Electro Harmonix Double Tracker

 

Second box of the day. This one arrive DOA. Someone had boogered it up inside with some shoddy tech work and ya know, why make an EH pedal worse than it already is? These charmingly janky boxes that do a good job of falling apart on their own.

I got this one working by re-wiring the battery cables. The switch was intermittent so I replaced that and it worked brilliantly for about 3 minutes then POOF!

Power supply issue. I needed to replace the 2n4302 FET in the power supply. They are rare and spendy. I first tried a recommended substitute but that failed after 10 minutes. I replaced all of the electrolytic caps with the same values and replaced the tantalum cap with another tantalum. I also replaced the 13v zener diode (this pedal is 18v, takes two 9v batteries.)

I don't find much joy in working on janky pedals but it is nice when there is success and I've learned something.

How is it? It's a two trick pony.... slap back and faster slap back plus blend. That's it. I can do better with just a delay box. However, it sounds wickedly trashy! If I had a studio I would own one of these. I'm not sure there is anything else that quite sounds like this box.....

Maestro Envelope Modifier

 

Ok, I know it's not a tube amp but whatever. It's old, it's vintage and it's effing weirdly kinda cool.  

I've received a box of pedals from Southside Guitars in Brooklyn. Pedals are not my idea of a good time but I do like bringing things back from the dead. 

This one arrived DOA. If you are lucky that just means a bad battery cable or a bad joint. You should also heat up EVERY solder joint and clean every pot twice minimum. Did that and still nothing.

In this case I needed to change the Optocoupler to get it going. I bought one and the thing made sound but did nothing else than that. I also re-capped the thing, still no effect. I was at a loss as to what to do. So I consulted the interweb and found a guy on the Facebook who had success with one of these. I followed his advice and made my own optocoupler with a white LED and a GL5528 photo sensitive resistor.

(Shout out to Pete's Pedals in St Louis for the help!!)

And, it started to do, erm, something! I needed to re-solder the batter connectors on both ends of the cable and clean the pots once again and now it works. I needed to adjust the little trim pot on the inside to make the LED maximum bright. The cool thing about making your own optocoupler is you can see how that light is actually behaving.

It's a very rare box with good reason..... not much use for a guitar player like me. I can pretty much make my fingers do what this does but I can see one of my analog synth addict friends having a good time with this box. You play it softer and it lets more sound through in one mode. Play it louder and it cuts the volume. That's in Bow mode. Percussion  appears to be the opposite. You hit the note hard and it really spikes. 

Can't really tell much from my little demo but here we go anyway......