'Reverse' ABY signal degredation problem

Discussion in 'Effects [BG]' started by PhilDean, Jan 21, 2022.

  1. PhilDean


    May 4, 2018
    Hi All

    I've been trying to work out a cheap Pedalboard effects BI-amp system (got a main board with a really cool but £££ dual loop with lpf & hpf but I'm trying to equip a low cost back up). I've got an ABY at the beginning with phase inverter options which works great, then each line goes through a separate graphic EQ (to make a rough low vs high frequency split) + appropriate pedals. Finally they go into another ABY working as 2 into 1 (pedal blurb confirms it will work in this fashion).
    But when the 2nd ABY is set to Y mode the signal gets dirty and quiet. I've tried switching phase but to no avail (A to Out and B to Out sound fine independently). I'm sure I'm missing something so I'm reaching out for some advice.
  2. ABY pedals are not well known for being good at mixing (they'll do it, but rarely well). Also, I think graphic EQ is the wrong tool to faux biamp. I think most are designed so there's very little overlap on the frequencies so instead of getting a full shelved dropoff you get a jagged edge curve.

    If you get it working with what you're using I'll go over there and stop talking.
  3. Ba55Man1ac

    Ba55Man1ac Gold Supporting Member

    Apr 22, 2004
    Sydney, Australia
    cheapbasslovin likes this.
  4. PhilDean


    May 4, 2018
    Thanks for the reply. I agree, my original intent was to run each line to different amps but that's a bit too much extra gear to lug around. I know Graphic EQs aren't ideal but I'm working with what I've got - if it proves unfeasible to approximate bi-amping it would still be useful to have two effects chains. I've seen a splitter/combiner pedal advertised that incorporates summing resistors to balance level, maybe that might be an improvement.
  5. sunbeast

    sunbeast Supporting Member

    Jul 19, 2006
    Denver, CO
    Passive summing of signals is always going to be non-ideal and prone to all sorts of weird interactions. You will be much better off with an active mixer solution like a Boss LS-2 (summing resistors in a passive mixer are still going to allow far more loading/interaction between sources than separately buffered signals). If you can solder, I instead recommend picking up a Schalltechnik Omnilooper kit- they are not expensive and have a better version of everything you are suggesting (full-on crossover FX loops/mixer) built into one box: OMNILOOPER – Schalltechnik_04
    PhilDean likes this.
  6. PhilDean


    May 4, 2018
    Hi, I think you're right about the passive summing, it was a bit of an outside chance I wanted to try. The Omnilooper looks like it's similar the KMA Machines Tyler Deluxe I recently bought for my main board (and started this experiment) - which is excellent if anyone is thinking of doing something similar - I may well look at it in the future. For now, I've just remembered that I've got an unused Behringer mini mixer that might serve the job. I'm going to give that a try.
  7. @PhilDean simple solution is the Boss LS2 instead of all that extra junk. One box to split and sum that you can process the 2 chains as you wish.
    Steveaux likes this.
  8. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

    May 28, 2022

Share This Page