KISS Amp 300B Ultrafi finalized; circuit updated
 

Don Pearce wrote:

Defining on cost has exactly the result I was describing. There is
nothing in a solid state high end amp that would force cost up to the
levels demanded by anything with tubes and a sensible amount of power
- the sheer physical mass simply isn't there. So defining by cost is
essentially the same as defining by tube content.


Have you priced some of the stuff out there lately. There is not much
to choose between tube and SS in prices. These guys charge what they
charge because they can. In the immortal words of W.C. Fields (or
Edward Albee if you are of that persuasion): Never give a sucker an
even break.

As in most things, 'fashion' drives the very top end of the industry.
Once that is understood, the rest follows.

Peter Wieck
Wyncote, PA

KISS Amp 300B Ultrafi finalized; circuit updated
 

On 14 Jan 2007 23:51:59 -0800, "Andre Jute" wrote:


wrote:
Just one question - why the battery?

This is the circuit under discussion:
http://members.lycos.co.uk/fiultra/T...trafi-crct.jpg

All components have sonic signature. Some have very little, or are
difficult to use for sound shaping.

There is absolutely no point in building an amp this expensive unless
for some purpose beyond the bragging rights of "I have Western Electric
300Bs in my amp, which of course I built myself." A good purpose is to
take charge of the quality of your sound, rather than leave it in the
hands of some zero-culture, long-since deaf, totally uncivilized,
supercilious, smug silicon slime, of which we can see ample samples on
these conferences. (There are also some very cultured and agreeable
silicon designers but they are successful and don't need my help.)

The WE417A driver tube was chosen for its particular signature. I had
already designed a much more precise reference SE300B amp for Western
Electric tubes with two 6SN7 stages, of which the most popular version
is he
http://members.lycos.co.uk/fiultra/T44bis-'Populaire'-crct.jpg
But in the T39 I was stepping back, building an amp for hedonists, not
soulless technicians. The 417A is very suitable for hedonists, very
linear (but not as linear as a 6SN7), quite a bit warmer in the manner
of the double digit veteran directly heated triodes but much more
widely available. Count what besides the 417A is in that circuit. The
attenuator is a DACT, built by robots on Swiss goldplated switches with
SMD resistors: zero signature, as it should be. I have no belief in
anything more than marginal soundshaping with resistors; Kiwame are
slightly but perceptibly warmer than the common Beyschlagg I also like,
and the rest leave me indifferent to the difference between them, if
any; I believe in overspeccing my resistors to run them cool and so
avoid various kinds of resistor noise which can be important in small
signal circuits.

So that leaves the tube itself, whose sound we can shape by the value
of the resistor in the plate circuit and whatever we decide to put in
the cathode circuit. Taking the plate circuit first, we can lower the
resistor value and thereby make the sound dirtier at the volume
extremes, which to the uninitiated might sound like more bass
(analogous to what you hear on boomboxes on the street or from little
passing hatchbacks owned by wannabe gangsta but of course not degraded
quite that far). That isn't quite my style, so I load the plate up to
the maximum I can within the available power supply, thereby
linearizing the response. I should explain that my style is first to
extract the maximum silence that good engineering allows, which from
tubes is much more impressive than you might imagine when you read the
silicon slime who hang out here to tell us how wrong we are because
they can't get any other employment. After that I back off to a
suitable level of hedonism. This isn't quite euphonious distortion, it
is more like a sense of balance and perspective, and an understanding
of psychoacoustics (I'm by training an economist and psychologist).

At this point we can then choose from four ways to implement a cathode
circuit. One, by constant current sink, I dismiss immediately as too
complicated for an amp announced as KISS (keep it simple, stupid); in
my next project I shall return to CCS because there their complication
is the least of the evils. That leaves three ways of doing it: a
resistor alone, a resistor bypassed by a cap, and battery bias.

Of these, the bypassed resistor is my instinctive fave. It is simple,
it is selfadjusting, and if you spend the time and the money on
development and components, you will eventually choose the right
capacitor; I have long since done my homework and know what I will use.
Open another circuit:
http://members.lycos.co.uk/fiultra/t...17acircuit.jpg
This is a complete amp built only from the first stage of the T39 (in
fact it was made by removing the 300B from a T39). It should now become
clear to you that if I substitute the battery with a resistor and a
cap), the cap becomes the sole determinant of the sonic quality of the
stage. With so little in the circuit, the cap really looms large. An
unbypassed resistor has feedback which changes the sound adversely by
making it harder, more crystalline and by tilting the response towards
the bass when in fact I want to tilt the 417A's "natural" tendency the
other way -- I just want a slightly warm amp, not a hot, gushy amp.
That leaves a battery, which, while not a soundshaping element under my
control (in that there is only one choice of operating conditions for a
417A with battery bias if you already decided the plate voltage), is at
least perfectly neutral. The battery also has a tendency to stabilize
everything around it which is a good thing as I have already paid a
heavy price in efficiency for ballasts and other devices to stablilize
important electrical points and any"free" margin is welcome.

So, by a process of elimination, I am left only with the battery. This
thought process is described in
http://members.lycos.co.uk/fiultra/T...mp%20INDEX.htm

If you study the T68bis "Minus Zero" circuit even cursorily, you will
immediately see that the other big sonic influence, besides a putative,
potential, possible cathode bypass cap, is the power supply. But that
is fully developed and fixed in a desirable sonic already, and is
anyway a large loose cannon on deck if you lose control of it, so you
don't want to mess with success if instead you can do the job by
working with one or at most two cathode circuit components, which
brings us back to the battery decision, which by its impedance in turn
makes any remaining solecism of the power supply a moot point.

All roads lead to Rome. In the T68bis you can see how all currents must
pass through that battery. It is the very dream of every control freak,
though the wannabe control freaks on RAT and UKRA lack the subtlety to
understand what is happening.

OK 2 questions... why the 4 paralleled input resistors? Noise?

The WE417A has wonderful sonics once the designer grasps how to handle
it; in the hands of the usual pretenders it quickly turns to expensive
noise because nobody told them it is a radio frequency tube. Almost all
tubes are, of course, but the 417A is especially efficient in the RF.
It has four grid pins which can pick up radio rubbish, so each one
requires a grid stopper and the signal can be put in to any of them,
though one is better than the others by far for simple reasons of
physics that may be determined by observation.

HTH.

If this is more information than you wanted, next time don't ask such
a(n only apparently) simple question!


Not too much at all - it was a great read! ( I din't have time yet to follow
the links but I will.)

I also build amps, have been since the 60s ( hence the moniker) and noise is
very important to me, since lots of recordings I have are very quiet (read weak)
and amp noise can be overwhelming.

My choice for power supply is hefty sand diodes and hundreds of µf of
capacity... I believe it eliminates the PS from the equations. I also spider
wire everything, no series de-coupling for me... ( except if you count the
multi-cap distribution resistors!.) OK I lied... I also float the caps from
the chassis, I like to have the final word in where the earth point is...

One thing - did you put a scope to the battery? Is there any signal visible on
it or is it a good ground?

Thanks

KISS Amp 300B Ultrafi finalized; circuit updated
 

wrote:

One thing - did you put a scope to the battery? Is there any signal visible on
it or is it a good ground?

You need to keep in mind thjat Mr. McCoy has not built it yet.

Peter Wieck
Wyncote, PA

KISS Amp 300B Ultrafi finalized; circuit updated
 

"Jon Yaeger" wrote in message
...

There are a lot of SS systems that are "accurate" from a THD & IM
perspective but are not sonically pleasing. If the elusive, subjective
concept of "sonically pleasing" applies to "upper end", then there would
certainly be a place for tube gear.

Jon

It does. There is.
Iain

KISS Amp 300B Ultrafi finalized; circuit updated
 

Don Pearce wrote:

On 15 Jan 2007 12:54:58 -0800, "Peter Wieck" wrote:
Arny Krueger wrote:

When you have some audited stats from an independent source, be sure to post
them Iain. Until then, it looks like you're talking out of the back of your
neck, as usual. ;-(

Arny:

Relax. Iain rarely makes stuff up, and in this case, he may be dead-on
target. Just parse the claim:

Top end of the market. Dominated by tubes.

With absolute respect to those very few in the top end of any market
who are there because they actually demand the best and are willing to
pay for it, most anyone paying nose-bleed prices for stereo equipment
are typically not overly gifted with either taste or common sense. They
purchase what is in fashion at the moment, mostly because they can.

It is certainly the case that tube equipment happens to be "in fashion"
at this moment. My friend at the local High end ship (The Stereo
Trading Outlet in Jenkintown, PA) has started to move a great deal of
tube stuff lately and the trend is increasing.

It would not surprise me one bit if Iain's claim is true. How long it
remains true is a different question, as trends evolve.


Peter Wieck
Wyncote, PA

It is no more than a begged question. If you choose to define the top
end of the market as that using tubes, then the top end will be
dominated by tubes. On the other had if, like anyone sensible, you
define the top end of the market as that with the most accurate
systems, there won't be a tube in sight. So just a standard logical
fallacy (or trick if you are being critical) in operation.

d

Another thing to bear in mind is whether whatever the 'top end of the market' finds
to be flavour of the month is any valid indicator that one should pay attention to
when considering such products' merits.

Graham

KISS Amp 300B Ultrafi finalized; circuit updated
 

Jon Yaeger wrote:

There are a lot of SS systems that are "accurate" from a THD & IM
perspective but are not sonically pleasing.

By whose criteria ?

Graham

KISS Amp 300B Ultrafi finalized; circuit updated
 

In article ,
Eeyore wrote:
You build tube amps to have the tone quality under your own control.
Most audiophiles arrived there by observing that silicon amps do not
faithfully reproduce the experience of the concert hall.

Absence of any answer noted.

Is that a polite version of bull****?

--
*Oh, what a tangled website we weave when first we practice *

Dave Plowman London SW
To e-mail, change noise into sound.

KISS Amp 300B Ultrafi finalized; circuit updated
 

"Dave Plowman (News)" wrote:

Eeyore wrote:
You build tube amps to have the tone quality under your own control.
Most audiophiles arrived there by observing that silicon amps do not
faithfully reproduce the experience of the concert hall.

Absence of any answer noted.

Is that a polite version of bull****?

It was actually an indication that Joot failed to answer my question in fact,
posting instead some his usual rambling nonsense.

That he also writes bull**** is incidental to that point.

Graham

Why you should feel sorry for Brian McCarty, the loser who tries to persecute Bob Morein
 

Andrew Jute McCoy blathered:

BTW, if you were smart, instead of crossing Robert Morein, you would
have recruited him. He's a holy fool and anyone who can harness the
force of such can be rich. I know, I worked in advertising. You're too
thick and slow for your own good, McCarty. You'll be no loss to the
gene pool.

Always ready to advise exploitation. Somehow that is exactly in your
character.

Morein may be a fool, he may even be "holy" as you suggest as he
certainly tilts at many windmills and has the general attitude of the
obsessed. All-and-at-the-same-time, he is at least human. A
characteristic that you lack to any discernable degree.

Peter Wieck
Wyncote, PA

Why you should feel sorry for Brian McCarty, the loser who tries to persecute Bob Morein
 

"Soundhaspriority" wrote in message

"Andre Jute" wrote in message
ps.com...

Brian McCarty, pretending to be Robert Morein, wrote:
In article
,
"Andre Jute" wrote:

[snip]

BTW, if you were smart, instead of crossing Robert
Morein, you would have recruited him. He's a holy fool
and anyone who can harness the force of such can be rich.

Andre, do elaborate :):):)!!!

Obviously Robert, you're a true believer in any number of audio myths.