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Re: cowbell sound problem, not the right 808 sound
Posted: Mar 25th, '14, 20:49
by seven
My friend has just built my Yocto for me, but the clap and cowbell didn't sound right, I have now sorted the clap,
I have found 2 oscillators for the CB, but tuning them to be in harmony does not give me the high pitched sound I know, it all seem to low - whatever I do with the osc's,
Is something connect wrong?
Thanks in advance...
seven
Re: cowbell sound problem, not the right 808 sound
Posted: Mar 25th, '14, 22:43
by lfo2vco
Hi Seven,
I have the same problem despite changing R44 & R45 as per the build instructions. My Cowbell is too low and the output from my Schmitt Trigger looks more like white noise (on the Oscilloscope) than a square wave.
I am also discussing this problem in this thread:
viewtopic.php?f=16&t=209
I have a replacement Schmitt Trigger IC that I plan to swap out and then retest, I’ll report back if it makes any difference.
Re: cowbell sound problem, not the right 808 sound
Posted: Mar 25th, '14, 23:11
by mrglf
I've used Ableton Spectrum Analyzer for calibrate the cowbell because it's easy to compare the original sound and the Yocto cowbell this way (and I didn't want to use the oscilloscope and start to count squares). I've changed both resistors and setting TRIM1 fully clockwise I still having a detuned tone in the lower freq (540Hz and the original seems to be around 560Hz). So I'll need a lower resistor value for increase the pitch. Nailed high freq tone.

On the image are displayed both cowbells of 808 and Yocto (this one with the detuned tone).

Re: cowbell sound problem, not the right 808 sound
Posted: Mar 26th, '14, 11:12
by seven
lfo2vco wrote:Hi Seven,
I have the same problem despite changing R44 & R45 as per the build instructions. My Cowbell is too low and the output from my Schmitt Trigger looks more like white noise (on the Oscilloscope) than a square wave.
I am also discussing this problem in this thread:
viewtopic.php?f=16&t=209
I have a replacement Schmitt Trigger IC that I plan to swap out and then retest, I’ll report back if it makes any difference.
Please do report back yes, I actually thought e-licktronic himself may be more pro-active on this forum...
Re: cowbell sound problem, not the right 808 sound
Posted: Mar 26th, '14, 19:36
by lfo2vco
OK, so I swapped out U1 4584N for another generic Hex Schmitt Trigger and it made absolutely no difference
Both the pitch and the image on the scope were exactly the same as before.
So I guess the problem lies elsewhere.
Re: cowbell sound problem, not the right 808 sound
Posted: Mar 26th, '14, 19:42
by seven
lfo2vco wrote:OK, so I swapped out U1 4584N for another generic Hex Schmitt Trigger and it made absolutely no difference
Both the pitch and the image on the scope were exactly the same as before.
So I guess the problem lies elsewhere.
OK, thanks - has it anything to do with this part of the Cymbal installation...
Adjust TM1* up to a period of 1.85ms. If TM1* adjustment range is not large enough for this period change the value of R44 * per a resistor of 100Kohm. (supplied in kit)
Adjust TM2 * up to a period of 1.25ms. If TM2* adjustment range does not allow you to get this period change the value of R45 * per 68kohm. (Supplied with the kit).
Would it be advisable for me to try this above on mine - or is this unrelated
Re: cowbell sound problem, not the right 808 sound
Posted: Mar 26th, '14, 20:17
by lfo2vco
As I understand it; U1 supplies square waves to both the Cymbal and the Cowbell.
TM1* & TM2* adjust the pitch of the Cowbell. U1 can output six square waves, I don’t think the Cymbal shares the same outputs as the Cowbell.
However this is just what I have read and I stand to be corrected by anyone with more knowledge on the Matter.

Re: cowbell sound problem, not the right 808 sound
Posted: Mar 26th, '14, 20:23
by seven
lfo2vco wrote:As I understand it; U1 supplies square waves to both the Cymbal and the Cowbell.
TM1* & TM2* adjust the pitch of the Cowbell. U1 can output six square waves, I don’t think the Cymbal shares the same outputs as the Cowbell.
However this is just what I have read and I stand to be corrected by anyone with more knowledge on the Matter.

I have no problem with the sound of the Cymbal to my knowledge if that helps, could dodgy a TM1 and TM2 be the fault maybe, I wish e-lictronik would chime in....

Re: cowbell sound problem, not the right 808 sound
Posted: Mar 31st, '14, 10:18
by e-licktronic
Dear,
Do you make scope test on R44* and R45*?. It would be easier to debug your cowbell sound
Best regards,
e-licktronic
Re: cowbell sound problem, not the right 808 sound
Posted: May 24th, '14, 09:11
by Check Mate
Hi Guys,
I only have a minor issue with my Cowbell. The Tuning-Range of TM1 is not enough although I already changed the Resistor to a 100k.
I get a C with max Trimmer Setting but I cannot get a good Cis (as it is supposed to be).
Is there anything I can do to extend the tuning range (maybe change the resitor to an even lower value)?