The bandwidth extends to about -3DB at 200 kHz with a 600 ohm source
impedance, and with a 50 ohm source, it makes a decent little AM transmitter.
Of course the audience for such an amplifier will only want to know about the
sound. How does it compare with SETs from a subjective point of view? Having
made a variety of these amplifiers at this point I can say that first off, they can be
made to sound exquisitely in many of the systems that would enjoy the
performance of a SET amplifier.
These would be your high sensitivity loudspeakers featuring compression
drivers or “wide band” drivers with big magnets and light paper cones.
Here is a comment made by a listener who lived with a simple prototype SIT
amplifier driving Lowthers:
The amp sounds "big". There is a large, open sound stage that fills the room,
that is the first thing that you notice when the amp is plugged in. The effect is a
little intoxicating. ...the SIT seems to bring a lot more control & detail to the
speaker. The tube sweetness is present, yet the presentation is very clean. This
is like a very nice low distortion SET. The SIT presents details, but with properdynamic contrast. Details do not poke you in the eye, they just naturally unfold
as part of the music.
Do simple SIT amplifiers sound the same as single-ended Triodes (SETs)? That
would be a matter of opinion. Without an output transformer with its significant
limitations, the SIT has a bandwidth and distortion edge. On the other hand,
some people like the sound of their transformers.
Me, I like to listen to the sound of different amplifiers. I don't see a practical
point in actually duplicating a SET amplifier. The SIT gives me an opportunity to
listen to the best that a single gain device can do. Surrounded only by a few
well-chosen passive parts, this transistor speaks with a single voice.
It doesn't sound quite like anything else.