e-licktronic Forum

Hello there!

Finished my 1.02 build and tried to start it, but got no 5V at TP1 (no matter how much I turned TM2)
nore does a LED or the Display light up. Then I noticed that I got a strange voltage failure in the Sequencer Circuitry,
IC1 got 15V on the positive pin and-15V on the ground pin.
All other ICs in the sequencer part shows around 100mA, so for me it seems like that I have made a mistake around IC1.
So for troubleshooting I would appreciate a hint or the newer 1.02 Layout, as the 1.01 doesnt help a lot.

Did you test the voltage coming out of the power supply section on the IO board? Double check your wiring of the IO board to the main board and ensure that you connected pin1 to pin1, etc.

Thanks!
Partly that was the issue! In lack of a crimp wrench I soldered all crimp connectors and had some bad connections, so
I've ordered another 40 kk molex crimp connectors and lend me the smallest crimp wrench which was available at my workplace.
And got a free crimping lesson from a curious electrician (I'm a metalworker so crimping is not my business).

So now everything is working, except for hi-tom and a quiet, missing noise snare.(sounds like a low rimshot)

And still got no +5V at TP1

The 1.02 layout is updated now in the shop

Pesca wrote:Thanks!
Partly that was the issue! In lack of a crimp wrench I soldered all crimp connectors and had some bad connections, so
I've ordered another 40 kk molex crimp connectors and lend me the smallest crimp wrench which was available at my workplace.
And got a free crimping lesson from a curious electrician (I'm a metalworker so crimping is not my business).

So now everything is working, except for hi-tom and a quiet, missing noise snare.(sounds like a low rimshot)

And still got no +5V at TP1

The 1.02 layout is updated now in the shop

How does the vco of your snare sound without the noise? Is the decay time ok? Does it sound like this? https://vocaroo.com/i/s0KdGLUPVfyZ

I got most of the sequencer built today and am also getting 0V at TP1. I get near 5V between TP1 and analog ground. It appears to be because there is instruction to ever place R40 on the power board so digital ground isn't grounded. R40 seems new to the 1.02 board. There also is no BRD file so (AFAIK) it's impossible to know what to place there. I was guessing a 0R as that was how Yocto2 was built but seems like a risky guess.

KlangGenerator - you seem to have made it past this point on a 1.02 board. What did you place in R40 (right next to pin1 of J10)?

I found the other thread that indicates to place 0R for R40. I now have voltage at the ICs (but haven't soldered the ICs in yet). I will get those in tomorrow and hopefully have a good reading at TP1. I misread the instructions and thought I was supposed to adjust TM2 prior to placing ICs.

KlangGenerator wrote:How does the vco of your snare sound without the noise? Is the decay time ok? Does it sound like this? https://vocaroo.com/i/s0KdGLUPVfyZ

Mine sounds excact like your sample in the first 10 seconds. just the noise is missing, meaning "tone" and "snappy" has no function.
No matter how I tweak those two pots, there is no change noticeable.
Vco1 and 2, Noise, Env 1-5 are sounding, when i put my headphone probe on it. Just Env 1 and 4 seems a little bit quieter than the others.
Bridging the pins of the pots also shows no effects.

Pesca wrote:

KlangGenerator wrote:How does the vco of your snare sound without the noise? Is the decay time ok? Does it sound like this? https://vocaroo.com/i/s0KdGLUPVfyZ

Mine sounds excact like your sample in the first 10 seconds. just the noise is missing, meaning "tone" and "snappy" has no function.
No matter how I tweak those two pots, there is no change noticeable.
Vco1 and 2, Noise, Env 1-5 are sounding, when i put my headphone probe on it. Just Env 1 and 4 seems a little bit quieter than the others.
Bridging the pins of the pots also shows no effects.

If your noise is missing then the reason could be a dead IC32 or IC33. I often experienced these to be faulty in my builds.

Please check the VCO decay again carefully. Is it really so short like in this audio sample:

https://vocaroo.com/i/s0KdGLUPVfyZ

or long like in this sample?

https://vocaroo.com/i/s0PIgOB4e5yx

No, clicky short like in the first sample. I got all the signals at the testpoints in the snare part on the pcb (Env 1-4, Vco 1+2, Noise)
Just got no snare noise at the output.

Ok, thanks!