A NEW (IMPROVED) VERSION OF THE YUSYNTH ADSR

[yusynth]

Hi All

I now propose an improved design of the yusynth ADSR.
The changes are :

Now the input stage is a discrete Schmitt trigger. As such any signal (this means not necessarily a regular GATE signal) can be used to trigger the ADSR as soon as its level goes above 2V.

The input impedance is now very high which makes it possible to feed more than four ADSR on the same GATE signal source without problem.

A buffering stage as been added between the SUSTAIN potentiometer and the DECAY potentiometer. This fixes a slight bug that made the DECAY rate dependant of the SUSTAIN setting. Now they are completly independant.

A short/long envelope option is now provided by setting jumpers on the PCB which select proper timing capacitors and ATTACK resistors. Note that this can be as well connected to an "on panel" DPDT switch to allow interactive selection of the ADSR mode.

And ultimatly, a resistor can be added or ignored to set the range of the REVERSE ADSR mode. Without resistor, the range is 0V (quiet status) to -10V (max range); with the the resistor installed, the range is +10V (quiet mode) to 0V (max range).

Check this at http://yusynth.net/Modular/EN/ADSR/index.html

Another important change is that from now the yusynth PCBs will provide prints for both DOTCOM style PSU connector and MOTM style PSU connector !

[Sebo]

That's great!!!
I will build one for my new cabinet.
Thanks for sharing it, and happy 2011!!!

[mph]

Thanks Yves!

So I plan to build two more ADSR, now with the updated version, when I'd have finished the main cabinet!
It's going to be a very busy year.

Happy new year.

[iopop3]

The bom say, "(or any other CMOS version of the NE555, DO NOT USE A NE555 !)".

Is this because a cmos version of the 555 is more stable, draws less current and overall improved compared to the original NE555. Or are there other reasons?

[yusynth]

[chrisp]

nooooooo i just finessed 10 old!! ADSRs and now i wait the front panels

Happy 2011

[yusynth]

[kkissinger]

[yusynth]

[Danno Gee Ray]

Yves,

The schematic, parts list, and the component location diagram show C-4 to be 10nf. The color wiring diagram shows this to be 15nf. I assume 10nf is the correct value?

Thanks,

Dan

[yusynth]

Yes it's 10n although 15n would'nt be a problem, I'll fix this discrepancy.

[Franky]

Hello Yves,

It's nice to see this problem solved! Is it critical to switch the Attack limitation resistor as well as the caps? (I bet you understand why I'm asking you this )

Nice work anyway, an interesting mod would be to add a potentiometer to blend the normal and inverted outputs, to make a third output with polarized amount (negative on CCW, positive on CW, null when centered).

[yusynth]

[bubzy]

hi, ive etched and built this circuit. however im getting some strange behaviour from Q1. theres a short between C and E, although E is Not Connected. im no electronics genius just a lowly board stuffer, but everything looks to be ok, ive tried different transistors and that doesnt seem to work. if anyone can shed some light on what ive done wrong, that would be great.

[yusynth]

[yusynth]

[bubzy]

Fantastic! Works very well, thank you for your replies and an excellent circuit!

[JRock]

Hi. I etched a pcb and built this but I can't seem to get it to work
I used a TLC555 which is a CMOS chip. The LED doesn't light and the VCA and the filter just stay open when I plug them in. Any ideas?

I'll check out Q1 and Q2 and make sure their emitters are connected.


Thanks!

[yusynth]

[JRock]

Wow. Thanks for the quick response! And thanks for your generous and well documented distribution of knowledge on your website! Your modules are awesome and I'll definitely be building more

I downloaded it a few weeks ago... I'm not positive when exactly. I'm just about to check it and contrast and compare and see which one I have. I keep you posted.
Thanks!

[JRock]

Awesome!!! It was the older version so I connected the emitters from Q1 and Q2 and it works

I have another question

I added the DPDT switch to select fast or slow. When I use the gate button everything acts the way I would imagine but when I send a gate signal to the input the decay doesn't start until I've released the gate. Is that normal?
I connected the three fast/slow pads under the tantalum caps but not the 3 to the right of the diodes. Is that correct?

[yusynth]

[JRock]

Sorry I took so long. I had to get batteries for my camera. I hope I got a good enough photo. Right now I have the Long selection jumpered and I have the DPDT switch hooked up but it isn't doing anything. If I desolder the jumper then it makes a high pitched noise when I have it switched down.

It still stays open as long as the gate is open...

I did my best on the photos If you need better i can try again or if you have any questions for me please don't hesitate.

I really appreciate you taking the time to to take a peek at my build. Thank you

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[VW]

A while ago I was looking for a relatively simple basic envelope generator and bumped onto this fantastic design. I already had most of the required components and decided to build a quad version on protoboard. The manual gate and inverted output were omitted. A separate quad led driver will be built onto a stripboard, using TL074 which allowed me to use TL072 for output and sustain level buffers for each individual envelope circuit. The transistors BC547C's were substituted with BC548C's, major difference between those being the maximum voltage rating. Short/Long toggle switch will be mounted onto front panel.
Next up is making the panel + wiring. Can't wait to try and start using it!
Attached is the image of the finished board.

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[yusynth]

Nice quad ADSR !