| Author |
Message |
John Stewart
Guest
|
 Posted:
Sun Sep 25, 2005 7:13 pm Post subject:
Re: 2A3 - Really a beautiful power tube! |
|
|
Patrick Turner wrote:
| Quote: | I finally have hooked up the stereo amp which uses 2A3
to my speakers which are about 90dB sensitivity.
I find I could listen all day and night to this underpowered
amplifier.
Whatever its doing it is doing it RIGHT.
The conditions are as follows.
Power tranny is Hammond type 370FX, and with
a 240V: 2 x 2.5V filament tranny.
Hammond 10H choke used with a quad of Sonic Frontier
PS caps of 1,100 uF each, so that with seriesed caps
I have 550uF, 10H, 550uF, as the CLC to supply power to the
pair of amp channels.
Rectifiers are IN5408 SS diodes. I don't strictly believe in tube
rectifiers;
I like them, I even use them sometimes; I just don't think they are
indispensible.
But in this case the use of a tube rectifier would have reduced the
available B+
and forced me to use fixed bias, which I don't like for any SE amps.
No need to dual mono power supplies.
180uF used to further filter the input and driver stages.
Output tubes are 2A3, RCA, NOS?, maybe used, not sure.
Ea = +270V, Ia = 57mA, cathode bias with 820ohms
bypassed with good quality 100V x 470uF.
heaters are AC 2.5V with a pot for hum nulling.
OPT is a 2.5k : 4/8/16 Hammond 25 watt rated SET gapped OPT
type 1627SE.
OPT is set up to match 2.5k to 4ohms, but I find 5 ohms is the most
correct load.
At 4Watts I get excellent open loop BW with this OPT
and freedom from saturation, of which there is only a slight trace at
about
7 Hz.
The OPT has queer resonances above 30kHz, makinf the use of
global NFB difficult for ppl with no clue about how to overcome such
connundrums.
It must be due to primary being wound close to the secondary,
and the absence of enough interleavings of windings, and the absence of
sufficient
insulation thickness.
Nevertheless, the 1627SE did turn out to be very usable, and sound is
glorious.
Driver tube is an ancient Radiotron 'made in australia' 6SN7,
used but OK. 1k Rk bypassed with 470uF, RL = 34k, 0.47 uF Wima coupling
cap,
150k grid bias R for 2A3, 1.8k series grid stopper.
The 6SN7 is operating fairly linearly and comfortably.
Without Ck bypass, the driver thd reduces, but then overall thd rises
a lot since less even order Dn cancelation takes place.
The fully bypassed Rk on the 6SN7 gives lowish Ra of about 5k for the
paralleled tube
and is thus a sufficiently low enough drive resistance to enhance the
micro detail behaviour of the
2A3, ( very necessary imho to get the best out of not just a triode
output tube,
but ALL output tubes.)
The input tube is 1/2 a 12AU7 of unknown lineage; it measured nicely,
and I like the 12AU7 for inputs; its warm, accurate, and sounds
glorious.
Its Rk is 1.8k, and also bypassed with 470uF, and taken then to 100 ohms
for
the global NFB to be applied.
RL is 50k, 0.47uF to a network for LF gain stepping, 1M+0.033uF
plus 220k, typical in many of my amps to vastly
improve the bass stability when the 12dB of global FB is applied.
The FB resistor divider network is 750 ohms to 100 ohms
with a phase tweaker bypass cap across the 750 ohms = 1,000 pF.
There is a 470pF plus 2.7k zobel network connected from the
driver grid to 0V to control the HF gain and ultimate phase shift of the
12AU7 to 6SN7 interface.
A further 5.6ohms+0.47uF Zobel network is across the OPT secondary,
and finally I got the amp to be fairly ring free when connected to
any value of cap without a pure R load, and when using a square wave.
Open loop BW with all compensation zobels in place was 20Hz to 20kHz,
-3dB,
and with 12 dB of FB the full power BW is 5Hz to 55kHz, 5 ohms.
It remains the same at lower levels of power.
A 5 kHz square wave is a bit ragged due to the mentioned OPT design
simplicity,
but the sine wave response between 30Hz and 20hHz right up to clipping
is dead flat.
A 50k Alps Black pot is used for the gain control.
Input sensitivity with 12dB applied global NFB is 0.7Vrms.
The amp's use with an CD player is fine.
Just no need for any preamp.
The sound is that of a far more powerful amplifier,
with tremendous sense of rightness, instrument detail, warmth without
muddle, not the slightest hint of any lack of bass, the usual beautiful
mids, and detailed top end.
The amp measures well at less than 1% thd at 4 watts into 5 ohms,
mainly all 2H.
But at normal levels of a watt the 3H and other H are present below the
2H
which can be seen on the CRO when monitoring the THD at all levels.
Ro is 0.47 ohm, and although my speakers vary between
4 and 20ohms, the sound appears firm, well timbred, and there isn't any
hint
of the sound being that from an inadequate amplifier.
I played Handel's water music, the sound track of 'The Pianist' for my
tests plus
a not so wonderful Naxos CD, 'The Best of Bach'.
Who says SET amps suck?
Certainly not I!.
Methinks that if the owner wanted more power, he could simply swap the
2A3 for a KT90 since the PT has a 6.3V heater winding, and then
remove the series R I have placed in the B+ lines to trim the B+
to where I want it, and with 270V, and with the UL tap on the
OPT that is provided, maybe 9+ watts of SEUL would be available.
The now unused 1670 OPT UL tap is at 40%.
But it could be at 60%, if you use the plate winding reversed,
thus further drifting a tetrode towards triode, but still not
suffering a huge loss of power due to grid current limitations.
300B could also be used, and with slightly more Ia,
but with the same low Ea, thus suiting moderate power and good matching
to
low value loads, which is a major failing in many SET amps;
they try to match so max power is at 8ohms, but that is
nearly always wrong with modern speakers, and
max power should occur at 3 or 4 ohms.
Patrick Turner.
|
Whats this I see? Patrick T. using Hammond? Or something brought in by a
customer?
I'm back into sales again. Lots of manual labour on the house this summer as
well. Not much time for tubes.
But if I get time I have a couple of interesting projects in mind. One is a
hybrid. But don't know when.
Cheers, John
|
|
| Back to top |
|
 |
Patrick Turner
Guest
|
| Posted:
Sun Sep 25, 2005 8:36 pm Post subject:
Re: 2A3 - Really a beautiful power tube! |
|
|
John Stewart wrote:
| Quote: | Patrick Turner wrote:
I finally have hooked up the stereo amp which uses 2A3
to my speakers which are about 90dB sensitivity.
I find I could listen all day and night to this underpowered
amplifier.
Whatever its doing it is doing it RIGHT.
The conditions are as follows.
Power tranny is Hammond type 370FX, and with
a 240V: 2 x 2.5V filament tranny.
Hammond 10H choke used with a quad of Sonic Frontier
PS caps of 1,100 uF each, so that with seriesed caps
I have 550uF, 10H, 550uF, as the CLC to supply power to the
pair of amp channels.
Rectifiers are IN5408 SS diodes. I don't strictly believe in tube
rectifiers;
I like them, I even use them sometimes; I just don't think they are
indispensible.
But in this case the use of a tube rectifier would have reduced the
available B+
and forced me to use fixed bias, which I don't like for any SE amps.
No need to dual mono power supplies.
180uF used to further filter the input and driver stages.
Output tubes are 2A3, RCA, NOS?, maybe used, not sure.
Ea = +270V, Ia = 57mA, cathode bias with 820ohms
bypassed with good quality 100V x 470uF.
heaters are AC 2.5V with a pot for hum nulling.
OPT is a 2.5k : 4/8/16 Hammond 25 watt rated SET gapped OPT
type 1627SE.
OPT is set up to match 2.5k to 4ohms, but I find 5 ohms is the most
correct load.
At 4Watts I get excellent open loop BW with this OPT
and freedom from saturation, of which there is only a slight trace at
about
7 Hz.
The OPT has queer resonances above 30kHz, makinf the use of
global NFB difficult for ppl with no clue about how to overcome such
connundrums.
It must be due to primary being wound close to the secondary,
and the absence of enough interleavings of windings, and the absence of
sufficient
insulation thickness.
Nevertheless, the 1627SE did turn out to be very usable, and sound is
glorious.
Driver tube is an ancient Radiotron 'made in australia' 6SN7,
used but OK. 1k Rk bypassed with 470uF, RL = 34k, 0.47 uF Wima coupling
cap,
150k grid bias R for 2A3, 1.8k series grid stopper.
The 6SN7 is operating fairly linearly and comfortably.
Without Ck bypass, the driver thd reduces, but then overall thd rises
a lot since less even order Dn cancelation takes place.
The fully bypassed Rk on the 6SN7 gives lowish Ra of about 5k for the
paralleled tube
and is thus a sufficiently low enough drive resistance to enhance the
micro detail behaviour of the
2A3, ( very necessary imho to get the best out of not just a triode
output tube,
but ALL output tubes.)
The input tube is 1/2 a 12AU7 of unknown lineage; it measured nicely,
and I like the 12AU7 for inputs; its warm, accurate, and sounds
glorious.
Its Rk is 1.8k, and also bypassed with 470uF, and taken then to 100 ohms
for
the global NFB to be applied.
RL is 50k, 0.47uF to a network for LF gain stepping, 1M+0.033uF
plus 220k, typical in many of my amps to vastly
improve the bass stability when the 12dB of global FB is applied.
The FB resistor divider network is 750 ohms to 100 ohms
with a phase tweaker bypass cap across the 750 ohms = 1,000 pF.
There is a 470pF plus 2.7k zobel network connected from the
driver grid to 0V to control the HF gain and ultimate phase shift of the
12AU7 to 6SN7 interface.
A further 5.6ohms+0.47uF Zobel network is across the OPT secondary,
and finally I got the amp to be fairly ring free when connected to
any value of cap without a pure R load, and when using a square wave.
Open loop BW with all compensation zobels in place was 20Hz to 20kHz,
-3dB,
and with 12 dB of FB the full power BW is 5Hz to 55kHz, 5 ohms.
It remains the same at lower levels of power.
A 5 kHz square wave is a bit ragged due to the mentioned OPT design
simplicity,
but the sine wave response between 30Hz and 20hHz right up to clipping
is dead flat.
A 50k Alps Black pot is used for the gain control.
Input sensitivity with 12dB applied global NFB is 0.7Vrms.
The amp's use with an CD player is fine.
Just no need for any preamp.
The sound is that of a far more powerful amplifier,
with tremendous sense of rightness, instrument detail, warmth without
muddle, not the slightest hint of any lack of bass, the usual beautiful
mids, and detailed top end.
The amp measures well at less than 1% thd at 4 watts into 5 ohms,
mainly all 2H.
But at normal levels of a watt the 3H and other H are present below the
2H
which can be seen on the CRO when monitoring the THD at all levels.
Ro is 0.47 ohm, and although my speakers vary between
4 and 20ohms, the sound appears firm, well timbred, and there isn't any
hint
of the sound being that from an inadequate amplifier.
I played Handel's water music, the sound track of 'The Pianist' for my
tests plus
a not so wonderful Naxos CD, 'The Best of Bach'.
Who says SET amps suck?
Certainly not I!.
Methinks that if the owner wanted more power, he could simply swap the
2A3 for a KT90 since the PT has a 6.3V heater winding, and then
remove the series R I have placed in the B+ lines to trim the B+
to where I want it, and with 270V, and with the UL tap on the
OPT that is provided, maybe 9+ watts of SEUL would be available.
The now unused 1670 OPT UL tap is at 40%.
But it could be at 60%, if you use the plate winding reversed,
thus further drifting a tetrode towards triode, but still not
suffering a huge loss of power due to grid current limitations.
300B could also be used, and with slightly more Ia,
but with the same low Ea, thus suiting moderate power and good matching
to
low value loads, which is a major failing in many SET amps;
they try to match so max power is at 8ohms, but that is
nearly always wrong with modern speakers, and
max power should occur at 3 or 4 ohms.
Patrick Turner.
Whats this I see? Patrick T. using Hammond? Or something brought in by a
customer?
|
The customer of mine was not prepared to pay for my one-off
trannies, and so he supplied Hammonds for me to use
They turned out OK.
Patrick Turner.
| Quote: |
I'm back into sales again. Lots of manual labour on the house this summer as
well. Not much time for tubes.
But if I get time I have a couple of interesting projects in mind. One is a
hybrid. But don't know when.
Cheers, John |
|
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| Back to top |
|
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Bret Ludwig
Guest
|
| Posted:
Thu Sep 29, 2005 4:43 am Post subject:
Re: 2A3 - Really a beautiful power tube! |
|
|
west wrote:
| Quote: |
Professor, are you using your custom built speakers or a commercial type
with you SE amp? Why is there so little mention at your web site about your
speakers? BTW, John: Nice article you wrote in recent issue of AudioXpress.
Try not to totally abandon the articles. Life is too short. Wow, little ole
me between the Twin Towers of tubes!
west
|
It was an okay article but most people want to put some money into a
serious project and not piddle around with cheap transformers if they
are going to spend the time to build one. Best grade OPT's are the way
to go. |
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| Back to top |
|
|
west
Guest
|
| Posted:
Thu Sep 29, 2005 4:43 am Post subject:
Re: 2A3 - Really a beautiful power tube! |
|
|
"Patrick Turner" <info@turneraudio.com.au> wrote in message
news:4336C30B.7F0B94C0@turneraudio.com.au...
| Quote: |
John Stewart wrote:
Patrick Turner wrote:
|
< huge snip >
| Quote: |
Patrick Turner.
Whats this I see? Patrick T. using Hammond? Or something brought in by a
customer?
The customer of mine was not prepared to pay for my one-off
trannies, and so he supplied Hammonds for me to use
They turned out OK.
Patrick Turner.
I'm back into sales again. Lots of manual labour on the house this
summer as
well. Not much time for tubes.
But if I get time I have a couple of interesting projects in mind. One
is a
hybrid. But don't know when.
Cheers, John
|
Professor, are you using your custom built speakers or a commercial type
with you SE amp? Why is there so little mention at your web site about your
speakers? BTW, John: Nice article you wrote in recent issue of AudioXpress.
Try not to totally abandon the articles. Life is too short. Wow, little ole
me between the Twin Towers of tubes!
west
> |
|
| Back to top |
|
|
John Stewart
Guest
|
| Posted:
Thu Sep 29, 2005 3:39 pm Post subject:
Re: 2A3 - Really a beautiful power tube! |
|
|
Bret Ludwig wrote:
| Quote: | west wrote:
Professor, are you using your custom built speakers or a commercial type
with you SE amp? Why is there so little mention at your web site about your
speakers? BTW, John: Nice article you wrote in recent issue of AudioXpress.
Try not to totally abandon the articles. Life is too short. Wow, little ole
me between the Twin Towers of tubes!
west
It was an okay article but most people want to put some money into a
serious project and not piddle around with cheap transformers if they
are going to spend the time to build one. Best grade OPT's are the way
to go.
|
Be our guest. Author an article for publishing. Amp of your choice.
I will look forward to seeing you in print some day!
JLS |
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| Back to top |
|
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Patrick Turner
Guest
|
| Posted:
Thu Sep 29, 2005 4:50 pm Post subject:
Re: 2A3 - Really a beautiful power tube! |
|
|
west wrote:
| Quote: | "Patrick Turner" <info@turneraudio.com.au> wrote in message
news:4336C30B.7F0B94C0@turneraudio.com.au...
John Stewart wrote:
Patrick Turner wrote:
huge snip
Patrick Turner.
Whats this I see? Patrick T. using Hammond? Or something brought in by a
customer?
The customer of mine was not prepared to pay for my one-off
trannies, and so he supplied Hammonds for me to use
They turned out OK.
Patrick Turner.
I'm back into sales again. Lots of manual labour on the house this
summer as
well. Not much time for tubes.
But if I get time I have a couple of interesting projects in mind. One
is a
hybrid. But don't know when.
Cheers, John
Professor, are you using your custom built speakers or a commercial type
with you SE amp?
|
The 2A3 amps were a commissioned job for a client who supplied me with tubes and
a set
of Hammond trannies after i told him which ones to get.
I demoed the 2A3 amp to my client using my speakers which are about 88dB/W/M
efficient.
4 watts had a lot of work to do, but we could hear the 2A3 were doing it right,
although not quite as loud as we would like for the speakers on the big
orchestral stuff.
He wanted the 2A3 to drive JBL horn slot tweeters of about 104dB/W/M efficiency.
| Quote: | Why is there so little mention at your web site about your
speakers?
|
Because they are not my main focus of attention.
IMHO, I think my speakers are second to none; since I have not heard anything
better,
its hard to know how to make improvements.
But trying to sell speakers via the Web has been an utter flop for me.
The prices shown at the website are a bargain, but I can't expect ppl
to agree with that. There are no official magazine reviews which all cost
huge piles of $$$$ that I have not got.
The Audiophile Society of NSW is always very coy about saying how
good/bad ones speakers are in their magazine/website, and you would have had to
have been there
when i demoed my gear.
But all the folks including myself who have demoed gear to such clubs have never
done any good
commercially as a result of driving a truckload of stuff and setting it all up,
and risking damage etc....
If I tried to place my speakers in the local hi-fi shops, they'd
expect 50% commission from the price which would the same as at the website,
which BTW is now
getting quite ancient; 3 years without an update!
Consider a pair of speakers with a price of $4,000 in a hi-fi shop.
I get $2,000 from a sale.
Since such handcrafted speakers take about 4 weeks of work to make and
since the materials cost is about $1,500, then I get only $500 for 4 weeks of
hard slog.
So, damn the shops and their cheap asian junk selling for prices which have no
relation
to the asian labour costs.
95% of speaker sales are determined by a woman who likes small speakers that are
almost invisible.
In 5 years I have had only 2 emails about my speakers.
Its possible to sell an occasional amp via the Web because the people
know tubes make good music, and maybe they realise I have at least some idea
how to go about making an amp.
But I should have started 40 years ago....
Patrick Turner. |
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| Back to top |
|
|
Patrick Turner
Guest
|
| Posted:
Thu Sep 29, 2005 5:20 pm Post subject:
Re: 2A3 - Really a beautiful power tube! |
|
|
Bret Ludwig wrote:
| Quote: | west wrote:
Professor, are you using your custom built speakers or a commercial type
with you SE amp? Why is there so little mention at your web site about your
speakers? BTW, John: Nice article you wrote in recent issue of AudioXpress.
Try not to totally abandon the articles. Life is too short. Wow, little ole
me between the Twin Towers of tubes!
west
It was an okay article but most people want to put some money into a
serious project and not piddle around with cheap transformers if they
are going to spend the time to build one. Best grade OPT's are the way
to go.
|
JS likes to perpetuate the idea that anyone who wants to build a tube amp needn't
spend much money on OPTs, and that tube sound is quite a cheap hobby.
This probably appeals to and panders to the hundreds of DIYers of 50yrs old
who dare not spend much more than peanuts on their hobby, lest
they feel they are spending too much, just like a kid of 16 thinking he
mustn't spend too much on the new bicycle rims for the bike he's building, since
hobbies must be cheap,
and affordable, especially if the wife thinks hubbie's soldering efforts are
some crazy thing, and she controls the purse strings.
Meanwhile, although the latter day big kid agonisers over the costs
of OPTs, and whether the extra $1 coupling cap is necessary,
he pays $1,000 per mth on medical insurance, and goodness knows what
on other household expenses.....
For as long as i can remember, kits for all sorts of things in magazines
were about making something that performed barely well enough and for
a fraction of the price of something in a shop.
I have built some kits for frequency measurement, ( impossible with tubes )
and some distortion measurement gear, also based on chips.
But the use of such kits was always lacking in any real ability;
kits are mostly glorified toys, so I then set out to seriously study the details
and
design and build my own distortion testing gear, milivolt meters
with BW from a useful 2Hz to 2Mhz at high Z, and so on.
I applaud JH for devoting his time to those he caters for.
He helps keep good men from going bad in a pub, and it generally fosters
interest in tubecraft.
They will mostly never buy the Real Mcoy item that has correct weight OPTs and
has been designed to a standard, not down to a price, and after wrestling with
getting their amp going, most will turn to some other interest later.....
Maybe 2% of the ppl that take up tubecraft as a result of the lead John has given
them will
go on to become a little more fanatic about it all and begin to think seriously
for themselves
about their audio constructions, guided by what they hear, and see on a CRO.
Patrick Turner. |
|
| Back to top |
|
|
Jon Yaeger
Guest
|
| Posted:
Thu Sep 29, 2005 6:06 pm Post subject:
Re: 2A3 - Really a beautiful power tube! |
|
|
I've got an idea that probably won't fly, but here goes.
You've got to give John a lot of credit for his many contributions to
tubecraft. I don't know of anyone who is more productive, both in writing
and designing stuff that actually works.
So I propose that in appreciation, we R.A.T.s take up a collection of stuff
that we think might make a good amp, and send it to John to do a "R.A.T.
Sponsored Design."
That would accomplish a couple of things, including make other folks aware
of the R.A.T. newsgroup who are more interested in arguing about tubes
instead of Jesus and global warming.
Count me in for an enclosure. Hey Patrick, how about some OPT iron??
Jon
in article 433BDB07.EAE80170@turneraudio.com.au, Patrick Turner at
info@turneraudio.com.au wrote on 9/29/05 8:20 AM:
| Quote: |
Bret Ludwig wrote:
west wrote:
Professor, are you using your custom built speakers or a commercial type
with you SE amp? Why is there so little mention at your web site about your
speakers? BTW, John: Nice article you wrote in recent issue of AudioXpress.
Try not to totally abandon the articles. Life is too short. Wow, little ole
me between the Twin Towers of tubes!
west
It was an okay article but most people want to put some money into a
serious project and not piddle around with cheap transformers if they
are going to spend the time to build one. Best grade OPT's are the way
to go.
JS likes to perpetuate the idea that anyone who wants to build a tube amp
needn't
spend much money on OPTs, and that tube sound is quite a cheap hobby.
This probably appeals to and panders to the hundreds of DIYers of 50yrs old
who dare not spend much more than peanuts on their hobby, lest
they feel they are spending too much, just like a kid of 16 thinking he
mustn't spend too much on the new bicycle rims for the bike he's building,
since
hobbies must be cheap,
and affordable, especially if the wife thinks hubbie's soldering efforts are
some crazy thing, and she controls the purse strings.
Meanwhile, although the latter day big kid agonisers over the costs
of OPTs, and whether the extra $1 coupling cap is necessary,
he pays $1,000 per mth on medical insurance, and goodness knows what
on other household expenses.....
For as long as i can remember, kits for all sorts of things in magazines
were about making something that performed barely well enough and for
a fraction of the price of something in a shop.
I have built some kits for frequency measurement, ( impossible with tubes )
and some distortion measurement gear, also based on chips.
But the use of such kits was always lacking in any real ability;
kits are mostly glorified toys, so I then set out to seriously study the
details
and
design and build my own distortion testing gear, milivolt meters
with BW from a useful 2Hz to 2Mhz at high Z, and so on.
I applaud JH for devoting his time to those he caters for.
He helps keep good men from going bad in a pub, and it generally fosters
interest in tubecraft.
They will mostly never buy the Real Mcoy item that has correct weight OPTs and
has been designed to a standard, not down to a price, and after wrestling with
getting their amp going, most will turn to some other interest later.....
Maybe 2% of the ppl that take up tubecraft as a result of the lead John has
given
them will
go on to become a little more fanatic about it all and begin to think
seriously
for themselves
about their audio constructions, guided by what they hear, and see on a CRO.
Patrick Turner.
|
|
|
| Back to top |
|
|
Patrick Turner
Guest
|
| Posted:
Thu Sep 29, 2005 11:29 pm Post subject:
Re: 2A3 - Really a beautiful power tube! |
|
|
Jon Yaeger wrote:
| Quote: | I've got an idea that probably won't fly, but here goes.
You've got to give John a lot of credit for his many contributions to
tubecraft. I don't know of anyone who is more productive, both in writing
and designing stuff that actually works.
So I propose that in appreciation, we R.A.T.s take up a collection of stuff
that we think might make a good amp, and send it to John to do a "R.A.T.
Sponsored Design."
That would accomplish a couple of things, including make other folks aware
of the R.A.T. newsgroup who are more interested in arguing about tubes
instead of Jesus and global warming.
Count me in for an enclosure. Hey Patrick, how about some OPT iron??
|
There are a bunch of fully worked out designs at my website.
Also a couple of samples of OPT that anyone can wind.
I had hoped someone would have addopted my design and wound a quantity to sell back
to me
but not even the dumb chinese were able to work out what i have at my site.
But several amateur audio ppl persevered to wind my OPT No1, and got good results.
How does one define a real audio tube crafter? One who winds his OPTs,
chokes, PTs, crossovers, and makes his chassis, and works out the whole design from
first principles.
Not many of thse ppl around anymore, either they have got old, or are too short
of time or enthusiasm.
Audio Express may not want to direct ppl to rec.audio.tubes or form any association
with us.
I am sure they'd prefer readers to stay dependant on buying the magazine.
Forums on the web allow ppl the luxury of talking to blokes who have been through
all the problems before their turn comes along, so they don't even need to buy
copies of AE.
I used to write long articles for the news letter of an audio club based in Sydney.
Membership was about 100 members, and only about 3 blokes understood anything I
said.
Having an active presence in an audio club proved quite useless to my business,
and they only wanted amps if they were priced next to nothing.
I am no longer a member of any audio clubs, and i am sure they know where I am,
and if they wanted to follow along with the sensible discussions here I am sure they
could have, but NOT ONE HAS out of two clubs with a total membership of
over 200 over the last 5 years.
Tube gear ownership amoungst all these audiophiles is way above the national
average,
and DIYing is fairly active, but methinks they don't like me much because I know
more than they do, and i have a completely methodical approach; no guessing, and
not much adherence to audio myths, and I don't endorse BS.
I could be wrong about all Audio Express; but you'd think AE ppl would have
perhaps contributed to discussions here but perhaps they think that the public
newsgroups are a sewer
of crappy chatter, and have stayed well away, like so many have,
because they are genteel ppl who don't like being set upon by the mad dogs
that lurk here.
The world wide web provides ppl like myself to stay sharp with tube craft
in an active forum. I am not shy about pitting my wits
against the best and the worst here, and Its a damn sight more rewarding
than posting to newsletters of audio clubs, and never ever getting any response,
and I enjoy complete editorial freedom here which is preferable to the
crap that I have seen go on in some audio mags when people who make amps have had
feature
articles done on their gear.
I established a website to encompass all I really need to say;
if anyone wants to know more they only have to email me.
The only exception is Phil Allison, who knows his emails get deleted with spam,
and his phone calls terminated.
I don't take shit from nobody, but I have helped maybe
hundreds with their problems.
I hope you follow my salient thoughts about amp building
and the prosletizing of tubecraft.
The interactive nature of the web and its active helpful contributors
is priceless; to real thinkers, magazines may not have the prominence
they used to; they are a media of the past.
Patrick Turner.
| Quote: |
Jon
in article 433BDB07.EAE80170@turneraudio.com.au, Patrick Turner at
info@turneraudio.com.au wrote on 9/29/05 8:20 AM:
Bret Ludwig wrote:
west wrote:
Professor, are you using your custom built speakers or a commercial type
with you SE amp? Why is there so little mention at your web site about your
speakers? BTW, John: Nice article you wrote in recent issue of AudioXpress.
Try not to totally abandon the articles. Life is too short. Wow, little ole
me between the Twin Towers of tubes!
west
It was an okay article but most people want to put some money into a
serious project and not piddle around with cheap transformers if they
are going to spend the time to build one. Best grade OPT's are the way
to go.
JS likes to perpetuate the idea that anyone who wants to build a tube amp
needn't
spend much money on OPTs, and that tube sound is quite a cheap hobby.
This probably appeals to and panders to the hundreds of DIYers of 50yrs old
who dare not spend much more than peanuts on their hobby, lest
they feel they are spending too much, just like a kid of 16 thinking he
mustn't spend too much on the new bicycle rims for the bike he's building,
since
hobbies must be cheap,
and affordable, especially if the wife thinks hubbie's soldering efforts are
some crazy thing, and she controls the purse strings.
Meanwhile, although the latter day big kid agonisers over the costs
of OPTs, and whether the extra $1 coupling cap is necessary,
he pays $1,000 per mth on medical insurance, and goodness knows what
on other household expenses.....
For as long as i can remember, kits for all sorts of things in magazines
were about making something that performed barely well enough and for
a fraction of the price of something in a shop.
I have built some kits for frequency measurement, ( impossible with tubes )
and some distortion measurement gear, also based on chips.
But the use of such kits was always lacking in any real ability;
kits are mostly glorified toys, so I then set out to seriously study the
details
and
design and build my own distortion testing gear, milivolt meters
with BW from a useful 2Hz to 2Mhz at high Z, and so on.
I applaud JH for devoting his time to those he caters for.
He helps keep good men from going bad in a pub, and it generally fosters
interest in tubecraft.
They will mostly never buy the Real Mcoy item that has correct weight OPTs and
has been designed to a standard, not down to a price, and after wrestling with
getting their amp going, most will turn to some other interest later.....
Maybe 2% of the ppl that take up tubecraft as a result of the lead John has
given
them will
go on to become a little more fanatic about it all and begin to think
seriously
for themselves
about their audio constructions, guided by what they hear, and see on a CRO.
Patrick Turner.
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