Advice on best effects loop design!

Discussion in 'The Squawk Box' started by Freddy G, Mar 8, 2018.

  1. Freddy G

    Freddy G V.I.P. Member

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    Hey you amp gurus!

    I would kindly appreciate your input (bada boom!) on which effects loop designs you like and why.


    I want to install them in some of my amps....particularly my Hiwatt and also a matched pair of homebrew amps.

    Thanks in advance!
     
  2. bilbarstow

    bilbarstow Premium Member

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    I remember that Don (Soul Tramp) did a bunch of work to determine that for his amps. You might ask him directly ?
     
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  3. Lungo

    Lungo Silver Supporter

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    I'm not sure if this applies, but I like foot switchable effects loops. I've owned Mesa Boogie amps with that feature and it really came in handy.
     
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  4. mmd

    mmd Senior Member

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    I prefer tube-driven, parallel effects loops with send and return controls, footswitch-able (of course). I prefer this design for a couple of reasons.

    First, being parallel, I always have some original signal in the "blend". Much like adding effects in a mix, my guitar sound stays more focused when not drenched/saturated by the effect.

    I like tube driven because, if I am choosing to not use any effects I have an extra gain stage (my Riveras have this and it works great as a tube driven boost) - plus it works as a great buffer.

    The variable send/return is ESSENTIAL for me (and as a recording dude, you'll get this) because it lets me get the best signal/noise ratio along with blend/ratio of wet/dry signal. I can dial in my effect the way it sounds best at the unit (pedal or rack, though I usually still use rack units in the loop), and then have control of the "mix" at the amp too.
     
  5. Freddy G

    Freddy G V.I.P. Member

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  6. Soul Tramp

    Soul Tramp Speaker Snob V.I.P. Member MLP Vendor

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    Freddy, here are the features of the loop I designed after considerable trail & error:

    1) Tube buffered
    2) Tube gain recovery stage on return
    3) Toggle to bypass loop and remove from signal path (loops can be a bit of a tone suck)
    3) Toggle to switch the loop between parallel and serial modes (some pedal work better in one mode vs the other)
    4) Knob to adjust the loop gain
    5) Knob to mix the wet and dry signals
     
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  7. Freddy G

    Freddy G V.I.P. Member

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    OK...Sounds like you've covered all the bases! Do you sell these babies?
     
  8. Soul Tramp

    Soul Tramp Speaker Snob V.I.P. Member MLP Vendor

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    I sorry, but I don't sell them. I'm apprehensive about my schematic getting out into the public domain.
     
  9. Freddy G

    Freddy G V.I.P. Member

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    Booo!

    Bummer. Oh well.. can you recommend one?
     
  10. Soul Tramp

    Soul Tramp Speaker Snob V.I.P. Member MLP Vendor

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    I'm sorry Freddy, but I don't keep up with what's on the market. Are you able to design your own circuit (with help)?
     
  11. Freddy G

    Freddy G V.I.P. Member

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    Sure, I don't think I need parallel.... just series. All I want to do is insert time based effects....delay, modulation and reverb. And also preamp channel switching.
     
  12. Soul Tramp

    Soul Tramp Speaker Snob V.I.P. Member MLP Vendor

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    A serial loop is fairly simple. A quick google search brought up the following schematic that looks fine. It has all the features you'd need.

    http://www.blueguitar.org/new/schem/misc_mod/fx_loop.gif
     
  13. Freddy G

    Freddy G V.I.P. Member

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    Thanks Don.
    That does look simple....I don't think I'll even bother etching boards for that!
     
  14. Soul Tramp

    Soul Tramp Speaker Snob V.I.P. Member MLP Vendor

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    It would be a simple turret or eyelet board. Are you able to fab either?
     
  15. Freddy G

    Freddy G V.I.P. Member

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    Yeah...I've got some turrets left over from a mic pre I built:

    IMG_0149.JPG

    IMG_0146.JPG
     
  16. Soul Tramp

    Soul Tramp Speaker Snob V.I.P. Member MLP Vendor

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    If you need board material, I have FR4 G10 glass epoxy I use for my boards, I can send you.
     
  17. KP11520

    KP11520 Senior Member

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    Could you please share this journey on this or another thread?

    I'd bet many would love to have an effective FX loop modded into their amps that don't have one. Thanks!
     
  18. Freddy G

    Freddy G V.I.P. Member

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    thanks Don....I have the material I need.

    Sure.
     
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  19. KP11520

    KP11520 Senior Member

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    THANKS! Yeah, I'm a wannabe NERD!

    I'm looking forward to it!
     
  20. RAG7890

    RAG7890 Premium Member

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    Freddy I believe lot of people just buy the Metroplex Loop that George developed?

    I think this is what Dave Friedman uses & it's a great Loop............& you can buy them.

    Cheers, Rudi
     

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