I’m quite new to electronics, and using the Daisy Seed to develop some kind of “hardware prototyping framework” for my Eurorack modular needs. There is something I don’t understand well with the Daisy Patch Gate In schematic.
The Gate In circuit has a voltage divider, shows a 100k impendance to the outside world, and the other resistor is 1M. From what I understand, this would mean that the tension of the transistor base is VIN * 1M / (1M + 1k) ~ VIN.
A “normal” gate signal is +5V, but the electrical eurorack specifications say that the A-100 modules can take up to 12V.
Eurorack users could make mistakes by connecting for example an ADSR into a Gate. Furthermore, the popular Arturia Beat Step Pro delivers gates at +12V.
At the same time, the maximum rating of the MMBT3904 for the Emitter — Base Voltage is 6V.
Would using the Beat Step Pro with the Daisy Patch damage the Gate In over time? Or is there something I didn’t quite well understand in the circuit? Why not using a 100k or slightly lower in place of the 1M resistor?
And somehow same question if the user connects a LFO to the Gate In, so the Base — Emitter could see a reverse voltage of -5V. The datasheet puts a 1N916 diode for that on page 2, wouldn’t that be required as well to short the input to GND if a negative tension is applied?
Thanks for any information on that matter!