[amandarae]

Hello Jim,

I was reading the manual for the Piccolo and I would like to ask the ff:

What is the relationship of R1 to R2?  Also, I want to change the loading values of the one I am building to 14, 25, 40, 100, 47K respectively as the selector choices.  Is it better to do this by changing the resistor values on the board or would you recommend not to alter that and just do the calculations from a relatively close setting and then use external RCA tees to parallel resistors in the input to come up with the desired value?

Thanks

Abe

[hagtech]

What is the relationship of R1 to R2?

None.  They are completely independent.  The idea was to make gain and loading independent.  Of course, there will be some slight gain shifts due to loading of the cart, but only because the cart has internal impedance.  The actual gain of the FET amplifier is not changing.

For loading, I would recommend to choose your values first, then solder into locations R1A-F.  I picked a suitable range to cover the majority of cartridges out there.  Almost.  Some might like 20 ohm loading.  Some like 100k.  If you know this in advance, then change resistor values accordingly.  You can greatly narrow the range around your expected sweet spot.

jh

[amandarae]

Thanks Jim!

I asked because I saw the table on the schematic diagram page.  I just want to make sure 

regards,
Abe