Aion Quadratron (Lovetone Doppelganger)

[danfrank]

Hi Everyone,
Here is my build of the Aion Quadratron project. Too many controls, confusing! Lol! I guess that comes with the territory making Lovetone circuits...
The build was very straightforward, Mr Aion has always done an excellent job with documentation of his projects. I matched the LED brightness and the resistances of the LDRs so all 4 of each would be close in specs to each other. I have found that this helps with getting a strong phasing sound with optical phasers. I always knew that LDR tolerances are pretty widespread but I was surprised at how wide the tolerances of LEDs of the same type are!
As you can see in the attached pics, the jacks on the back are extremely close to each other, especially the 2 expression pedal jacks. I used the "Cliffs" style jacks that LMS sells and I had to do some major manipulation/modification to get the jacks placed according to the drill template. In the end, it's all good and everything fits and works as it should. If I were to build this again, I'd move the DC power jack to the left, closer to the "dry out" jack so the 2 expression pedal jacks have more room.
I also found some 4.7uf mylar caps and used those instead of the 10uf electrolytic caps. I really liked how Aion give the builder a choice in which to use.
How's it sound? Great, but I don't know what the heck I'm doing! This will take some time to learn what the controls do and how they interact with each other. For example, the two "span" pots act weird in certain situations... On some control combinations, the widest depth is at the midpoint on the span controls, any more advancement of the span controls actually lessens the depth of the phasing. But in other situations, the added span control definitely gives other depth options. I think I read somewhere that Lovetone pedals are a pedal tweakers dream and that is very true.
Anyway, thanks Aion for a really great project!

[jimilee]

Woohoo! Looking good. That enclosure is all the way full. I've built a couple of those, and I must say. They're not really practical for anything outside of the studio, at least for bar gigs. Love it!

[danfrank]

Hell yeah, Phaser Jimi!!
Wait till you get a load of what I have planned for next. I think you will like it. I ain't sayin nuthin else! Lol!

[jjjimi84]

Looking good! Those lovetone pedals are something else, i agree with you jimilee great for studio use but not for a gig

[jimilee]

Hell yeah, Phaser Jimi!!
Wait till you get a load of what I have planned for next. I think you will like it. I ain't sayin nuthin else! Lol!

Uh oh....I'm anxiously awaiting.

[benny_profane]

Great looking build! I had originally tried to use other insulated jacks, but there was absolutely no fitting them. I had to dig around my stock for some Neutrik jacks to get the fit right. Nice work getting those in there! I agree with what you're saying about studio rather than live use.

I think I'm experiencing the same thing you are with the span control: In single LFO mode, the entire range of knob is useful. In dual LFO mode, the upper third or so locks up the LED at full brightness with no oscillation. Is that your experience with the build? I used B2K for the span controls as suggested by the build doc.

[danfrank]

Yes I get the same with the span controls on mine. I used 2K also. On some settings the upper 1/3 of the span controls actually reduces depth, like you're saying. The LEDs stay lit in a steady state

[LaceSensor]

IF it is written that B2K is recommended...perhaps it shouldnt be. Thats a mod, and not how the original is.
Depending on what LED and LDRs people end up using, 2k might not be appropriate.

YMMV

[benny_profane]

It's listed as a suggested modification (the stock B1K is also indicated) but it's listed as the default value in the BOM and the schematic.

With all of the suggested parts, it works in single LFO mode and has the extended range. The issue arises with dual LFO mode. In dual mode, the effective range of the pot's sweep is limited to about 2/3rds, with the last 1/3rd locking up the LED for each respective LFO.

It adds certain functionality (i.e., extended range in single LFO mode), however, it makes switching between the LFO modes impossible without adjustment or working within limits.

In the Lovetone pedal, how does that behavior work? Is it a smooth transition from single to dual modes?

[LaceSensor]

The single and dual modes are two different animals.
You have to take into account that the LF and HF filter pairs are modulated independantly in the dual mode and they dont sound the same on their own as when modulated together.

Here is my real one. You can see that in Dual Mode, the extent of modulation (at least, indicated by the panel LED, but we can rely on that as the internal LED act the same) is much less in the Dual LFO mode compared to the single LFO mode.

https://youtu.be/i_yZWp9cg6Y

[benny_profane]

Thank you very much for taking the time to make and upload the video. The issue seems to be that the modified value for the span controls are taking that shallower modulation evidenced in your video and shifting it further up so that there isn't a pulsing. So, a shallower sweep is to be expected, but the shift may be too extreme if the stock pot values aren't used.

[LaceSensor]

Yeah you may be right however I was the first person to R/E the doppelgänger and the first person to do the B2K mod and I never felt that there was a "freezing" effect

I found that you got a bit more vowel like or even Wah type sounds which was pretty cool.

I suspect having the right LED and LDR combo is quite key here
Would be interesting to check the values and also that the 2ks are actually 2ks and not something bigger

Still, the B2K is a mod not the default or necesssarily recommended part

[benny_profane]

Yeah you may be right however I was the first person to R/E the doppelgänger and the first person to do the B2K mod and I never felt that there was a "freezing" effect

I found that you got a bit more vowel like or even Wah type sounds which was pretty cool.

I suspect having the right LED and LDR combo is quite key here
Would be interesting to check the values and also that the 2ks are actually 2ks and not something bigger

Still, the B2K is a mod not the default or necesssarily recommended part

I think, for the time being, it's safe to rule out the LDR here since there's visual feedback with the indicator LED staying solid.

I used the green Tayda LEDs recommended by Kevin for the build. In my batch, there was some Fv variation, but all within spec (i.e., 2.3–2.5V). I can open my build and get a measurement for the pots in the next couple days. It should be possible to get a good reading in circuit (but that might also be wishful thinking). I'm really not looking forward to taking this apart!

[LaceSensor]

You should try and video it like I did


Ps @op:  Nice build!!

[danfrank]

@ Lace Sensor
Yes, that's pretty much the way mine works in the two modes. There is pulsing, but in one mode it's much more obvious, in the other the LEDs  look pretty much steady state, they don't go anywhere close to turning off.