# Unison Double Tracker



## jjourard (Apr 23, 2020)

I could not find a single description of what this pedal does, nor any sound samples anywhere, at least not under the name Unison Double Tracker.  So I decided to try it out anyway just to see.  I built it with no modifications other than a much higher value resistor to tame the insanely bright blue LED I chose. It was my second time soldering a SMT device; I went really slow and it worked the first time.  I still don't know what the two sweep knobs are doing but some excellent settings are possible and when they are both doing whatever it is they do, I get a non-cycling pitch bend chorus without that tedious up-and-down, up-and-down effect that gets on my nerves with a standard chorus. The pedal still produces a very nice, light pitch effect even when the miniswitch is in the off position and the first parameter knob is turned way up; the second knob doesn't seem to do anything in that mode.
Having now built it and played with the controls for a while, I think it does a good job of approximating the Abbey Road Automatic Double Tracking "ADT" system.
I can use it as a very distinct effect, especially with an overdrive or fuzz either before or after, but I am finding that it's most useful with the toggle in the up position and the other controls set to very mild settings.  It just lifts the guitar up a bit and makes it feel like it's floating, but it's so subtle that it never gets old.
It's one of those things that I don't notice it all that much but I definitely miss it when it's off - everything seems flat and dead without it.


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## Barry (Apr 23, 2020)

Looks great!


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## phi1 (Apr 23, 2020)

Nice build.  Yeah I like the non-swimming chorus-y sound too.

If you look on this page there's info at the bottom of the chart for these 3 patches.  I believe detune 1 is the pitch bend down, and detune 2 is up.









						EEPROM Builder - PedalPCB.com
					

Custom Programmed EEPROM




					www.pedalpcb.com


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## jjourard (Apr 23, 2020)

I see what you mean.  But I would never have known to look there for that information.  I didn't come at this project knowing what a Pythagoras was or that a Unison was a subset of Pythagoras - I just saw "Double-Tracker" and that looked intriguing.  It was also the least informative and least documented project I've ever tried to build.  The graphics are wrong, the docs are incomplete and I was just lost at sea until I pulled information from seemingly all over the place and decided to take a crack at it with what I had.  Fortunately, it worked out.  Now that I have ventured into the frontier of PedalPCB and navigated its "ways"  I could probably handle another project now without seeking psychiatric help...


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## jjourard (Apr 23, 2020)

Oh - and thanks!  Since the effect reminds me of Abbey Road's ADT, I tried to do a look that might have been in style at the time of the Beatles in London.


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## cooder (Apr 23, 2020)

Great build and cool looks! I have one as well and feel the same: I miss it and everything is a bit dull without it. It's an always on pedal for me.


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## Nostradoomus (Apr 24, 2020)

I always figured it was based on the Keeley 30ms double tracker


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## jjourard (Apr 24, 2020)

Beats me.  Does the Keeley use a FV-1 chip?  Sounds like ADT to me since you can blend pitch bend and delay which the ADT did.  The Keeley has reverb, this one doesn't and neither did ADT.  You could be right...


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## daeg (Apr 24, 2020)

It's the Keeley 30ms set in 'Pro' mode or whatever where you trade the added reverb for independent detune controls (and independent modulation rate and depth in abbey mode).

Sounds great.


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## jjourard (Apr 24, 2020)

Well -- I had no idea there was any precedent for this thing... now I know.  I do like it.


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## Cucurbitam0schata (Apr 24, 2020)

The Mike Hermans clip of the Keeley pedal has made me consider the PedalPCB's Double Tracker, for sure. @jjourard and @daeg , you think this is pretty close to the effects you get with your Double Trackers?


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## daeg (Apr 24, 2020)

Cucurbitam0schata said:


> The Mike Hermans clip of the Keeley pedal has made me consider the PedalPCB's Double Tracker, for sure. @jjourard and @daeg , you think this is pretty close to the effects you get with your Double Trackers?



It's exactly the same, minus the option for built-in reverb.


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## jjourard (Apr 24, 2020)

From what I can tell, yes.  I really do like the Unison, it's going on my board.  daeg says it's the same as the Keeley set to the Abbey mode.  Which figures - without knowing anything about the Keeley, I immediately thought of ADT once I got the Unison up and running.


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## jjourard (Apr 24, 2020)

Cucurbitam0schata said:


> The Mike Hermans clip of the Keeley pedal has made me consider the PedalPCB's Double Tracker, for sure. @jjourard and @daeg , you think this is pretty close to the effects you get with your Double Trackers?


The Keeleys seem to sell for around $150 or so.  Here's one at $129 I just saw that's in Jakarta:




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						Reverb
					






					reverb.com


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## daeg (Apr 24, 2020)

jjourard said:


> From what I can tell, yes.  I really do like the Unison, it's going on my board.  daeg says it's the same as the Keeley set to the Abbey mode.  Which figures - without knowing anything about the Keeley, I immediately thought of ADT once I got the Unison up and running.



Wait, I want to clear something up. The Unison has _all_ 3 modes that the Keeley has, in the same positions. Abbey is the Chorus-Delay mode when the switch is center, but it also has the other 2 modes that the Keeley has as well. The Keeley just has some internal dip switch that swaps out the Reverb for extra control of each mode -- Keeley calls it 'Pro Mode' or 'Studio Mode' or something. That is what the Unison does, the Keeley 30ms in 'Pro Mode'.


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## jjourard (Apr 24, 2020)

Maybe mine isn't working properly.  Mine works like this:  Switch up: "fast" mode - short delay, both tuning knobs function; switch center: no delay, one pitch knob works and produces a typical up and down sweep but very faint -have to turn the one working knob nearly all the way up, the second knob doesn't do anything; switch down: "slow" mode - same as the up position except longer delay.


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## daeg (Apr 24, 2020)

jjourard said:


> Maybe mine isn't working properly.  Mine works like this:  Switch up: "fast" mode - short delay, both tuning knobs function; switch center: no delay, one pitch knob works and produces a typical up and down sweep but very faint -have to turn the one working knob nearly all the way up, the second knob doesn't do anything; switch down: "slow" mode - same as the up position except longer delay.



You've got me a little confused and it's possible that everything is working as intended (and the same as on the Keeley unit). Could you look through this thread and tell us exactly which controls aren't working.


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## daeg (Apr 24, 2020)

If you're trying to understand what this pedal is conceptually, it's a slapback delay (no regeneration) with chorus and detune. I suspect the pedal is working as intended, but your expectations of what is does might be different.


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## jjourard (Apr 24, 2020)

No, it's great and I love it.  barely any expectations, I was just intrigued by the idea of a Double Tracker and I had no awareness at all of the Keeley.
My controls behave as I described and I have a use for all the sounds it produces whether it matches the 30ms or not.  All I was saying is that my pedal doesn't seem to match the 30ms controls description, but it doesn't much matter to me if they do or don't.  If nothing else, I learned here that the Keeley exists and the Unison is a workalike.  Unison is destined for a long residency on my board.


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