On 12/27/18 19:11, tubeguy@myshop.com wrote:

The most important tubes ever made.....

12AX7
12AU7
12AT7

6V6
6L6

etc.

well maybe for audio but you're forgetting why tubes were more or less used/invented in the first place, to receive radio signals, and the
audio amplifier portion was just a part of that.

For radios the pentagrid converter tube comes to mind as one of the most universally used tubes ever for AM radio, in home sets and cars in
particular. For FM sets there are a number of VHF RF amplifiers.

Then there's the sharp cutoff pentode, which is ideal for an IF strip
with high gain, relatively low noise, and AGC.

And don't forget the CRT. For that one, there was a model that nearly eveything used for about a decade [higher end sets anyway], a 25 inch
diagonal square color tube from RCA [I forget the number].

And there are many specialized tubes for microwave oscillation and amplification that are STILL USED on satellites, last I heard.

And that magnetron in your home microwave. That's right, it's a tube.
Invented in the late 30's, for use in RADAR systems.

So yeah tube audio is one usage, and maybe those tube numbers are some
of the most important in the audio world [especially guitar amplifiers].
But overall, I think some of the others deserve a mention.


/me has even conceived of a 'graviton generator' using something similar
to a magnetron filed with Xe gas. You'd need tremendous power to make
anything useful out of it, but the resonant cavities [in theory] would
emit gravitons when spinning a heavy gas in tight little circles like
that...

so yeah, it's likely that tube tech isn't going away any time soon, and
will continue to improve over time. In space this may become even MORE important, depending.


--
(aka 'Bombastic Bob' in case you wondered)

'Feeling with my fingers, and thinking with my brain' - me

'your story is so touching, but it sounds just like a lie'
"Straighten up and fly right"

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On Thursday, December 27, 2018 at 10:11:51 PM UTC-5, tub...@myshop.com wrote:

The most important tubes ever made.....

12AX7
12AU7
12AT7

6V6
6L6

807

EL34

5U4
5Y3

6X4 or 12X4

35C5 or 50C5

35W4

12BA6

12BE6

6SA7

6SK7 or 12SK7

12SQ7

12AV6

6SN7

A list like this is like a list of the best guitar players ever. But it is good to see activity in this forum again. So, my list would add the 6550 & 6SJ7GT at least And Billy Gibbons to the latest guitar picker list I read the other day!

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On Mon, 31 Dec 2018 19:19:24 -0800 (PST), MarkS <maschuckert@gmail.com>
wrote:

On Thursday, December 27, 2018 at 10:11:51 PM UTC-5, tub...@myshop.com wrote: >> The most important tubes ever made.....

12AX7
12AU7
12AT7

6V6
6L6

807

EL34

5U4
5Y3

6X4 or 12X4

35C5 or 50C5

35W4

12BA6

12BE6

6SA7

6SK7 or 12SK7

12SQ7

12AV6

6SN7

A list like this is like a list of the best guitar players ever. But it is good to see activity
in this forum again. So, my list would add the 6550 & 6SJ7GT at least And Billy
Gibbons to the latest guitar picker list I read the other day!

I am glad this forum is still here and sort of active. I enjoy working
on tube equip for my hobby. If I had to work on solid state stuff, my
soldering iron would have been packed away in the attic years ago. I do
on occasion work on some early transistor stuff, but when I see ICs, the
device goes right out the door, untouched.

You added some good tubes to the list.

--
I'm having a problem with the New Year. I keep writing 1920 instead of
2019. Maybe I am showing my age :)

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On Mon, 31 Dec 2018 11:38:54 -0800, Big Bad Bob <BigBadBob-at-mrp3-dot-com@testing.local> wrote:

On 12/27/18 19:11, tubeguy@myshop.com wrote:

The most important tubes ever made.....

12AX7
12AU7
12AT7

6V6
6L6

etc.

well maybe for audio but you're forgetting why tubes were more or less >used/invented in the first place, to receive radio signals, and the
audio amplifier portion was just a part of that.

For radios the pentagrid converter tube comes to mind as one of the most >universally used tubes ever for AM radio, in home sets and cars in >particular. For FM sets there are a number of VHF RF amplifiers.

Then there's the sharp cutoff pentode, which is ideal for an IF strip
with high gain, relatively low noise, and AGC.

And don't forget the CRT. For that one, there was a model that nearly >eveything used for about a decade [higher end sets anyway], a 25 inch >diagonal square color tube from RCA [I forget the number].

And there are many specialized tubes for microwave oscillation and >amplification that are STILL USED on satellites, last I heard.

And that magnetron in your home microwave. That's right, it's a tube. >Invented in the late 30's, for use in RADAR systems.

So yeah tube audio is one usage, and maybe those tube numbers are some
of the most important in the audio world [especially guitar amplifiers].
But overall, I think some of the others deserve a mention.

/me has even conceived of a 'graviton generator' using something similar
to a magnetron filed with Xe gas. You'd need tremendous power to make >anything useful out of it, but the resonant cavities [in theory] would
emit gravitons when spinning a heavy gas in tight little circles like
that...

so yeah, it's likely that tube tech isn't going away any time soon, and
will continue to improve over time. In space this may become even MORE >important, depending.

Yea, I know microwaves have tubes, and I did consider CRTs on the list
but I was mostly thinking in terms of home radios and audio amps.

Please add some tube numbers for those small tubes you mentioned above.
I would like to see what you and others have to say.

I also neglected to include some of the major transmitting tubes, mostly because I dont know the numbers. Although I do know the 807 was used
quite a lot in the early days. That tube became the 6L6 without the
plate on the cap. But the 807 also worked great for audio.

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On 01/03/19 14:54, tubeguy@myshop.com wrote:

I am glad this forum is still here and sort of active. I enjoy working
on tube equip for my hobby. If I had to work on solid state stuff, my soldering iron would have been packed away in the attic years ago. I do
on occasion work on some early transistor stuff, but when I see ICs, the device goes right out the door, untouched.

heh yeah, tubes made the electronics easier to deal with, that's for
sure. An IC with an OEM label on it is like a 'mystery black box' and
if you don't have an adequate schematic for the thing, damn near
impossible to troubleshoot. I've had to deal with desoldering and
replacing ICs and you can't do it to test-troubleshoot, especially CPUs
and logic arrays. Best method to deal with those is clip the leads,
desolder them, then re-solder a new device where the old one was and
hope that was it, unless you have some really detailed information on
how to confirm that it's bad (etc.).

Trying to desolder an IC such that you preserve it to re-solder back in
place is likely to damage the circuit board. That goes double with
surface mount.

Tubes are also fun in that they actually look like they're doing
something, especially beam power tubes with the blue glow.

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On Wed, 16 Jan 2019 18:43:45 -0800, Big Bad Bob <BigBadBob-at-mrp3-dot-com@testing.local> wrote:

On 01/03/19 14:54, tubeguy@myshop.com wrote:

I am glad this forum is still here and sort of active. I enjoy working
on tube equip for my hobby. If I had to work on solid state stuff, my
soldering iron would have been packed away in the attic years ago. I do
on occasion work on some early transistor stuff, but when I see ICs, the
device goes right out the door, untouched.

heh yeah, tubes made the electronics easier to deal with, that's for
sure. An IC with an OEM label on it is like a 'mystery black box' and
if you don't have an adequate schematic for the thing, damn near
impossible to troubleshoot. I've had to deal with desoldering and
replacing ICs and you can't do it to test-troubleshoot, especially CPUs
and logic arrays. Best method to deal with those is clip the leads,
desolder them, then re-solder a new device where the old one was and
hope that was it, unless you have some really detailed information on
how to confirm that it's bad (etc.).

Trying to desolder an IC such that you preserve it to re-solder back in
place is likely to damage the circuit board. That goes double with
surface mount.

An 8 pin IC, like an op-amp can be desoldered, but not those big
suckers.... I'll work on some amps that have those small Op-amps, but I
dont care to work on any solid state stuff. If it wasn't for my 60 year
old tube signal tracer, to guide me thru the circuits, I'd probably
never fix that stuff.

Even so, working on solid state stuff just lacks something. It's like
working on rocks, and in many ways, silicon is a rock, so it's very
true. And it lacks the dangerous high voltages, which in some ways takes
away the thrill. Yea, I got zapped in the past and I learned to be safe
the hard way. But I often think that working on high voltage gear,
activates me. Some of that high voltage leaks into the air and i feel
it, even if its not shocking me.

Tubes are also fun in that they actually look like they're doing
something, especially beam power tubes with the blue glow.

You think like I do. Not long ago, I said something very similar. I
always find tubes to have some "life: to them. The filaments glow, and
that blue-purple glow is really cool. My favorite tube has always been
the 6L6. Those beam power pentodes are awesome. Being a guy raised in
the 50s and 60s, I think back and realize almost all the rock bands we
loved were using 6L6 outputs on their guitar amps. Even today, they are
still the most used tube in guitar amps, and no solid state amp can give
that warm tube sound. I built a 3 channel stereo back in the late 60s,
modeled after the Altec Lansing cinema systems. There were twelve 6L6
tubes in the system, plus six 5U4 rectifiers and nine more tubes. Thats
27 tubes (just in the power amps). It kicked out around 350 watts of
clean awesome RMS power. And I loved to sit back, drink some beers and
do some other funny stuff, and watch them 6L6s dance in blue. I still
recall the one night I opened it up wide open, and blew out several
windows in the house.

Yep, those were the days.... Almost makes me want to turn on some of my Ventures albums and listen to that wonderful warm tube sound along with
those spring reverbs.... Now that was music.....

Unfortunately these days I am running solid state amps. 1100 watts RMS
to be exact. It has good sound, but there is still something missing,
namely the tubes.

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On 01/24/19 16:36, tubeguy@myshop.com wrote:

Unfortunately these days I am running solid state amps. 1100 watts RMS
to be exact. It has good sound, but there is still something missing,
namely the tubes.

yeah, the natural tube distortion is the sound you're looking for,
probably. Modern transistorized amplifiers are "perfect" and add
nothing to the sound. The guitar amplifiers, however, altered the sound
as a part of how they work.

I personally never noticed the difference between solid state and an
older tube stereo system, but that tube system had reasonably low
distortion and physically large output transformers for maximum
fidelity. I think it used 6BQ5's in an ultra-linear config, as I
recall, 12W per channel, good enough for a reasonably sized room. So in
that case, the tubes didn't really add anything to the sound.

On the other hand, your typical Fender guitar amp WOULD add "something"
to the sound, because of how they designed the amplifiers to operate.
Any kind of open gain triode pre-amp will have some amount of 'tube distortion'. So when you see bypass capacitors on the cathode resistor,
nearly all of the negative feedback for the stage goes byby, and you're
dealing with pure 'mu' gain on that stage. And that changes the sound.

Also guitar amps tend NOT to have a lot of negative feedback in them.
So they'll have more "tube sound" distortion than a stereo system, for
example.

And of course a guitar amp is probably going to be designed to pass a
more limited frequency range. You can see that when you look at
replacement output transformers, typically rated for 100Hz to maybe 4kHz
as opposed to a 20Hz-20kHz range for hifi/stereo amplifiers.

[that, too, is part of "the sound" of a tube guitar amp]

--
(aka 'Bombastic Bob' in case you wondered)

'Feeling with my fingers, and thinking with my brain' - me

'your story is so touching, but it sounds just like a lie'
"Straighten up and fly right"

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Big Bad Bob wrote:

And of course a guitar amp is probably going to be designed to pass a
more limited frequency range. You can see that when you look at
replacement output transformers, typically rated for 100Hz to maybe 4kHz
as opposed to a 20Hz-20kHz range for hifi/stereo amplifiers.

** The output transformers used in tube guitar amps are normally a lot better than you suggest.

Eg: A Marshall 50W output transformer has its upper -3dB point at 45kHz.

The small signal, low frequency response is -3dB at 1Hz (yes, one Hertz) but core saturation at rated power becomes dominant below about 5OHz.

IME most output transformers used in brand name amps have similar specs.



.... Phil

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On 02/02/19 17:26, pallison49@gmail.com wrote:

Big Bad Bob wrote:

And of course a guitar amp is probably going to be designed to pass a
more limited frequency range. You can see that when you look at
replacement output transformers, typically rated for 100Hz to maybe 4kHz
as opposed to a 20Hz-20kHz range for hifi/stereo amplifiers.

** The output transformers used in tube guitar amps are normally a lot better than you suggest.

Eg: A Marshall 50W output transformer has its upper -3dB point at 45kHz.

The small signal, low frequency response is -3dB at 1Hz (yes, one Hertz) but core saturation at rated power becomes dominant below about 5OHz.

IME most output transformers used in brand name amps have similar specs.

hmmm, that goes against what I've read over on 'amplifiedparts.com' for 'original replacement' transformers, as opposed to the ones made by
Hammond (which are nearly always better).

the DC blocking capacitors in guitar amps _are_ de-rated a bit over what
you'd see in a hi fi system, last I went through one. Tone controls are
also a little strange compared to hi fi equivalents. But it's part of
"the sound" [and also costs less, which I think is what drove it].

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Big Bad Bob wrote:

And of course a guitar amp is probably going to be designed to pass a
more limited frequency range. You can see that when you look at
replacement output transformers, typically rated for 100Hz to maybe 4kHz >> as opposed to a 20Hz-20kHz range for hifi/stereo amplifiers.

** The output transformers used in tube guitar amps are normally a lot better than you suggest.

Eg: A Marshall 50W output transformer has its upper -3dB point at 45kHz.

The small signal, low frequency response is -3dB at 1Hz (yes, one Hertz) but core saturation at rated power becomes dominant below about 5OHz.

IME most output transformers used in brand name amps have similar specs.

hmmm, that goes against what I've read over on 'amplifiedparts.com' for 'original replacement' transformers, as opposed to the ones made by
Hammond (which are nearly always better).

** Never rely on " information " posted on web sites written by musicians and storekeepers.

the DC blocking capacitors in guitar amps _are_ de-rated a bit over what you'd see in a hi fi system, last I went through one. Tone controls are
also a little strange compared to hi fi equivalents. But it's part of
"the sound" [and also costs less, which I think is what drove it].

** Guitar amps have many differences from " hi-fi" amps, the most significant of which are:

1. Low or no negative feedback around the output stage, so THD is relatively high at 2 to 5% below clipping.

2. Low class AB bias, so full power operation is mainly class B exaggerating point 1.

3. High output impedance, due mainly to point 1.

4. Non flat response from the tone circuits ( typically the treble end is boosted ) and deliberate distortion incorporated in same.

Of course, the speakers fitted to combo amps have limited response, 70 to 4kHz with a presence peak around 2 to 3 KHz being typical.

But they ARE damn efficient, up to 105dB/watt for some 12 inch models.


.... Phil

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On Sun, 3 Feb 2019 16:17:27 -0800 (PST), Phil Allison
<pallison49@gmail.com> wrote:

Big Bad Bob wrote:

And of course a guitar amp is probably going to be designed to pass a
more limited frequency range. You can see that when you look at
replacement output transformers, typically rated for 100Hz to maybe 4kHz >> >> as opposed to a 20Hz-20kHz range for hifi/stereo amplifiers.

** The output transformers used in tube guitar amps are normally a lot better than you suggest.

Eg: A Marshall 50W output transformer has its upper -3dB point at 45kHz. >> >
The small signal, low frequency response is -3dB at 1Hz (yes, one Hertz) but core saturation at rated power becomes dominant below about 5OHz.

IME most output transformers used in brand name amps have similar specs. >>

hmmm, that goes against what I've read over on 'amplifiedparts.com' for
'original replacement' transformers, as opposed to the ones made by
Hammond (which are nearly always better).

** Never rely on " information " posted on web sites written by musicians and storekeepers.

the DC blocking capacitors in guitar amps _are_ de-rated a bit over what
you'd see in a hi fi system, last I went through one. Tone controls are
also a little strange compared to hi fi equivalents. But it's part of
"the sound" [and also costs less, which I think is what drove it].

** Guitar amps have many differences from " hi-fi" amps, the most significant of which are:

1. Low or no negative feedback around the output stage, so THD is relatively high at 2 to 5% below clipping.

2. Low class AB bias, so full power operation is mainly class B exaggerating point 1.

3. High output impedance, due mainly to point 1.

4. Non flat response from the tone circuits ( typically the treble end is boosted ) and deliberate distortion incorporated in same.

Of course, the speakers fitted to combo amps have limited response, 70 to 4kHz with a presence peak around 2 to 3 KHz being typical.

But they ARE damn efficient, up to 105dB/watt for some 12 inch models.

.... Phil

This is all vital stuff. You must consider that a guitar amplifier is
not a reproduction device. It is an integral part of the instrument,
and confers a large amount of the sound of the instrument. Flat
response and low distortion are the last things a guitar amplifier
designer is looking for.

d

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On 02/04/19 00:35, Don Pearce wrote:

On Sun, 3 Feb 2019 16:17:27 -0800 (PST), Phil Allison
<pallison49@gmail.com> wrote:

Of course, the speakers fitted to combo amps have limited response, 70 to 4kHz with a presence peak around 2 to 3 KHz being typical.

But they ARE damn efficient, up to 105dB/watt for some 12 inch models.


.... Phil

This is all vital stuff. You must consider that a guitar amplifier is
not a reproduction device. It is an integral part of the instrument,
and confers a large amount of the sound of the instrument. Flat
response and low distortion are the last things a guitar amplifier
designer is looking for.

right, a slightly different way of saying what I did earlier, about the amplifier being part of "the sound". So then it also matters who made
the tubes, among other things, as they are part of "the sound" as well.

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