"Pickup LesLee": An onboard pickup-blending tremolo circuit

[foxmilder]

I had a quick look, and I don't think anybody else has posted this. My apologies if I've missed an earlier thread.

AllParts are selling this curious contraption:





As the marketing department would have it, the "Pickup LesLee® is a cool little piece of analog onboard technology that extends the sonic spectrum of the electric guitar. It utilizes the two native voices of your bridge and neck pickups to generate a distinct percussive tremo-vibe sound simply by auto-alternating the pickup signals! Featuring onboard speed control."

There's plenty more industrial-strength marketing copy where that came from: "All LesLee® units are based on the new motherboard V2 that switches your original passive pickup signals in their pure analog quality. They're not altered, neither when LesLee is ON (analog processing) nor when LesLee is OFF (true bypass)."

It gets stranger:
"Instead of a battery LesLee® uses a custom made supercapacitor with an ultralong life span. The minimal recharge cycle count on the data sheet promises 10.000 charges, but in real life you can reach 3-5 times that. So, Pickup LesLee® is maintenance free for some 50-100 years until the supercapacitor would need to be renewed. I can only guess at this point in time, but probably the speed pot will need to be replaced before the supercapacitor is due."

This is well beyond my ability to comprehend — to be honest, I wasn't even sure which board I ought to post it to — but it does seem like an interesting idea — absurdly overpriced though it may be. Is anybody able to shed some light on exactly what this product is and/or isn't doing? I'm too new to the forums to even know who to tag, but I suspect, say, antigua and ms might be able to make better sense of it.

It appears to me that a DIY approximation of such a device would be feasible, given the low parts count and largely generic components. The only exotic ingredient here is the supercapacitor used in place of a battery. I'm not sure what the rationale is for that decision. There is a reason, after all, that we use batteries and not capacitors as power sources! The following paragraph of (nigh-on unreadable) ad copy leaves me with the distinct suspicion that the "rather square" effect is not "by design", but is in fact a limitation imposed by the basic characteristics of the capacitor itself:

"By design the switching is rather square and results in LesLee's distinct percussive characteristic, which inspires to even adopt new or reduced playing styles within this new tonal behavior and its extra layer of attacks .. similar to playing a rhythmical delay .. but different, as it's not repeating played attacks but sculpting new ones into sustaining notes."

In any case, it's certainly an unusual product.

What do we make of it?

[newey]

As a big fan of tremolo effects, yes, I'm curious about this as well. Wondering how the supercapacitor gets charged, I can't imagine there's enough voltage generated just from the pickup signal itself to "trickle-charge" the thing (and it would only be doing so when playing with the effect "off", which would presumably limit how much one uses it.) But the copy doesn't discuss charging, just the number of charging cycles.

Since the tone pot apparently controls the mono/stereo function, looks like a push/pull (or push/push) pot on the tone control turns the thing on/off, at the same time switching between normal tone control operation and the mono/stereo setting- but then presumably turning the tone knob a bit selects the stereo setting, like we sometimes use pots to split a HB? And it would seem like the stock vol pot is not part of the system here, so how is stereo separation maintained if there's a single master volume?

Clearly, they're a bit tight-lipped about the functioning so as to protect any sort of trade secrets involved, so someone would need to buy the thing to really check it out.

[JohnH]

Interesting gadget!

I'm thinking it's a thing that switches suddenly between the pickups (the 'rather square' response), backwards and forwards at a given adjustable frequency, rather than as a smooth wave, like an old tremolo.

But using the two pickups does seem nice, and that makes sense as an on-board device, the only place if can easily be to get easy connection to two pickups.

Guitar circuits don't reslly need to drive much power, so they can be low current if so designed. A super-capacitor could hold enough charge for quite a while. It notes how it's charged by plugging in a battery for a few seconds. Seems a neat idea and saves having to access batteries inside.

[mikecg]

A nod to the late Donald Leslie?

[newey]

Dec 5, 2023 10:00:14 GMT -5 mikecg said:

A nod to the late Donald Leslie?

Clearly it would seem so. And a Leslie cabinet is a type of tremolo effect (i.e., amplitude modulation). But playing through an actual Leslie cabinet has never sounded to me as being much like an electronic tremolo effect.

[sumgai]

Hoo boy where to begin, where to begin.


OK, my memory of history is not littered with definitive facts today, I'm only all about a general abstraction. Any of you can look up and corroborate, or argue against, what I'm about to espouse, that's all on you.


In history, Ampeg was actually the first amp maker to devise a circuit that imitated a Leslie effect. Fender did so a few years later, but Leo's circuit was a bastardization of his "Vibrato", and he was roundly called out for it. That was in the mid-to-late fifties, IIRC.

In the instance at bar, we're seeing a simplified version of the above, where two sources are combined in an orderly fashion to derive a new tonal palette. However, as noted, the waveform used to switch between the sources is now a square wave, and not the traditional triangle (or sometimes a sawtooth) waveform. This will cause a rather jarring effect insofar as what you hear. Will such be pleasing to the ear, or otherwise, that's the magic question.

And in the end of all things, a square wave is not analog, it's digital - that's the definition accepted in most engineering circles I've ever attended. Which is to say, it's only a control signal, imposed upon an analog signal. The final result is still analog through and through, but the modification to it along the way, that's what makes things interesting.... or distasteful, that's up to the listener.

I've heard a lot, in my time, about supercapacitors. Space-age stuff. Will it work here? Perhaps that's the reason for the high cost, who knows. But for me, the indicator is always the length of time any warranty or guarantee expires. If it's good for only a short period (less than one year is my baseline), then the company flat-out expects the thing to die an early death. Here's one of the few instances where a high price might be justified by a much longer warranty period - the company doesn't expect the thing to go kerblooey any time soon.

Food for thought, that's all.

[/daily core dump]

HTH






sumgai

[JohnH]

I'd add that, if instead, a normal battery supply was allowed, this effect would probably be fairly easy to replicate DIY.