octal preamp tube questions

Your RCA book is your friend ... it's not uncommon to see 12ax7
in the entire (voltage) amp stages .. why *not* 6Sl7 ?

DH82C

2008-05-17 17:18:32 UTC

Your RCA book is your friend ... it's not uncommon to see 12ax7
in the entire (voltage) amp stages .. why *not* 6Sl7 ?

Funny this came up. I have an old (1954) Gibson GA-40 that chassis
that I was going to canibalise and have been thinking of getting
running first just for shits and giggles. When looking for the octal
preamp tubes (6sj7 and 6sn7) should I avoid metal tubes and stick to
glass? Seems to me I read that metal are more microphonic.
Phil, in my GA-40 the phase inverter is half a 6sn7 (cathodyne?..
plate to one 6v6 grid.. cathode to the other 6v6 grid).
OT: the driver for the tremolo is a 6v6 .. go figure :)
If you want the schematic let me know drew dot rsm at gmail dot com

Cheers

Drew

J.P.

2008-05-17 19:28:35 UTC

Post by DH82C

Your RCA book is your friend ... it's not uncommon to see 12ax7
in the entire (voltage) amp stages .. why *not* 6Sl7 ?

Sell that thing on Ebay and use the money to get some new iron...

2008-05-17 23:03:44 UTC

Post by DH82C
OT: the driver for the tremolo is a 6v6 .. go figure :)
If you want the schematic let me know drew dot rsm at gmail dot com

check your email !

Elvis Kabong

2008-05-17 21:21:27 UTC

Post by Phil S.
Oh, just thinking here...I've got a recycled chassis drilled for 5 octal
sockets. I was thinking maybe a pair of 6V6, and two or three 6SL7. Then
I got to thinking about doing something different with the PI, not sure
what. So, the wild hair raises the questions.
1) Is there an octal equivalent to a 12AT7?
2) Aside from the lower gain factor, is there anything in particular I
should be aware of in working with a 6SL7? How good/bad are current
production tubes?
3) Is there a significant difference between 6SC7 and 6SL7? Is this a bit
like comparing a 5751 to a 12AX7?
I already know there is a 6SN7, roughly a 12AU7 equivalent. What's in
between that and the 6SN7 with Ra in the 5k-15k range?

Gee Phil, you mean to tell us you *still* haven't bought
the "RCA Receiving Tube Manual" (in paperback)
or the "GE Essential Characteristics" also in paperback
yet? Sheeks! All of your answers are in those books!

J.P.

2008-05-17 21:48:48 UTC

On Sat, 17 May 2008 16:21:27 -0500, "Elvis Kabong"

Didn't I see those online? PMillet or somewhere?

Elvis Kabong

2008-05-18 02:55:13 UTC

Post by J.P.
On Sat, 17 May 2008 16:21:27 -0500, "Elvis Kabong"

Post by Phil S.
Oh, just thinking here...I've got a recycled chassis drilled for 5 octal
sockets. I was thinking maybe a pair of 6V6, and two or three 6SL7.
Then
I got to thinking about doing something different with the PI, not sure
what. So, the wild hair raises the questions.
1) Is there an octal equivalent to a 12AT7?
2) Aside from the lower gain factor, is there anything in particular I
should be aware of in working with a 6SL7? How good/bad are current
production tubes?
3) Is there a significant difference between 6SC7 and 6SL7? Is this a bit
like comparing a 5751 to a 12AX7?
I already know there is a 6SN7, roughly a 12AU7 equivalent. What's in
between that and the 6SN7 with Ra in the 5k-15k range?

Didn't I see those online? PMillet or somewhere?

Antique Electronics sells reprints of them, among other books.

DH82C

2008-05-18 19:01:14 UTC

Post by J.P.
On Sat, 17 May 2008 16:21:27 -0500, "Elvis Kabong"

Post by Phil S.
Oh, just thinking here...I've got a recycled chassis drilled for 5 octal
sockets. I was thinking maybe a pair of 6V6, and two or three 6SL7.
Then
I got to thinking about doing something different with the PI, not sure
what. So, the wild hair raises the questions.
1) Is there an octal equivalent to a 12AT7?
2) Aside from the lower gain factor, is there anything in particular I
should be aware of in working with a 6SL7? How good/bad are current
production tubes?
3) Is there a significant difference between 6SC7 and 6SL7? Is this a
bit
like comparing a 5751 to a 12AX7?
I already know there is a 6SN7, roughly a 12AU7 equivalent. What's in
between that and the 6SN7 with Ra in the 5k-15k range?

Didn't I see those online? PMillet or somewhere?

Antique Electronics sells reprints of them, among other books.- Hide quoted text -
- Show quoted text -

Dunno if it is legal but the GE Essential Characteristics is available
on pdf from emule..

J.P.

2008-05-18 20:25:36 UTC

Post by DH82C

Post by J.P.
On Sat, 17 May 2008 16:21:27 -0500, "Elvis Kabong"

Post by Phil S.
Oh, just thinking here...I've got a recycled chassis drilled for 5 octal
sockets. I was thinking maybe a pair of 6V6, and two or three 6SL7.
Then
I got to thinking about doing something different with the PI, not sure
what. So, the wild hair raises the questions.
1) Is there an octal equivalent to a 12AT7?
2) Aside from the lower gain factor, is there anything in particular I
should be aware of in working with a 6SL7? How good/bad are current
production tubes?
3) Is there a significant difference between 6SC7 and 6SL7? Is this a
bit
like comparing a 5751 to a 12AX7?
I already know there is a 6SN7, roughly a 12AU7 equivalent. What's in
between that and the 6SN7 with Ra in the 5k-15k range?

Didn't I see those online? PMillet or somewhere?

Antique Electronics sells reprints of them, among other books.- Hide quoted text -
- Show quoted text -

Dunno if it is legal but the GE Essential Characteristics is available
on pdf from emule..

I got one of those from LV...RC30 ...thing is about an 11/4" thick or
so...

2008-05-17 22:37:38 UTC

Post by Elvis Kabong
Gee Phil, you mean to tell us you *still* haven't bought
the "RCA Receiving Tube Manual" (in paperback)

The RCA books are actually online .. I have them bookmarked ...
SOMEWHERE ...on one of my computers ...

I have RCA Rc-14, and rc-16 too, one which original 6L6 power amp,
couple of Rc-30 ( Radio Shack 70's ) .

I troll Amazon every once and awhile and grab them for $1.
E-bay is *way* too expense.!

Phil S.

2008-05-19 23:35:59 UTC

Post by Elvis Kabong
Gee Phil, you mean to tell us you *still* haven't bought
the "RCA Receiving Tube Manual" (in paperback)

The RCA books are actually online .. I have them bookmarked ...
SOMEWHERE ...on one of my computers ...
I have RCA Rc-14, and rc-16 too, one which original 6L6 power amp,
couple of Rc-30 ( Radio Shack 70's ) .
I troll Amazon every once and awhile and grab them for $1.
E-bay is *way* too expense.!

I've been off line. I was away for the weekend, then Comcast had some
"engineering problem".

I tried to post through Google, but it doesn't seem to be here.

Anyhow, thanks to all for the advice.

I downloaded RC-30. This is something one wants to thumb through, not read
at the computer. My brief perusal didn't turn up an octal sub for a 12AT7.
Anyone who doesn't mind throwing me a bone?

So, I broke down and bought both the GE and RCA at Amazon today, as they
appeared to be cheaper there compared to eBay. At worst, it's even with
eBay. I figure they always have resale value. They should be here by the
end of the week.

--Phil

Elvis Kabong

2008-05-20 00:08:20 UTC

Post by Elvis Kabong
Gee Phil, you mean to tell us you *still* haven't bought
the "RCA Receiving Tube Manual" (in paperback)

The RCA books are actually online .. I have them bookmarked ...
SOMEWHERE ...on one of my computers ...
I have RCA Rc-14, and rc-16 too, one which original 6L6 power amp,
couple of Rc-30 ( Radio Shack 70's ) .
I troll Amazon every once and awhile and grab them for $1.
E-bay is *way* too expense.!

I've been off line. I was away for the weekend, then Comcast had some
"engineering problem".
I tried to post through Google, but it doesn't seem to be here.
Anyhow, thanks to all for the advice.
I downloaded RC-30. This is something one wants to thumb through, not
read at the computer. My brief perusal didn't turn up an octal sub for a
12AT7. Anyone who doesn't mind throwing me a bone?
So, I broke down and bought both the GE and RCA at Amazon today, as they
appeared to be cheaper there compared to eBay. At worst, it's even with
eBay. I figure they always have resale value. They should be here by the
end of the week.
--Phil

Hi Phil - all I could find with a quick glance were 3 octal twin triodes
with a 70 mu factor, a 6SC7, a 6SL7 and a 6SU7. Couldn't find
any with a 60 mu. BTW, the 6SC7 has a common cathode.

Phil S.

2008-05-20 00:26:03 UTC

Post by Elvis Kabong
Gee Phil, you mean to tell us you *still* haven't bought
the "RCA Receiving Tube Manual" (in paperback)

The RCA books are actually online .. I have them bookmarked ...
SOMEWHERE ...on one of my computers ...
I have RCA Rc-14, and rc-16 too, one which original 6L6 power amp,
couple of Rc-30 ( Radio Shack 70's ) .
I troll Amazon every once and awhile and grab them for $1.
E-bay is *way* too expense.!

I've been off line. I was away for the weekend, then Comcast had some
"engineering problem".
I tried to post through Google, but it doesn't seem to be here.
Anyhow, thanks to all for the advice.
I downloaded RC-30. This is something one wants to thumb through, not
read at the computer. My brief perusal didn't turn up an octal sub for a
12AT7. Anyone who doesn't mind throwing me a bone?
So, I broke down and bought both the GE and RCA at Amazon today, as they
appeared to be cheaper there compared to eBay. At worst, it's even with
eBay. I figure they always have resale value. They should be here by
the end of the week.
--Phil

Hi Phil - all I could find with a quick glance were 3 octal twin triodes
with a 70 mu factor, a 6SC7, a 6SL7 and a 6SU7. Couldn't find
any with a 60 mu. BTW, the 6SC7 has a common cathode.

Hi Ed,
12AT7 Ra= 11,000

6SC7 Ra=53,000
6SL7 Ra= 44,000
6SU7 Ra=44,000

IMO, these Ra numbers make the tubes better as 12AX7 subs, but not at 12AT7
subs. That's what's prompting the question.

Thanks for looking, and I really appreciate it.

Phil

Elvis Kabong

2008-05-20 05:52:28 UTC

Post by Elvis Kabong
Gee Phil, you mean to tell us you *still* haven't bought
the "RCA Receiving Tube Manual" (in paperback)

The RCA books are actually online .. I have them bookmarked ...
SOMEWHERE ...on one of my computers ...
I have RCA Rc-14, and rc-16 too, one which original 6L6 power amp,
couple of Rc-30 ( Radio Shack 70's ) .
I troll Amazon every once and awhile and grab them for $1.
E-bay is *way* too expense.!

I've been off line. I was away for the weekend, then Comcast had some
"engineering problem".
I tried to post through Google, but it doesn't seem to be here.
Anyhow, thanks to all for the advice.
I downloaded RC-30. This is something one wants to thumb through, not
read at the computer. My brief perusal didn't turn up an octal sub for
a 12AT7. Anyone who doesn't mind throwing me a bone?
So, I broke down and bought both the GE and RCA at Amazon today, as they
appeared to be cheaper there compared to eBay. At worst, it's even with
eBay. I figure they always have resale value. They should be here by
the end of the week.
--Phil

Hi Phil - all I could find with a quick glance were 3 octal twin triodes
with a 70 mu factor, a 6SC7, a 6SL7 and a 6SU7. Couldn't find
any with a 60 mu. BTW, the 6SC7 has a common cathode.

Hi Ed,
12AT7 Ra= 11,000
6SC7 Ra=53,000
6SL7 Ra= 44,000
6SU7 Ra=44,000
IMO, these Ra numbers make the tubes better as 12AX7 subs, but not at
12AT7 subs. That's what's prompting the question.
Thanks for looking, and I really appreciate it.
Phil

Well Phil, if you are gonna limit your search parameters
to Plate resistance, check out 6N7.

12AT7 10,900 Rp / 5,500 Gm / 60 mu
6N7 11,000 Rp / 3,200 gm / 35 mu @ 294 PV instead
of 250V. (Also contains common cathode)
Though I wouldn't expect as much gain as a 12AT7 provides.

2008-05-20 00:26:13 UTC

Post by Phil S.
I downloaded RC-30. This is something one wants to thumb through, not read
at the computer.

( for AA'ers )
You will have a RC-25, 30, 16, 14 in every one of your bathrooms,
camper and boat heads, and if your travel, on your laptop.

Post by Phil S.
My brief perusal didn't turn up an octal sub for a 12AT7.
Anyone who doesn't mind throwing me a bone?

bark bark .. here Phil !

RC-30 ($2.95, 1975) page 108. section 19. Phase Inverters/Splitters.

The RC-25 ($1.25,1966) has more tubes in the list.

Post by Phil S.
So, I broke down and bought both the GE and RCA at Amazon today, as they
appeared to be cheaper there compared to eBay.

Yeah . ebaiters learned that a *classic* tube book will fetch some
cash. Amazon sells things at *fair market value* .

Phil S.

2008-05-20 00:28:42 UTC

Post by Phil S.
I downloaded RC-30. This is something one wants to thumb through, not
read at the computer.

( for AA'ers )
You will have a RC-25, 30, 16, 14 in every one of your bathrooms,
camper and boat heads, and if your travel, on your laptop.

Post by Phil S.
My brief perusal didn't turn up an octal sub for a 12AT7. Anyone who
doesn't mind throwing me a bone?

bark bark .. here Phil !
RC-30 ($2.95, 1975) page 108. section 19. Phase Inverters/Splitters.
The RC-25 ($1.25,1966) has more tubes in the list.

Do you mean to say I bought the "wrong" one? <woof> I appreciate this
bone. I will get the RC-25 on-line.

Post by Phil S.
So, I broke down and bought both the GE and RCA at Amazon today, as they
appeared to be cheaper there compared to eBay.

Yeah . ebaiters learned that a *classic* tube book will fetch some
cash. Amazon sells things at *fair market value* .

2008-05-20 00:51:57 UTC

Post by Phil S.
I downloaded RC-30. This is something one wants to thumb through, not
read at the computer.

( for AA'ers )
You will have a RC-25, 30, 16, 14 in every one of your bathrooms,
camper and boat heads, and if your travel, on your laptop.

Post by Phil S.
My brief perusal didn't turn up an octal sub for a 12AT7. Anyone who
doesn't mind throwing me a bone?

bark bark .. here Phil !
RC-30 ($2.95, 1975) page 108. section 19. Phase Inverters/Splitters.
The RC-25 ($1.25,1966) has more tubes in the list.

Do you mean to say I bought the "wrong" one? <woof> I appreciate this
bone. I will get the RC-25 on-line.

No. no., no.
RC-25 simply has more (tube) selections in 1966 then the 1975 version.

I'll scan my rc-25 page(s) for you. ping me over at b24warbaby at
gmail.com .

g***@gmail.com

2008-05-20 00:54:51 UTC

Post by Phil S.
Oh, just thinking here...I've got a recycled chassis drilled for 5 octal
sockets. I was thinking maybe a pair of 6V6, and two or three 6SL7. Then I
got to thinking about doing something different with the PI, not sure what.
So, the wild hair raises the questions.
1) Is there an octal equivalent to a 12AT7?
2) Aside from the lower gain factor, is there anything in particular I
should be aware of in working with a 6SL7? How good/bad are current
production tubes?
3) Is there a significant difference between 6SC7 and 6SL7? Is this a bit
like comparing a 5751 to a 12AX7?
I already know there is a 6SN7, roughly a 12AU7 equivalent. What's in
between that and the 6SN7 with Ra in the 5k-15k range?

Last year I made a 6V6 amp using a 6SL7 in the PI. Also, 2 6SC7 tubes
as preamp, each wired with the two internal triodes in parallel to
lower the plate z and get a little more gain. Sounds great.

Config is 6SC7:1st vol pot:6SC7:tone stack:master vol pot:PI:6V6pair

2008-05-20 12:57:21 UTC

Post by g***@gmail.com
Last year I made a 6V6 amp using a 6SL7 in the PI. Also, 2 6SC7 tubes
as preamp, each wired with the two internal triodes in parallel to
lower the plate z and get a little more gain. Sounds great.
Config is 6SC7:1st vol pot:6SC7:tone stack:master vol pot:PI:6V6pair

There you go !
Did you happen to make a schematic too ?

g***@gmail.com

2008-05-20 23:29:32 UTC

There you go !
Did you happen to make a schematic too ?

WB and Phil,

Here is a link to my amp schematic.

Loading Image...

Phil S.

2008-05-21 02:33:47 UTC

There you go !
Did you happen to make a schematic too ?

WB and Phil,
Here is a link to my amp schematic.
http://i304.photobucket.com/albums/nn190/triode1000/6V6with6sc7.jpg

Thanks very much. If not too imposing, what is the HT secondary rating?
Or, if you don't remember that, maybe you remember the plate voltage?

Folks seem to like to push the 6V6 well above design center ratings. I was
wondering what you did with it.

Regards,
Phil

g***@gmail.com

2008-05-21 04:07:31 UTC

There you go !
Did you happen to make a schematic too ?

WB and Phil,
Here is a link to my amp schematic.
http://i304.photobucket.com/albums/nn190/triode1000/6V6with6sc7.jpg

Thanks very much. If not too imposing, what is the HT secondary rating?
Or, if you don't remember that, maybe you remember the plate voltage?
Folks seem to like to push the 6V6 well above design center ratings. I was
wondering what you did with it.
Regards,
Phil

I think the secondary was 300V, anyway the HT was definitely about
385V at the screen resistor. There are some fairly high supply
resistors to the preamp stages to get a fair bit of sag and lower the
headroom, this is intentional, I like it this way. The 6V6's I have
are old Brimars, and I think they are running at about 25mA quiescent.
For the bias I chose a quality 10 turn pot since I have a few lying
around. I chose 6SC7's because a local shop (Australia) had them at a
good price. Originally I had a 6SJ7 pentode in the first preamp but it
was horribly microphonic at about 60Hz.

I just added a photo of the amp to the photobucket site. If you have
any other questions I don't mind answering.

2008-05-21 23:16:59 UTC

Post by g***@gmail.com
I just added a photo of the amp to the photobucket site. If you have
any other questions I don't mind answering.

Nice home brew ! We're going have to see some *beaver shots* though.

g***@gmail.com

2008-05-21 23:52:07 UTC

Post by g***@gmail.com
I just added a photo of the amp to the photobucket site. If you have
any other questions I don't mind answering.

Nice home brew ! We're going have to see some *beaver shots* though.

Thanks, but it is pretty ugly inside because I converted the chassis
from a PA that a deceased ham made in the 50's. So there is a chassis
within the main cabinet. I ripped out his design though, just kept the
transformers and some of the octals. The only thing I actually bought
was the 6SC7's. The black face panel is a 19 inch anodised generic
panel, the grille is a stainless steel throwaway where the oval punch
holes are from washers which are the only parts of use from this. The
knobs, including the giant volume knob, are bakelite from and old
Philips X-ray machine for that retro look.

Anyway, I'll see what other pics I have of the top of the chassis at
least. In the meantime, if you go to these links you should be able to
see a couple of beaver shots of my 60 watt SE triode amp using a 1500
watt industrial triode as the only power device.

Loading Image...

Loading Image...

Ether

2008-05-22 07:04:55 UTC

Post by g***@gmail.com
I just added a photo of the amp to the photobucket site. If you have
any other questions I don't mind answering.

Nice home brew ! We're going have to see some *beaver shots* though.

Thanks, but it is pretty ugly inside because I converted the chassis
from a PA that a deceased ham made in the 50's. So there is a chassis
within the main cabinet. I ripped out his design though, just kept the
transformers and some of the octals. The only thing I actually bought
was the 6SC7's. The black face panel is a 19 inch anodised generic
panel, the grille is a stainless steel throwaway where the oval punch
holes are from washers which are the only parts of use from this. The
knobs, including the giant volume knob, are bakelite from and old
Philips X-ray machine for that retro look.
Anyway, I'll see what other pics I have of the top of the chassis at
least. In the meantime, if you go to these links you should be able to
see a couple of beaver shots of my 60 watt SE triode amp using a 1500
watt industrial triode as the only power device.
http://i304.photobucket.com/albums/nn190/triode1000/t1000a.jpg
http://i304.photobucket.com/albums/nn190/triode1000/t1000b.jpg

Um...when you turn that thing on, does Frankenstein's monster stagger
to life in the corner?

--E

g***@gmail.com

2008-05-22 07:17:18 UTC

Post by Ether

Post by g***@gmail.com
I just added a photo of the amp to the photobucket site. If you have
any other questions I don't mind answering.

Nice home brew ! We're going have to see some *beaver shots* though.

Thanks, but it is pretty ugly inside because I converted the chassis
from a PA that a deceased ham made in the 50's. So there is a chassis
within the main cabinet. I ripped out his design though, just kept the
transformers and some of the octals. The only thing I actually bought
was the 6SC7's. The black face panel is a 19 inch anodised generic
panel, the grille is a stainless steel throwaway where the oval punch
holes are from washers which are the only parts of use from this. The
knobs, including the giant volume knob, are bakelite from and old
Philips X-ray machine for that retro look.
Anyway, I'll see what other pics I have of the top of the chassis at
least. In the meantime, if you go to these links you should be able to
see a couple of beaver shots of my 60 watt SE triode amp using a 1500
watt industrial triode as the only power device.
http://i304.photobucket.com/albums/nn190/triode1000/t1000a.jpg
http://i304.photobucket.com/albums/nn190/triode1000/t1000b.jpg

Um...when you turn that thing on, does Frankenstein's monster stagger
to life in the corner?
--E

LOL. no but you've got to be careful working on it, with 700V of B+

Pozitronik Vibe

2008-05-22 13:29:39 UTC

Post by Ether

Post by g***@gmail.com
I just added a photo of the amp to the photobucket site. If you have
any other questions I don't mind answering.

Nice home brew ! We're going have to see some *beaver shots* though.

Thanks, but it is pretty ugly inside because I converted the chassis
from a PA that a deceased ham made in the 50's. So there is a chassis
within the main cabinet. I ripped out his design though, just kept the
transformers and some of the octals. The only thing I actually bought
was the 6SC7's. The black face panel is a 19 inch anodised generic
panel, the grille is a stainless steel throwaway where the oval punch
holes are from washers which are the only parts of use from this. The
knobs, including the giant volume knob, are bakelite from and old
Philips X-ray machine for that retro look.
Anyway, I'll see what other pics I have of the top of the chassis at
least. In the meantime, if you go to these links you should be able to
see a couple of beaver shots of my 60 watt SE triode amp using a 1500
watt industrial triode as the only power device.
http://i304.photobucket.com/albums/nn190/triode1000/t1000a.jpg
http://i304.photobucket.com/albums/nn190/triode1000/t1000b.jpg

Um...when you turn that thing on, does Frankenstein's monster stagger
to life in the corner?
--E

LOL. no but you've got to be careful working on it, with 700V of B+

MusicMan HD210 One*Fifty (700V of B+)

Elvis Kabong

2008-05-22 08:16:53 UTC

Post by g***@gmail.com
I just added a photo of the amp to the photobucket site. If you have
any other questions I don't mind answering.

Nice home brew ! We're going have to see some *beaver shots* though.

Thanks, but it is pretty ugly inside because I converted the chassis
from a PA that a deceased ham made in the 50's. So there is a chassis
within the main cabinet. I ripped out his design though, just kept the
transformers and some of the octals. The only thing I actually bought
was the 6SC7's. The black face panel is a 19 inch anodised generic
panel, the grille is a stainless steel throwaway where the oval punch
holes are from washers which are the only parts of use from this. The
knobs, including the giant volume knob, are bakelite from and old
Philips X-ray machine for that retro look.
Anyway, I'll see what other pics I have of the top of the chassis at
least. In the meantime, if you go to these links you should be able to
see a couple of beaver shots of my 60 watt SE triode amp using a 1500
watt industrial triode as the only power device.
http://i304.photobucket.com/albums/nn190/triode1000/t1000a.jpg
http://i304.photobucket.com/albums/nn190/triode1000/t1000b.jpg

Sure that's not for a kinetics art light show?

Color organs aren't that hard to build, you know.

Doggone

2008-05-23 00:39:00 UTC

Post by g***@gmail.com
I just added a photo of the amp to the photobucket site. If you have
any other questions I don't mind answering.

Nice home brew ! We're going have to see some *beaver shots* though.

Thanks, but it is pretty ugly inside because I converted the chassis
from a PA that a deceased ham made in the 50's. So there is a chassis
within the main cabinet. I ripped out his design though, just kept the
transformers and some of the octals. The only thing I actually bought
was the 6SC7's. The black face panel is a 19 inch anodised generic
panel, the grille is a stainless steel throwaway where the oval punch
holes are from washers which are the only parts of use from this. The
knobs, including the giant volume knob, are bakelite from and old
Philips X-ray machine for that retro look.
Anyway, I'll see what other pics I have of the top of the chassis at
least. In the meantime, if you go to these links you should be able to
see a couple of beaver shots of my 60 watt SE triode amp using a 1500
watt industrial triode as the only power device.
http://i304.photobucket.com/albums/nn190/triode1000/t1000a.jpg
http://i304.photobucket.com/albums/nn190/triode1000/t1000b.jpg

Now, that IS a killer amp. Quite literally.

--
If it's not broken, fix it till it is.

Phil S.

2008-05-20 13:04:56 UTC