Mr. Black Dark Echo- pt2399 based? modulation?

[claytushaywood]

Anyone know anything about the Dark Echo?  to me it sounds like a pt2399 based delay- and it has 450ms of delay time, which would make it longer than a single 3005 and shorter than a dual... and definitely shorter than another digital chip.

can anyone confirm this?

what about the sweet modulation circuit?  sounds like a very slow "swaying" modulation- seems kinda unique.  I'd love to learn more about it as I'm trying to implement some sort of cool modulation into a pt2399+boost pedal.

thanks!

[jkokura]

I remember that it was supposed to be PT2399, but it had some sort of secret to it, so perhaps it wasn't. That was a good number of years ago now. I think we had a non-verbal agreement setup that it was a project we weren't going to clone, but I don't remember why.

Perhaps one of the other guys (CJ? Brian?) might remember more than me.

Jacob

[culturejam]

Yes, it's PT2399-based. I had one but didn't trace it out of respect for Jack Deville...well, that and it's on a 4-layer board and was well beyond my skills in 2012. The LFO's single control simultaneously adjusts speed and depth, but inversely. So low depth + high speed on one end, and deep and slow on the other.

Here's what Jack said at FSB after I posted gut shots:

Two dual opamps in the circuit. Opamps on the DC jack side of the board create the oscillator, which is a simple, yet cool and stable circuit. Here are a few hints: sway control at minimum, oscillator shuts off. Sway control at maximum, oscillator frequency is at minimum.

---

The real prize in that circuit is the modulation control circuit. No current wasting LED/opto rig. Nope. This one is hipper and more obscure than that. 

Gut shot attached because it's so purty.

[culturejam]

Actually, looking back at the FSB thread, Jack said it was only a 2-layer board. Still, beyond my chops 5+ years ago.

[claytushaywood]

wow- thats a layout right there.  how tf do you even arrange something like that lol.  i cant believe those pedals are going for less than $100 used. 

[Scruffie]

IIRC the LFO is done by varying the resistor from the output of the LFO to the non-inverting input of the schmitt, despite it being a nice solution to having one knob modulation personally I never found it that useful though, I prefer slower rates to have a lower depth and vice versa.

[287m]

OOT
just amazed look at layout, beautiful OCD! love it

what trannies is that? and function?

[claytushaywood]

IIRC the LFO is done by varying the resistor from the output of the LFO to the non-inverting input of the schmitt, despite it being a nice solution to having one knob modulation personally I never found it that useful though, I prefer slower rates to have a lower depth and vice versa.

you may be the only one- it is very commong for people to want slow speed high depth and faster speed lower depth on modulation effects.  but to each his own!  I just thought it sounded better than most modulation circuits

[madbean]

His layouts are always unreal.

[Scruffie]

IIRC the LFO is done by varying the resistor from the output of the LFO to the non-inverting input of the schmitt, despite it being a nice solution to having one knob modulation personally I never found it that useful though, I prefer slower rates to have a lower depth and vice versa.

you may be the only one- it is very commong for people to want slow speed high depth and faster speed lower depth on modulation effects.  but to each his own!  I just thought it sounded better than most modulation circuits

Ah, yes, for a standard modulation pedal I do prefer it that way and there it's useful, I mean strictly for modulation of a delay.