i've actually got the week off. one of the positive things about teaching. i couldn't sleep the other day so i built 5 board that i've got to get the enclosures done so i can being boxing. granted 3 of them are PCBs (sagan delay, ibanez ad80, and multiplex), the other 2 are a one knobbie fuzz and another brassmaster which is being wired up as i type (waiting to post pics until the 2nd is done).
i've got plans this week for a few other builds too: 3 tonebenders, modded buzzaround, okko diablo modded for bass and 11 knobs, superfuzz, and 4 more PCB builds another mutron phaser II, electric mistress clone, mutron III and dirtbaby. i think i've got enough planned for the week . i'm hoping that i'll have time to build a tremshifter. i really love everything rob designs, seriously great stuff and awesome guy.
Board is 32x35
CLR is just 3-5k standard resistor for LED
Seems like the blue LED labeled D3 is for the LFO light(s)? In the demo there are two for the alien's eyes:)
You can easily sub a 3PDT switch for DPDT use, just eliminate/ignore the middle column like this:
1 - x - 4
2 - x - 5
3 - x - 6
Going to build this sometime this weekend. My brain hurts already but I need this
Out of curiosity, does anyone know if you could add a delay time pot for each pt2399? Also, if anyone else has built this yet, do your delays go into self oscillation? Mine don't, but I know that I've had different results with swapping different 2399s in and out in previous delays.
I had the same thought, actually... this would allow for taps that aren't multiples of the first taps' delay time, right? Having four independent delay times would make this pedal a lot more interesting, but would also make it very difficult to synchronize them the way they're set up now. I'm not an expert so this could be way off, but I think the way this circuit is set up doesn't allow for control over each IC's delay time.. I imagine that would require fine-tuning of some kind when building the circuit and I don't see any trimmers or anything like that, just standard values. Logically speaking that's what makes sense to me, but I don't have nearly as much knowledge of electronics as most people here so this could just be nonsense.
I'll be keeping a close eye on this thread. Amazing layout!
It would be perfectly possible to just replace each of the transistors and associated resistors on each pin 6 with a 47/50k pot to ground and have four independent time controls. As pointed out above, having a single time pot control all four chips allows the delays to be fixed at divisions of 1/4, 1/2, 3/4 and one full length repeat (since they are run in series and set to the same delay length so each chip contributes exactly one quarter of the total delay time set by the master pot). Individual pots sounds like it would be cool, but adjusting the length of any individual repeat would also alter the length of the repeats on the downstream chips. For two, three or four independent delays, you would probably want to run them in parallel, or have them in series but actually as four fully independent delay circuits, without a shared delay path. A better/simpler mod to this actual circuit might be just to use a switch to bypass either the second or third chip, so you would get the option of 1/3, 2/3 and whole note repeats as an alternative to the quarter-notes repeats.
sagan delay is what you're asking for. it has 3 pt2399 and you can synchronize the delay times like 1+2+3 or 1+2 or 1+3. it has independent delay pots. it has a really difficult to wire switching system though...
but yeah...sagan is a very interesting delay effect. anyway...if you look closely at both schematics, you can understand how the whole idea goes.