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SOLVED! Everything looks ok but no sound

PostPosted: Sep 21st, '14, 15:42
by rv0
finished my built yesterday, everything seemed fine, but i tested and got no sound (flatcables and audio cable are installed of course)

today i measured all voltages, everything is ok, everywhere (op amps)
i also tuned TM1 and TM2 with scope.
i checked the trigger outs of IC5 and IC9, i get a trig on each active sep, so that is ok too.
yet still, no sound, not from main out, not from ind. out, also check with scope


any clues?


edit: solved.. it seems..update fw and removed some excess solder from a pot that may have been touching/shorting gnd.

Re: Everything looks ok but no sound

PostPosted: Sep 21st, '14, 18:19
by Dr.Knob
It's strange! It does not work either in expander?

Re: Everything looks ok but no sound

PostPosted: Sep 21st, '14, 21:06
by rv0
Dr.Knob wrote:It's strange! It does not work either in expander?

strange indeed.

expander mode, same thing, i check pin 1 of IC5 and i do get the triggers on scope, but again, no sound

Re: Everything looks ok but no sound

PostPosted: Sep 22nd, '14, 00:08
by gihaume
Are the cables linking the 2 PCB in good condition? I had some of them broken after turning again and again the PCBs.

Re: Everything looks ok but no sound

PostPosted: Sep 22nd, '14, 08:19
by rv0
gihaume wrote:Are the cables linking the 2 PCB in good condition? I had some of them broken after turning again and again the PCBs.


Sure, I only soldered the cables between 2 PCB in the last step, so they are in perfect condition.
I checked with a (soundcard) probe on R175 lead (BD OUT) and I don't seem to get anything. I'm using GND point on the ICSP footprint in all my measurements btw.
I must have made some global mistake in all voices .. I don't get it .. Will fully debug the BD tonight and hopefully that will give some clues.

Thanks for the help so far!

Re: Everything looks ok but no sound

PostPosted: Sep 22nd, '14, 15:38
by Dr.Knob
yes that's exactly what we need to do, first try to debeug the bass drum, then after the other instuments. One by one and with separate outputs, as the master module is not essential for the firsts tests. Although the master unit does not work in theory , you can still try each instrument separately.
Check your power supply too.

Re: Everything looks ok but no sound

PostPosted: Sep 22nd, '14, 22:53
by rv0
A friend of mine pointed out to me that the problem may originate in the accent section, due to the way the accent influences the triggers. And it looks like he's right!
I first replaced the 4011 as I read there's problems with some of them, and replaced it with a CD4011BCN.
That did not fix the problem.

Then, by mere accident I slipped my audio probe against R101, and yes, the yocto starts playing his pattern.

So whenever I touch R101 with probe I hear the (lovely) sounds.. I think the solution is near, but I'm too stupid to find it. I reflowed all nearby components.
Any more suggestions?

Re: Everything looks ok but no sound

PostPosted: Sep 23rd, '14, 18:49
by Dr.Knob
If you sequence a bass drum and that there isn't enough voltage on any side of R155, so that means say that the accent unit is faulty.

Re: Everything looks ok but no sound

PostPosted: Sep 23rd, '14, 21:10
by rv0
R151 was burned (see r 151 accent resistor burns) .. replaced it now. but still not working.

Re: Everything looks ok but no sound

PostPosted: Sep 23rd, '14, 22:41
by Snoozr
Maybe check Gnd continuity all the way through to just before the power socket? I think I saw in another thread that Vincent said grounding was an explanation for no sound throughout. It's funny that your multimeter probe makes things work.