On Thu, 10 Sep 2009 22:18:20 +0100, "Keith G"
wrote:


"Don Pearce" wrote in message
news:4aac51d2.31855500@localhost...
On Thu, 10 Sep 2009 18:15:09 +0100, "Keith G"
wrote:


OK, I have recorded identical samples with and without Tic Tacs and
there's
not an iota of difference that I can hear.

And here's another pair of traces of difference, this time microphony.
The turntable is not spinning - the stylus is simply sitting on a
stationary record, responding to reasonably loud room noises.

The blue trace shows the flat platter, the green is the six-point
suspension.


How did you get 6 points of contact? I use 3 Tic Tacs for obvious reasons!


I used six small cork discs that were once under chair legs until they
lost their sticky.


So much for the record not acting as a diaphragm in this
condition.


I have no doubt that a record deck (needle down) makes a good 'transducer'
but the word is still *discernable*...???

???

Oh yes. Especially if you wind up the volume a bit. I tried and with
the pointy suspension it did not to be terribly loud before feedback
howl started.




There is a little hum spike there that I really ought to deal with.


http://81.174.169.10/odds/microphony.gif


That ain't hum - this is **hummmm**:

http://www.moirac.adsl24.co.uk/showntell/Hum.jpg


(At the end of the side, before and after 'auto-return'... :-)


Oh, that really isn't pretty.

d

--
Pearce Consulting
http://www.pearce.uk.com