Hey so I just built the TR-808 stripboard module and cowbell module clones from electro-music.com and both work pretty good! Question is that it doesn’t sound quite like the TR-808 cowbell and I think it has to do with tuning the oscillators on the sound source module. It is noted on the website that, "The cow bell component of this circuit uses only two of the oscillators and each are tuned with the trim pots. Cow bell tuning A needs to be tuned to a frequency of 1.85 ms, cow bell tuning B at a frequency of 1.25 ms. It is worth noting that to achieve this range I had to change R15 from 150K to 100K, and R8 from 100K to 68K. " My question is with the tuning for 1.85 and 1.25 ms, is that referring to the Hz, cycle, or pulse width on the oscilloscope? Because I’m using a cheap jyetech dso oscilloscope and every time I zoom into the oscilloscope, those values also increase and decrease, can anyone help with what I’m looking for?
That’s the cycle duration.
So the frequemcies are :
1/1.25ms = 800Hz
1/1.85ms = 540Hz
I think I remember the jyetech does display the frequency.
does this help? I tune mine by ear.
It absolutely helped a lot! I already tuned it, have it working with the cowbell module and the hihats modules and they sound fantastic! Thank you so much!
Actually one question regarding the snare drum module. I noticed one of the parts needed is a PN100 transistor and I can’t exactly find one of Tayda or Amazon and the only ones available are kind of expensive from eBay. Is there a substitute I can use that would function the same as the PN100 for the module or is that component not able not to be replaced?
Glad that helped. I built the kick, snare, cowbell, cymbal & high hats. Couldn’t get the high hats to work. For the snare, the electro-music thread lists the PN100 alternative of 2N3704 which is available from Tayda. You may have to swap the legs around though. I don’t recall.
Couldn’t recall hearing of 2N3704 before so I took a look… from this:
it sounds like a 2N3904 ought to work just as well provided it’s not trying to sink more than 100 mA… and I hope one snare module isn’t drawing 100 mA! (2N3904 and 2N3704 have different pinouts though.)