Vampire Slayer DIY PCB?

[vigilante398]

`I just checked the PCB to the schematic, component ref's do not match so follow value on PCB's I would say.
27k resistors should be 2 off (R1,R2 on PCB)
47k resistor should be 2 off (R5, R6 on PCB)
1M resistor should be 1 off (R3 on PCB)
All else seems fine to me.
Cheers
Mick

That's fair. In all of my projects in the case of discrepancy between the build doc and the PCB, always follow the PCB, the PCB is always correct.

Designators are a crapshoot because while they are often correct, due to my rampant laziness sometimes things are copied between documents (most notably the power supply schematics) without regard to the actual designators used on the PCB.

 

[matmonster58]

Would it be noisy to have the input resistor on a switch?

I've read some people prefer 5.6 meg and some people prefer 10 meg for piezos. I'd like to try both out

 

[vigilante398]

Would it be noisy to have the input resistor on a switch?

I've read some people prefer 5.6 meg and some people prefer 10 meg for piezos. I'd like to try both out

My recommendation would probably be to have the 10MΩ as a constant connection then use a switch to add another 10MΩ in parallel so you can get 10MΩ or 5MΩ.

Back when I did these for customers I had a few requests for 10MΩ input impedance, but I generally hear from piezo players that 5.6MΩ is still high enough to work well.