1157 MINI ADSR Module

[Farabide]

Been there, done that, never did get the T-shirt!

[twinturbo]

quick one as I can’t be ARSD to look…(Have I invented a Geek Synth Term) is the MOM to the top of the PCB and Latch to the bottom or the other way round.

Switches here

Rob

[fredrik]

Doesn’t matter, really – both directions go to the same input (gate/trigger) so it’s up to you what you prefer.

[twinturbo]

Ahh Perfect…

Will have that finishe tomorrow then, bar the knobs.

Rob

[JonGreen]

Oh yeah! These things went together easy as pie once the (On) - off - On switches turned up!

[Maxhirez]

@Farabide

Been there, done that, never did get the T-shirt!

That’s because you didn’t click “Submit my order.” (Yes, Jason, that was the joke…)

[fredrik]

Never followed up in this one, but @Dud just posted a drawing:

Mini adsr switch trick

Nothing revolutionary but can maybe helped some. For those like me who build this module with a stripborad or at least a diy panel this is a little trick for the cursed switch! a normal switch (on / off / on not momentary) + a push switch button for manual trigger that’s how i did it [Sans titre]

[opavel]

Hello everyone

Run into a problem. I only have negative output in my mini ADSR module. I checked all the connections and also replaced R12 and R15. Didn’t seem to help.

Would be grateful to hear any advice.

[Dud]

hello sos breakdown service I listen, I will give you a specialist as soon as it is available, good day to you

(joke)

[fredrik]

@opavel

I only have negative output

As in “only the negative output is working” or “all outputs are negative”? Do you have signal at pin 7? Are pins 5, 6, and 7 properly soldered, and properly seated in the socket (if in doubt, check continuity from IC pin to solder joint).

[opavel]

Should have been more specific. Only negative output is working, all three positive outputs are not. I checked positive pins with oscilloscope and no signal, just flat line. Reheated the solder on 5,6,7.

I think checking the continuity from the IC socket will be my next step.

Thanks for your advice anyway

[analogoutput]

What the positive outputs have in common, but not the negative, are R12, R15, and pins 5, 6, and 7 on the TL072. Try focusing on them.

[Mechamilk]

Hello,
i buit the circuit following the schematic but i have an output envelope only if i touch the metal d-shaft of the potentiometers with my fingers.
What could be the cause of this?
I share all GND of the potentiometers and i tried adding the 100nf caps.
Thank you.
P.S. i didn’t use the opamp and i have only 1 out at the moment.

[sebastian]

Sounds like a grounding issue… have you connected the shared ground from the potentiometers to the ground on your stripboard?

[Mechamilk]

I checked again and i replaced a potentiometer… aaaand i found a pin of the socket chip was not soldered correctly. It works now.
Thank you.

[Caustic]

It sucks to have to comb through everything sometimes, but usually it ends up being one of these things. I am glad you have a working module now!

[sebastian]

I was looking at the LED driver for the output and input:

In the kassutronics asr he uses a similar setup, but with different values:

For the LED okai, different LEDs, different preferences for brightness, but the one before the transistor? Also: Why does Caspar split the resistors in the “LED path” into two before and after Q1?

[fredrik]

The difference is the emitter voltage, I think. In the first design, the emitter will never go above the LED’s forward voltage (the resistor takes the rest of the 12 V, minus a tiny drop across the transistor), in the latter part of the 12 V will be dropped across the 2k2 resistor. Since a transistor works as an amplifier until the base voltage exceeds the emitter voltage with about 0.6 V, at which point it turns into a switch, the second design turns fully on (saturates) a bit later.

EDIT: Well, ok, it starts conducting earlier as well, since the emitter voltage will increase linearly as the current through the transistor increases, unlike for the very non-linear LED. It’s basically using the transistor as an amplifier, instead of using it as a switch (it’ll still saturate at higher voltages, since there’s no biasing on the base side of things, but you get a larger usable range).

[Caustic]

So, per the dumbass thread:

A litany of dumbassery

Tonight I decided to get around to makin the Kosmo ADSR. Everything went great, but at the last second i soldered the chip sockets in on the wrong side. Managed to de-solder the sockets, but now im going to have a hell of a time getting this sorted. It was going so well too! Anyone have any experience with this and maybe have some pointers? @fredrik? Im just glad i noticed before frying the damn ADSR chip. [juice.PNG]

I managed to clean out the holes enough to put the chips in. Plugged it in and immediately unplugged. Thankfully, the first thing i test whenever there is a sketch build is: “does the op-amp get hot”? I dont plug in anything else until i rule that out. Thankfully, since after plugging this thing in, it was scorchy. Afterwards, i test continuity and everything seems to be connected per the schematic. Connectivity to ground, +12, -12 are where i expect them to be. I think i might just have to call this a loss. At first i thought i must have put the cursed opamp in backwards but it was not the case.

Ill have to keep lookin’ and stuff, but given that i kinda botched the chip soldering by originally doing it on the wrong side and having to de-solder etc, i think its time to call it.

[ChristianBloch]

Don’t give up! Surely it can be salvaged.