Serge Auckland wrote:

"David Looser" wrote in message
...
"Woody" wrote in message
...

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


Theory and practice always match, if it appears otherwise then you've
misunderstood the theory or there's some other factors involved that
you weren't aware of. The use of shunt capacitors acroos the replay
heads of analogue tape machines to boost the HF response was standard
practice, often these capacitors were switched according to the speed
selected with larger capacitor values being used on the lower speeds.

David.


The cartridge is rather dull, not bright, and I know about the
recommended capacitative load, but that's not what I'm after. In the mid
'70s, somebody, and I think it was either Shure themselves, or possibly
SME, published a cartridge equaliser circuit which consisted of one or
two resistors and a capacitor, may have been two caps, and which had the
effect of lifting the lower treble suck-out, and the extreme hf droop.
It also had the effect of dropping the total output by a couple of dB as
I recall. It's that circuit I'm looking for and sadly can't find.

You can see the frequency response I'm getting
http://audiopages.googlepages.com/V1...full;init:.png


My other cartridges, using the same test LP are fine. As an example, my
EMT cartridge does this:-

http://audiopages.googlepages.com/TS...full;init:.png


S.


Something a little odd there because the Shure appears to have an HF
droop of more like 10dB, and using just passive components you need to
lose that much to flatten things out. The response error looks like it
can be easily corrected with a very slight tweak of a standard treble
tone control; do you have one on your amplifier?

d