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獅子口
Guest
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 Posted:
Fri Nov 11, 2005 9:46 pm Post subject:
My Mcintosh MC240 output transformer with primary windings s |
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All information about the properties of the enamelled wires, winding
structure, insulation materials, inductance of windings,
leakage inductance, capacitance between primary and secondary, for hand
winding the Unity Coupled Output Transformers again.
Anybody knows the details or knows where to get the details please help.
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Bret Ludwig
Guest
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| Posted:
Sat Nov 12, 2005 5:42 am Post subject:
Re: My Mcintosh MC240 output transformer with primary windin |
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獅子口 wrote:
| Quote: | All information about the properties of the enamelled wires, winding
structure, insulation materials, inductance of windings,
leakage inductance, capacitance between primary and secondary, for hand
winding the Unity Coupled Output Transformers again.
Anybody knows the details or knows where to get the details please help.
|
There is a guy in Wisconsin who will happily rewind your xfmr but the
price is high and he's not about to help you or anyone else DIY.
You could tear it down, document it, and rewind it but you will need
to build some fixturing. It's not a impossible job but if you have
never worked in a transformer shop this is not an ideal first project.
If you were to very carefully document the job and do a web page you
would be a real hero on Usenet.
Start with the patents , the numbers are on Roger Russell's web page
and are free for viewing at www.uspto.gov. There is additional useful
information in the blue and white JFK/MM era Audio Cyclopedia and in
Crowhurst's articles in the Audio Anthologies. Also you may want copies
of Bereskin's article on building a Class B amp with explicit winding
data from the old IEEE papers someone has put on the Web somewhere.
I have long held that repro'ing these would be a good seller for
hobbyists and restorers alike. |
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Patrick Turner
Guest
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| Posted:
Sat Nov 12, 2005 8:40 pm Post subject:
Re: My Mcintosh MC240 output transformer with primary windin |
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Bret Ludwig wrote:
| Quote: | 獅子口 wrote:
All information about the properties of the enamelled wires, winding
structure, insulation materials, inductance of windings,
leakage inductance, capacitance between primary and secondary, for hand
winding the Unity Coupled Output Transformers again.
Anybody knows the details or knows where to get the details please help.
There is a guy in Wisconsin who will happily rewind your xfmr but the
price is high and he's not about to help you or anyone else DIY.
You could tear it down, document it, and rewind it but you will need
to build some fixturing. It's not a impossible job but if you have
never worked in a transformer shop this is not an ideal first project.
If you were to very carefully document the job and do a web page you
would be a real hero on Usenet.
Start with the patents , the numbers are on Roger Russell's web page
and are free for viewing at www.uspto.gov. There is additional useful
information in the blue and white JFK/MM era Audio Cyclopedia and in
Crowhurst's articles in the Audio Anthologies. Also you may want copies
of Bereskin's article on building a Class B amp with explicit winding
data from the old IEEE papers someone has put on the Web somewhere.
I have long held that repro'ing these would be a good seller for
hobbyists and restorers alike.
|
McIntosh OPTs are not easily rewound to the original spec because they
require triple insulated winding wire and bifilar wound windings.
But enough information to design and build your own OPT
exits at my website.
But you have to become an expert in the process.
And when you are done, you will find that there isn't any need for bifilar
windings if you know what EAR does with their unity gain OPTs.
Nearly every person gives up trying to wind their own OPTs
especially McIntosh reproductions because its all too much
bother to get it 100% right.
Patrick Turner. |
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Bob
Guest
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| Posted:
Sun Nov 13, 2005 1:51 pm Post subject:
Re: My Mcintosh MC240 output transformer with primary windin |
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You also need to fix whatever burned out the transformer before it
kills a replacement. |
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west
Guest
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| Posted:
Mon Nov 14, 2005 12:27 am Post subject:
Re: My Mcintosh MC240 output transformer with primary windin |
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"Patrick Turner" <info@turneraudio.com.au> wrote in message
news:4375FD93.EEB2573A@turneraudio.com.au...
| Quote: |
Bret Ludwig wrote:
獅子口 wrote:
All information about the properties of the enamelled wires, winding
structure, insulation materials, inductance of windings,
leakage inductance, capacitance between primary and secondary, for
hand
winding the Unity Coupled Output Transformers again.
Anybody knows the details or knows where to get the details please
help.
There is a guy in Wisconsin who will happily rewind your xfmr but the
price is high and he's not about to help you or anyone else DIY.
You could tear it down, document it, and rewind it but you will need
to build some fixturing. It's not a impossible job but if you have
never worked in a transformer shop this is not an ideal first project.
If you were to very carefully document the job and do a web page you
would be a real hero on Usenet.
Start with the patents , the numbers are on Roger Russell's web page
and are free for viewing at www.uspto.gov. There is additional useful
information in the blue and white JFK/MM era Audio Cyclopedia and in
Crowhurst's articles in the Audio Anthologies. Also you may want copies
of Bereskin's article on building a Class B amp with explicit winding
data from the old IEEE papers someone has put on the Web somewhere.
I have long held that repro'ing these would be a good seller for
hobbyists and restorers alike.
McIntosh OPTs are not easily rewound to the original spec because they
require triple insulated winding wire and bifilar wound windings.
But enough information to design and build your own OPT
exits at my website.
But you have to become an expert in the process.
And when you are done, you will find that there isn't any need for bifilar
windings if you know what EAR does with their unity gain OPTs.
Nearly every person gives up trying to wind their own OPTs
especially McIntosh reproductions because its all too much
bother to get it 100% right.
Patrick Turner.
What a grand gesture it would be if Prof. Turner had a step-by-step |
instruction, with pixs, on winding your own xfrs. I bet something like that
would become world famous. Probably not an easy undertaking, but
nevertheless much needed.
west
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Jon Yaeger
Guest
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| Posted:
Mon Nov 14, 2005 12:55 am Post subject:
Re: My Mcintosh MC240 output transformer with primary windin |
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| Quote: |
What a grand gesture it would be if Prof. Turner had a step-by-step
instruction, with pixs, on winding your own xfrs. I bet something like that
would become world famous. Probably not an easy undertaking, but
nevertheless much needed.
west
|
It might be famous in the very small (and steadily shrinking) world of
tube-o-philes. Maybe he'd sell 40 copies max.
West, maybe you could figure it out yourself and post it on your website.
;-) |
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Bret Ludwig
Guest
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| Posted:
Mon Nov 14, 2005 3:06 am Post subject:
Re: My Mcintosh MC240 output transformer with primary windin |
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Patrick Turner wrote:
| Quote: | Bret Ludwig wrote:
獅子口 wrote:
All information about the properties of the enamelled wires, winding
structure, insulation materials, inductance of windings,
leakage inductance, capacitance between primary and secondary, for hand
winding the Unity Coupled Output Transformers again.
Anybody knows the details or knows where to get the details please help.
There is a guy in Wisconsin who will happily rewind your xfmr but the
price is high and he's not about to help you or anyone else DIY.
You could tear it down, document it, and rewind it but you will need
to build some fixturing. It's not a impossible job but if you have
never worked in a transformer shop this is not an ideal first project.
If you were to very carefully document the job and do a web page you
would be a real hero on Usenet.
Start with the patents , the numbers are on Roger Russell's web page
and are free for viewing at www.uspto.gov. There is additional useful
information in the blue and white JFK/MM era Audio Cyclopedia and in
Crowhurst's articles in the Audio Anthologies. Also you may want copies
of Bereskin's article on building a Class B amp with explicit winding
data from the old IEEE papers someone has put on the Web somewhere.
I have long held that repro'ing these would be a good seller for
hobbyists and restorers alike.
McIntosh OPTs are not easily rewound to the original spec because they
require triple insulated winding wire and bifilar wound windings.
But enough information to design and build your own OPT
exits at my website.
But you have to become an expert in the process.
And when you are done, you will find that there isn't any need for bifilar
windings if you know what EAR does with their unity gain OPTs.
Nearly every person gives up trying to wind their own OPTs
especially McIntosh reproductions because its all too much
bother to get it 100% right.
|
Winding the McIntosh transformer is simpler than many of the
"conventional" high quality transformers such as the UTC and Peerless
20-20 Plus series, the Marantz 8B and 5 outputs, or the units in the
Fairchild 275 or the HK Citations. The "secret" of McIntosh was its
"high D factor"- the ratio of sale price to build cost was high.
Tim de Paravicini's design is not as good as the true McIntosh design.
It's simpler in that he straps sweep tubes as triodes, not in the
conventional way, but by making them act more or less as Class B zero
bias triodes. This is not new to de Paravicini-I challenge anyone to
show me what is-it was used in the RCA theatre amps (which are not
considered prizes sonically) and is described in Orr's W6SAI Radio
Handbook for use as a AM modulator. The 509 and 549 are decent amps,
but not as good as what can be built around the true McIntosh circuit.
The key to doing the McIntosh xfmr is being willing to pay the piper
in terms of ordering a run of the right wire ($3000 to a wire mill, but
you'll get enough for a LOT of xfmrs) and getting the right C-cores,
and building some wind fixturing. It is not rocket science but it is
not a job for a stock Universal or a Gorman.
Coupling the McIntosh output circuit to better drivers and a proper
power supply produces the best possible tube amplifier that can be
built while having any semblance of power output and efficiency. A
Williamson design optimized to run a pair of 807s or KT66s at what I
would call their "natural lifespan" is going to be a 20 watt amp. The
MC275 gets an honest 80 watts per either channel with KT88s at the same
tube life. Milojub Nestoriovic understood that and his amps are really
good.
John Stewart and others have revisited the Crowhurst explorations in
an effort to use cheap components. I don't want to use cheap
components, I want to do it elegantly and right. That means the
McIntosh transformer, and not on E-I cores like the Mickey Mouse 275
reissue and not on toroids. On proper C-cores gapped with "Larry paper"
tensioned to get the BH loop right. (Insiders will get the joke....) |
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Patrick Turner
Guest
|
| Posted:
Mon Nov 14, 2005 5:42 am Post subject:
Re: My Mcintosh MC240 output transformer with primary windin |
|
|
west wrote:
| Quote: | "Patrick Turner" <info@turneraudio.com.au> wrote in message
news:4375FD93.EEB2573A@turneraudio.com.au...
Bret Ludwig wrote:
獅子口 wrote:
All information about the properties of the enamelled wires, winding
structure, insulation materials, inductance of windings,
leakage inductance, capacitance between primary and secondary, for
hand
winding the Unity Coupled Output Transformers again.
Anybody knows the details or knows where to get the details please
help.
There is a guy in Wisconsin who will happily rewind your xfmr but the
price is high and he's not about to help you or anyone else DIY.
You could tear it down, document it, and rewind it but you will need
to build some fixturing. It's not a impossible job but if you have
never worked in a transformer shop this is not an ideal first project.
If you were to very carefully document the job and do a web page you
would be a real hero on Usenet.
Start with the patents , the numbers are on Roger Russell's web page
and are free for viewing at www.uspto.gov. There is additional useful
information in the blue and white JFK/MM era Audio Cyclopedia and in
Crowhurst's articles in the Audio Anthologies. Also you may want copies
of Bereskin's article on building a Class B amp with explicit winding
data from the old IEEE papers someone has put on the Web somewhere.
I have long held that repro'ing these would be a good seller for
hobbyists and restorers alike.
McIntosh OPTs are not easily rewound to the original spec because they
require triple insulated winding wire and bifilar wound windings.
But enough information to design and build your own OPT
exits at my website.
But you have to become an expert in the process.
And when you are done, you will find that there isn't any need for bifilar
windings if you know what EAR does with their unity gain OPTs.
Nearly every person gives up trying to wind their own OPTs
especially McIntosh reproductions because its all too much
bother to get it 100% right.
Patrick Turner.
What a grand gesture it would be if Prof. Turner had a step-by-step
instruction, with pixs, on winding your own xfrs. I bet something like that
would become world famous. Probably not an easy undertaking, but
nevertheless much needed.
|
What a grand gesture it would be if someome made a grand payment for
all the design work involved along with building and testing to make sure what I
have
designed meets the spec.
America's equipment is old and failing, and the cheap fix with a chinese made
horror
looks certain to only become more popular.
I have limited time for such things; I am way too busy, and these last few weeks
have
seen the development of repetitive strain aches and pains in my best arm.
There is enough info at my website for anyone
with average intelligence but with a large amount of willpower,
patience etc to design whatever they want.
Then unfortunately there are much needed fixes for the other
369 varieties of OPTs used in ancient old gear that nobody wants to pay the
right price to fix.
I cannot be a benevolent society.
If you want it, DO IT YOURSELF!
Patrick Turner
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Patrick Turner
Guest
|
| Posted:
Mon Nov 14, 2005 5:42 am Post subject:
Re: My Mcintosh MC240 output transformer with primary windin |
|
|
Bret Ludwig wrote:
| Quote: | Patrick Turner wrote:
Bret Ludwig wrote:
獅子口 wrote:
All information about the properties of the enamelled wires, winding
structure, insulation materials, inductance of windings,
leakage inductance, capacitance between primary and secondary, for hand
winding the Unity Coupled Output Transformers again.
Anybody knows the details or knows where to get the details please help.
There is a guy in Wisconsin who will happily rewind your xfmr but the
price is high and he's not about to help you or anyone else DIY.
You could tear it down, document it, and rewind it but you will need
to build some fixturing. It's not a impossible job but if you have
never worked in a transformer shop this is not an ideal first project.
If you were to very carefully document the job and do a web page you
would be a real hero on Usenet.
Start with the patents , the numbers are on Roger Russell's web page
and are free for viewing at www.uspto.gov. There is additional useful
information in the blue and white JFK/MM era Audio Cyclopedia and in
Crowhurst's articles in the Audio Anthologies. Also you may want copies
of Bereskin's article on building a Class B amp with explicit winding
data from the old IEEE papers someone has put on the Web somewhere.
I have long held that repro'ing these would be a good seller for
hobbyists and restorers alike.
McIntosh OPTs are not easily rewound to the original spec because they
require triple insulated winding wire and bifilar wound windings.
But enough information to design and build your own OPT
exits at my website.
But you have to become an expert in the process.
And when you are done, you will find that there isn't any need for bifilar
windings if you know what EAR does with their unity gain OPTs.
Nearly every person gives up trying to wind their own OPTs
especially McIntosh reproductions because its all too much
bother to get it 100% right.
Winding the McIntosh transformer is simpler than many of the
"conventional" high quality transformers such as the UTC and Peerless
20-20 Plus series, the Marantz 8B and 5 outputs, or the units in the
Fairchild 275 or the HK Citations. The "secret" of McIntosh was its
"high D factor"- the ratio of sale price to build cost was high.
|
All very well but people have been spoilde by chinese prices.
They may have spent up big on McI amps when they earned well and
were bushy tailed and bright eyed, but 40 years later they hate repair expenses.
The labour in the McI remains the same.
| Quote: |
Tim de Paravicini's design is not as good as the true McIntosh design.
It's simpler in that he straps sweep tubes as triodes, not in the
conventional way, but by making them act more or less as Class B zero
bias triodes.
|
His EAR 509 amp does not use the PL509 tubes in triode.
It is set up identically in principle to McI, but with separate screen windings
to have the G2 running at 1/2 the B+.
But the AC working is real pentode with 1/2 the voltage betwen a and k fed back at
the cathode,
and with the loading as it is in EAR509, this is pentode mode with 12dB of local
NFB.
The tubes are dangerously biased high to make a small but significant
amount of class A power before lurching into mainly class B.
Strapping windings with C where windings have the same AC and different DC
potential is a practice
promoted by GE back in 1957, and the cap shunting ties windings tightly together
like the bifilar windings achieve.
| Quote: | This is not new to de Paravicini-I challenge anyone to
show me what is-it was used in the RCA theatre amps (which are not
considered prizes sonically) and is described in Orr's W6SAI Radio
Handbook for use as a AM modulator. The 509 and 549 are decent amps,
but not as good as what can be built around the true McIntosh circuit.
|
The 509 is a horrid amp because its far too much class AB and uses ghastly
tubes such as the EL/PL 509, KT88 would be better, and that TdeP
used PL509 to begin with was stoopid; maybe someone sold him
10,000 tubes nobody wanted for a $.
Why 40 V heaters?
The total amount of applied NFB in 3 loops in EAR509 = 44dB.
It measures no better than what I would achieve with 4 EL34 and
10 times less NFB and one stage less NFB.
The sound is harsh after the first few watts.
| Quote: |
The key to doing the McIntosh xfmr is being willing to pay the piper
in terms of ordering a run of the right wire ($3000 to a wire mill, but
you'll get enough for a LOT of xfmrs) and getting the right C-cores,
and building some wind fixturing. It is not rocket science but it is
not a job for a stock Universal or a Gorman.
|
The only time such things are viable is if someone such as McIntosh make a run of
retro amps with a pile of trannies that can be supported by the profit made from
the
retro models sold.
Then you have to wait 20 years to sell the spare but genuine spec trannies.
| Quote: |
Coupling the McIntosh output circuit to better drivers and a proper
power supply produces the best possible tube amplifier that can be
built while having any semblance of power output and efficiency. A
Williamson design optimized to run a pair of 807s or KT66s at what I
would call their "natural lifespan" is going to be a 20 watt amp.
|
The Williamson can use a sixpack of KT88
and be 75 watts of AB triode.
I use 12 x 6550 in large amps, and the OPTs were
easy to layer wind since the higher the power, the larger the core,
but less turns are used, and its nice thick wire.
| Quote: | The
MC275 gets an honest 80 watts per either channel with KT88s at the same
tube life. Milojub Nestoriovic understood that and his amps are really
good.
John Stewart and others have revisited the Crowhurst explorations in
an effort to use cheap components. I don't want to use cheap
components, I want to do it elegantly and right. That means the
McIntosh transformer, and not on E-I cores like the Mickey Mouse 275
reissue and not on toroids. On proper C-cores gapped with "Larry paper"
tensioned to get the BH loop right. (Insiders will get the joke....)
|
I have used C-cores for OPTs gapped with plastic shopping bag
material; it gave a fine gap to tailor the saturation characteristic.
Eilor make very nice C-cores; just select the right size of C-core
and design the windings around it.
Nothing is impossible if patience, willpower, knowledge and
intelligence are sufficient.
Patrick Turner. |
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