PCB offer: Thomas Henry's CMOS ADSR (blinkin' lights)

[smidirin]

thanks fonik, got pcb's & they're your usual top quality

[StormB]

Hi,
Is it still possible to get 2PCB CMOS ADSR

[crashlander42]

I have no idea what I've done wrong with this module. It doesn't seem to want to trigger in the right order in gate mode (A-R-D) and then A-R-D-S in trigger mode. I've repeatedly gone over my wiring and can't figure this one out.

Anyone else run into anything similar or am I just stupid?

[fonik]

most important, use CMOS capable of +15V, and definetely use a CMOS timer, as shown on the BOM. a common 555 won't do.

additionally, a valued customer recently spotted an error on the circuit PCB. i did not recognize this error just because the two prototypes i built worked flawless from the start w/o any corrections.

The minor error on the PCB routing: +V is connected to IC2/pin8 (CMOS Timer) via C7, however, this capacitor should be mounted in parallel. So here is the fix:

[crashlander42]

I'll give that a try. I'm using the ICM7555, which worked fine on the LFO's, so I'd assumed it would be fine here.

[crashlander42]

Weirdest thing. No matter what it seems to get to sustain and just stop.

[fonik]

the multiplexer is addressed by the gate input and the timer. so i suspect the 555 to not working properly.
did you apply the fix yet?

[crashlander42]

I applied the fix. I'm going to replace the 555 when I get home from work with a new TLC555 and see if that does it.

[StormB]

Hello
just yesterday my CMOS ADSR soldered and finished
found that it works great with einemTLC555 or NE555
then when I tried it with an ICM555 the envelope curve does not work properly

[fonik]

[crashlander42]

[crashlander42]

SO I replaced my ICM7555 with a TLC555 and I'm getting the same result. It just stops at Sustain and stays there.

I'm going to build my second board out and see how it works.

[crashlander42]

Ok, so now it works as expected with a gate, but when it gets a trigger or I try to use it as an LFO it stops at sustain.

With a gate signal it works fine.

[fonik]

[fonik]

oh wait. it STOPS at sustain? turn the sustain fully down.

[crashlander42]

Yup, it stops at sustain when I give it a trigger or use the LFO switch. I have it sustain turned all the way down and I've jacked around with the Trimmer.

[fonik]

[crashlander42]

Nope. I tried manually patching it first. I populated both boards at the same time, so I probably did the same stupid thing on both of them.

[fonik]

i would try to test the end trigger. look at a scope, or just try to trigger another module with it.

if i understood you correct anything else is working? so you can use it with an external trigger in AD mode (trigger only, sustain & release fully down)?

[crashlander42]

With a gate signal it seems to work fine, with a trigger it goes through A-D and then sticks on sustain even if i have sustain and release fully down.

I looked at the end pulse out on my scope and I see nothing. I'm going to go back over the board and make sure I didn't do any stupid resistor mix-ups on both boards.

I may just be spoiled by everything I've built lately working perfectly right when I plug it in sorry for the questions.

[fonik]

[crashlander42]

Just tried running my sequential switches and sequencer with the end pulse and nothing. Even while repeatedly triggering via gate.

[fonik]

now you know where to troubleshoot. there is somthing wrong with the comparator creating the end pulse. no end pulse, no loop in AD mode (LFO)

take a look at the circuitry in my additional documentation. check if the comparator output changes when envelop goes down.

[alangave]

Hi,

I know, I'm a bit late on this thread, but I wonder, Is it still possible to get 1PCB CMOS ADSR + front pannel ?

Regards

[fonik]