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

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 :x
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 :x
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)?