Hey Shotgunn! It’s Jon Phipps, the guy who was probably your first Micro synth mod customer! How’s it going?

I only just got round to doing the mods on the micro synth this week, i had been distracted in recent months and never got round to doing it until now. The mods sound amazing and i’m very pleased with it. I did all the mods aside from the expression pedal mod (i haven’t ordered the stereo DPDT jack socket yet).

The voice mixer is now much more equally balanced, and i find that the voices are strong enough to work individually now, where as before i would blend them. The sub octave and the F.A mod are incredibly phat and juicey, while the upper octave is so much brighter and more spikey.

However, i’ve had a few problems with it as well.

The resonance slider seems to have next to no effect at the moment. You said in your notes to experiment with different caps for the resonance cap: i haven’t done this yet as i didn’t know where to start but i presume this is probably the cause of the problem. What type of capacitor do you recommend for this? Do you reckon the resonance slider’s inactivity is soley because i haven’t changed the capacitor to compensate for the other mods that have been done to the pedal?

I was just watching your youtube demos of your modified micro synth and realized another problem with mine. The ‘guitar’ voice which on my pedal used to be clean and on your modified pedal is clean, but on my modified pedal the guitar voice sounds very distorted, much like the square-wave voice.

Where do you suggest i start trouble-shooting for problems with the ‘guitar’ voice? The true-bypass works fine so i don’t know why the guitar voice is kicking in with distortion.

Thanks again for giving me all the info and photos on your mods, it’s been interesting working on the micro synth and i’m enjoying the sounds i can get out of it so far! I will do the expression pedal mod very soon as that sounds super cool. Did you work out how to do the expression mod for the LP filter on the POG in the end?

Keep up the good work Shotgunn, have you come up with any other cool EHX mods laterly?

bugger! As i said, that micro synth mod seems to have been a good solution, maybe it’s worth contacting ‘shotgunn’ regarding how he did the expression pedal mod to his pedal

Hi there, it sounds like the switch isn’t wired correctly or has a faulty connection.

I presume it’s true bypass, so it should be wired like this:

http://gaussmarkov.net/wordpress/thoughts/wiring-up-a-1590b/

Good luck solving the problem!

Hi there!

I’ve recently purchased a faulty POG that needed repair: it’s fixed now and sounds great! I think your idea for the expression pedal control of the LP filter is a great idea, i’d like to try it myself. The slide pots have three solder terminals just like a normal rotary pot. My idea:

Remove the slider pot for the LP filter

Install a stereo jack into the POG

connect the pot input terminal to the jack tip terminal , the pot wiper terminal to the jack ring terminal and the pot ground terminal to the jack ground terminal.

I’ve opened up my bespeco expression pedal (nothing special). By the looks of things i think this minor modification should do the job for you, with the slider pot terminals corresponding to the wiring of expression pedal pot via the stereo jack. I’m going to try it and let you know how i get on!

Some one please correct me if my idea is wrong, but i’ll try it and let you know if it works or not otherwise!

Thanks for the inspiration, i think this will be most effective in LP filter mode 1 so you can just fade the harmonics in over the guitar sound at will.

Another thing you could try is to install a rotary pot and use an Option Knob (http://www.optionknob.com/) to enable foot control of the LP filter without the need for an expression pedal cluttering up your pedal board

I hope this has been helpful..!

P.S. the ‘yellow wire’ is only reference to the diagram on that link, i’m not saying there’s a yellow wire in your pedal, but your be able to find which wire is the output of the circuit by working backwards from the switch

Hi guys!

I’ve repaired 2 vintage doctor Q pedals before (pedal repair is a hobbie of mine). I know what you mean by the high hissing and supposedly ‘inactive’ sound of the effect when you switch to the bass setting in some cases. This can often be remedied by opening up the unit and tweaking the ‘range trim’ pot on the circuit board to focus on the relevant range of frequencies that your playing on your instrument (whether your playing guitar or bass). All you need is a set of screw drivers to sort this problem out if the problem with your pedals is the same as what i’ve delt with before.

I hope this is helpful to you guys, good luck!