How to raise Cornet input capacitance???

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Bill Epstein

How to raise Cornet input capacitance???
« on: 2 Oct 2009, 12:32 am »
I searched and found Jim is mighty proud of an input capacitance of 40pF but I'm after a Soundsmith SMMC-1 which wants >400pF.

If I have to ask, does that mean a tree will fall on me sometime soon?

Brinkman

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Re: How to raise Cornet input capacitance???
« Reply #1 on: 2 Oct 2009, 01:51 am »
You could jumper each of the 47K ohm loading resistors (R100/200) with a 390pF polystyrene cap. The 390pF caps plus the tonearm wiring capacitance and interconnect capacitance should put you well over 400pF.

And as far as I know, they don't make any better audiophile caps in the picofarad range than polystyrene.

Bill Epstein

Re: How to raise Cornet input capacitance???
« Reply #2 on: 4 Oct 2009, 11:09 pm »
Thanks Brinkmann.

I decided to simplify; sold the Ace and Sonata LO, bought a Sonata HO and temporarily retired the Cinemags. Hope the HO Grado sounds as good as the LO, then no worries about impedances or ohmages. Can't wait for it to arrive.

You can see the SME III is also gone. The Cherry arm with Cardas wire on it's native black walnut armboard is my new standard. :thumb:




Brinkman

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  • Posts: 195
Re: How to raise Cornet input capacitance???
« Reply #3 on: 5 Oct 2009, 01:49 am »
The chassis work looks great. :thumb:

I plan on adding a dual-sectioned air-variable capacitor to my piccolo build so it can be optimized to whatever cartridge I end up using.

Blue Jeans Cables makes some pretty low-capacitance RCA interconnects that I'm going to wire to my Pro-Ject, making the variable cap the determining factor for cartridge [capacitance] loading. Certainly more convenient than soldering caps to the inputs of a phono pre.

hagtech

Re: How to raise Cornet input capacitance???
« Reply #4 on: 6 Oct 2009, 09:16 pm »
I would listen with and without the added capacitance, find out which you prefer. 

Traditionally, the added capacitance requirement is a bandaid for poor bandwidth.  It is supposed to ring with the cartridge's inductance, thereby creating a peak in the upper treble.  That's great for measurements, but often it leads to harshness, stridency. 

Listen to various capacitors.  Some people like silver mica, some like polystyrene in that position.

jh