[Bruce_S]

OK new to DIY for audio units. I can solder good, but I'm dumb about electronic circuits and how they work.

I use mostly Shure cartridges; in fact usually use a V15III. All 4 shure cartridges need 400-500 pf and seems the sweet spot is right around 400pf. I used a friends NAD 3155 for a sound stage and using the 200pf switch to add pf worked great.

Now the thousand dollar question is what changes in caps do I need to achieve this 200pf increase? THe turntable and cables measured approximately 190pf and the bugle is 14pf for a total of lets say 204 pf.

Tried to find someplace to figure this out, but I had no luck.

Can anyone help me out? Thanks in advance.

[poty]

Jim, the inventor of the circuit, mentioned several times that the caps are not nessesary. But you can buy several capacitors with different values and try to add them in the R16, R34 positions. It is almost impossible to predict (or count) what exactly you should use, too many components to consider.

[Bruce_S]

Thanks...I figured as much  , but still wanted to ask someone with some knowledge.

The easier way is probably to use a couple of Y - phono cable adapters and just plug different loads into the unused connector. Am I thinking right here?

Cheers

[poty]

With so many contacts on the way of tiny signal (for Y-adapter) - It's not what I would intended to do. If you insist on using changeable capacitance loading IMHO it's better to use any kind of small sockets (for IC, multipin cables...) - the idea used several times in the Piccolo design for changing the set of values (and manufacturers also) of loading resistors.

[hagtech]

For the Shure cart - try changing the loading to 100k (not 47k) and keep zero added capacitance.  People say that seems to open things up a bit. 

jh

[Bruce_S]

Thanks Jim. I figured you'd bump into my post.