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Scott Dorsey Scott Dorsey is offline
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Default Input transformer for Spectra Sonics 101 preamp

Rick Ruskin wrote:

Are you saying that a step-up transformer on the input simply will not
work or just that it will alter the performance of the card?


The step-up transformer doesn't give you free gain.... power is conserved
so there is no way to get power out of nowhere.

What the step-up transformer can do is to match a low-impedance load to
a high impedance load, so you lose less power in the process. This works
well if the load is severely mismatched (say, a microphone that wants to
see 600 ohms going into a 1M tube stage) but if the load is already matched it
doesn't help any.

Would adding a resistor to the feedback loop along with the 502 eq
that is already there do anything to increase gain?


Dunno, I'd have to sit down and do the math.

As far as I know, the 101 was used as the front end on all
Spectra sonics consoles until the 110 came along.


It was. It was also used as make-up gain for all kinds of other things.
It was a handy general-purpose gain module.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."