WTB: 211/vt4c or 845 or equal
Remco Stoutjesdijk
For my next project (directly driving an ESL) I'd like to use a
high-voltage capable tube such as the 211/vt4c or the 845, or another
good triode which can be driven at over 1000 volts. I'll be needing 4 of
'em, or two matched pairs or even a matched quad.
Does anyone have a bunch lying around he/she wants to sell?
I don't have much experience with transcontinental postage, so I'd
prefer anyone in the Netherlands or close. But don't hesitate to mail me
your offer.
Regards,
Remco
--
-----------------------------------------------------------------
e-mail: r.m.stou...@student.utwente.nl
Integrated Circuit Design group
University of Twente, The Netherlands
http://icd.el.utwente.nl
rms audio
Getfertweg 141
7512 BB Enschede
The Netherlands
phone (+)31-(0)53 432 88 14
http://listen.to/rmsaudio/
-----------------------------------------------------------------
Oloranger
I have 4 matched GE 211/4TC tubes. They were originally in military boxes but
all boxes rotted off due to age. I will guranteed that they are they are
unused. They were all tested with a static grid test where the minimum was 148
milliamps.I will provide the test results if you like.
I would like $260 US dollars for the four plus shipping/insurance.
I just sold some 211's to a buyer in Hong Kong. The transaction consisted of
him sending me a international money order in US dollars. I sent him the tubes
as soon as I received the money order.
Another suggestion would be use a bank transfer. You would transfer money from
your bank to my bank. I think the drawback to that method is that there is a
fee for the transaction from your bank. You will need to check with your bank
on how much it will cost.
Good Luck,
Fred
PS., I am down to eight 211's. They all test within 2 milliamps of each other.
If you're interested in buying all 8, I will sell them for $500 US dollars.
Andre Jute
I don't have any tubes to sell you, but permit me to direct your
attention to Svetlana's SV572-xx series of tubes, which are smaller
*and* beefier than the 845/211 variety and would probaby suit your
project better. They are 125W tubes, genuinely capable of their 1000V
max (the 211/845 only go up to 1250V and you really shouldn't drive
Chinese tubes all the way up there), have much greater current
capability (I have driven them at 114mA without fear) than the 211/845
which again makes them more suitable for driving panels, and the three
versions suitable for your project, -3, -10 and -30 allow sonic tuning.
A matching 300mA/3000V rectifier, Svetlana's 6D22S (from memory, someone
correct me if I got the number wrong) is also available. Check
Svetlana's netsite for spec sheets.
You can get help, if you need it, from Mattisj de Vries at your
university. He has a netsite called Machmat, and might be able to help
you find the tubes.
Jim de Kort of the VT52 or maybe VT-52 netsite also sells tubes.
Good luck.
Andre
--
Andre Jute
an...@indigo.ie COMMUNICATION JUTE
--we support pages for music lovers, writers and audiophiles at
http://indigo.ie/~andre/ComJuteF1.html
Andre Jute
draft for the money drawn in dollars on a US bank. It costs a small fee
(a few bucks), is secure, and the draft is as good as cash at the
seller's bank.
Telegraphic transfers cost real money...
Andre
Oloranger <olor...@aol.com> wrote:
> I would like $260 US dollars for the four plus shipping/insurance. I just
> sold some 211's to a buyer in Hong Kong. The transaction consisted of him
> sending me a international money order in US dollars. I sent him the
> tubes as soon as I received the money order. Another suggestion would be
> use a bank transfer. You would transfer money from your bank to my bank.
> I think the drawback to that method is that there is a fee for the
> transaction from your bank.
--
Andre Jute an...@indigo.ie COMMUNICATION JUTE
--come with Andre's Jute's Classical Jukebox live to the
West Cork Chamber Music Festival
http://indigo.ie/~andre/WestCorkChamberMusicFest.html
tarku...@my-deja.com
I have 3 unused NOS G.E. JAN 211/VT4C tubes for sale. $75 each.
In ORIGINAL boxes, dated 1942, original packing material & data sheet
wrapped around each tube. I'm not interested in SE amps, however, I am
hacking a 100W pp-p with Svetlana SV6556C's.
You live anywhere near Petten? I've worked with engineers at
Scanditronix...
Good luck,
dave
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
Remco Stoutjesdijk
> I don't have any tubes to sell you, but permit me to direct your
> attention to Svetlana's SV572-xx series of tubes, which are smaller
> *and* beefier than the 845/211 variety and would probaby suit your
> project better. They are 125W tubes, genuinely capable of their 1000V
> max
Thanx for the advice!
1000V is what Svetlana uses for typical and for maximum rating, indeed. I hope
that that is enough to get some noise.
Mattijs de Vries has made a design draft using this tube. He also tried using
a PP EL36 design at approx 400 volts, which was way too powerless. In the
second design, he drove the Svetlana's with the EL36's. He never got around to
building this.
I think it could work. However, I have two hesitations:
-Mattijs had to use many correction networks to maintain a straight frequency
curve, because of the varying load of the panels. The 572 is relatively
susceptible to load changes due to its high output impedance. The 211 and 845
have a much lower output impedance.
-As Jac van de Walle pointed out, they are biased very high and run in Class
A2 mode. That's not what they were originally designed for and I don't think
you get the best out of 'em @ that biasing point. 211/845 were designed with
these bias points in mind.
> (the 211/845 only go up to 1250V and you really shouldn't drive
> Chinese tubes all the way up there),
Well, there also are American 211/845's... Providing you have a GOOD 211/845,
I think you _should_ drive them as high as that. It is the range they perform
best in. I have experiences with tubes that run better at (too) low biasing,
but from the datasheets of the 211/845 you can see that the extra 'headroom'
surely pays off.
I have heard some great sounding Chinese tubes @ high bias, though. I could be
prejudiced, maybe, but don't want to shut that option...
> have much greater current
> capability (I have driven them at 114mA without fear) than the 211/845
> which again makes them more suitable for driving panels, and the three
> versions suitable for your project, -3, -10 and -30 allow sonic tuning.
> A matching 300mA/3000V rectifier, Svetlana's 6D22S (from memory, someone
> correct me if I got the number wrong) is also available. Check
> Svetlana's netsite for spec sheets.
>
> You can get help, if you need it, from Mattisj de Vries at your
> university. He has a netsite called Machmat, and might be able to help
> you find the tubes.
Yes, I know Mattijs. We hope to develope some designs together, and guess
where I got the panels ;-) At the moment, he is 'off the earth' (in his words
:-) for one and a half months.
> Jim de Kort of the VT52 or maybe VT-52 netsite also sells tubes.
And he is the new distributor of AVVT. But the AV520 does not handle over 550
volts, unfortunately. What I saw at Mattijs' convinced me on the quality of
AVVT tubes for good!
> Good luck.
Thanx again! It looks like I still have quite some thinking to do.
BobCZ
Remco Stoutjesdijk <r.m.stou...@student.utwente.nl> wrote in message
news:37737765...@student.utwente.nl...
> Andre Jute wrote:
>
> > I don't have any tubes to sell you,
Hi Remco,
Please beware that Mr. Jute has never built an amplifier, he is a fiction
writer ONLY, so anything he recommends is just fiction, or possibly
plagiarized from someone else. He attempts to legitimize himself by
association, i.e. name dropping of decent honest people who are really in
this hobby. Please don't take his advice too seriously it may be dangerous,
or at least sonically unrewarding.
BC
Andre Jute
> Andre Jute wrote:
>
> > I don't have any tubes to sell you, but permit me to direct your
> > attention to Svetlana's SV572-xx series of tubes, which are smaller
> > *and* beefier than the 845/211 variety and would probaby suit your
> > project better. They are 125W tubes, genuinely capable of their 1000V
> > max
>
> Thanx for the advice!
> 1000V is what Svetlana uses for typical and for maximum rating, indeed. I hope
> that that is enough to get some noise.
> Mattijs de Vries has made a design draft using this tube. He also tried using
> a PP EL36 design at approx 400 volts, which was way too powerless. In the
> second design, he drove the Svetlana's with the EL36's. He never got around to
> building this.
Yes, this is probably fairly common experience. I started out driving
SV572-xx with other SV572-xx (the -10 driving the -3 was a particularly
fine-sounding combination) but my latest proto is set up to drive them
with 300B, simply because in the original lashups I just drove them with
whatever 300B amp was to hand, with the primary of the SE output used as
a choke load (secondary unconnected). These tubes really need a booster
and the 300B driving them just made a wonderful sonic combination.
>
> I think it could work. However, I have two hesitations:
> -Mattijs had to use many correction networks to maintain a straight frequency
> curve, because of the varying load of the panels. The 572 is relatively
> susceptible to load changes due to its high output impedance.
A clear case for parallelling. <G>
> The 211 and 845
> have a much lower output impedance.
> -As Jac van de Walle pointed out, they are biased very high and run in Class
> A2 mode. That's not what they were originally designed for and I don't think
> you get the best out of 'em @ that biasing point. 211/845 were designed with
> these bias points in mind.
This is theoretically right, but once you start doing it you soon
discover that it needn't constrict you. The -3 for instance, if you
operate it at high enough voltage and current, as I imagine you would
want to do, arrives at the signal max current cutoff before it goes into
A2.
You'll get nothing much out of a 211 if you don't operate it well into
A2. The 845 is a gloriously different matter--it will deliver a lot of
clean and very pleasing power in A1. Until I heard the SV572, I did not
believe there could ever be another tube as pleasing as a high voltage,
high current 845. I'm biassed, as you can see!
>
> > (the 211/845 only go up to 1250V and you really shouldn't drive
> > Chinese tubes all the way up there),
>
> Well, there also are American 211/845's... Providing you have a GOOD 211/845,
> I think you _should_ drive them as high as that. It is the range they perform
> best in. I have experiences with tubes that run better at (too) low biasing,
Can you tell us more, please.
> but from the datasheets of the 211/845 you can see that the extra 'headroom'
> surely pays off.
I like around 960-1040V and 85-90mA with about -145 to -155V of bias,
which is as high as I dare run the Chinese tubes--and that already gives
the conservative engineering types a tight feeling in the chest... I
have very little experience of the NOS ones, but their cost might
prevent me running them even that high.
> I have heard some great sounding Chinese tubes @ high bias, though. I could be
> prejudiced, maybe, but don't want to shut that option...
>
>
> > have much greater current
> > capability (I have driven them at 114mA without fear) than the 211/845
> > which again makes them more suitable for driving panels, and the three
> > versions suitable for your project, -3, -10 and -30 allow sonic tuning.
> > A matching 300mA/3000V rectifier, Svetlana's 6D22S (from memory, someone
> > correct me if I got the number wrong) is also available. Check
> > Svetlana's netsite for spec sheets.
> >
> > You can get help, if you need it, from Mattisj de Vries at your
> > university. He has a netsite called Machmat, and might be able to help
> > you find the tubes.
>
> Yes, I know Mattijs. We hope to develope some designs together, and guess
> where I got the panels ;-) At the moment, he is 'off the earth' (in his words
> :-) for one and a half months.
>
> > Jim de Kort of the VT52 or maybe VT-52 netsite also sells tubes.
>
> And he is the new distributor of AVVT. But the AV520 does not handle over 550
> volts, unfortunately. What I saw at Mattijs' convinced me on the quality of
> AVVT tubes for good!
My Vaic tubes come from KR! <G> (Only an idiot buys a new Ferrari. The
best Ferrari are the ones someone else paid in blood and frustration and
money to have debugged...)
>
> > Good luck.
>
> Thanx again! It looks like I still have quite some thinking to do.
> Remco
You might also look up the Joenet archives. There was a long discussion
there, with worked examples for directly coupled amp and panels. I think
it is Tim Reese, who comes here, who keeps the index of that archive.
(Someone throw in the URLs, please!)
Andre
> --
>
> -----------------------------------------------------------------
> e-mail: r.m.stou...@student.utwente.nl
>
> Integrated Circuit Design group
> University of Twente, The Netherlands
> http://icd.el.utwente.nl
>
> rms audio
> Getfertweg 141
> 7512 BB Enschede
> The Netherlands
> phone (+)31-(0)53 432 88 14
> http://listen.to/rmsaudio/
> -----------------------------------------------------------------
Phil Frakes
I wanted to add here that I have a pair of parallel single ended 845
mono blocks that I built. I use Chinese 845s in it run at 1250V and
75ma. Haven't had a lick of problems yet (about 1.5 years of
operation). And they sound great. I admit I haven't heard any NOS 845s
in it, but for the cost the Chinese tubes are pretty darn good.
-Phil
Grover Gardner
dissipation. I've had no problems, nor has a friend of mine who squeezes 140
watts out of them in PP. I would add that we both use a directly-coupled
cathode-follower driver, which improves their stability, so... Of course,
there's always a bum batch out there, but generally everyone who's used these
seems to feel they are an excellent buy.
BTW, at 950vdc/80-90mA mine bias at between -110 and -115, significantly lower
than the RCA specs, so you get a bit of a break in the driver department...
--
Grover Gardner
gro...@postoffice.att.net
dang...@earthlink.net
Click here for a datasheet:
http://tubes.ru/techinfo/ModulatorTubes/gm-70.html
The have a website with many similar tubes. Click here:
If you're really set on a 211 or 845, see "The Big List !". I posted
an update yesterday.
BTW, I used to be involved with IC design. Is anyone still using Gray
and Meyer? Anything better come along recently?
Regards,
Dangerdave
ilj
dang...@earthlink.net wrote in message
<3777571b...@news.earthlink.net>...
>How about a GM-70?
>
>Click here for a datasheet:
>
>http://tubes.ru/techinfo/ModulatorTubes/gm-70.html
>
Those are some lousy looking curves.
Compare the curves of the 845 to those of the GM-70, newer is not always
better.
http://www.triodeel.com/845_p2.gif
Regards,
Ivan
Andre Jute
Bit of an unfair comparison really. Not many power tubes approach to
within a mile of the awesome linearity of an 845. There's the 300B, and
what else?
There's another thread concurrently about sweet spots in 845; it breaks
out every now and again; and the 300B operating points debate runs
almost continuously, being restarted every time some innocent decides to
defend the operating point an inadequate transformer forces on him as an
article of religious faith. These threads are made possible by the
linearity of these tubes, which makes for many, many sweet spots. (And
sometimes their adaptability leads someone into horrid solecisms, as we
saw when "bobcx" Chernofsky's Magnequest DS-050 amp was analysed for
distortion and its asymmetric clipping behaviour by John Byrns and me.)
Tubes of less awesome linearity need not sound less good. It just takes
more work to find the sweet spot(s). This is one of the really good
reasons to do your initial design work by trial and error directly on
the curves.
What I would really like to see is some manufacturer scaling up the 6SN7
to 100W per plate, so that one would have a beefy driver and output of
very great linearity for PSE or PP operation in one envelope. It would
probably be physically big enough to substitute for a whole Corvette in
the mating displays of some less socially adept RATters.
Which raises the question, is making a tube more powerful merely a
matter of scaling it up? (Sounds too easy to be possible.) What are the
parameters of tube power?
Andre
bobcx
> Not many con-men approach within a mile the awesome lowness of me,
Andre >Jute, who enjoys being impaled by the mighty 845.
>Please read Timmie. It is "MY" story.
********************************************
How to become a Timmie!
BE 'ANARTIST' WITHOUT EVER CREATING ANYTHING EXCEPT
DENUNCIATIONS OF YOUR LETTERS
I know one fellow who really wants to be an author Well,
actually, he'd like to be an artist of any kind. It doesn't
matter what sort. Understand, he doesn't have any creative
urge, or even ideas that itch for expression. what he really
wants to be is to be 'a somebody'. He's got this idea in his
head, perhaps because there were artists in his family,
perhaps because he sees pop intellectuals being interviewed
on the television, that artists are accorded respect beyond
that given to, say, council employees or accountants.
He wants to be an artist so badly, he has run the words
together, 'anauthor' .
Let's call him Timmie. Of course he has no talent. But that
is no inpediment to being 'anauthor' . Nor does he have the
discipline to write anything extended. But don't let that worry
you either. This chapter tells how even a Timmie can define
himself as an intellectual without the need ever to do any
intellectual work. First, get some kind of a career on the
fringes of the arts. Desktop publishing is good because you
can call yourself a graphic designer without bothering to be
trained or otherwise inform yourself. Public relations, especially
for television, is also good- Next, join some group where you
are likely to run into real intellectuals, preferably with achievements
to their name. Published books are good, as are plays, even musicals;
painters are okay but musicians insist on technical jargon that is a
bore to learn. Give architects a miss; most of them are unemployed
and unemployable. If you are short of ideas, check out Chapter 3
"Hanging Out Right, er,Left--PC Places and People"
Having chosen your forum, ingratiate yourself- Be a clown, tell jokes.
Don't for, god's sake, actually attempt any serious work; if and people
can use it to judge the quality of your mind, your career as an intellectual
will be finished before you have even started. Let it be known you
are working on a magnum opus but are too modest to let anyone see any
part of it. You will of course imply at every opportunity that one day the
world will be stunned by your brilliance.
After a while you will be a fixture. You will not have to prove that you
belong. Now, pick on some prominent fellow with real achievements.
Suck up to him with flattery before you launch your attack. Be absolutely
certain that there is no cause for the attack except your ambition; people
will be too embarrassed to point out you are acting from envy alone.
Above all you don't want to be involved in a real argument. The best sort
to pick on is someone too busy to fight back, preferably someone with
strong, consistent opinions- Dont for the time being attack the opinions,
instead pick on some personal aspect of the great man's feet of clay.
Does he lack modesty? Condemn him as a braggart. If he is modest,
attack him for hypocrisy. If he wears glasses, attack him for
shortsightedness. That is a good start.
Now demonstrate how ruthless you are by attacking without
provocation a member of his family, preferably a child. That should
frighten him badly enough to shut him up while you go your merry way.
If he is over thirty, attack him as 'an old tart' Now switch the attack.
If he has strong opinions, attack him for stubbornness. If he is always
reasonable, attack him for being indecisive.
If in selfdefense he makes an appeal to intellectual honesty in discourse,
immediately and repeatedly accuse him of being a snob.
You can pretend to find fault with his work. Read up some past criticism
bun don't get bogged down in serious argument. If he has solid achievement
it has survived criticism and you as a wannabe are by definition incapable
of bringing serious criticism of substantial work. The best compromise is
to find a set of criticisms so lightweight that the obvious lack of
enterprise is in itself an insult.
Tell a lot of brazen lies brazenly. Do not deign to argue the merits of
these lies when challenged. Simply think up some bigger lies and make new
charges. Or repeat old ones in slightly different words. Take a high moral
tone; claim to be making the charges as a public duty. Study the career of
Joseph Goebbels, Hitler's propaganda minister; Goebbels was the greatest
PR man of the century.
Make everything you say a personal insult. Nothing is more dangerous than
the facts. The minute you allow the facts to be discussed seriously, it will
become clear that you are in a card game where you haven't price of a
stake.
Now, of course sometimes you will pick badly and some intellectual
heavyweight will emerge languidly to maul your tender sensitivities. In
that case smile with boyish charm and say it was all a bit of a joke,
wasn't it. If he doesn't believe you, accuse him of lacking a sense of
humour.
Retire as gracefully as you can manage. Write a grovelling private letter
saying you were under stress because your mother is sick and you of
course apologize abjectly. Appeal to his decency to let it end right there.
That way you can survive to betray someone else upon another day.
Don't make the stupid mistake of attacking someone who has rolled
over you once a second time. Lie in wait for a softer touch. Sooner
or later you will find a weakling and you will by lying about him be able
to destroy his confidence. Then your name will be made. You will be
the man who destroyed X!s reputation. You will never have to do anything
so brow wrinkling and perspiration-breaking as creating something original.
For the rest of your life you can do what you are best at, pose as
something you are not.
CASE STUDY
Now let us take Timmie and spot the mistakes he made on the way to
perfection because he didn't buy my book and follow my rules precisely.
First, he picked on a fellow who had already demonstrated that he would
wipe his backside with impertinent snots. Next, the fellow Timmie picked on
has had so many careers, he cannot remember all his achievements
(he offers visitors an expanding rule to measure his hardcover first
editions
in shelf-feet, for instance) ; even a serious critical attack on some part
of
his work simply leaves him fall back on the prestige of the rest while he
brings the less than brilliant part up to scratch. This was insensitive of
Timmie. Wannabe artists must at least pretend to sensitivity, or if they
lack it be lucky enough not to be caught out this badly.
Timmie should have had the intelligence to pick on someone whose single
achievement or few achievements are treasured like children. It also helps
no pick on someone who doesn't already possess monumental self confidence.
Many artists of perfectly good achievement have poor self-image and they
are easier to reduce to snivelling wrecks.
Bad signs in your choice include high academic honours, high-level business
experience and competence; political experience; military experience;
sporting achievements at national or international level particularly in
contact sports but most especially in sports where people die like
auto-racing or competitive transocean yachting.
Don't let ambition lead you to fucking with someone utterly out of your
league, as it did to Timmie. You're not going to believe this: Timmie
picked on a guy to whom a government erected a statue in his own lifetime,
the most monumental confidence-builder imaginable. If by now you're
thinking Timmie is so stupid I must have made him up, believe me, I didn't.
he is real- And there are a multitude more like him out there. He's a
lowest. common denominator case.
Then Timmie picked on this heavyweight bruiser not once, but again after
he was warned off, three times in all. This is seriously stupid. You have
to finish the job the first time or give it up for good. Worse, he tried
his luck the last time after it had been cogently pointed out, and never
contested, that Timmie was acting purely from envy. Not too bright, our
Timmie, as you have already observed. But this is only where the nightmare
starts.
Next Timmie made the serious mistake of protesting too much. It became
quite clear that he was not acting from high-minded public duty but from a
desire to be precisely like the great man, or whatever his misconception of
this fellow was. He admitted as much through his attempts to vary his
attack. This is dumb. You must not try for literary excellence -if you had
any, you wouldn't be following this route--but ram the same simple message
home again and again.
Timmie made the appalling mistake of conceding that this fellow's
achievements were substantial and unassailable. Wrong! wrong
Wrong! A cleverer wannabe simply concludes that the works are in fact
assailable by someone of real talent but keeps quiet about it.
One trick all wannabes should learn before they try their luck is when to
shut up- Timmie was so impressed with his clever gush of meaningless
words he did not know there was a point where they would stop being
meaningless and start hurting him.
Timmie's list of criticisms was so slight they could not pass even as an
insult; it was too clear to everyone that he had tried hard and failed.
He made the worse mistake of panting eagerly to be thrown another titbit
from the table of the great man's creativity when the correct approach
would be avidly to devour in secret everything the great man made,
consumption to be announced only when serious shortcomings were
discovered. discreet secrecy otherwise to be maintained with a lofty
disinterest expressed publicly at every opportunity.
Timmie is of course a good argument for permitting genetic scanning
and abortion of fetuses too low on the food chain to be anything but
a burden on society, but even Timmie could have succeeded if only he
had followed rny guidelines carefully.
Don't be a smartass and end up like Timmie, a well-known arsehole
and butt of cocktail party sniggers, the original for the sneering
admonition
'Don't be such a Timmie. He used not to be invited because of his pushy
personality, now he is not invited because everyone knows he's a no-talent;
an arsehole and a three-time loser.
If you were smart enough to modify the rules you wouldn't need this book.
Trust me.
Andre Jute
>
> Andre
> --
> Andre Jute andrak@igoeeeeeie CON MAN JUTE
> --come with Andre's Jute's CON MAN Junkbox live to the
> Wet Cork Boys Speedo Slumber Festival
> http://igo.eeeeee/~and/WetCorkBoys.html
dang...@earthlink.net
>Compare the curves of the 845 to those of the GM-70, newer is not always
>better.
>Regards,
>Ivan
>
Better curves are not always better - after all, what does a "curve"
sound like?
VTV ran a comparison test, and 845 and GM-70 were about the same,
based on listening tests and measurements. But if it's curves you
want, why not buy yourself a low cost solid state system with loads of
NFB? They have great "curves".
Regards,
Dangerdave
ilj
<37781cbe...@news.earthlink.net>...
>>On Sat, 26 Jun 1999 16:51:13 -0700, "ilj" <i...@pe.net> wrote:
>
>
>Better curves are not always better - after all, what does a "curve"
>sound like?
>
As an EE, you should know better.
>VTV ran a comparison test, and 845 and GM-70 were about the same,
>based on listening tests and measurements. But if it's curves you
>want, why not buy yourself a low cost solid state system with loads of
>NFB? They have great "curves".
>
Intrinsic linearity is the issue. It is difficult to beat an 845 when it
comes to intrinsic linearity. Most any SS or vacuum tube can be linearized
with enough feedback. We all know that, but who cares?
I read the VTV test, and found it virtually worthless as far as 845s are
concerned. Their test setup was not designed to drive an 845, it was
intended to drive tubes like the 211 and GM-70, which require much lower
drive levels. Comparing the 845 to the 211 or GM-70 using the same amplifier
front-end is not a valid comparison, unless the front-end is designed to
meet the drive requirements of the 845.
Regards,
Ivan
ilj
BTW, I forgot to point out that VTV did not publish any measurments for the
845 in comparison to the 211 or GM-70. They recognized that it would not be
a fair comparison.
It sure is amusing the way it bothers some people that these relics from the
late 20s and early 30s are still among those devices that are "setting the
standard" for intrinsic linearity, even as we are approaching the new
millenia.
Regards,
Ivan
Grover Gardner
Remco Stoutjesdijk wrote:
> That is indeed a brilliant driver, I have even seen a new Marantz that
> drives 845's with 300B's. The crap text they used in the add however
> made me shiver. "The two 845 diodes rectify the output". Thank u, Ken
> Ishiwata.
--
Grover Gardner
gro...@postoffice.att.net
Acrosound
Remco Stoutjesdijk wrote:
> That is indeed a brilliant driver, I have even seen a new Marantz that
> drives 845's with 300B's. The crap text they used in the add however
> made me shiver. "The two 845 diodes rectify the output".
I believe your referring to the Marantz T1 amplifiers. 300B PP driving 300BPP
driving 845PP. And, yep, the rectifiers are also 845 tubes.
Gorgeous amplifier... saw it in NYC at the stereophile show about two years
ago. Still saving my pennies for a pair <g>.
The schematic for this amplifier was published in Sound practices magazine
though I forget which issue.
MSL
tommy
rectifiers? That just seems ridiculous. That amp is obviously competing in
the "I cost more than your car" leagues, and it just seems absolutely
senseless. 845's as rectifiers indeed. I will argue till I'm blue in the
face that tubes for audio are a worthy cause, but I would have a hard time
defending such a blatant misuse of funds.
"Look at me everybody, I use piles of diamonds as door stops. I'm an
idiot."
Chris
ilj
tommy wrote in message <01bec19a$24825c40$9801ffc0@cterry>...
>Alright, I usually can keep my mouth shut, but good Lord! 845's as
>rectifiers? >
>idiot."
>
>Chris
Relax Chris, they only cost about $25 each, and last for years.
Regards,
Ivan
Andre Jute
> That is indeed a brilliant driver, I have even seen a new Marantz that
> drives 845's with 300B's. The crap text they used in the add however made
> me shiver. "The two 845 diodes rectify the output". Thank u, Ken Ishiwata.
> The crap text they used in the add however made
> me shiver. "The two 845 diodes rectify the output". Thank u, Ken Ishiwata.
I imagine they mean two 845 as rectifiers. A triode is a diode with a
grid... Here's a trick: if you can find switches of the correct rating,
you can build a switchable PSE/SE amp without major bother out what to
do with the "extra" current in the SE version: you switch the 2nd tube
to be a shunt regulator, and then you have an SE amp with regulated
plate supply of the same sonic signature as the output... If you have
845 rectifiers as well, you can go into sensory overload.
A Svet 6D22S would probably be a cheaper installation as a rectifier...
but six 845 for an SE amp would look way cool, and heat your house too.
Andre
Grover Gardner
very good current-production solution for rectifying extremely high voltages.
tommy wrote:
>
> Alright, I usually can keep my mouth shut, but good Lord! 845's as
> rectifiers? That just seems ridiculous. That amp is obviously competing in
> the "I cost more than your car" leagues, and it just seems absolutely
> senseless. 845's as rectifiers indeed. I will argue till I'm blue in the
> face that tubes for audio are a worthy cause, but I would have a hard time
> defending such a blatant misuse of funds.
>
> "Look at me everybody, I use piles of diamonds as door stops. I'm an
> idiot."
--
Grover Gardner
gro...@postoffice.att.net
tommy
get 845's for so cheap. I may consider them for my next big SE project
that is in the works. I am making a generic SE setup with Variac feeding
the main HI Voltage transformer for variable +B, and I might as well wire
in a socket for an 845 on each channel. The main design is based on a
SV572-3, and I'll be able to plug in an SV811-3 as well. Fixed bias,
capacitively coupled 6SN7 driver. How would a single 845 feel with a 5K
load at about 1000 V, 100 ma and about 300 Vp-p drive swing? I'll pull out
the curves and see for myself as well.
Hey, I learned something new today.
chris
Andre Jute
> How would a single 845 feel with a 5K
> load at about 1000 V, 100 ma and about 300 Vp-p
The nearer you can get to 10K the better, 85-90mA is safer--100mA is
max. 1000V and 300Vptp is right on.
Andre
Acrosound
tommy <to...@thewho.com> wrote:
> How would a single 845 feel with a 5K
> load at about 1000 V, 100 ma and about 300 Vp-p
>>
Purrrfectly.... you would be in very good company. Recall that the Komuro
amplifier (see absolute sound #104) was similar, albeit it used higher plate
volts.
MSL
bobcx
Andre Jute <an...@indigo.ie> wrote in message
> tommy <to...@thewho.com> wrote:
>
> > How would a single 845 feel with a 5K
> > load at about 1000 V, 100 ma and about 300 Vp-p
>
> The nearer you can get to 10K the better, 85-90mA is safer--100mA is
> max. 1000V and 300Vptp is right on.
>
Tommy can you hear me? Don't bother listing to his bull, a good 5K
transformer would be fine. Many great 845 amps are built by real people
using 5K. The above person is just a phony and con-man, he has never built
an amp. Ask him for some pictures of his 845 amps.
Good luck
BC
dang...@earthlnk.net
10X the current capacity of an 845.
Stressing the price advantage of using 845's as rectifiers is not very
convincing.
Are you selling 845's or something?
Regards,
Dangerdave
dang...@earthlnk.net
>Intrinsic linearity is the issue. It is difficult to beat an 845 when it
>comes to intrinsic linearity.
Well, for best linearity, a resistor is pretty good. But it takes
more than just linearity to make an amp, now doesn't it?
More generally, stressing a single feature of any electrical component
at the expense of all others, is a design approach fraught with
pitfalls.
For example, although it's linearity is good, the 845 has numerous,
serious problems. The filament is directly heated, so there is no
isolation to heater supply problems, like noise and ripple If AC
heated, the transverse E field modulates at 60/120Hz. If DC heated,
the fields are permanently skewed, and only a fraction of the cathode
participates in emission. This cause the tube to lose it's
correspondence to the one dimensional 3/2 law, and take on some new
transfer function, which varies with heater supply voltage, causing
linearity to be dependent upon heater supply. IDHT do not have these
problems..
The 845 power supply voltage requirement is very disadvantageous. All
associated and mandatory electrical componets (power supply, biasing,
coupling, driving stages) are more expensive and less available at
very high B+ voltages. Reliability is usually decreased with
increasing voltage stress. And the dangers of increased B+ voltage
are a turn-off to consumers, and may increase insurance liability.
And the very low gain and high input drive stage voltage requirment of
the 845 shifts a large burden to the driver stage. High power, high
voltage swing, low distortion, 845 driver stages are not easy to
build, may be expensive, and may themselves suffer reliability and
distortion disadvantages.
Properly implemented, the 845 and many other transmit triodes can be
used to make nice sounding audio tube amps. But ignoring the many
issues involved doesn't help anyone to achieve a better amp. I just
makes you sound like a bonehead, Sander.
>I read the VTV test, and found it virtually worthless as far as 845s are
>concerned.
Then start your own magazine and do things your way. I think VTV does
valid comparison tests, not only on 845, but many other tubes as well.
And the results, as always, are useful, if you understand the
limitations of the test and how to properly apply the results to your
own design efforts.
To be honest, Sander, you seem to be throwing the test results out,
simply because they do not match your assumptions. This is your
problem - not VTV's.
I like the 845 tube quite a lot. As a matter of fact, I have invested
more time in 845 amp design than I care to think about, because I am
participating in the design of one. However, as attractive as SOME of
the 845's features are, it is inarguably a problematic device to
design with. And it's not my first choice amount power output triodes
in any event.
Regards
Dangerdave
Grover Gardner
over all that. Given this fact, using the 845 as a high-voltage rectifier is
a rather elegant solution.
--
Grover Gardner
gro...@postoffice.att.net
George R. Gonzalez
dang...@earthlnk.net wrote in message
<377d8e64...@news.earthlink.net>...
>And PN diodes only cost a few cents each, last 10X longer, and have
>10X the current capacity of an 845.
Good 'ol Dave. Never one to let reality get in his way.
Over the last decade, I've tossed out: a garage door opener (diodes shorted,
burned up PC board), three modems (after a thunderstorm), two VCR's (after
other thunderstorms), two smoke detectors (wind storm), answering machine
(thunderstorm).
In the same time frame, not one of the 60 tube radios and amps in my house
has been hurt. Not one failed 5U4, blasted 5Y3, zapped 6X5, blown 80.
So let's see--- those "cheap" PN diodes and transistor junctions have cost
me about $2300.
yep, cheap is the right word to describe them.
George R. Gonzalez
dang...@earthlnk.net wrote in message
<377e8e8f...@news.earthlink.net>...
>Well, for best linearity, a resistor is pretty good. But it takes
>more than just linearity to make an amp, now doesn't it?
No, a linear negative resistance makes a dandy amplifier.
>For example, although it's linearity is good, the 845 has numerous,
>serious problems. The filament is directly heated, so there is no
>isolation to heater supply problems, like noise and ripple If AC
>heated, the transverse E field modulates at 60/120Hz.
It's been known for over 65 years that you can tune the filament so it's
electric and magnetic E fields mostly cancel out. The type 26 tube is an
excellent example of this. Used in a tuned RF amplifier, it can amplify
millivolt RF signals with no problem from the AC powered filament. In any
case, it doesnt matter-- see below.
> If DC heated,
>the fields are permanently skewed, and only a fraction of the cathode
>participates in emission. This cause the tube to lose it's
>correspondence to the one dimensional 3/2 law, and take on some new
>transfer function, which varies with heater supply voltage, causing
>linearity to be dependent upon heater supply.
This is ridiculous. First of all, most textbooks mention the 3/2 law, then
in the next sentence tell you it doesnt apply in any real tube. Dave's
short attrention span caused him to tune out after the first sentence-- not
his fault.
Next, a tube like the 845 needs hundreds of volts of grid swing, and many
times that amount of plate voltage. Do you really think it's going to worry
about a few little volts DC across the filament?
>The 845 power supply voltage requirement is very disadvantageous. All
>associated and mandatory electrical componets (power supply, biasing,
>coupling, driving stages) are more expensive and less available at
>very high B+ voltages. Reliability is usually decreased with
>increasing voltage stress.
Sure Dave. There's probably a billion TV's out there with 25KV or more on
the CRT.
They don't fail too often. Even less so foran 845 running at less than a
tenth that voltage.
>And the very low gain and high input drive stage voltage requirment of
>the 845 shifts a large burden to the driver stage. High power, high
>voltage swing, low distortion, 845 driver stages are not easy to
>build, may be expensive, and may themselves suffer reliability and
>distortion disadvantages.
It's been well-known for around 50 years how to build a medium-voltage
driver stage.
You just need a capable tube, like a 6SN7GTA. Maybe a little voltage
bootstrapping, and maybe a little cathode degeneration. Nothing that caused
any sweat to break out in 1950, shouldnt cause any palpitations nowdays.
>makes you sound like a bonehead, Sander.
I just knew he'd get around to the name-calling eventually!
dang...@earthlnk.net
rectifiers.
But based purely on sonics, I won't build any tube rectified supply.
Because tube impedance is so high, and the current capacity is so low,
compared to SS rectifiers. Thus building a very low impedance, very
low distortion PS is problematic using tubes of any type, particularly
in higher current applications, like the power amp. 845-rectified
jobs, discussed in this thread.
So where does this leave the argument for using 845's as rectifiers?
Sonics bad. Cost bad. Reliablity bad. Ergo. forget about it, and
read a book on high performance PS design, cira the 20th or 21st
centuries.
Regards,
Dangerdave
>On Thu, 01 Jul 1999 13:00:36 -0400, Grover Gardner <gro...@postoffice.att.net> wrote:
>Some people feel that tube rectification has sonic advantages. No need to go
>over all that. Given this fact, using the 845 as a high-voltage rectifier is
>a rather elegant solution.
>
>dang...@earthlnk.net wrote:
>>
>> And PN diodes only cost a few cents each, last 10X longer, and have
>> 10X the current capacity of an 845.
>>
bobcx
George R. Gonzalez <gr...@flash.net> wrote in message
news:IIPe3.259$CN1...@news.flash.net...
> Good 'ol Dave. Never one to let reality get in his way.
>
> Over the last decade, I've tossed out: a garage door opener (diodes
shorted,
> burned up PC board), three modems (after a thunderstorm), two VCR's
(after
> other thunderstorms), two smoke detectors (wind storm), answering
machine
> (thunderstorm).
Dangerdave would not have this problem. When he feels a storm approaching he
climbs to the roof and becomes a "sub-human" lightning rod to protect all
his 5 cent diodes.
BC
Sander deWaal
>>makes you sound like a bonehead, Sander.
>I just knew he'd get around to the name-calling eventually!
Huh??? Was he respondingto me???
I don't even know what 845s *are*... :-)
--
Sander deWaal
c...@wxs.nl
Andre Jute
> Next, a tube like the 845 needs hundreds of volts of grid swing,
Only for power freaks. Those of us tubies who have gone green and
conservationist try to conserve these rare tubes by not putting more
than a buck and a half on the grid.
> and many
> times that amount of plate voltage.
Hardly ever over a thousand volts!
>Do you really think it's going to worry
> about a few little volts DC across the filament?
I wrote earlier that SE people get used to a little hum as a tradeoff
for the superior sound of AC fils on most DHT, but scratched it as
unduly provocative.
Acrosound
George Gonzales wrote regarding longeeeeevity and reliabiliiiiiity of vacuum
tube rectifiers:
<< In the same time frame, not one of the 60 tube radios and amps in my house
has been hurt. Not one failed 5U4, blasted 5Y3, zapped 6X5, blown 80.<<
George: The above made me smile. I have often mused that over a period of
twenty plus years I cannot EVER remember having a rectifier fail on me in
actual tube amp service. Note even once.
knock on whood????
MSL
Brian McAllister
>Huh??? Was he respondingto me???
>I don't even know what 845s *are*... :-)
Well, that shows just how much of a bonehead you *are*...;-)
Actually he was replying to Ivan, but called him Sander. I guess he
figures that all Europeans are interchangeable. Typical collectivist
thinking.
Alles van die beste,
Brian McAllister
Durham NC
Vintage Radio and Audio Web Pages
http://mcallister.simplenet.com
Jac
it
sounds better, based on listening experience.
I can't hear that difference at all, so for me it makes no sence
to go through the cost and complexity of tube rectification.
Those who can hear the sound difference, have plenty of choice between
several types of rectifiers.
If you belong to that group, and want to rectify the Anode voltage for
the 845,
there are almost no tubes without top cap, that can rectify that high
voltage.
An 845 does 300mA at 70Volt with the grid connected to the Anode,
and this is more than you need. You need only 75mA for one
SE stage. -Jac
_________________________________________________________
Andre Jute
> An 845 does 300mA at 70Volt with the grid connected to the Anode,
> and this is more than you need. You need only 75mA for one
> SE stage. -Jac
Jac, you mean 700V, don't you?
This is fascinating. How did you determine these numbers? If you looked
them up somewhere rather than discovering it on the bench, is it on the
net?
henry_pa...@my-deja.com
an...@indigo.ie (Andre Jute) wrote:
> This is fascinating. How did you determine these numbers? If you
> looked them up somewhere rather than discovering it on the bench,
> is it on the net?
Andre, you've done a lot of designing with the 845, right? So
what, in your judgment, do you suppose would happen if you had an
845 running with 700V on the plate, and then you shorted the grid
to B+?
They're called plate curves: use them.
-Henry
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
x@y.z
>>Actually he was replying to Ivan, but called him Sander. I guess he
>figures that all Europeans are interchangeable. Typical collectivist
>thinking.
Actually, I figure that all boneheads are interchangeable.
Sorry to mix up boneheads. In the future, I shall strive to apply the
appropriate corrections to the appropriate bonehead, in a well
correlated manner.
Regards,
Dangerdave
Ken Gilbert
> Actually, I figure that all boneheads are interchangeable.
>
> Sorry to mix up boneheads. In the future, I shall strive to apply the
> appropriate corrections to the appropriate bonehead, in a well
> correlated manner.
It's going to get harder and harder, honeybuns, as more and more
boneheads gang up on you.
Is there anybody here who agrees with you about anything? Do you find
yourself with fewer and fewer compatriots as time ticks on?
Hell, even Andre's got supporters. I guess that doesn't bode well for
your charming personality.
--
Ken Gilbert
Tube Guitar Amp Design/Repair Technician
The Guitarist's Choice http://www.tgcguitar.com
http://www.geocities.com/SunsetStrip/Garage/5701
bobcx
news:7m2ka3$gak$1...@nnrp1.deja.com...
> Is there anybody here who agrees with you about anything? Do you find
> yourself with fewer and fewer compatriots as time ticks on?
Let's wait and see... He is bonding with Jute, soon they might run off
together and design imaginary amplifiers together. Isn't love grand...
> Hell, even Andre's got supporters. I guess that doesn't bode well for
> your charming personality.
Well as you know Jute was a famous athlete, so we know what kind of
supporters he has.
BC