I'd like to put a mic or trigger or something inside of our drummer's kick drum and have that trigger the arpeggiator on my sh-101. The SH-101 wants (I'm pretty sure) a squarewave clock pulse of +5v.
I was thinking of stuffing a hot mic (boundary perhaps) in the kick and hooking it up to something with a headphone out and then plugging that into the sh-101. Thought I'd ask here first before I blow something up! Will it even work or do I need some specialty box?
Kick mic to CV for analog triggery
-
- tinnitus
- Posts: 1135
- Joined: Sat Jun 03, 2006 8:19 am
- Location: beautiful Carlsbad, CA
- Contact:
A comparitor chip like a LM311 could be set up as a trigger pulse. Set the levels with a resistor divider and it will pop out 5 volt pulses if you use something to attenuate the level at 5 volts.
Or if in a fix, grab a fuzz box, set it so the kick drum squares up the output waveform and set the volume pot to get a 5 volt clipped waveform to trigger.
Or if in a fix, grab a fuzz box, set it so the kick drum squares up the output waveform and set the volume pot to get a 5 volt clipped waveform to trigger.
Jim Williams
Audio Upgrades
Audio Upgrades
Thanks both. Good idea about the gate.
When I see stuff like "+5v" the fact that I'm not a recording 'engineer' really shines! I'm guessing there's a correlation between signal amplitude and voltage but it's a bit of a black hole for me. I just know, anecdotally, that sometimes folks try to hook up CV stuff and it doesn't work because of voltage problems.
Plus, I bought the 101 in 1986?it was my first synth! As I get older I seem to get a ever more precious about it hence the somewhat atypical ask-before-try.
Jim, the distortion pedal idea is what I was thinking by using something with a headphone amp?overdrive the input to get it square up and then use the headphone level to set it. I have an old boss mulit-effect pedal with a distortion and a gate. Think I'll give that a shot instead.
When I see stuff like "+5v" the fact that I'm not a recording 'engineer' really shines! I'm guessing there's a correlation between signal amplitude and voltage but it's a bit of a black hole for me. I just know, anecdotally, that sometimes folks try to hook up CV stuff and it doesn't work because of voltage problems.
Plus, I bought the 101 in 1986?it was my first synth! As I get older I seem to get a ever more precious about it hence the somewhat atypical ask-before-try.
Jim, the distortion pedal idea is what I was thinking by using something with a headphone amp?overdrive the input to get it square up and then use the headphone level to set it. I have an old boss mulit-effect pedal with a distortion and a gate. Think I'll give that a shot instead.
-
- moves faders with mind
- Posts: 2746
- Joined: Thu Jul 03, 2003 11:26 pm
- Location: Denver, CO
- Contact:
Good schematics are available here:
http://www.synthfool.com/docs/Roland/SH ... Manual.pdf
Clock input comes onto the main board at point 101, Quadrant A7 on page 9. It looks like the external clock in runs thru a 100K to the base of a transistor. So moderately protected against external evils.
The fuzzbox idea might be a bit too brute force, and might cause double-triggering. The fuzz box would turn each kik hit into a series of pulses. Since it's an x0x, I'm not sure how long a pulse has to last for it to register with the CPU to trigger. I seem to recall that other x0x machines needed clocks of longer than 2 msec to register. Try it and see.
If it's a double triggering mess, a peak detector + comparator circuit would be a more complete solution, such as this one:
http://www.freeinfosociety.com/electron ... 720-11.gif
There are even more thorough solutions, using pairs of one-shots to more precisely define the pulse width, and set up a hold-off window, so it won't retrigger too soon after the initial trigger. Probably overkill, but worth mentioning...good drum brains use a scheme like that.
http://www.synthfool.com/docs/Roland/SH ... Manual.pdf
Clock input comes onto the main board at point 101, Quadrant A7 on page 9. It looks like the external clock in runs thru a 100K to the base of a transistor. So moderately protected against external evils.
The fuzzbox idea might be a bit too brute force, and might cause double-triggering. The fuzz box would turn each kik hit into a series of pulses. Since it's an x0x, I'm not sure how long a pulse has to last for it to register with the CPU to trigger. I seem to recall that other x0x machines needed clocks of longer than 2 msec to register. Try it and see.
If it's a double triggering mess, a peak detector + comparator circuit would be a more complete solution, such as this one:
http://www.freeinfosociety.com/electron ... 720-11.gif
There are even more thorough solutions, using pairs of one-shots to more precisely define the pulse width, and set up a hold-off window, so it won't retrigger too soon after the initial trigger. Probably overkill, but worth mentioning...good drum brains use a scheme like that.
"What fer?"
"Cat fur, to make kitten britches."
"Cat fur, to make kitten britches."
Who is online
Users browsing this forum: No registered users and 96 guests