does more power=better quality ?

The problem with all the comparisons to 8 watt SETs...
is that "all else is not equal".

Philefread,

Your 8 watt SET amp IS "loafing".

That 300B tube is capable of more than just 8 watts.

That tube can be used in amps putting out on the order
of 40 to 50 watts. For example, Cary uses it in a
15 watt SET power amp:

http://www.caryaudio.com/products/audio/cad300se.shtml

Therefore, in the context of my discussion on linearity -
the tube is not being taxed at all.

Your 300B SET amp is not limited by the 300B tube - it is
limited by the power supply.

The designer / manufacturer of your amp put in a low power
power supply - so you can't push the tube to anywhere near
its capability.

The manufacturer forced the tube into "loafing" by pairing
it with a relatively "anemic" power supply.

Your speakers may be relatively flat - but they don't have
an absolutely flat 8 ohm impedance. Do your speakers have
voice coils? Voice coils are inductors - and the impedance
of an inductor is not flat - it varies with frequency.

Dr. Gregory Greenman
Physicist

Raquel,

The problem with your argument is that in amps in which
there are more than a single output device; the output
devices are in parallel.

No - the signal is not going through more circuitry - all
the electrons see the same amount of circuitry. It's just
that all electrons don't see the same components.

If you have a tube amp with 2 paralleled 300B tubes; all the
electrons saw a single 300B output tube - just not the
same one - 50% saw one tube, 50% saw the other.

The comparison at Singer is worthless. A VERY BIG factor
is the size of the room. One was smaller, one was larger.
The rooms therefore had different resonant frequencies -
and Lord only knows how that affected the sound.

You can't conclude anything even remotely meaningful from
two different rooms, with two different speakers, with
two different amps...

Dr. Gregory Greenman
Physicist

pbb I will be up there in three weeks, do you want to get together?

Output transistors run in parallel need to be trimmed to work properly, and they are now up to trying lasers to get this right (Edge), which they really can't. If output tubes are used, they have to be properly biased (or self-biasing), and they are often not at peak bias in practice, thus introducing hum and other discontinuities into the sound.

The more output devices you have, the more collective residual noise you have. This becomes an issue with a system that features highly revealing upstream components, top cabling and top speakers, all fed by a well designed A/C power supply and set up carefully in a good room. Extra output devices are simply not needed if you have the ability to buy sensitive speakers with a benign load impedence. In addition, the more output devices there are, the more one is likely to fail (output tubes are generally easy to replace, but output transistors in well-known SS amps as young as ten years old have been known to go out of production, making the amp a door stop).

I qualified the Singer anecdote thoroughly -- read what I wrote again.

While a monster amp is desirable with inefficient speakers, this is just not the way to go in my opinion -- partnering sensitive, easy to drive speakers with an amp that uses a simple circuit featuring a minimum number of output devices and the very highest quality parts will yield superior sound. High-powered amps have a use -- digital home theater systems, where maximum dinosaur stomping seems to be the goal -- they are a poor choice, in my opinion, in high-end, two-channel analog-based systems. In short, I stand by what I wrote.

PS - My amps run 300B's -- now that's a linear amplifying device.

are all output transistors created equal.given the same manufacture, mode...etc do they all sound alike?
if not, is it possible to have just one output transistor?