jack, thinking this essentially will then let me plug an instrument cable into the Low jack and run it to a separate amp when I would like to run two amps.

    Can anyone tell me if this is correct and safe? I would be disconnecting whatever is currently hooked up to the Low jack. I would need the amp to function normally if an instrument was plugged into the High and I did not have anything connected to Low.
     
  2. South Park

    South Park Well-Known Member

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    Plug it in and try it . It just might work if not it would take a lot of work to get to work . And the amp might not be the same
     
  3. JM5010

    JM5010 Active Member

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    Don't mod it, get a A/B/Y box (whatever they're called).

    That is a good amp, don't hurt the value of it!
     
  4. South Park

    South Park Well-Known Member

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    I just got a Moore reverb pedal that you can run both amps . That might be what you are looking for
     
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  5. Joe Levens

    Joe Levens New Member

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    Thank you. I appreciate the very thoughtful advice.
     
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  6. Joe Levens

    Joe Levens New Member

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    Thank you. I will look into it. I only use three pedals (Wah, tube screamer, and reverb) and the reverb is the last in the chain, so this might work out well. Thanks.
     
  7. South Park

    South Park Well-Known Member

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    The model I have is Mooer shim verb pro it has outputs for duel amps
     
  8. StingRay85

    StingRay85 Well-Known Member

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    The low input bypasses V1A. Therefore it doesnt distort even with gain maxed out. I think it has very nice cleans and also good for bass. Theoretically you can surely remove that input, and rewire the jack socket to allow dasy chaining to a different amp, but like people say why mess with such a fine amp when there are other possibilities
     
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  9. Joe Levens

    Joe Levens New Member

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    Thank you for that.
     
  10. Gene Ballzz

    Gene Ballzz Well-Known Member

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    @Joe Levens
    You could likely just jumper across to terminals of the LOW jack (to make it NOT break the circuit between the first and second triodes) and use that LOW jack as an output after the first triode. This would probably work quite well for your intended purposes, as well as being minimally invasive and easy to undo, if and when necessary. You may find that you need to run the PREAMP VOLUME/GAIN a tiny bit higher to make up for the small signal loss of tapping off that output. Hum and proper grounding between the two amps to eliminate that hum will be crucial, but can likely be easily dealt with when and if you get that far.
    Just Sayin'
    Gene
     
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  11. Joe Levens

    Joe Levens New Member

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    Thank you very much, Gene.
     
  12. Gene Ballzz

    Gene Ballzz Well-Known Member

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    Basically you would simply need to defeat the switching function indicated by the blue arrow and make it so the connection is always made. Of course, all this depends on whether yours is the cascaded or non-cascaded version. The one below has V1A & V1B cascaded! 2203u copy.gif


    And here is a "non-cascaded" version:

    image.gif


    Just Sharin'
    Gene
     
    Last edited: Aug 14, 2020
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  13. pedecamp

    pedecamp Well-Known Member

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    Not much point doing what youre suggesting, all you need is an ABY pedal to plug your guitar into 2 amps at the same time, you dont need to mess with your 2204 inputs at all. :yesway:
     
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  14. Gene Ballzz

    Gene Ballzz Well-Known Member

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    While I generally agree, it would all depend on the intended outcome. A passive A/B/Y will lose ~3db of signal in the process of "Y-ing" the single signal to two different amp inputs. If the A/B/Y is active, that opens up a whole new can of worms! Extra gain stages, op-amps, etc. With my proposed mod, the output tap to the extra amp would be after the first gain stage, making it a slightly stronger signal as well as separating/buffering that tap from the actual HI input.

    Again, Depends On What You're Hoping To Accomplish!
    Gene
     
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  15. Joe Levens

    Joe Levens New Member

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    I was thinking of doing the mod rather than getting a Y pedal because I do not use many pedals and it would be another one I have to carry around. I don't use a pedalboard. I just keep a wah at the mic and a tubescreamer and reverb back near the amp, always on. One person here pointed out there is a reverb pedal that has two outputs, and since that pedal is the last in the chain for me, that seems like a good idea too. Many thanks for everyone's insight!
     
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  16. pedecamp

    pedecamp Well-Known Member

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    Come on bud its a 2204, any perceived signal loss can be made up by turning the volume up, having the volume on 2 or 3 will shake the house as it is! Without knowing how the OP uses his amp I guess its all moot anyway, if he has a pedalboard to add an ABY pedal to the mix would be a no brainer. I think modding the amp is overkill for the simple solution he really needs.:shrug:
     
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  17. pedecamp

    pedecamp Well-Known Member

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    A Boss LS-2 pedal is also a good solution. The reverb pedal with 2 outputs sounds like a really good solution too. I just think modding your amp is overkill for what you need. I know you said you dont have a pedalboard but you already have 3 pedals, they make small boards to put them on, I use an old laptop case as a small pedalboard, I can fit a wah and 6 pedals in it. :yesway:
     
    Last edited: Aug 14, 2020
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  18. Jethro Rocker

    Jethro Rocker Well-Known Member Silver Supporting Member

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    Mooer audio also makes a tiny mini ABY pedal that you can use active or passive. Takes up no room. Don't start modifying that classic amp IMO. Easier methods out there. Plus you can decide when to use extra amp without unplugging things

    [​IMG]
     
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  19. Gene Ballzz

    Gene Ballzz Well-Known Member

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    Great alternative solutions listed above. I was simply answering the amp mod question as asked. Multiple ways to skin this same cat!
    Just My $.02 & Likely Worth Much Less!
    Gene
     
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  20. Joe Levens

    Joe Levens New Member

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    Thanks, guys. I figured out one more solution. I failed to mention that the other amp was a Fender Twin Reverb (which really isn't my cup of tea. I use a THD Hot Plate to get the dirty sound). Here's how I did it: Plug guitar into Custom channel 1 input on the Fender. Run an instrument cable from Custom channel 2 input to Vintage channel 1 input. Now run an instrument cable from Vintage channel 2 input to the 2204. Seems to work fine!
     
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