[IN STOCK] L-1 VC ADSR, Mouser cart added, page 5.

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livefreela
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Post by livefreela » Sat May 21, 2016 2:06 am

thanks for the clarification l-1! sammy, i got mine straightened out - i wound reflowing the joints on the tl074s running vertically on the board. two looked dodgy so i also replaced those chips to be sure. decay/release times now work as intended. maybe that's of some help to you...

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pix
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Post by pix » Thu Jun 09, 2016 7:15 am

L-1 wrote:
fragletrollet wrote:As my values are pretty far from 5V (more like 2,8/2,9V), is this a problem related to the mentioned resistor? Do I need to change both the LM13700 and the resistors? I used a 13700 from Tayda, that has been sold me several bad chips lately, so I could see it being faulty.
Yes, swap both resistors, one for each generator.
No need to change 13700.
2.9V it's correct with 150K.

I used fake therefore this difference in gain.

Alex, how far did you go when trying this? Is there a way to increase the gain to 10V output?

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Post by L-1 » Fri Jun 10, 2016 4:54 pm

pix wrote:

Alex, how far did you go when trying this? Is there a way to increase the gain to 10V output?

510K gives gain to have 10V amplitude at the out. These resistors near the LM13700, sighned 150K but installed 255K.

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Post by dksynth » Sun Jun 26, 2016 2:18 pm

-deleteeeeee-
Last edited by Guest on Sat Feb 06, 2021 1:37 am, edited 0 times in total.
Reason: undoing the damage

YannickD
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Post by YannickD » Fri Jul 29, 2016 5:13 am

I got a weird problem with mine: the envelopes are triggering but they behave differently. the second one works as expected but the first one never reaches the release phase, doesn't matter how i turn the knobs. instead it sometimes looks like it jumps back to the decay stage.
also during calibration the first envelope never turns of all the lights when shorting the gate. the sustain light always stays on.

anyone has an idea what this could be? gonna reflow my sockets as well, maybe its just one of the tl074s.

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Post by qualitypetrol » Thu Sep 22, 2016 6:24 pm

Hi, where is the link to the assembly guide? For the Quad VCA it is on the product page, but i can't find the assembly guide link for the ADSR on its product page

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Post by L-1 » Fri Sep 23, 2016 11:38 am

qualitypetrol wrote:Hi, where is the link to the assembly guide? For the Quad VCA it is on the product page, but i can't find the assembly guide link for the ADSR on its product page
Better is to start from the Quad VCA or other small module.
Pretty tight soldering in the VC ADSR. Assembly order is the same as in the Quad VCA.

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Post by appliancide » Sun Oct 23, 2016 11:17 pm

Hi Alex. Could you please point out which resistor sets the brightness for the decay LED?

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Post by L-1 » Mon Oct 24, 2016 1:12 pm

These ones but together with release LEDs.


Image

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appliancide
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Post by appliancide » Sat Nov 05, 2016 8:16 pm

One more question for you...

Could you point to the section(s) of the PCB where I would troubleshoot the decay of the top envelope? It doesn't respond to the knob or VC, if that helps narrow the area down. I have the schematic, but it's hard to match up with the board.

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Post by L-1 » Wed Nov 09, 2016 12:33 pm

appliancide wrote:One more question for you...

Could you point to the section(s) of the PCB where I would troubleshoot the decay of the top envelope? It doesn't respond to the knob or VC, if that helps narrow the area down. I have the schematic, but it's hard to match up with the board.
Check at first the voltage at Dec pot. Also 3906 transistor top right.
I can send the board image if needed.

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Post by YannickD » Wed Nov 09, 2016 6:37 pm

Alex, since I got a similar problem, could you please post the needed voltages and test points here? A picture of the board with where to measure would be great.


appliancide: can you calibrate the first envelope correctly as per the instructions?

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appliancide
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Post by appliancide » Wed Nov 09, 2016 6:56 pm

YannickD wrote:Alex, since I got a similar problem, could you please post the needed voltages and test points here? A picture of the board with where to measure would be great.


appliancide: can you calibrate the first envelope correctly as per the instructions?
Yes, both envelopes are calibrated. I have very little time for DIY during the week, so I haven't messed with it since I found the problem. I believe the problem on mine is going to be the 3906 that Alex told me to check. I don't remember the voltages that should be on the pots (I want to say it was -5 and +10, or maybe the other way around), just that mine were the same on both envelopes. That and the fact that the VC input has no effect, pretty much points to the 3906 in my case.

Hope you get yours working soon! I will update when I fix mine, if that helps.

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appliancide
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Post by appliancide » Wed Nov 09, 2016 8:17 pm

L-1 wrote:
appliancide wrote:One more question for you...

Could you point to the section(s) of the PCB where I would troubleshoot the decay of the top envelope? It doesn't respond to the knob or VC, if that helps narrow the area down. I have the schematic, but it's hard to match up with the board.
Check at first the voltage at Dec pot. Also 3906 transistor top right.
I can send the board image if needed.
Voltages look good, or at least the same as on the fully functional half. -5 and +10 sound right? I swapped out the 3906 as well without a change.

Does your board image have the part designators on it? That would be very helpful.

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appliancide
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Post by appliancide » Thu Nov 10, 2016 9:37 pm

Amynio wrote::yay: :yay:
I would ask but how to find him... and tell him he is wonderful!
I'm really not sure how this will help, :hmm: but just in case, you are wonderful Alex!

Anyway, I am a bit perplexed. The same part of the That340 handles the decay and release right? When the (inverted) gate is high, the 3906 will open and the decay voltage will be fed into that part of the circuit, and when it goes low, the 3904 will open and the release voltage will feed into that part of the circuit.

If this is right, the problem has to be before that part of the circuit, since the release stage is working fine. This is the part that has me baffled. There are less than a dozen parts, and I've redlined that whole section. According to my continuity testing, everything part is connected to the parts it should be. It has to be something simple!

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Post by samuraipizzacat29 » Fri Nov 11, 2016 7:52 am

If you have the schematic, it might be time to start cutting traces. It wouldn't be the first time a bit of stray copper kept something from functioning properly.

.... if you've reflowed and/or replaced every part in question that is.
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Post by appliancide » Fri Nov 11, 2016 10:34 pm

Sure enough there was a connection that shouldn't have been. I never found it or cut any traces though. Through testing I was able to narrow the problem down to a short on R120 or the base of the 3906 (T8). I couldn't see where it was, so I removed R120 and soldered it directly to R115. I lifted the middle leg of the 3906 and ran a wire from it to the other side of R120, and the decay came to life!

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Post by qualitypetrol » Wed Mar 15, 2017 3:12 pm

I'm gonna replace my post from last night because i have a voltage meter now. So when i short the gate out and i measure the DC voltage, it is 0.00 - when i take the cable from gate out, only the second generator goes to sustain and the first one is stuck on the attack LED.

Other observations:

initially i was getting an actual envelope signal with the first testings. the time stages on the 2nd generator, or at least the decay stage, seemed much slower (a little too slow to be useful really) than the first generator - both were set to the same value for lin/exp of course. Also, the sustain - when set to zero - was obviously not returning to zero. These conclusions were of course made before i did the calibration procedure and before the output became mute somehow.

After trying to measure the outputs (where both the gate low and sustain states measure 0.00), suddenly nothing that i connect to the output of either one of the envelopes gets modulated anymore. so there is basically no voltage coming from the outputs at any time.

when i gate the module, the 2nd generator visually cycles through the stages, the first seems stuck in the attack stage: attack led on during gate high and release led lights during release, but nothing else. in the very beginning, all the leds were definitely working. also, the fact that the attack led stays lit means the decay and sustain stages are not being run through

i tried adjusting the back trimmers to see if anything changes somehow, but it didnt help

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rdomain
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Post by rdomain » Thu Jul 27, 2017 11:47 pm

Quick question...

Am I able to use the Thonk PJ301BM Jacks so I don't have to solder on all the ground wires? The other jacks I have currently are the Thonkiconns.

Thanks.
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Post by teebeehex » Fri Jul 28, 2017 3:41 am

rdomain wrote: Am I able to use the Thonk PJ301BM Jacks so I don't have to solder on all the ground wires? The other jacks I have currently are the Thonkiconns.
Looking at the L-1 site, at the pcb pics, it appears to be suitable for both thonkiconns and the PJ301BMs.

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rdomain
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Post by rdomain » Fri Jul 28, 2017 7:13 am

So no need for a ground wire for either sort then? Thonkiconns have 3 legs whilst the PJ301BMs have 4. The PJ301BMs also don't fill one hole that the Thoniconns fill hence my confusion. :hmm:
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teebeehex
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Post by teebeehex » Fri Jul 28, 2017 8:07 am

Both those jacks have ground connections in place. The process of soldering the ground lead applies if you are using Kobiconns (or similar) which have a short loop near the top of the jack.

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rdomain
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Post by rdomain » Fri Jul 28, 2017 8:47 am

teebeehex wrote:Both those jacks have ground connections in place. The process of soldering the ground lead applies if you are using Kobiconns (or similar) which have a short loop near the top of the jack.
Ah ok. Great to know. Thonkiconns it is then :) Thanks for the info!
aritchie.com

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Post by rdomain » Tue Jan 22, 2019 2:25 am

Finally got round to completing this build. I've done the initial calibration and everything seems ok except for Release on both channels. It appears Release is getting triggered the same time as Attack on both channels so Release ends up having no effect.
I'm guessing this probably points to an obvious area to check for the more knowledgeable?

Thanks!
aritchie.com

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Post by L-1 » Wed Jan 23, 2019 5:55 am

rdomain

Check the voltage at both ends of the Release pots.

Send me a hires photo of the board.

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