Building my own valve amp
 

"Trevor Wilson" wrote in message
...

"Iain Churches" wrote in message
ti.fi...

"Keith G" wrote in message
...

"Andy Evans" wrote in message
oups.com...
"we can see audible flaws" v. "we can see no obviously audible
flaws." (Trevor)

This is really the problem with your thinking here. You can't "see"
sound in its entirity. You can "see" a representation which, like
all
representations, is merely acting in place of the original. I can
see
quite clearly that your desire to refer your arguments to such
representations is seductive to your own ways of analysis, but it's
clear from our panel of "SET idiots" here that it doesn't satisfy
the
musical brains of discriminating listeners who need to actually
hear
those minute musical differences which, for instance, discriminate
between a Stradivarius and a practice violin.


There is no big mystery AFAIAC - valves give more clarity, 'air' and
*life* than any SS I've heard; SETs add more depth and better
imaging than
PP, making the sound more *natural*....

Is that too simple??

Gosh Keith. You statement that "SETs add more depth and better
imaging"
is incredibly deja-vu. It was a comment also made by another poster
on
another NG a while ago, in another thread, which you probably have
not seen. Trevor took exception to this immediately, despite the
fact
that it is an important and fundamental reason why people choose SET.

**I have never denied that microphonics (a form of distortion, well
beyond your ability to understand) is commonly mistaken for 'depth'.



Don't forget the 'Internal FB' label also....

Building my own valve amp
 

"Trevor Wilson" wrote in message
...

"Nick Gorham" wrote in message
...
Trevor Wilson wrote:

Here is another, quite decent amplifier (US$899.00):

http://stereophile.com/integratedamp...ad/index5.html


Ahh, so what you are suggesting, is that anyone who decides to spend
more than £450 on a solid state amplifier is a "idiot" (never saw
your definition BTW). I could live with that as a logical argument.

**Non-sequitur. Feel free to demonstrate how you reached that little
leap of logic. I could use a laugh today.


So, what is it that you make again?

**Fools of people who think they know better.


Lemme see...

Nick can (and has) fixed some of my valve amp problems via email, on the
phone and occasionally by post here - you can do what? (Other than try
to wipe your own prejudices off on others halfway round the world...)

??

Building my own valve amp
 

"Trevor Wilson" wrote in message
...

"Keith G" wrote in message
...

"Trevor Wilson" wrote


snip magazine reviews and personal OSAFs


When examining the frequency response plots of the SET amps we can
see serious, highly audible flaws. When examining the distortion
plots, we can see serious audible flaws in most models at realistic
listening powers. Examining the plots of the other amplifiers, we
can see no obviously audible flaws. Choosing a SET amp over a push
pull amp, is therefore the deliberate choice of audible problems.
Those audible problems are completely artificial artefacts, not
present in the original sources.


Your problems are not everybody's problems - choice of a SET is to
choose an amp for its characteristics. The bit you can't choke down
is that people buying/choosing/using SET amps consider those
characteristics to be beneficial.

**Which characteristics? Which SET amp? They're all different. Is it
the crap frequency repsonse? The high levels of distortion? Or the
poor load tolerance?


You forgot the *cabbage smell*....


SETs are a fashion statement.



No, that's iPods...


They're not serious high fidelity products.


So what? Most people I know who like and/or use SETs do so just to hear
the *music*...

('Fidelity' is an interesting notion....)

Building my own valve amp
 

On Oct 30, 4:15 pm, max graff wrote:
Hi guys,

I am planning on building my own valve amp and need a starting point
viz. books, forums etc. Any tips would be of good help.

I have proved to myself that I can solder well and don't have shakey
hands and did EE in my previous life.

Cheer Max.

Hey, Max:

I don't have time to read all the agitations of the silicon slime
trying to rain on your parade before it starts, so I don't know if
someone has asked about your speakers yet. If you sensitive speakers,
there is a quick, simple, cheap amp on my netsite called the SEntry,
trioded EL34 in SE for about 2W. There is also on my netsite a design
for a speaker that is both sensitive and cheap to build, The
Impresario; the compromise for the low cost and ease of build is that
it is rather large. I emphasize cheap because my experience is that no
one builds only one tube amp: there is always something else they want
to try.

There are four books you must have: Radio Designer's Handbook by F
Langford-Smith, 4th ed; Valve Amplifiers by Morgan Jones: a late RCA
tube ref for the specs: a tube era ARRL manual (surprisingly many main
libraries still have them in the stacks, or any library can get it for
you from the British Library). A good tube-era author to dip into is
Norman Crowhurst.

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

Building my own valve amp
 

"mick" wrote in message
.uk...
On Thu, 01 Nov 2007 09:54:21 +1100, Trevor Wilson wrote:

snip

**How will he know what to build, unless he can listen to it? Valve
amps
mostly sound different to each other. Their sound is largely
differentiated by the topolgy, the output transformers and the valves
used. Without a good listen to the amps, it is a total crap shoot.
MUCH
better to listen to several amps and make a choice from those.

snip


Keith was quite right though; it's almost impossible to find a dealer
in
the UK that has *any* valve amps to listen to, never mind several to
compare. It just isn't feasible to hear quality valve sound without
building your own unless you have access to just a few of the top-line
dealers - who have no interest at all in giving you any tech
information
whatever as they want the lucrative maintenance contract on the gear.


Even if you do go to a dealer with a selection of valve amps and even if
he *will* let you **** about with them for hours on end it will tell you
*nothing* on the shop's speakers, in the shop's demo room. It will
still take a good while to settle with them if/when you get the home. If
it's valves, it'll take weeks for them to *brown in*, in any case!

(It's a bit like buying an astronomical telescope - any 'scope that will
clearly split Alcor and Mizar will do, but how TF do you check that
during shop opening hours? ;-)

Building my own valve amp
 

On Oct 31, 4:05 pm, Andy Evans wrote:
Quite a few of us started out by repairing our old Leak Stereo 20s and
the like. It's still a great road into amp building. for a first step
I'd do exactly that - buy a Leak Stereo 20 and upgrade it with modern
componants. It's all point to point wiring and totally accessible.
Plus you have the leak group as backing to talk you through it. Morgan
Jones even has a suggested circuit for it in his Valve Amplifiers,
which you absolutely must buy. (that's an order!!!)

I think to date I've been through about 30 different circuits in my
Leak Stereo 20!!!



I can offer you the very, very rare Leak Stereo 30 Plus at a good
price...

Andre Jute
"I was at a board meeting for the LA Chapter of the Audio Engineering
Society last night on XM Satellite radio audio and data transmission.
Sadly, we missed you there, and at the SMPTE and Acoustical Society
recent meetings as well. Everyone was asking, 'Where is that wonderful
Andre Jute? The world just doesn't rotate without him...'" -- John
Mayberry, Emmaco

PS ... Pay no attention, Max. This is an insider-joke. The Leak Stereo
30 Plus is a very early silicon amp and it is truly, truly wretched to
the extent that I almost give it the Australian pronunciation of "rat
****". Mind you, my Leak Stereo 30 Plus has appeared in Glass Audio,
the temple of the ultrafidelista tubies, where it is shown as the
distribution amp in my review of the Electric Tonalities SEX kit amp.
It must therefore be famous as the worst amp ever shown in GA.

PPS The SEX kit as above is super for what you want; SEX stands for
Single Ended eXperimenter's amp but the carriage from Poulsbo near
Seattle will be a killer. A super kit if it is still made is the Arion
Adonis (their base the last time I heard was in Northern Ireland),
about 20W from 5881, lovely casework with a polished stainless
topplate and excellent transformers designed by the sainted Simon
Shilton.

Building my own valve amp
 

On Nov 2, 1:29?am, "Keith G" wrote:
"Trevor Wilson" wrote

snip magazine reviews and personal OSAFs

When examining the frequency response plots of the SET amps we can see
serious, highly audible flaws. When examining the distortion plots, we
can see serious audible flaws in most models at realistic listening
powers. Examining the plots of the other amplifiers, we can see no
obviously audible flaws. Choosing a SET amp over a push pull amp, is
therefore the deliberate choice of audible problems. Those audible
problems are completely artificial artefacts, not present in the
original sources.

Your problems are not everybody's problems - choice of a SET is to
choose an amp for its characteristics. The bit you can't choke down is
that people buying/choosing/using SET amps consider those
characteristics to be beneficial. Three members of the 'St Neots Six'
(local enthusiasts) own and use SETS, one of the others prefers my SET
to my PP amps, another would like a SET and the last one keeps
threatening to build one but probably never will as he is getting
perhaps a bit to old for more building - otherwise that could easily
become a *100%* instance of SETs here!!

I'm going to take a rest from trying to grapple with the considerable
weirdness of TWs mind (he now alternates between calling people
logically inconsistent and lying pieces of ****...), and note that the
above is exactly what happened at one of our London Audiocircle meets,
where we auditioned about 10 amps - 845, 300b, 2a3, KT88, EL34 and
probably something I forgot. Everyone fell in love with the Bez 300b
SET. A month later four of our members had their own SET amps -
including me. Two guys bought 300b Music Angels, I built a 300b amp
and the other was an 805 amp. This does show that the 300b SET is a
mightly seductive little thing. Reasons for liking it were just that
it was naturally musical - not a "reason" as such, just a listening
preference. So, is this an infatuation with a honeymoon period or a
permanent preference. Well, in my case I don't quite know. I've been
very happy listening to the 300b for a week. But on the other hand
I've been listening to my latest 2a3 PP amp for a few days and it's
bloody good as well. Listening to this 2a3 amp you wonder if you'll go
back to the SET. I should say that all my amps now are total-DHT, all
valves directly heated. So we're not getting an unequal playing field
like a PP EL34 amp versus a 300b SET. All I can safely say is that if
you use good transformers, all DHTs, and use interstage trannies for
coupling rather than caps, then it's a mighty close thing. You may be
familiar with the Amity design and its sequels, which put PP
interstage coupled DHT amps on the map again (they did exist 60 years
before!!), if not check out http://www.nutshellhifi.com/.
My preliminary findings - SET more lush with excellent tonal and
timbral detail, PP cleaner with better leading edge attack. But make
no mistake, PP can give you that spooky "they're in the room in front
of me" feeling. I listened to Brahms violin sonata 2 in a lifelike
recording, and you could nearly smell the rosin and see the pianist
turning pages. Right now I'm perplexed which way to go in construction
terms - I can see virtues in both. I've built three PP 2a3 amps now
and one 300b SET. I guess to really know I need to build a 300b PP
amp. A 2a3 SET would be nice, but a bit low powered. Mind you, other
things beckon like a low voltage (450v) 845 PP amp and in particular a
PP 10Y amp. On the far side is a 2E22 amp - maybe even in SE pentode
to rock the boat. I'm sceptical but it has been done!
So my conclusion for now is that if you used the same valves and the
same transformer coupling, you would have two good amps, and it might
be hard to actually choose.

Building my own valve amp
 

You fall for the trap, by assuming a REPRODUCTION system has
any relation to a CREATION system

No trap, just a straw man argument. As a gigging musician I'm quite
aware of the difference, in fact I believe a 10 year old child would
be.
The more subtle point is whether you are able to accept that:
a) musicians can distinguish between a Stradovarius and a practice
violin in a live context, and that is their identical goal in a
recorded context SHOULD THEY BE INTERESTED IN THIS. I say this because
some musicians are indifferent to recordings because the bulk of their
sound input is live music and additionally because if they want to
look at details in a work they read the score. Musicians can also
quite easily run through music they know in their head. So as
musicians we're pretty weary of the "I know a musician who listens on
his kitchen radio, which shows that musicians don't understand
reproduction" kind of anecdotes.
b) no reproduction is perfect, and some flaws are more objectionable
to some listeners than to others. In particular musicians, as above,
are sensitive to timbre and tone and can easily prefer a system with
less than perfect frequency response to one with dull and wooden tone.
As has been said many times, timbre is one of the SET qualities.
Question of preference here.

Building my own valve amp
 

I can offer you the very, very rare Leak Stereo 30 Plus at a good
price...

I might just sacrifice my collection of Max Bygraves records for that!

Building my own valve amp
 

A good tube-era author to dip into is
Norman Crowhurst.

Very true and very overlooked. He writes very clearly. So does Bruce
Rozenblit when he's not counting his patents.