Chalumeau / Mid-Fi Clari(not) Delay Control

Does the stock wiring of the Chalumeau's delay potentiometer have the longest delay setting at full CCW and reduce the delay time as the pot moves CW?
 

Jbanks

Member
Yes that’s correct. It took me a minute to catch that when I was trying it out. There also is a minimum level the volume has to be at (at least 9 o’clock) for it to kick in the effects. Same for the feedback pot as well.
 
Thanks, that's what I thought. Is the 'depth' wired "backwards" as well? I realize that depth/delay are not at all independent of one another and very interactive.

When you mention the feedback pot, what do you mean? In the build doc, feedback is listed as a control, but there isn't a feedback in the schematic? Did you mean the depth?

I actually wired up a feedback knob between the junction of pt2399 pins 11-14 and 15-16 (with a resistor and extra filtering cap) to add more repeats. A bit of a rudimentary integration of the feedback used in other pt2399 delays.
 

Jbanks

Member
I think it says feedback on the PCB or a diagram and then it says depth elsewhere. The upper right hand knob!

But yes, I think that one has to be turned up a certain amount (past 9 o’clock at least like the volume) to get the delay and pitch to really start having a noticeable effect.

I still want to wire up the mod to turn off the fuzz. It gets in the way sometimes!
 
Ah thanks! Yeah I’ve got a setup with the trace between IC.1 and IC.8 cut and connected via a SPST for fuzz. I’m thinking about using a buffer to split the signal so that the LM386 still has the gain to push the LED/LDR for modulation even while ‘lifting’ the fuzz. That’s a bit more involved, though. I’ve already got an optional LFO in addition to the feedback knob. Lots going on here!
 

Jbanks

Member
I broke down and bought myself a ZOIA by Empress effects. Last night I basically made a clone of the Chalumeau on it. With more manageable fuzz. Lol. But I want to try to SPST switch mod to the IC legs as well. Can you do that while still using a IC socket? Not sure if I can just pop the legs out and connect it or if I have to bend the socket itself out of the PCB.
 

zgrav

Active member
Not sure if I can just pop the legs out and connect it or if I have to bend the socket itself out of the PCB.
Those should be equivalent -- I would just bend the pins out of the socket because it is simpler and easy to undo if you change your mind.
 
I just cut the trace on the pcb and doubled up on the solder pads with wires to a switch. If I add the buffer option, I’m going to have to reconnect it and cut somewhere before the junction of the resistors leading to pt2399 pins 15/16 since the signal output from the LM386 will have to be grounded after driving the LED in ‘clean’ mode.

Keep in mind that if you cut pins 1 and 8 of the LM386, you’re reducing the signal output to the LED driving the envelope modulation. It’s still there, but not as prominent (depending on your input signal and LED choice).

That ZOIA is wild. I’ll have to do a deeper dive into that.
 

K Pedals

Well-known member
I broke down and bought myself a ZOIA by Empress effects. Last night I basically made a clone of the Chalumeau on it. With more manageable fuzz. Lol. But I want to try to SPST switch mod to the IC legs as well. Can you do that while still using a IC socket? Not sure if I can just pop the legs out and connect it or if I have to bend the socket itself out of the PCB.
I love the Zoia
 
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