Troubleshooting

[CeeFo]

I've got everything working but the bass drum. Bass drum just makes faint clicking sound when triggered. Component values all double-checked. Any ideas?

[Circuitbenders]

suspect transistors or transistors with a different pionout?

Assuming you're using the trigger conditioning, you could try the trigger from a different channel at the TRIG_IN2 header i.e. try triggering the rimshot at TRIG_IN1 and shorting the conditioned rimshot trigger on the middle pin of TRIG_IN2 to the bass drum on pin 4. If the bassdrum triggers ok then its possibly the bassdrum trigger conditioning thats faulty.

[CeeFo]

Good tip. Took your advice and tried the trig 2 route, I notice that when I trigger the rimshot and short it to bass drum trig2 it cuts the rim shot out (mostly). The snare and hats trigger with the rimshot in this fashion but a bit of a short to the bass drum trig2. Hmmm.

[ElSmurf]

I've been trying to get some sound out of my board for a while now. Today I hooked it up to a scope to see what was going on with the triggers, and it looks like I have nice 12ms triggers coming from Trig_2 when applying 6V on Trig_1. But none of the voices produce any signal, not on the main out, nor on the jumpers. Any ideas?

I used 2SC495s and a J201, and all polar caps and diodes are in the right way.

[Circuitbenders]

That might suggest your 2SC945's ( iassume you mean 2SC945 when you say 2SC495) might have a different pinout for some reason.

[ElSmurf]

As mentioned in another thread, I did not get 2SC945s but KSC945s (even though they were sold as being 2SC) and after removing all of them and bending the legs everything works but the noise. I'm assuming I fried one or both of the transistors in that part when desoldering or bending them. It'll probably be all good once I replace them.

[pbb]

Hello,

I finished the soldering of the pcb but I din't have sound with trigger on HH and nothing on master (it's not a problem for the master cos I only want to use individual outs).
So I tried different thinks :
- change transistors T6 and T7
- verify all components values
- change VR2 value (turned it on maximum with snare sound)

But I have nothing on J2 and J4.

I putted an audio jack to listen what happened and there is noise on R70 (next to C35) and I have a bass drum sound (...) on R67 (next to C34).
So I'm disillusioned...
Do you have an idea to resolve these ?

Thank for your help

[sirgavalot]

I have finished populating my circuit board and have began testing everything, but I get nothing other than a loud buzzing sound. I started off being able to hear the trigger input through connected speakers through both sets of trigger points but after having started checking things, resoldering a few possibly-suspect joints etc that has gone, only the buzzing remains. This gets worse when I touch the volume and tone pots, and some other random bits, such as the bare metal round the lower right hand screw hole. I guess maybe I have 2 problems: the buzzing is a grounding problem, right? And the other being that it's not working.

I'm using a Beatstep Pro to trigger, using a 100k and a 68k resistor in a voltage divider which gives an output of about 4.7V which should be ok?
Got all the components as listed from Tayda, except, I got a J107 JFET as I read "somewhere" it was an acceptable replacement for a J201, the tantanum cap and the 47uH inductor from Farnell.
Using a 12V PSA from a Behringer mixer to power which works ok with the mixer, but I've also used a Boss 9V.
Had a go at testing the voltages at various points with a multimeter, got power going through some and not others so I'm going to map these when I get free time. Funny thing is I'm getting roughly double the voltages that netpusher wrote on his photo on the initial post - just over 12V near C4 and C33 and just over 19V on that leg of the chip and near C2.

Please help! Have I broken/overheated something? Is it my bad soldering? I reeeeally want this to work, it seemed so straight forward from the guide...

[Circuitbenders]

is your behringer power supply 12 AC rather than DC?

[sirgavalot]

Indeed it was, so that noise is sorted, thank you.

Currently, everything sounds out ok, something has happened with the hats so that the noise pot acts as an overall level to the hihat sound, but this is the biggest problem:

https://youtu.be/O3efE2hnktQ

Not clear from that crap video but as I plug in the instrument circuits that electric gale sound increases so km guessing something earlier in the circuit is making this horrible sound, but I know too little to figure out what

And TRIG2 doesn't work. Maybe it's all related?

[Circuitbenders]

something has happened with the hats so that the noise pot acts as an overall level to the hihat sound,

If i recall correctly the noise level pot will always act as an overall level for the hihat sound, in that the hihats are made from pure noise.

It would probably have been a better idea to use one of the recommended JFET's at Q1. I have no idea how others might work.

If you've had 12v AC connected to ground and +12v instead of DC, then theres a very real possibility that you've fried several transistors and maybe electrolytic caps.

[sirgavalot]

Ah ok thanks for that.

Providing I can remove them neatly would it feasible to just replace the transistors and polarized components or should I really just start again?

Through the horrible noise it sounds really good! Would live to actually finish this properly

[Circuitbenders]

Hmmm, thats a tricky one. The problem is that you can't really reliably test stuff like diodes and transistors in circuit, although you should be able to use the continuity tester on a multimeter to get an idea if things have gone short.
Electrolytics would have probably just blown up in your face if they were going to go. They might be damaged, but you can probably leave them in for now. I would maybe replace C1 and C3 in the power supply section anyway though
Make sure you're getting a steady +9v and +6v at the outputs of the voltage regulators.

Is that weird noise leaking in when you have the snare outputs on J1 and J3 connected as well as the hat outputs?

I'd be a a little dubious of T4, T5, T7, and T8

[sirgavalot]

The weird noise is present with every output and seems to increase when more than one output is connected regardless of whether it's being triggered.

Got approx. 9V and 6V at the regulators, just under 12V at C1 and C3. T4 and T5 0V ~2.5V and ~0.5V, T7 and T8 0V ~6V and 0V.

Loads of resistors and caps with no voltage, dunno if it's because of there being no trigger or anything (eg R1-3 and R6-7, C5-6...). Argh. Too many. Going to start again. Was fun making it even if I broke it a bit. Cheers!

[blakeAlbion]

Hello,

I ordered from the bom for Tayda. They were prompt to deliver and the cost was delightful in itself.
I was able to get the noise filter to stop squealing.
I can hear a very faint bass, rim, snare, and hi-hat. Turning up the volume knob increases gain and hum, but the sound remains very weak. I just printed the schematic and I will go over it.

Finally, the snare does not seem to have any "snare noise"; just the pop of the drum. Are there any known reasons for this, considering my hi-hat does have white noise?

Thanks,

Ben