Unison Double Tracker In Stereo? *Solved*

Jovi Bon Kenobi

Well-known member
I'd like to try connecting the input buffer to the ring of a stereo out jack for a left wet, right dry configuration. Where exactly is the input buffer on the PCB?
 
There are a few different revisions of that PCB, can you post a pic of the one you have?
 
596

So, I soldered in a stereo output jack and reconnected the tip & sleeve. The orange wire runs from the ring lug to a 1k resistor under the shrinkwrap. I then connected that to the point you circled and tested it out by using a TRS Y cable running to two amps. I only had the mono signal coming out of the tip and nothing from the ring.
 
One A+ for your documentation, another for your tidy work.

What you may consider is to use a buffer/splitter before you ever get to the first part of the Unison circuit, then turn the Blend on the Unison to max. That way you split your signal into two paths: a clean bypass which reconnects to the stereo output and one that's a fully wet signal from going through the circuit.

Here's a simple, easy buffer (three outs, but just don't built the third): http://www.muzique.com/lab/splitter.htm
 
You really shouldn't need the splitter circuit, the first stage is already a unity gain buffer....

The problem here is that (like an idiot) I didn't keep a good archive of the trace layout for that particular revision of the PCB. I was hoping we could get by using a single resistor, but no such luck....

Use a 1K resistor in series with a 1uF MLCC (or box film) cap to connect Pin 1 of IC1 (TL072 on the left) to the Ring of your output jack...

That should do it.
 
So glad I found this on the forum! The Unison Doubletracker sounds so incredibly good with this mod! Any chance of simply adding this as a revision to the boards themselves? I could see it coming in handy for a number of these FV-1 builds and it seems like it wouldn't hurt anything by including it.
 
Hey, so I tried this on an organ donor. I'm taking a line from the buffer (IC1, pin 1) to a separate mono jack to use as a dry out. I have a wet and dry when the pedal is engaged, but no signal comes through the dry output jack when bypassed.... Am I missing something?
 
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