View Single Post
  #12  
Old November 29th 19, 04:46 AM posted to rec.audio.pro
Scott Dorsey
external usenet poster
 
Posts: 16,686
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."
Ads