On 6/18/2014 7:52 AM, Mark Durenberger Mobile wrote:
> It's sometimes defined as "Fast Slew-rate," as a function of transient
> response in op-amps.
> "Soft" and "warm" to some ears might be labeled as "Slew-rate limited"
> to others.
Tube equipment doesn't usually slew in the strict definition of the
tube; the risetime limitations of tube power amplifiers usually come
from bandwidth limitation. Most tube phono preamps have quick risetimes
-- they don't have transformers in them.
That isn't to say that tube circuits *can't* go into slew limiting -- in
fact, the first description I know about of slew limiting comes from the
1953 edition of the Radiotron Designer's Handbook. It was a known issue
in radar circuits during World War II.
> It all gets back to: "to hell with the specs; do I like the sound?"
Well, maybe. If the specs are well-thought-out they can correlate with
the sound. Mostly, though, they're not.