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2015-07-04 by Richard Brewster
Then I will just have to find out and report back. Thanks, RIchard Brewster On 7/3/15 11:27 PM, Ken Stone otherunicorn@... [cgs_synth] wrote: I really don't know! I've never measured it. Nothing on it on Rene's site either. On Sat, Jul 4, 2015 at 5:16 AM, Richard Brewster pugix@.
2015-07-04 by Ken Stone
I really don't know! I've never measured it. Nothing on it on Rene's site either. On Sat, Jul 4, 2015 at 5:16 AM, Richard Brewster pugix@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: Hello, I'm building a pair of CGS64 VCAs and I need to know what the unity gain CV level is,
2015-07-03 by Richard Brewster
Hello, I'm building a pair of CGS64 VCAs and I need to know what the unity gain CV level is, probably +5V, but I didn't see this in the docs. Reason to ask is that I am using the optional initial gain pot, which is shown hooking to a 100K resistor. If that pot goes zero to +15V,
2015-06-29 by spunraddish
More construction error - I found that pin 9 of the 4051 multiplexer had another lifted trace, so now all channels work with very minimal bleed, though it's still there. Now off to find what is hopefully the final error that is not allowing the reset to work. Thanks again! Eric
2015-06-26 by spunraddish
Yes, construction error indeed - I found that the diode of channel 6 was not connected due to a lifted trace via continuity test, so now I have no more bleed from distant channels. The problems that are still there are that channel 2 and 4's inputs pass no signal, but accept full
2015-06-26 by Ken Stone
People are too quick to blame the parts. Usually it is a construction error. On Fri, Jun 26, 2015 at 2:22 PM, spunraddish@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: I checked all the diodes visually, cross-referencing the circuit diagram to make sure there were no mis-mar
2015-06-26 by spunraddish
I checked all the diodes visually, cross-referencing the circuit diagram to make sure there were no mis-markings, and of course there weren't. I did a diode test on each, and they all came back normal for 4148s. What would cause this to run backwards (8-1) when this is wired "cor
2015-06-26 by Ken Stone
16, 7 and 8 are fine. Anything below 5V is fine on pin 6 when the INH input is low. When the INH input goes high (i.e. gets a gate input), pin 6 will go to something over 7V (12V?). It's a digital input,so the exact voltage isn't important. Make sure your diodes are not backwards
2015-06-26 by spunraddish
Hi Ken, I've checked the mutliplexing 4051; I found that power is at ~ +11.25V at pin 16, and pins 7 and 8 are at -.69V. Pin 6 is at a steady 1.35V. Is that alright? Thanks, Eric
2015-06-25 by Ken Stone
Start with checking the voltages to the power rails of the chip. Make sure the -0.6 is working (-0.7 V is acceptable). Ken On Fri, Jun 26, 2015 at 2:39 AM, spunraddish@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: This should be my last question here for a bit, seeing as I'v
2015-06-25 by spunraddish
This should be my last question here for a bit, seeing as I've got the other 15 or so PCBs working on their own; I've built up my sequential switch, and it has some funny behavior. The clocking is perfect and the state address is mostly correct, but hte default state is backwards
2015-06-22 by Ken Stone
The output of that clock probably has sloped transitions. On Tue, Jun 23, 2015 at 4:26 AM, spunraddish@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: Thanks everyone! I switched out the 072 and placed a cap across the power pins of the 4015 and it works just fine! I find that
2015-06-22 by spunraddish
Thanks everyone! I switched out the 072 and placed a cap across the power pins of the 4015 and it works just fine! I find that I get the previous issues only with a particular source of clock in my staple system as it pertains to the gated comparator, and I know it's not pulse wi
2015-06-19 by Ken Stone
Lower resistances between the op-amp pins would not help. It's a measure to speed up the transition time. Try a different TL072. "End of life" for chips means they aren't making them any more. The chip itself is still viable. Add another 100n directly across the 4015's power pins
2015-06-19 by neilbaldwin70
If you can I'd definitely try more 4015s. I had a terrible time with them recently when building a Rollz-5. The problem I had was one or more of the gates not closing down properly and allowing signal to bleed through. I tried 4 different ones before landing one that worked prope
2015-06-19 by spunraddish
Hi again Ken and Richard, Thanks for your help. I've tried placing a 2M trimmer between legs 5 and 7 of that particular 072, but without results until rsistance too low locked up the 072 - I may try one from a different manufacturer, since I'm getting a slightly different set of
2015-06-19 by Richard Brewster
When the 4015 was swapped, did you try a different manufacturer? I discovered years ago when I built the Burst Generator that some CMOS chips can have spurious output glitches. Now I use only Texas Instruments CMOS chips. Richard Brewster http://pugix.com On 6/18/15 6:40 PM, Ken
2015-06-18 by Ken Stone
It may have more to do with the speed of the clock chip. Try adding a 1M between pins 7 and 5 of the TL072 that is used to process the clock signal. On Fri, Jun 19, 2015 at 4:37 AM, spunraddish@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: Nope, did that and did a few more m
2015-06-18 by spunraddish
Nope, did that and did a few more mods, to no effect - in loop mode there are only 4 eventualities - no steps on, 3 steps on, two steps on with a space between them, and 7 steps on. When not in loop mode, it seems there may be a sort of logic to when step 6-8 stay on and off, as
2015-06-18 by spunraddish
Might it also be that my loop switch in ON position is open and ungrounded, or should that never be an issue in a switch?
2015-06-18 by spunraddish
Thanks for the response, Ken. I replaced the capacitor to a film one, reheated a bunch of joints, and added a few jumpers just to be safe, and nothing in regards to the reorganization of the patterns- there are specific clock frequencies that seem to be more inclined to erasing a
2015-06-18 by Ken Stone
There should be an RC lag built into the data line at the 4-5 junction to deal with this issue. Make sure the capacitor is installed and connected. On Thu, Jun 18, 2015 at 12:06 PM, spunraddish@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: Hi again guys, I just built up a ga
2015-06-18 by spunraddish
Hi again guys, I just built up a gated comparator and it works - with some reservations. I find that certain pulses reallocate and disappear around step 5-6, sometimes removing pulses 5 through 8. There are only specific patterns that seem to hold (as movement) during loop enable
2015-06-16 by Ken Stone
Your requirements really need to be spelled out. - do you want a 16 step random pulse train as a clock for a single purpose? (yes, 2x gated comparators could be used in series) - do you wish to randomly select from one of 16 outputs at a time? (I don't have anything that does thi
2015-06-16 by oivind60
I want a random gate sequenser and I am wondering if the gated comparator can be used? Need 16 step
2015-06-15 by Jorgen van de Burgt
Cool, saves me a lot of work! Thanks for the awesome module Ken (you and Serge, and Clarke for the panel) :) On Mon, Jun 15, 2015 at 1:02 PM, Ken Stone otherunicorn@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: As long as the module is using the same power supply as your oth
2015-06-15 by Ken Stone
As long as the module is using the same power supply as your other modules, the jacks don't need grounding. After all, that is how banana jacks work. Cheers, Ken On Mon, Jun 15, 2015 at 7:34 PM, jorgen.vandeburgt@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: So, good news an
2015-06-15 by jorgen.vandeburgt
So, good news and bad news. The good news is it's fixed. The bad news is that I'm an idiot. I thought I'd connected a ground line on all the jacks, but I'd connected the wrong terminal meaning all jacks were connected all the time. Removed these connections and now I'm golden...
2015-06-12 by Ken Stone
The first step is to check voltages - at the power pins of the chips. Feel about to make sure no part is getting hot. Make sure you have the diodes all the right way around, Make sure you haven't mixed the zener with a regular diode. Second - check the voltages at the outer tabs
2015-06-12 by Jorgen Van De Burgt
It's 3904 and 3906s all round as specified. I used a component kit from Elby. Coincidentally, the one problematic jack is the only different one from all the others. Still, that's not what is giving me the other issues... Op 12 jun. 2015 om 13:51 heeft Ken Stone otherunicorn@...
2015-06-12 by Ken Stone
It is almost certainly a construction error on both counts. It's hard for me to say what is going on when I have never seen the fault condition myself. "Transistors all in backwards" worries me because you did not specify the type of transistors you are using. They may not need t
2015-06-12 by jorgen.vandeburgt
Ok this is interesting. Problem #2 persists after I disconnect the wire from D to the problematic jack. Since only the ground line is connected, what's going on? None of the other jacks that are on the same ground line show this behaviour :S Any input on the lack of oscillating B
2015-06-12 by Ken Stone
or at very least, disconnect the wire to it. On Fri, Jun 12, 2015 at 8:25 PM, jorgen.vandeburgt@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: Yup, it's not showing itself though. Might change out the jack itself. -- Ken Stone otherunicorn@... Modular Synth PCBs for sale http
2015-06-12 by jorgen.vandeburgt
Yup, it's not showing itself though. Might change out the jack itself.
2015-06-12 by cg_synth
The first thing to do is find the wiring error that is causing the short circuit!
2015-06-12 by jorgen.vandeburgt
Hi All, I've seen this behaviour with others who had trouble with this circuit on the forums, but unfortunately no solution: I've built a Quad Slope for eurorack, and it's not entirely disfunctional, but the LEDs are always on, and self-oscillation does not work for either of the
2015-06-08 by oivind60
Thanks Ken Then I will order a cgs 28 next time. I have a couple of Serge panels in my backlog
2015-06-08 by Ken Stone
Yes, the 88 has a maximum input of around 7V. You have two choices - limit the voltage that goes into them with a voltage divider, or, as you say, use a CGS28. (connect inputs 1 and 5, 2 and 6, etc.) And it even has it's own LED drivers. Cheers, Ken On Mon, Jun 8, 2015 at 10:01 P
2015-06-08 by oivind60
Tried to isolate them for testing and they still bleeding. But they only bleeds when the pots on the TPS are high. When I use audio they are fine. Dmitri mentioned the problem can be because the voltage is to high. Can it be a sollution to use the cgs28 as someone has sugested?
2015-06-04 by Ken Stone
yes, isolating it may be the only way. On Thu, Jun 4, 2015 at 6:07 PM, oeiols@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: I maybe have to live with it for now and when I get time for it I will split the router and test it like a triple router. -- Ken Stone otherunicorn@...
2015-06-04 by oivind60
I maybe have to live with it for now and when I get time for it I will split the router and test it like a triple router.
2015-06-03 by Ken Stone
Other than testing the 4007 in circuit, no, there is no easy way. Have a chat to Dmitri and see if he had any similar issues. The TPS is his project after all. On Thu, Jun 4, 2015 at 6:14 AM, oeiols@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: For the leds I´m using only a
2015-06-03 by oivind60
For the leds I´m using only a board with only the 4007 and share psu. I have disconnected this board for now. And I am using antistatic arm wrist band and a metal plate on my workbench. All earthed. Maybe I have got bad 4007s. I have got them from Tayda but I have never had any p
2015-06-03 by Ken Stone
I really don't know what is going on. The voltages you show are indicative of the divider doing what it should. Are you controlling the LED board 4007s from the 4013 on the voltage switching board? You should be. Does each board have it's own LM3900, or are you sharing the PSU? F
2015-06-02 by oivind60
The links are ok. I have desoldered the board for the leds too. Nothing. Before I did that the leds blinking when I moved my hand under the board? I have tried to measure while steping and have got those results. LM3900 pin 5: 5,8V alternating -6,8V 4013 pin 11: 7,6V alt -6,9V 40
2015-06-01 by Ken Stone
Check your BH and CL links on both boards. On Tue, Jun 2, 2015 at 4:36 AM, oeiols@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: Now I've got all the chips and tried to run it. Seems like I have some bleedthrough on both PCB`s. I´m using one for the vertical steps on the TPS
2015-06-01 by oivind60
Now I've got all the chips and tried to run it. Seems like I have some bleedthrough on both PCB`s. I´m using one for the vertical steps on the TPS and the other one for the leds. Coupled the other way. PCB`s are connected together only with power and M/N/O. I see the leds blinkin
2015-05-22 by oivind60
Thank you Ken. Helpful as always.
2015-05-22 by Ken Stone
If you duplicate the switching part of the 88 (or use a second one in parallel), yes, you can select LEDs that way. Or you could use a CD4051 or 4052 to do it too. On Fri, May 22, 2015 at 8:25 PM, oeiols@... [cgs_synth] cgs_synth@yahoogroups.com > wrote: I'm using the cgs88 as a
2015-05-22 by oivind60
I'm using the cgs88 as a Quad bi dir router in my TPS (Dmitri`s TKB) and want leds to indicate the vertical steps. How can I do that? Is it a sollution to make a board with three CD4007and connect the SW in parallel with the chips on the board and use the four outs for the leds?