Please read again, I wrote only what I wrote, i.e. 92 db at least, and 95 dB peak is a normal listening level for myself and many other audiophiles that I know. I never said that it is enough, and neither questioned your personal preferences. :-)
I did read it, and said that 6 watts, no matter what the preference is insufficient, I said why. Done with this topic, ok?
There are people who do restoration of vintage cars, and if there is the demand, they make copies. It is their business, not mine.
300B triodes were designed when people knew not much about sound reproduction, capacitors and resistors were quite expensive; it was cheaper to wind transformers and chokes.
Incorrect. Caps and resistors were not expensive compared to transformers and chokes at that time.
The 300B was designed by Western Electric's Bell Labs.
You can read the literature, it is free and online now. Bell Labs Journal.
They had available larger tubes as well.
In order to get linear sound reproduction they designed special tubes, compromising amplification factor for linearity and low output impedance. They were especially crafted tubes to use in as simple as possible amplifiers. The end result of such amplifiers depends very much on particular tubes. In order to get stereo amplifier you have to match many tubes to find one matched pair. To get better sound you have to select better tubes. Why Western Electric 300B tubes are so expensive, because they were made to sound best in simple amplifiers where everything relied on tubes. Such amplifiers can nor drive properly any speakers. They need speakers that have particular mechanical damping.
Historically inaccurate.
The 300B was not designed as a tube for audio amplifiers.
Western Electric designed amplifiers used feedback and did not rely upon close matching
of tubes.
Western Electric tubes are expensive TODAY because not that many original examples survived
into the latter part of the 20th century, far fewer were ever made compared to things like the
807 or 6L6. They were more expensive in the 1960s than a similar power RCA or GE tube (for example).
And they produced less power in a typical circuit, at a time when making power was an important
criterion. So, not nearly as popular.
However, today we know more, resistors and capacitors are cheaper than in 1930'Th, and can design amps that do not require so strict selection of 300B tubes, but what's the point then if their major properties are not used? For modern amps more convenient tubes are available, they are much cheaper, and are in current production.
As you ought to know there are some very nice Ruskie sweep tubes that when their grids and screens are
tied produce lovely, superior to 300B even, curves.
IF
curves are your criterion??
For example, in my Edelweiss-3 I can use 6L6, 5881, EL34, KT77, KT88, KT120 tubes, adjusting self-bias by a single potentiometer observing bias on digital gauges under tubes. I can select high output impedance for "current drive" of some speakers like pentode amplifiers without feedback do. For other speakers I can select medium output impedance like triode amps (including 300B) have. I can select low output impedance to drive modern hi-fi speakers that want solid state amplifiers. Or even negative output impedance for servo-damping of speakers making frequency response on bass frequencies more even and extended.
This is a very nice feature.
Why is it named Edelweiss?
If he is a designer/engineer, I don't think I am familiar with him.
More information is appreciated.
You can PM, or email, since this is clearly not ham radio related at all!
Frequency response of my amps is pretty wide, from 6 Hz to 90 KHz, without special output transformers that cost today a fortune.
This is a very strong claim.
I'd like to see your square wave at 1kHz for example - using a
fast square wave as input...
for example from the calibrator on a 100mHz Tek scope or equivalent.
I scratch my head at the idea that common output iron will reach 90kHz on a good day going
downhill... (again feel free to email - I won't bite!)
<snip>
And once again, my amps are not SET. They use 2 pentode stages with 3 nested feedback loops, to get transfer curves especially crafted, similar to what Western Electric were getting specially crafting tubes.
In short, Western Electric were trading gain of the tube for desired transfer curves using precise internal geometry. I trade gain of pentodes using external components for similar transfer curves, to get better results cheaper. :-)
Nested feedback loops will lock the thing in... up to a point. And it is a perfectly valid approach to
design.
I'd suggest you look at the harmonic spectrum out a ways to see what you've actually got going.
Love to see a screen shot both at low power (under 1 watt) mid power and within a fraction of
a dB of "the wall"... but again this is not a ham radio topic.
Anatoliy, I don't have a personal love of the 300B. Imho it has a particular flaw. One that can not
be eliminated by any known means. I think there are better tubes in a practical sense.
You may be shocked to know that my amplification typically is solid state of my own design.
And most of that, now relatively anciently produced.
I am retired.
Worn out from these endless "debates" on audio. Don't care any longer. Something close to 98% of
all "audiophiles" I think have significant hearing deficits, so they'll
never hear what I
used to be
able to easily perceive. So, I can't hear what I used to either - now I know what they all
are hearing now... HA! It's a bad joke. To me anyhow.
Doing ham radio.
Much more fun now.
So what are you doing in HAM RADIO??attached is an image of my DC coupled 35w/ch SE MOSFET amp from about 1995... for reference.
(thus the heatsinks)