Bricksnbeatles
Member known well
Just ordered an Expresso pcb, and since I had some questions about it, I thought it might be a good idea to have a general questions thread for it, especially since its a PPCB original, so there isn't the trove of info out there that there is for, say, a tubescreamer circuit.
I'll start with these questions for @Robert ...
First, as far as the Digi-pots go, am I correct in assuming that the MCP41010 can be subbed out for a MCP41050 or MCP41100 if a 50k or 100k expression output is needed? and that not all three digi-pots necessarily need to be the same value— say, 10k for A and B, and 100k for C?
Secondly, is there a specific expression input value-range that it's designed to work with?
Lastly, am i correct in my understanding of the MCP41010 datasheet that the maximum rating of the voltage divider is equivalent to the 5v supply voltage of the chip? So otherwise, the expresso should only be used with pedals that stick to the 0-5v CV standard, and not anything that uses a 0-9v CV? This should be as simple as connecting a multimeter to the ring and sleeve connections of a pedal's expression jack to see that the reference voltage is sub-5v, right?
I'll start with these questions for @Robert ...
First, as far as the Digi-pots go, am I correct in assuming that the MCP41010 can be subbed out for a MCP41050 or MCP41100 if a 50k or 100k expression output is needed? and that not all three digi-pots necessarily need to be the same value— say, 10k for A and B, and 100k for C?
Secondly, is there a specific expression input value-range that it's designed to work with?
Lastly, am i correct in my understanding of the MCP41010 datasheet that the maximum rating of the voltage divider is equivalent to the 5v supply voltage of the chip? So otherwise, the expresso should only be used with pedals that stick to the 0-5v CV standard, and not anything that uses a 0-9v CV? This should be as simple as connecting a multimeter to the ring and sleeve connections of a pedal's expression jack to see that the reference voltage is sub-5v, right?
