and I disagree...squarewave said:Please enlighten me JR. Like I said, I qualified my post with the clause that we're not talking about cost. Otherwise, my understanding has always been that (cost aside) a transformer is superior in every metric.
a preampEven if noise of a high-perf transistor is less than a transformer under whatever confluence of circumstances you're citing,
It isn't just noise but frequency response and linearity too....it seems to me you could use a 1:1. But another benefit of the transformer is that you can match the OSI of the transistors behind it. So if my understanding is incorrect, please explain the details under which an active circuit can beat a transformer in any metric, noise, cmrr, whatever. A transformer is a passive device. So where is this noise coming from that is being spanked?
A transformer involves converting voltage into a magnetic flux, couples that flux from primary to secondary, then converts it back to voltage. A very good transformer can be very good, but not even close to a straight wire with gain... Of course solid state preamps are not perfect either but the design decision I made almost half a century ago was that the cost of premium transformers was just not justified wrt to comparable performance.
If cost was no object I still wouldn't use a transformer (personal choice, I'm frugal), but as I already shared they have their benefits for live sound dealing with questionable grounds, in a "show must go on" time pressure environment. In a permanent studio application we have the luxury of time to sort out ground problems.
JR
PS: We used a good transformer inside the Peavey tube mic preamp, but that was a homage to classic design, not a best numbers exercise. Tubes don't work well transformer-less.