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Taming Mini Q-Tron

Discussion in 'Effects [BG]' started by bass-shy, Apr 2, 2005.


  1. bass-shy

    bass-shy

    Jan 11, 2005
    Florida
    I bought a Mini Q-Tron last week and I really like it. The only problem is the huge increase in output when I switch it on. Does anyone know of any mods to control this? I can't put a compressor after it because there isn't enough room on my pedalboard. What I really need is a wiring diagram and the right value pot. Anyone know where to come by this info? Thanks.
     
  2. If I'm not mistaken you can put a resistor in series with the volume pot to calm it down.
     
  3. Yep, one friend of mine installed effect volume in my mini Q, really solved the problem
     
  4. bass-shy

    bass-shy

    Jan 11, 2005
    Florida
    Does anyone know what value pot to use in installing a volume control?
     
  5. Basstyra

    Basstyra Commercial User

    Apr 3, 2005
    France
    CTO @ Two notes Audio Engineering
    A simple volume pot will do the job, I think. Wired just at the end, just before the output jack.

    A 25k log pot would work ok.
     
  6. bass-shy

    bass-shy

    Jan 11, 2005
    Florida
    Sweet. Thanks much. I'll post back after I've done the mod and let you know how it works out. Thanks again.
     
  7. Basstyra

    Basstyra Commercial User

    Apr 3, 2005
    France
    CTO @ Two notes Audio Engineering
    Think of it as a volume pedal put just after the effect. That's exactly what this pot will do.
     
  8. bass-shy

    bass-shy

    Jan 11, 2005
    Florida
    Where can I find a wiring diagram?
     
  9. Basstyra

    Basstyra Commercial User

    Apr 3, 2005
    France
    CTO @ Two notes Audio Engineering
    Here you have :
    [​IMG]

    The pot is shown from behind, the turning part is on the other side. It's a simple volume pot. As it is at the output of an effect, 25k seems to be a good value. Log, not linear.

    I don't think the Qtron is stereo, so it should be ok.
     
  10. I think if you use that wiring diagram, you might be cutting your bypassed volume as well as the effect output, both by the same amount. So, the difference between the effect volume and the bypassed volume will still be there.

    I'm not familiar the mini-Q, specifically. But, conceptually, I think you want your new (effect output) volume pot to go between the PCB (effect out) and the bypass stompswitch. That way, when the effect is engaged, the volume pot will allow you to trim the effect output level, and when you switch to bypass, the volume pot gets bypassed too, with the effect.

    ~ Charlie
     
  11. Basstyra

    Basstyra Commercial User

    Apr 3, 2005
    France
    CTO @ Two notes Audio Engineering
    Good point. Shame on me, I didn't see this far.
     
  12. allotropic

    allotropic

    Mar 22, 2005
    The following was taken from Aron's Stompbox Forum

     
  13. bass-shy

    bass-shy

    Jan 11, 2005
    Florida
    Yeah, and what is R-13? Is that what they call the pot that I will be adding?
     
  14. R13 sounds like a connection on the PCB to me, it will probably be marked by R13 on the board.

    Check that before modifying! :D
     
  15. Again, I don't own a miniQ, so I could be wrong about this. But, from the way the description of the mod is written, and since they wrote "mother contact" and not "mother contacts" (plural), I'm guessing that the hp/bp/lp switch is a SP3T (single pole triple throw) rotary switch - one wire going to a contact in the center of the switch, and three wires going to three contacts on the perimiter of the switch. The 'mother' contact is probably referring to the 'pole,' the contact in the center.

    R13 is a resistor that is on the PCB. Like f_b_g said, it's likely labeled. If not, you can probably find it by following the wire that goes from the 'mother' contact to the PCB. You might then have to follow a trace on the PCB until you get to a resistor, most likely R13.

    Good luck!
    ~ Charlie
     
  16. teonigil

    teonigil

    Apr 21, 2005
    ISRAEL
    [​IMG]

    [​IMG]

    1 .Drill a new hole for the trimmer pot in the exact location shown in picture (5.2 mm from top and 5.2 mm from right ).

    2. Use a 25 or 50 KOhm logarithmic (not linear) pot.

    3. Disconnect blue wire from switch.

    4. Connect 1st pot leg to the pot cover (grounded)

    5. Connect two new wires to the other two pot legs. (A)

    6. Connect the blue wire to one of the new wires. (C)

    7. Connect the other wire to the switch where the blue wire was. (B)

    Optional - Connect the blue wire directly to the new pot and save a wire.

    That's it, you're done.

    This trimmer will only affect the wet level.
     
  17. Zachass

    Zachass Peavey Partizan

    Does anyone have a copy of the diagram in the post preceding mine? I'm about to attempt this mod, and while it seems i could figure it out from the information provided, a picture is worth a thousand words. If so, PM it to me or something. Thanks.
     
  18. teonigil

    teonigil

    Apr 21, 2005
    ISRAEL
    Here you go...

    [​IMG]

    [​IMG]
     
  19. bass-shy

    bass-shy

    Jan 11, 2005
    Florida
    Wow, I haven't thought about the Mini-Q for a while! I should have mentioned that my "fix" included buying an EMMA Discumbobulator and a Maxon AF-9 and selling the Mini Q-Tron. It worked flawlessly.

    Also, thanks for the suggestions, especially the last pics. They will be very helpful to others with more patience than myself.