Spin Semiconductor

For reasons (described below) I may end up needing to momentarily switch patches (S0-S2) or banks (T0) with a microcontroller, then switch it back.

i.e. toggle pin 13, then toggle it back. Or the same for one of 16-18.

Questions:
A. Is one option faster or otherwise preferable to the other?

B. What's a reasonable amount of time to wait before toggling it back. A few ms?

Reason:
This is a backup plan, and I hope to avoid it. But I have a slight noise when engaging/disengaging the pedal and a delay repeats that noise and makes it more noticeable and annoying. I've tried muting or quieting it with an optocoupler without success. It happens with both a latching foot switch and a relay. I have a few more experiments I'll try and I hope to get rid of it.... but if this fails then it'll be nice to have a backup to reduce and mitigate the symptoms. By switching the program, the echos from the FV-1 obviously stop.

Reading in program code takes ~18ms at 32767Hz crystal. I think you should wait at least 20ms.
But your problem looks like bad PCB design.

Switching between internal ROM programs is faster than switching between programs in the EEPROM as the speed of changing is limited by how long it takes to clear the internal RAM for a ROM program and how long it takes to load a program from EEPROM foran EEPROM based program.

It is impossible to give exact timing on changing programs, the FV-1 starts a program change after it detects a state change on a select pin and after it has completed a sample period so it does not cut off in the middle of a program. It also does a very fast ramp down on volume to avoid a pop. Also as ZibiSound pointed out timing depends on sample rate.

If your programs are loaded from EEPROM then just switch one of the SX pins, why route an additional line to toggle to the internals if they are never used.

Thank you both, this really helps.

I'll obviously try to fix the root issue first. Failing that I'll try toggling an Sx lines and waiting about 20ms, then toggling back.

Hi Mark, from your description it sounds mode like you have a bypass switch pop noise when switching between effect and bypass rather than noise from effect changing (Sx). I would look at your bypass switching first to see if you have a problem there.

ice-nine wrote: ↑Thu Dec 09, 2021 12:58 pm Hi Mark, from your description it sounds mode like you have a bypass switch pop noise when switching between effect and bypass rather than noise from effect changing (Sx). I would look at your bypass switching first to see if you have a problem there.

OH yes, that's exactly what I think is going on. The idea to switch patches is just a hack to dump the memory and avoid the small noise from being repeated by the delay.

Unfortunately every single commonly recommended remedy for switching noise has left me empty handed (input/output pull downs, removing LEDs, etc). It's a very small noise, to be fair, but when inserted into a delay it repeats making it much more noticeable.

The current plan is to just try JFET switching.