I got got a couple of Allen Organ monoblock chassis in trade.

Each amp uses a quad of 6L6s. The iron is HUGE. The output trannies are
Airdesign 0-40112.

I'm thinking about modding these for audio amplifiers.

Anyone have knowledge of or experience with Allen or Airdesign?

Thanks in advance,

Jon

"Jon Yaeger" wrote in message
...
I got got a couple of Allen Organ monoblock chassis in trade.

Each amp uses a quad of 6L6s. The iron is HUGE. The output trannies are
Airdesign 0-40112.

I'm thinking about modding these for audio amplifiers.

Anyone have knowledge of or experience with Allen or Airdesign?

Thanks in advance,

Jon

Hi Jon,
I saw a pair of those at an Antique Radio swap meet last weekend in Kutztown
PA. Big suckers aren't they! I knew they weren't going to be cheap so I
didn't ask about the price. Some hold the Allen amps in high regard, I never
heard one. I scored a Sherwood 8000 at the meet to screw around with.
Mark S

Mark,

Thanks for your reply.

I've rebuilt some of the Sherwood 8000 series and know a bit about them
(have schematics, etc). They had avant-garde styling in their day.

Let me know if I can help.

Jon



in article t, Mark S at
wrote on 5/19/05 9:44 PM:


"Jon Yaeger" wrote in message
...
I got got a couple of Allen Organ monoblock chassis in trade.

Each amp uses a quad of 6L6s. The iron is HUGE. The output trannies are
Airdesign 0-40112.

I'm thinking about modding these for audio amplifiers.

Anyone have knowledge of or experience with Allen or Airdesign?

Thanks in advance,

Jon

Hi Jon,
I saw a pair of those at an Antique Radio swap meet last weekend in Kutztown
PA. Big suckers aren't they! I knew they weren't going to be cheap so I
didn't ask about the price. Some hold the Allen amps in high regard, I never
heard one. I scored a Sherwood 8000 at the meet to screw around with.
Mark S

On Fri, 20 May 2005 01:44:46 GMT, "Mark S"
wrote:

I saw a pair of those at an Antique Radio swap meet last weekend in Kutztown
PA.

I still consider Kutztown/Allentown to be my hometown, even more
than three decades gone. Got a sister living on a farm northeast
of K-town.

Most amazing collection of eccentric mechanicals I've ever seen;
BMW Isetta's and single-lung Triumph's can still be seen on the
roads and ham radio antennae larger than a car abound. But in fall,
you might have to stop in the road to let a flock of wild
turkeys walk across. *They* know the season.

Also, the best collection of college radio stations anywhere, but
that memory is dated and I'd love to be proven wrong.

I can remember a time when the good burgers *wouldn't* have
indoor toilets, because... well, it's just not something you
do indoors. Gotta love it.

Chris Hornbeck
"They're in *everybody's* eggs."

Hi John,
Yep, the 8000 stlying is pretty unique. I spotted this beast amonst a pile
of SS clone crap. When I asked the seller if it was working he replied
"well, the tubes light up, that's as far as I tested it"....'nother words,
um no. But the faceplate paint was flawless and all the knobs were there and
in geat shape so what the hell, I bought it. Price was reasonable. Upon my
initial eval, I saw that there were some power supply "issues" in burnt
wires, resistors...uh oh. Looks like all the transformers survived and all
the damage was caused by an output tube with a shorted G2. The PS series
dropping resistor just prior to the screen connection is what detonated.
I've rebuilt and tested the PS and with a new set of EH 7868's from Uncle
Ned, I'm ready to go with the initial power up. This is when I going to find
out just what shape the FM section is in. If you would have a schematic of
an original 8000, (not II, III or IV), I'd be very interested.
Thanks
Mark

"Jon Yaeger" wrote in message
...

Mark,

Thanks for your reply.

I've rebuilt some of the Sherwood 8000 series and know a bit about them
(have schematics, etc). They had avant-garde styling in their day.

Let me know if I can help.

Jon



in article t, Mark S at
wrote on 5/19/05 9:44 PM:


"Jon Yaeger" wrote in message
...
I got got a couple of Allen Organ monoblock chassis in trade.

Each amp uses a quad of 6L6s. The iron is HUGE. The output trannies
are
Airdesign 0-40112.

I'm thinking about modding these for audio amplifiers.

Anyone have knowledge of or experience with Allen or Airdesign?

Thanks in advance,

Jon

Hi Jon,
I saw a pair of those at an Antique Radio swap meet last weekend in
Kutztown
PA. Big suckers aren't they! I knew they weren't going to be cheap so I
didn't ask about the price. Some hold the Allen amps in high regard, I
never
heard one. I scored a Sherwood 8000 at the meet to screw around with.
Mark S

Hi Chris,
I love that part of PA, brick houses and all. Renninger's is a great place.
My mom's side of the family are Bethlehem natives, Granddad and most uncles
were steelers, if you get my drift.
Mark


"Chris Hornbeck" wrote in message
...
On Fri, 20 May 2005 01:44:46 GMT, "Mark S"
wrote:

I saw a pair of those at an Antique Radio swap meet last weekend in
Kutztown
PA.

I still consider Kutztown/Allentown to be my hometown, even more
than three decades gone. Got a sister living on a farm northeast
of K-town.

Most amazing collection of eccentric mechanicals I've ever seen;
BMW Isetta's and single-lung Triumph's can still be seen on the
roads and ham radio antennae larger than a car abound. But in fall,
you might have to stop in the road to let a flock of wild
turkeys walk across. *They* know the season.

Also, the best collection of college radio stations anywhere, but
that memory is dated and I'd love to be proven wrong.

I can remember a time when the good burgers *wouldn't* have
indoor toilets, because... well, it's just not something you
do indoors. Gotta love it.

Chris Hornbeck
"They're in *everybody's* eggs."

in article et, Mark S at
wrote on 5/20/05 10:08 PM:

Hi John,
Yep, the 8000 stlying is pretty unique. I spotted this beast amonst a pile
of SS clone crap. When I asked the seller if it was working he replied
"well, the tubes light up, that's as far as I tested it"....'nother words,
um no. But the faceplate paint was flawless and all the knobs were there and
in geat shape so what the hell, I bought it. Price was reasonable. Upon my
initial eval, I saw that there were some power supply "issues" in burnt
wires, resistors...uh oh. Looks like all the transformers survived and all
the damage was caused by an output tube with a shorted G2. The PS series
dropping resistor just prior to the screen connection is what detonated.
I've rebuilt and tested the PS and with a new set of EH 7868's from Uncle
Ned, I'm ready to go with the initial power up. This is when I going to find
out just what shape the FM section is in. If you would have a schematic of
an original 8000, (not II, III or IV), I'd be very interested.
Thanks
Mark

"Jon Yaeger" wrote in message
...

Mark,

I don't have the schematic on .pdf but if you send me your snail mail
address privately I'll drop it into the mail.

Check also the 'lytic cans. A short or leak across them will can out a
dropping resistor, too. My experience is that usually one or more are bad.
I trust that you're reforming the caps with a variac.

At lower voltage check the cans for heat. One of them has a 7W resistor
beneath so don't let that mislead you.

There are a couple of phenolic precursors to ICs. With a circuit diagram
you can check the resistances, at least. These can change value rather
dramatically, and since they are a part of the tone control circuit, will
alter the sound.

I've replace more than one with a discrete circuit that I built up on perf
board. I then dip the board in the goo that they sell at Home Depot to put
plastic "handles" on pliers and the like. It encapsulates it nicely.

I checked many of the coupling caps for leakage and they seem to hold up
fine. Nonetheless, I'd install new polypropylene coupling caps on the
output tubes.

Jon

On Sat, 21 May 2005 02:18:57 GMT, "Mark S"
wrote:

Hi Chris,
I love that part of PA, brick houses and all. Renninger's is a great place.
My mom's side of the family are Bethlehem natives, Granddad and most uncles
were steelers, if you get my drift.

It's terribly sad to see the Steel now. Do not, under any
circumstances, go to see it. It's just too much.

Thanks,

Chris Hornbeck
"The judge is on vinyl,
decisions are final,
Nobody gets a reprieve"
-Elliott Smith, "King's Crossing"

"Chris Hornbeck" wrote in message
...
On Sat, 21 May 2005 02:18:57 GMT, "Mark S"
wrote:

Hi Chris,
I love that part of PA, brick houses and all. Renninger's is a great
place.
My mom's side of the family are Bethlehem natives, Granddad and most
uncles
were steelers, if you get my drift.

It's terribly sad to see the Steel now. Do not, under any
circumstances, go to see it. It's just too much.

Thanks,

Chris Hornbeck
"The judge is on vinyl,
decisions are final,
Nobody gets a reprieve"
-Elliott Smith, "King's Crossing"

Hi Chris,
I the see the steel, or what's left of it on a fairly regular basis, I know
what you mean. I still have alot of family there. Seems as though the city
has been fairly successful in transforming the local economy towards a
tourist basis believe it on not. Downtown around the hotel and that
marvelous place called the Moravian Bookstore look pretty good. I've stayed
at the hotel a few times in the past couple of years. SOME talk of
transforming the old blast furnaces into a national park. Bethlehem Steel is
a prime example of just what good management, or lack thereof, is worth.
Mark

"Jon Yaeger" wrote in message
...
in article et, Mark S at
wrote on 5/20/05 10:08 PM:

Hi John,
Yep, the 8000 stlying is pretty unique. I spotted this beast amonst a
pile
of SS clone crap. When I asked the seller if it was working he replied
"well, the tubes light up, that's as far as I tested it"....'nother
words,
um no. But the faceplate paint was flawless and all the knobs were there
and
in geat shape so what the hell, I bought it. Price was reasonable. Upon
my
initial eval, I saw that there were some power supply "issues" in burnt
wires, resistors...uh oh. Looks like all the transformers survived and
all
the damage was caused by an output tube with a shorted G2. The PS series
dropping resistor just prior to the screen connection is what detonated.
I've rebuilt and tested the PS and with a new set of EH 7868's from Uncle
Ned, I'm ready to go with the initial power up. This is when I going to
find
out just what shape the FM section is in. If you would have a schematic
of
an original 8000, (not II, III or IV), I'd be very interested.
Thanks
Mark

"Jon Yaeger" wrote in message
...

Mark,

I don't have the schematic on .pdf but if you send me your snail mail
address privately I'll drop it into the mail.

Check also the 'lytic cans. A short or leak across them will can out a
dropping resistor, too. My experience is that usually one or more are
bad.
I trust that you're reforming the caps with a variac.

At lower voltage check the cans for heat. One of them has a 7W resistor
beneath so don't let that mislead you.

There are a couple of phenolic precursors to ICs. With a circuit diagram
you can check the resistances, at least. These can change value rather
dramatically, and since they are a part of the tone control circuit, will
alter the sound.

I've replace more than one with a discrete circuit that I built up on perf
board. I then dip the board in the goo that they sell at Home Depot to
put
plastic "handles" on pliers and the like. It encapsulates it nicely.

I checked many of the coupling caps for leakage and they seem to hold up
fine. Nonetheless, I'd install new polypropylene coupling caps on the
output tubes.

Jon

Thanks Jon, sorry about misspelling your name in previous posts. I'll send
you my address. Believe it or not, the caps and the other parts of the unit
are in pretty good shape. Sheesh, I haven't even looked at the tone control
area you refer to yet, but I know the encapsulated criters you refer to,
there was one one a Fisher 400 that I had that cut the high frequency
response right off at ~15KHz. That's one thing I like about Scott's, they do
most things with discrete components.
Mark
Mark

The Allen Organ amps out of the Gyrosonic cabs are in fact one of the
few "vintage" good deals left. They are excellent amps pretty much as
is and except for component upgrades and the addition of suitable
connectors (for those who must...I'd rather leave the originals in
place and make up a set of cables to suit) are good just as they are.
Very, very few of the posters here are competent to "improve" on them.

Fisher and Scott amps....oh, I used to love gutting them out for the
output transformers, which were great for guitar amps. Hardly cost
effective to do that today though. Too bad because it was a win-win-you
got a better guitar amp and did away with a varmint stereo box.

in article ,
at wrote on 5/22/05 3:00 PM:


The Allen Organ amps out of the Gyrosonic cabs are in fact one of the
few "vintage" good deals left. They are excellent amps pretty much as
is and except for component upgrades and the addition of suitable
connectors (for those who must...I'd rather leave the originals in
place and make up a set of cables to suit) are good just as they are.
Very, very few of the posters here are competent to "improve" on them.

Why?

Forgot to ask . . .

What component upgrades do you suggest? (other than the usual cap
replacements, out-of-spec resistors, etc.)

I received these without any tubes. I don't have many vintage 6L6s on hand.
Was thinking about the Russian 5881s or if the iron can handle it, some GE
6550s. Bad idea?

TIA,

Jon

Most of them simply do not have the necessary all-around electronic
knowledge. A couple might, but the overall level is abysmal, it's less
than that found among Novice hams at any junior high in the late 50's.
Many take pride in their total lack of theory, their unwillingness to
learn basic construction skills, and their total refusal to invest in a
proper armamentarium of test equipment.

Not all fit this description. Howevwer many do, and the rest tolerate
them. I'm more oriented towards solid state equipment every day, just
because it demands a certain amount of technicianship.

Forgot to ask . . .

What component upgrades do you suggest? (other than the usual cap
replacements, out-of-spec resistors, etc.)

I received these without any tubes. I don't have many vintage 6L6s on
hand.
Was thinking about the Russian 5881s or if the iron can handle it, some
GE
6550s. Bad idea?


I would replace the filter caps first, assuming they are lytics (a few
of these may have had oil caps.) The resistors could be replaced with
modern ones and of course coupling caps, but I would listen first
before getting out the dikes.

Most of the Allen Organ amps I have seen use 6550s with a regulated
screen circuit, however yours may well have not. There is also a 6550
ultralinear variant. I would take the time to call or write Allen to
see which amp you have and get their recommenation if it didn't
originally use the 6550.

Personally I think the regulated screen 6550 Allen is the best 6550
using amp I have ever heard. I usually prefer 6L6's or especially
807's to 6550s but in this amp the 6550 is excellent. The ultralinear
6550 Allen amp is also pretty good. I would be loath to butcher either
one.

It has been my hope since AO bought Legacy that they would reissue
these, with a OPT just like the one in the originals. I am very certain
it's better than anything Mike Lefevre could wind even if he wanted to.
I believe AO still have prints and perhaps a legit winder could be
talked into a run. I am rarely enthusiastic about old amplifiers, but
the AO Gyro amp is very underrated. OTOH I wouldn't pay the stupid sums
Macs and Marantzes bring today...

The Gyro cabinet itself, as Lard Valve pointed out, is a poor affair
from a organ tone standpoint, but it is beautifully built. I hate to
part them out, but part them out one must. As organ tone cabs, they
don't pack the gear.

in article ,
at wrote on 5/22/05 4:00 PM:

Forgot to ask . . .

What component upgrades do you suggest? (other than the usual cap
replacements, out-of-spec resistors, etc.)

I received these without any tubes. I don't have many vintage 6L6s on
hand.
Was thinking about the Russian 5881s or if the iron can handle it, some
GE
6550s. Bad idea?


I would replace the filter caps first, assuming they are lytics (a few
of these may have had oil caps.) The resistors could be replaced with
modern ones and of course coupling caps, but I would listen first
before getting out the dikes.

Most of the Allen Organ amps I have seen use 6550s with a regulated
screen circuit, however yours may well have not. There is also a 6550
ultralinear variant. I would take the time to call or write Allen to
see which amp you have and get their recommenation if it didn't
originally use the 6550.

Personally I think the regulated screen 6550 Allen is the best 6550
using amp I have ever heard. I usually prefer 6L6's or especially
807's to 6550s but in this amp the 6550 is excellent. The ultralinear
6550 Allen amp is also pretty good. I would be loath to butcher either
one.

It has been my hope since AO bought Legacy that they would reissue
these, with a OPT just like the one in the originals. I am very certain
it's better than anything Mike Lefevre could wind even if he wanted to.
I believe AO still have prints and perhaps a legit winder could be
talked into a run. I am rarely enthusiastic about old amplifiers, but
the AO Gyro amp is very underrated. OTOH I wouldn't pay the stupid sums
Macs and Marantzes bring today...

The Gyro cabinet itself, as Lard Valve pointed out, is a poor affair
from a organ tone standpoint, but it is beautifully built. I hate to
part them out, but part them out one must. As organ tone cabs, they
don't pack the gear.

* * * *


Thanks for the add'l info. Organ amps often get a bad rap. I didn't
realize that I've got a pair of keepers . . .

I've got the regulated screen version of the 6L6 amplifier, using Airdesign
iron. Guess I'll order the glass from Jim and fire it up . . . The darn
things weigh 40 lbs. each.

Cheers,

Jon

Most "organ" amps were dreadful from a hi-fi perspective, because home
organs were usually cheaply built. No one designed them specifically to
provide a desirable or euphonic distortion: like guitar amps it was an
accident. Commercial electronic organs for liturgical use often
simply provided a line out and the speakers and amps were a PA problem.
The installers provided these although Altec or McIntosh were often
recommended. One manufacturer at least used an OEM McIntosh amp.

Hammond were an exception but only to a point. The mechanical
generators were expensive to build and the electronics were well-built,
but both Hammond's and Leslie's amps were nothing like hi-fi.

Allen did it right because....well,because. They were very expensive
and I suppose felt that they should use the best amplifier possible.
They certainly could afford to.

in article ,
at wrote on 5/22/05 5:43 PM:

Most "organ" amps were dreadful from a hi-fi perspective, because home
organs were usually cheaply built. No one designed them specifically to
provide a desirable or euphonic distortion: like guitar amps it was an
accident. Commercial electronic organs for liturgical use often
simply provided a line out and the speakers and amps were a PA problem.
The installers provided these although Altec or McIntosh were often
recommended. One manufacturer at least used an OEM McIntosh amp.

Hammond were an exception but only to a point. The mechanical
generators were expensive to build and the electronics were well-built,
but both Hammond's and Leslie's amps were nothing like hi-fi.

Allen did it right because....well,because. They were very expensive
and I suppose felt that they should use the best amplifier possible.
They certainly could afford to.


Calcerise,

Tonight I looked over one of the monoblocks and it is unconventional to the
point where I don't understand it. For example, pins 7,8,& 1 on each 6L6
are tied together (i.e. a filament lead and the cathode).

There aren't any cathode resistors. Nor is there an obvious fixed bias (no
adjustment anywhere). But the screen voltage IS regulated. Huhh?

I've been looking all over the net but can't find a schematic for it (it's
the model 60, apparently). Would love to find one so that I could get some
grasp of how it's supposed to work.

No wonder you cautioned against modifying it!

Cheers,

Jon

I've never seen this one.

Allen Organ are, or used to be, helpful if you called them.

Is there a resistor to ground in the heater loop? Do the output tubes
share the heater supply with the little guys? I don't know, having not
seen this one before.

Groove Tubes may have a schematic. I have sent them several over the
years even though I am not a big customer or fan, I figure this
information should be available. They have a lot of them.

Every AO amp I have ever seen has used 6550s. Most have regulated
screens with a gas regulator tube, some have ultralinear taps. I have
never listened to any in hi-fi service that did not work very
satisfactorily. In fact I have said that AO would do well to reissue
them through Legacy, which they own.