"Don Pearce" wrote in message
news
Woody wrote:
"Serge Auckland" wrote in message
...
I'm trying to improve the frequency response of my V15III/SME 3009
S2, and remember that Shure or SME had a little equaliser circuit
that flattened the response at the expense of a couple of dBs of
output. Something may have been published in HFN and/or Wireless
World in the '70s, but my HFNs don't go back that far, and I can't
find it in my WWs of the era.

I've been searching on-line for the circuit all afternoon, and can't
find anything. It was simply a capacitor and a resistor or two, but
I can't remember the configuration or values.

Does anyone have this info please?

Thanks

S.


--
http://audiopages.googlepages.com


Ah, now this is one I do know about - it applied more or less across
the Shure range.

Shure cartridges were designed to work into a load of 47K resistance
(like all others) in parallel with something around 360pF
capacitance. The pickup arm cables and the interconnect to the amp
would account for about 120-150pF, which leaves the cartridge
underloaded and thus rather peaky and bright.


The way the impedances work out, you get more peakiness as the load
goes up, not down. Adding an extra 200pF to the basic cartridge and
wires will increase the level at 10kHz by about 2.5dB. This is all
about the way the capacitance resonates with the inductance of the
cartridge.

d


Try it - it's cheap and simple enough. I used a 75EDII with this process
and it tamed it well.

Maybe one of those occassions where the theory and practice don't match?


--
Woody

harrogate three at ntlworld dot com