"Stewart Pinkerton" wrote in message
...
On Thu, 21 Apr 2005 12:46:07 +0100, "Keith G"
wrote:

"Andy Evans" wrote in message
groups.com...
Stewart's just written a balanced and informative post on SET amps
which I agree with completely. I need a good psychiatrist quickly.

You do - he's posted no such thing, just trotted out a load of Old Wifey's
Tales* that he's picked up over the years.

Bull**** - not that you'd know, anyway......

He's a 'Pencil Squeezer', he
doesn't ever *do* anything.....

I've designed and built more amplifiers than you've owned trucks, you
deaf old fart.


That'll be a couple of dozen or more (all told) then....

You need to put your reading glasses on - I said 'DO' not 'DID'. We were all
going to be Master Of The Universe once, Ancient History doesn't count and,
as you are always saying 'you're only as good as your latest gig'..... ;-)

"Stewart Pinkerton" wrote


Total = 197.75 (half the price of the entire project).....


Actually, taking out the cost of the hole punches, the trannies cost about
2/3 of the entire project.


...which is not much for a 'sensible' SET that is going to be used in a
small room....

As any regular RATter will rapidly remind you, Hammond do not sell
*really good output trannies*, hence the low cost......


OK, I'll concede the Hammond OPTs are more 'OK and good VFM' than 'really
good', but they are plenty good enough for a 'budget' or, in my case, a
first time 'scratch' build. If 'matching looks' are not important, the
chokes, power and filament trannies are all excellent AFAICS...

Incidentally, my OPTs *do* hum very slightly (you've got to be right over
them to hear it) hence my recent 'researches' into 'magnetostriction'. The
cheapo 'tin box' Hammond chassis and the fact that they are bolted straight
on to it doesn't help. but it is a non-existent problem in reality...


Again, not really - my 4wpc 2A3 SET sounds extremely good and *plenty*
loud
enough (see recent posted open mic recordings) on B&W DM2As which you
yourself informed me are only 84 dB....

Loud enough for *you* perhaps, but hopelessly inadequate for
generating realistic levels in most rooms, especially if you want to
keep the average output level to a small fraction of maximum. Note
that you'd be well into the horribly non-linear end of the 2A3 output,
with those speakers, even at low/medium listening levels. *You* might
*like* that sound, but it sure ain't natural!


You know that I am not overly hung up on 'fidelity' and I certainly don't
aspire to 'real life' levels in my listening environment. On much/most
material, I get plenty 'loud enough' with the volume at about halfway or a
little over. This is with no 'pre' treatment, using the souce directly
connected to what is essentially a power amp with a volume control. I was
particularly keen to keep 'pre-amplification' out of the equation to make
the build easier as it was my first 'scratch build' and reduce the
possibility of hum, which (knock on wood) seems to have worked - this is the
quietest amp I've got.

I have a Line Stage preamp which I could use (but don't) if I needed a bit
more oomph. What interests/bothers me is that I can swap straight to 91.5 dB
speakers and there doesn't seem to be much difference!!


Besides Keith, you already said that you know feck all about
electronics, so WTF are you doing arguing technical points?

;-)

Andy Evans wrote:
Stewart's just written a balanced and informative post on SET amps
which I agree with completely. I need a good psychiatrist quickly.

He blew it.

He said:

"...a properly-designed SET sounds like any other amp up to about a
fifth of its rated output power."

They don't becaues of their high source impedance. It's like putting a
randomly-set equalizer into the system.

Tubies seem to love randomly-set equalizers.

Someone should make a digital eq with a randomzing button on the front
panel, just for tubies.

On Fri, 22 Apr 2005 06:36:44 -0400, "Arny Krueger"
wrote:

Andy Evans wrote:
Stewart's just written a balanced and informative post on SET amps
which I agree with completely. I need a good psychiatrist quickly.

He blew it.

He said:

"...a properly-designed SET sounds like any other amp up to about a
fifth of its rated output power."

They don't becaues of their high source impedance. It's like putting a
randomly-set equalizer into the system.

A *properly designed* SET amp need not have a source impedance above
0.5 ohms. That some do, simply indicates an attempt to claim a max
power level which the amp can not in reality achieve.
--

Stewart Pinkerton | Music is Art - Audio is Engineering