Stop fussing. Buy my amplifiers instead.

http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

fryzz wrote:
Stop fussing. Buy my amplifiers instead.

http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1

The stock MC40s are a tolerable but not specially great sounding amp.
They do not compare to stock Marantz amps, or several modern amps such
as point wired early VTL or Quicksilver units, or some modified Dynacos
(despite the Dynaco OPTs being mediocre-oh, gullibards of Earth, do NOT
buy them from Ned, except for guitar amps, so he will lose money and
seek a better trans to clone, since he does not listen to good
advice....) even.

In fairness they do sound better than the 75s.

Well, I'd have to say that I agree with your comments about the
amplifiers. I don't know anything about Ned, so I have no opinion
there. My experience with McTubeamps is that the coupling caps they
used aren't all that great, and replacing them with something modern
makes for a significant improvement. Fresh caps in the power supply
help a lot too. The reason I'm selling mine is not that I don't like
them, though they are admitted flawed, but because I live off the power
grid, can no longer afford to feed them, and see no point in just
letting them sit out in the barn rusting.

fryzz wrote:
Well, I'd have to say that I agree with your comments about the
amplifiers. I don't know anything about Ned, so I have no opinion
there. My experience with McTubeamps is that the coupling caps they
used aren't all that great, and replacing them with something modern
makes for a significant improvement. Fresh caps in the power supply
help a lot too. The reason I'm selling mine is not that I don't like
them, though they are admitted flawed, but because I live off the power
grid, can no longer afford to feed them, and see no point in just
letting them sit out in the barn rusting.

Rust is actually a big problem on these because Mc used prechromed
steel. Heavily rusted tops can be stripped, buffed, triple-chrome
plated and re-silkscreened, but that would involve actual work and so
isn't done.

A much better alternative as I see it is to sell the old mcintosh amps
to the ollies and use the money to build new amps with reproduction
OPTs. However no one wants to make them, because that also would
involve actual work.

Only when the stock market implodes and we are in a deflationary
depression will anyone get off their ass and work (who speaks English
and has a 100+ IQ.) However, this may happen soon.

Bret Ludwig wrote:


A much better alternative as I see it is to sell the old mcintosh amps
to the ollies and use the money to build new amps with reproduction
OPTs. However no one wants to make them, because that also would
involve actual work.


Didn't they already sell a run of repro amps?

Only when the stock market implodes and we are in a deflationary
depression will anyone get off their ass and work (who speaks English
and has a 100+ IQ.) However, this may happen soon.

I bet you are actually on disability and have nothing better to do than
bitch out anyone who doesn't admit to the superiority of Mac. Yes we
know you like McIntosh and Marantz and early point wired VTL amps. How
about a new topic already. If you can't be helpful then shut the **** up.


Adam

Adam Stouffer wrote:
Bret Ludwig wrote:


A much better alternative as I see it is to sell the old mcintosh amps
to the ollies and use the money to build new amps with reproduction
OPTs. However no one wants to make them, because that also would
involve actual work.


Didn't they already sell a run of repro amps?

They reissued the MC275, after a fashion. A crude fashion.


Only when the stock market implodes and we are in a deflationary
depression will anyone get off their ass and work (who speaks English
and has a 100+ IQ.) However, this may happen soon.

I bet you are actually on disability and have nothing better to do than
bitch out anyone who doesn't admit to the superiority of Mac. Yes we
know you like McIntosh and Marantz and early point wired VTL amps. How
about a new topic already. If you can't be helpful then shut the **** up.

Lick me. I almost wish I was on disability, then I could build amps!


I have never said McIntosh was "the best". I said the Mac circuit was
the best sounding circuit for the power it develops from the tubes it
uses, and its transformers are less expensive to wind than top quality
conventional alternatives. I do not believe the Circlotron or the other
derivations of this circuit are as desireable. They are attempts in
most cases to beat the Mac patents or use cheap off the shelf parts.
There is no need to beat the Mac patents as they are expired and I
don't like cheap kluges.

The Audio Anthologies contain all the pertinent Norman Crowhurst
articles in which he goes through and explores the medieval doctrine of
plenitude, as it applies to amplifier configurations possible with one
polarity of output device (there is no such thing as a P-channel tube).
Although a fine writer, Crowhurst never built a first-rate piece of
audio equipment.

I went so far as to educate myself about electroplating, but it seems
like more trouble than it's worth when one wieghs the effort versus the
value added. I have also thought about building McIntosh repro amps,
since, as you have pointed out, the relevant patents are now expired.
Maybe the best thing would be to take apart one of the one's I have to
see how they're made. It just seems a shame to trash a working amp.

fryzz wrote:
I went so far as to educate myself about electroplating, but it seems
like more trouble than it's worth when one wieghs the effort versus the
value added. I have also thought about building McIntosh repro amps,
since, as you have pointed out, the relevant patents are now expired.
Maybe the best thing would be to take apart one of the one's I have to
see how they're made. It just seems a shame to trash a working amp.

I wouldn't trash the amp, I would probably carefully remove and bench
test an output transformer. If one were to actually repro it it would
be necessary to tear one down (though its can and core could be
reused.) But for R&D purposes,no.

The schematic, the patents and extensive technical writing are
available so there is no need to scrap one.

Althgough IMO the 40 is proabaly the better sounding of the Mac amps
in stock condition the main market demand for OPTs will probably be for
the 75s. If you were going to do one or the other the 75 would be the
one to do-especially because the 75 can be used in several variations
of the McIntosh circuit. Against this the 40 transformer would be a
little easier to wind. I don't know that the 40 transformer necessarily
makes for a better sounding amp than the 75, only that the stock 40
sounds better than the 75.

Neither is a terrific challenge: the UTC Linear Standards and the
Peerless 20-20 and 20-20 Plus Series as well as the Marantz 5 and 8B
OPT (which some claim to be a Peerless ripoff;although my source on
this has turned out to be a total douchebag...) would all give you a
better workout. The Mac may need a little fixturing out of the
ordinary: it won't wind on a Universal very easily, nor a toroid
machine like a Gorman.

The only thing you really need to figure out is the total turns count,
the interleaving and the proper gapping of the core which I'm told was
done by looking at a B-H curve display on an old crude scope and
inserting sanded pieces of fish paper betwixt the ends, then banded
with a common shipping box banding machine and supplies.

As Turner mentioned you are also going to need a wire with a high
grade of insulation and may need to special order some miles of it. But
for a 100 piece run+/- 10 the cost per unit should be reasonable. I
think you could sell 25 pairs in one week plus a few singletons for
repair or bass amps if it were satisfactorily proven yours were
absolutely identical to the originals, and pay for the run.

That's good information, thanks. It would probably suit me better to
wind transformers for the 75. I overhauled a 275 for someone who told
me that "price is no object, just make it perfect". I rebuilt it using
decent caps and resistors, matched the tubes for lowest HF distortion
as well as emission, and I must say that I was astonished by the
results. It sounded a lot better than my upgraded 40, and I have been
craving to own one ever since. When I get my windmill going, I'll even
be able to power one.

How come outfits like Hammond aren't building repro transformers? Are
they more expensive to make than standard issue? Are Hammond's
transformers any good?

On 15 Dec 2005 15:20:38 -0800, "fryzz"
wrote:

That's good information, thanks. It would probably suit me better to
wind transformers for the 75. I overhauled a 275 for someone who told
me that "price is no object, just make it perfect". I rebuilt it using
decent caps and resistors, matched the tubes for lowest HF distortion
as well as emission, and I must say that I was astonished by the
results. It sounded a lot better than my upgraded 40, and I have been
craving to own one ever since. When I get my windmill going, I'll even
be able to power one.


So when you did the 275, what did you use when you replaced the
electrolytics?

I've got a pair of 75's that a guy wanted me to bring up after
sitting for over 10 years. Looks like it'll be too difficult to do a
nice job on the electrolytics. I've decided to just bring them up on a
variac and then give the amps back to the guy.

How come outfits like Hammond aren't building repro transformers? Are
they more expensive to make than standard issue? Are Hammond's
transformers any good?

Gilbert Bates wrote:

So when you did the 275, what did you use when you replaced the
electrolytics?

Audio Crappics and others have a stock replacement lytic but it is
sort of expensive. I would use that for cosmetic reasons on actual Mac
amps.




I've got a pair of 75's that a guy wanted me to bring up after
sitting for over 10 years. Looks like it'll be too difficult to do a
nice job on the electrolytics. I've decided to just bring them up on a
variac and then give the amps back to the guy.

How come outfits like Hammond aren't building repro transformers? Are
they more expensive to make than standard issue? Are Hammond's
transformers any good?


Hammond's power transformers are OK and their output transformers are
of good quality comparable to standard series Thordarsons, Stancors,
Triads, etc., in other words good utility quality but not serious high
end products like the UTC LS series, Peerless, or the British
Partridges. They would be fine for guitar, juke box or organ amps or
getting old radios or consoles going.

The Mc transformers are unconventional in that they are wound on
C-cores, typically used on pole pig transformers and the like, and
apparently are fully symmetrical for DC. McIntosh has outsourced some
power transformers and the outputs for the MA230 integrated amp (which
are quite capable of handling 60 to 70 watts across the audio band) but
never a C-core transformer. The new "275" uses a simpler E-I core
transformer done inhouse and not, by their own admission, comparable to
the old one.

Lars Lundahl in Sweden makes a conventional output transformer on
C-cores and they have as much as said they could do a Mac compatible
part but Lundahl himself dislikes the circuit and so refuses to.

Sooner or later an oriental source will start making these, but
because oriental magnetics materials manufacturers are rarely as
consistent as Western ones in terms of silicon steels, they will
probably not be as good.

I found them at Antique Electronics Supply. This was back in '99, but
I was just over there and it looks like they've still got what you're
looking for, it's under Mallory\multisection. May not be exact, but I
think you'll find as good or better.

I lived in Bangkok when I was a teenager, I remember passing through
the "transformer district" where I saw ten year old kids cutting out
e-lams with tin snips from old coffee cans to use in building the
120/240 line volt transformers, for use by expatriots wanting to run
their 120V appliances of odf the local 240V power.

Actually, that brings me up to the next question(s). What steel is the
right steel? Where do you find the steel? How do you get the steel
cut into the shapes you want? If the answer is "you cannot buy that
steel", that is a whole 'nother discuission. If it is "talk to vendor
X and get a custom die made", or "talk to vendor X and the waterjet
cutting guys", that's cool, but it would be nice to find someone
already tooled up for that.

In the case of the Mcintosh transformers it's not a matter of lams
because they use C-cores which are affected not only by the steel but
the shape of the winding of the cores and the precision of the cutting
and the post-wind treatment used. However, you can be sure that proper
cores are available and indeed may permit better specifications than
the originals because C-cores have improved. The originals used
Westinghouse cores: I believe Westinghouse sold its magnetics business
a while ago, but their successors make all the old sizes to
Westinghouse standards for the power transformer industry.

Thanks for all the input, Bret.

Frank