<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">Oh yes, and one more thing. The Drumbrute uses 3.3V logic, so using transistors (with ~1K resistors on the base) was a much simpler approach than using level-shifters and logic chips or dedicated op-amp comparators.<br><div><br><blockquote type="cite"><div>On Sep 29, 2023, at 8:45 AM, Benjamin Tremblay via Synth-diy <synth-diy@synth-diy.org> wrote:</div><br class="Apple-interchange-newline"><div><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">Sorry, just to be clear here I will describe what I have seen, not what I think I know, which is probably flaky.<div><br></div><div><ul class="MailOutline"><li>In 1993, I bought a DR-110 from a local shop for some very small sum.</li><ul class="MailOutline"><li>I soldered the triggers into a TR-909, stuffed the DR-110 PCBs in a plastic bag, and duct-taped it into the 909, and drilled random holes into the 909 for 1/4” phone jacks. It sounded great. </li></ul><li>This year, I got a DR-110 for cheap on eBay. It powered on and sounded fine.</li><ul class="MailOutline"><li>Being older and wiser, I carefully took apart the DR-110, desoldered the ribbon connector between analog and digital boards, put the analog board onto my bench and powered it up with 6V.</li><li>I probed the wires, looking at the same service manual schematics as shown here.</li><li>I found: All the trigger inputs except the kick drum have pull-up resistors and respond when grounded.</li><ul class="MailOutline"><li>Because of the pull-ups, it was easy to use 2N3904 transistors to trigger them with a positive signal. </li></ul><li>The kick drum only responds to a positive pulse.</li><ul class="MailOutline"><li>It has a pretty big resistor at the input. I did not bother to make the resistor smaller for a clickier kick.</li></ul><li>The clap needs a clever sequence of pulses. I did not attempt to generate those pulses. Just pulsing the clap one time provides excellent backdrop for the Drumbrute clap.</li></ul></ul><div><br></div></div><br><br><div>
<div style="letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div style="letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div style="font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div style="font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div style="font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div style="font-family: Helvetica; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div>Benjamin Tremblay</div><div>btremblay@me.com</div><div>330 Fiske Street</div><div>Carlisle, MA 01741</div><div><br></div></div></div></div><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">
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