Effects Loop has too much gain and no controls

Discussion in 'Effects, Pedals, Strings & Things' started by tuberider, Jan 15, 2008.

  1. tuberider

    tuberider Supporting Member

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    I suppose am trying to LOWER the gain from my (no send and return controls) effects loop as it's overdriving my compressor and squealing with my delay unless I stick a volume control after the preamp out before the effects in.
    The volume control I'm now using is a passive thing called a Volume Box that has no volume for most of the pot's travel then it's full on very quickly (and loudly).
    Can anyone recommend a product that would help me in my search for attenuating the loop with out tone loss,smoother taper, mo betta etc.?
     
  2. cochese

    cochese Supporting Member

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    What amp are you using? Also a stompbox compressor doesn't usually work well in a guitar amp efx loop. Amps that don't have a dedicated send and return for the loop usually leave this task to the channel masters although without knowing which amp you have it's hard to tell.
     
  3. tuberider

    tuberider Supporting Member

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    Its a modded Musicman RD 50 with an add on loop that uses a stereo in /out jack for the loop.
     
  4. pgissi

    pgissi Member

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    yep, compressors not so nice in a loop since they process 100% of your signal, there is no mix control like in a delay or reverb etc.

    I am going to assume your going for somethin special, unique, odd, otherwise your better off getting what a comp gives before the amp, squash, leveling or sustain/level boost.

    Also, adding a passive volume control at that point is yes throwing away some gain, but tone with it also. By doing this you may be raising the noise floor (reducing difference between the level of noise and signal) of your signal and the compressor is boosting.

    Most comp's operate at line level and should be able to handle what you throw at it in the loop but maybe yours is not?

    Either way, its still not the best place for it but I am into bucking convention for the unusual and if you must, you want to use a good buffering pedal post pre-amp out and pre compressor, maybe a graphic eq pedal like the boss ge-7

    I use it in my loop to add a solo boost on the fly and its surprisingly transparent and plays nice with my Rivera R30 loop which does not have adjustable send/return levels. It should allow you to cut the level with minimal tonal coloration if you leave the faders flat, or adjust if needed.

    The volume box thing may be increasing od in the pre-amp to some point its too clipped for the compressor for some reason and this may be due that the loop is just not a good place for it.
     
  5. tuberider

    tuberider Supporting Member

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    Even with the compressor in front of the amp there seems to be too much gain going into the delay (TC nova with automatic input calibration no input trim).
    It was suggested I try a compressor in the loop to tame the uneven channel volumes but the compressor(keeley) seems to do it's thing up front as well.
    I noticed that when trying to use this loop there is way too much gain for either units. A buffered device that will both boost and cut (for my purposes) might be just the ticket. Any other suggestions besides a graphic EQ, maybe one that will cut all frequencies at once? Barber Launch pad comes to mind.
     
  6. pgissi

    pgissi Member

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    Its surprising that the delay is not liking the loop, I would try to verify if your loop is unusually hot or is the delay just not happy there. Its also dependent on hot your running the pre-amp.

    The launch pad does not provide cut, just unity to 20db kick in gain.

    Maybe you could try some parallel processing in the loop so you can control how much signal your dumping in to the delay while passing the dry also to preserve tone and signal and just blend the correct amount of delay thats been fed the right amount of signal.

    The only thing I can think of to do this is the Xotic X Blender which uses the pro audio console principle of blending a loop signal with the original. It will do both parallel and series signal routing.

    Parallel routing is the blend mode but I dont think the X B has a send level control but you could still employ and eq to cut the level to the delay and I am thinking the compressor may be evenbetter and work as you intend if not better than an eq pedal with the X Blender.

    It allows you to create the proper signal send level to the comp/delay then blend the amount you want avoiding dumping all of your signal through the comp.



    I think I need one myself, also have issue with my looped Reverb pedal and actually pulled my delay out of the loop due to what you describe, uneven output with different chans or pre-amp/pedal settings.
     
  7. pgissi

    pgissi Member

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    I forgot, about the alternative to the Xotic XBlender and at a mere $80 is the Boss LS-2

    Its a dual loop line selector (versus the xotic single loop) with various modes including blending.

    The Xotic is listed at $260 and the Boss is $80. Is there an audible difference, maybe. I am assuming the Xotic is maybe using some select componentry for the internal buffer and summing op-amp or other
     
  8. cochese

    cochese Supporting Member

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    With an after martket loop like that in an older amp I would guess that it is not properly executed. I would not recommend any type pedal effects in the loop as they are designed for instrument level and it seems your loop has a very hot signal maybe even hotter than a typical line level. Also the Nova delay has a very high input impedance which means it runs at instrument level. No big surprise there.

    You're best bet would be to run it in front of the amp because putting a volume knob ahead of the delay is like putting a bandaid on the problem. Many well designed efx loop don't play well with pedals.

    The other thing to try would be this product by Ebtech that can shift a loop from line level to instrument level.http://www.ebtechaudio.com/lls-2des.html
    I would just purchase it from a large retailer in case it doesn't work out you can always return it.
     
  9. pgissi

    pgissi Member

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    Coshese makes a good point, since your using an aftermarket loop and it may not be line level compatible.

    But I would avoid using any sort of impedance converter in the loop especialy if its the non-active type like the Ebtech which means its transformer coupled, it will not work in a guitar amp effects loop.

    From ebtechs page-


    The key is where they are stating "without the added noise of active electronics". The only way to accomplish Imp Matching without active buffering is using a mini audio matching transformer, it will kill tone and gain in your amp if used in the loop if you get it to work.​


    Modding the fx loop to work at line level is a matter of changng some resistors maybe a cap or so typically and I am sure you can find someone to do it or if you have some knowledge to do it yourself by comparing the component values in your modded musicman with a modern fx loop from amps available today.

    Schematics are available on the web and of course this is more complicated than it sounds, depends on how your current loop is installed, does it use IC's or Tubes etc.

    Consult someone and get a price, dont think it would be expensive at all, maybe an hours worth of labor and some very inexpensive parts like resistors, caps and maybe a ganged send/return pot that uses one hole in the chassis
     

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