Darkadiator rate mod?

[Mentaltossflycoon]

I recently built up a parasit darkadiator and it's a lot of fun but I feel like the lfo is kind of slow. Anyone have any suggestions for a mod to get either a broader range or at least skootch the existing range up a bit? This feels like something @DGWVI would've already done at some point but I didn't see anything in my searching.

Here's the schematic. I'm not afraid to get the solder sucker out and try some stuff but I only have uneducated guesses at this point.

 

[Feral Feline]

I'm betting I know less than you about this, but since nobody seems to be responding yet. Bumpity boo...

...C6 & C7 would be where I'd start the experimentation on the breadboard. Making them smaller would make them "fill up" more quickly.
In concert with that, the resistors supply them and the resistors preventing them from discharging would be targeted next.
Smaller resistors on both sides of the caps would allow them to fill up more quickly and drain more quickly, I'm guessing.

Perhaps best to experiment with one parameter at a time, but they seem to be all matched, so for instance I'd change out things in pairs: R11 & R12 at the same time with the same values. Then I'd put it back to stock and change out R10 & R13; put it back to stock and reduce R23 and R20 before resetting to stock and finally changing out R26 and R25.

Consulting my notes, I'd then try to make some guesses based on those findings and start trying two pairs of values at a time.
etc.

 

[Ginsly]

Not to derail, but can I ask what type/hfe transistors you used in your Darkadiator?

I had an issue with mine when I used all 2N3904s, and switching a few of them out to 2N2222A helped; still, there are settings that seem fairly different than any demos I've heard. I used a proper Parasit board, and everything seems correct component-wise.

Just curious!

 

[Mentaltossflycoon]

Not to derail, but can I ask what type/hfe transistors you used in your Darkadiator?

I had an issue with mine when I used all 2N3904s, and switching a few of them out to 2N2222A helped; still, there are settings that seem fairly different than any demos I've heard. I used a proper Parasit board, and everything seems correct component-wise.

Just curious!

They're all 3904 on mine. No substitutions.

 

[Ginsly]

They're all 3904 on mine. No substitutions.

Interesting - and everything works as expected? Maybe mine were all over the map gain-wise, dunno... hmm

 

[Mentaltossflycoon]

Interesting - and everything works as expected? Maybe mine were all over the map gain-wise, dunno... hmm

Yep, my only issue is the want for more speed.

 

[Feral Feline]

Yep, my only issue is the want for more speed.

Pore on that coal!

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Uh OH!​

 

[Mentaltossflycoon]

Update, I socketed c6 and c7. Indeed, 22uf was slower and 4.7uf was faster but now suddenly my lfo has died... I wonder what's borked now?

 

[Feral Feline]

If you go back to stock and reboot it, does the LFO fire up?

 

[Mentaltossflycoon]

If you go back to stock and reboot it, does the LFO fire up?

Not yet. I did put 10uf caps back in and nada.