re stage gates and end trigger:
i thought of adding another TL074 to buffer these outputs.
the end trigger would occure as soon as the ADSR goes into the release stage, otherwise one would have to add an additional comparator.
is an end trigger useful when in ADSR mode?
okay. i got thomas blessing to do PCBs for the other new projects, too. the CMOS ADSR will be the next one.
i just wanted to let you all know what is coming. i will design the PCB in the next weeks. the 555-VCO will be published in january, so i don't think the ADSR will come before february (have to order/build prototypes).
anyways, please don't place pre-orders here. much too early in the process _________________
Joined: Dec 03, 2011 Posts: 105 Location: East-Belgium
Posted: Fri Dec 07, 2012 9:31 am Post subject:
I'm not allowed to post pre-orders for nor the ADSR neither the 555-VCo here
I'm not allowed to post pre-orders for nor the ADSR neither the 555-VCo here
I'm not allowed to post pre-orders for nor the ADSR neither the 555-VCo here
I'm not allowed to post pre-orders for nor the ADSR neither the 555-VCo here
I'm not allowed to post pre-orders for nor the ADSR neither the 555-VCo here
I'm not allowed to post pre-orders for nor the ADSR neither the 555-VCo here
I'm not allowed to post pre-orders for nor the ADSR neither the 555-VCo here
...............
..............
but if I would be allowed I would pre-order ...
Your my hero Matthias _________________ greetings from belgium, Sascha
Wouldn't stage gate outputs plus a CV mixer allow the cascading/nesting of these modules?
That would enable the ability to build complex ADSRs if needed, no?
_________________ What makes a space ours, is what we put there, and what we do there.
i almost finished the prototype. i have to iron out some issues with the release stage gate output (does not work as expected, yet).
then i will try a few things. i initially thought of adding a switch for LFO mode, but i will have to try what i can achieve... the gate input is normalled to be high, and the trigger input is normalled to the gate"s input comparator. i will ahve to ponder about this a little bit. _________________
so here it is, and everything is working quite nice.
i took the gates from the LEDs to feed comparators, which then output nice high level gates for the outer world.
for the end trigger i initially tapped the release gate and fed it into an inverting comparator (what did i think?), which was not usefull. why?
in trigger mode the LFO does not go into the release stage. so i tapped the output signal.
now one can patch the end out trigger to the trigger input, and then you have a LFO with adjustable rise and fall times.
a new prototype has been finished tonight, incorporating two requested features:
the ADSR/LFO mode switch has been added to the eurorack front panel components PCB (actually just routing the end trigger to the trigger input)
the circuit PCB now offers a third timing cap, so that one could use a on-off-on toggle for the range switch. for the new prototype i used 47uF, 4.7uF, and 470uF. the 47uF is making this ADSR/LFO really slow, and i believe one could use even 100uF...
i will got o bed now, :dizzy:
so no pictures or measurements or whatever. in the next days i will start designing the front panel (will match the 555VCO and the Contr.LFO of course!). _________________
to be honest, i am too lazy right now to check the pinout
anyways, this CMOS ADSR has been built a lot, since PCBs and front panels are available via thonk and synthcube (with additional stage gate outputs). _________________
Joined: Dec 17, 2009 Posts: 497 Location: Rosmalen, Netherlands
Posted: Wed Oct 21, 2015 12:20 am Post subject:
Hi Matthias,
Thanks for the reply, in the meantime, I have deduced what the 4052 does, hopefully correctly so
Haven't sent the PCB out yet, but I have a few other designs done, so maybe next week or so.
Joined: Dec 17, 2009 Posts: 497 Location: Rosmalen, Netherlands
Posted: Wed Nov 18, 2015 5:44 am Post subject:
Got these boards in last friday, and immediately proceeded to assembling them
I did get the wrong type of 555 (bipolar rather than CMOS) but stuck one of them in anyway. (didn't realise you can still get bipolar 555's in SMT)
And it worked!
In the meantime, I've ordered and received CMOS 555's in SMT and now the ADSR behaves much better, the LED's are more of equal brightness now.
I am amazed how little questions and comments there are on this project though. It's meant to be driven from +/-15v, and with the bipolar 555 I got 4.4V max output, which is very little. With the CMOS 555 I get about 5V, which is better, but still not great.
I will change the voltage divider on the output to get a bit more oomph.
Given the popularity of eurorack, you'd think more people experience this.
By the way, because of availability (or lack thereof) I used a 10k slider for sustain, and 1M sliders on the rest. I used a 470nF cap rather than 1uF, so timing is about the same.
Posted: Fri Jul 01, 2016 6:13 am Post subject:
Re: CVin question
ungleichklang wrote:
Hello all,
is it possible to add VCin to the A D S and R?
I want to control these with a sequencer ...
Thanks in advance
for Attack i think it wouls be rather easy. just mix the pots voltage with an external voltage.
for the other stages i don't see an easy solution. one could maybe mix the Decay pots output voltage with an external voltage, however, the decay is dependent from the sustain level anyways.
maybe having Attack and Decay under voltage control would be sufficient? _________________
Posted: Fri Nov 24, 2017 7:21 pm Post subject:
Re: CVin question
fonik wrote:
ungleichklang wrote:
Hello all,
is it possible to add VCin to the A D S and R?
I want to control these with a sequencer ...
Thanks in advance
for Attack i think it wouls be rather easy. just mix the pots voltage with an external voltage.
for the other stages i don't see an easy solution. one could maybe mix the Decay pots output voltage with an external voltage, however, the decay is dependent from the sustain level anyways.
maybe having Attack and Decay under voltage control would be sufficient?
Hi and good day everybody! Bump!
Is it possible to convert this circuit to VADSR? I suspect that this can be made (with or without LEDs). So it can be used for polyphonic aims.
Yes, I know that probably it's better to do with a PIC... But then all envelopes will be too identical. Slightly different env. parameters of different voices can give more liveness. Also the most known env. generator (from ElectroDruid) has 10sec limitation. In analog envelopes you can swap capacitors and etc.
P.S. I've seen Rene Schmitz VADSR. It seems to be very good but very IC crowded.
Thank you, Fonik! It seems to be a great solution! I'll order 4052 and 4001 right now.
Do I need audio-taper potentiometers for A, D and R? Because i don't know how is the 2n3906 pair working in the circuit.
Can CA3080 be replaced with a usual op.amp + diodes? I can use LM13700... but it would be cool to just make it with a regular op.amp... IDK if it's cumbersome, possible or really hard to implement.
P.S. I've got that in the previous schematic Decay depends on Sustain... And I guess it can be split with a buffer like it was made in Schmitz's circuit. Or I'm mistaking.
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