Looking for Motorola output transistors for an SAE Mark XXXIB amp.
Joe
amplifier. I have the originals here, marked SAE 103 and SAE 204, and
those are no longer available. I tried Motorola's web page, even tried
to look for an E-mail address for recommendations on Motorola devices,
and all I see is their corporate bullshit. Can anyone recommend
replacements for these output transistors without all the corporate
crap? Sorry for the attitude, but I'm kind of disgusted with these
websites anymore, all they care for anymore is sucking the board of
directors' asses and their bottom line. What I want is a no-bullshit
website that can give me the info I need, without all that useless
corporate crap. International Rectifier was very good, they
recommended MOSFET's I needed for a UPS that I'm rebuilding, the
originals are no longer available for the UPS. This SAE amp is in
beautiful condition and I'll be damned if I am going to shitcan this
amp, because of crap like this. Please help!:)
A very disgusted (with these crap websites) Joe
T SCHWARTZ
Joe,
Don't be so disgusted with Motorola. The transistors you are asking
about are HOUSE numbered. If the marking was done by Motorola, then SAE
requested a private number so that you would HAVE to go to SAE for
original parts, even if the parts was identical to another Motorola
part. It is also possible that SAE removed the Motorola numbers and
printed their own, though that is less likely if the transistors still
have a Motorola logo on them. As I recall, SAE also used Toshiba output
transistors in some models.
Anyway, While I don't have service info on your amp, I've found the
Motorola MJ-15024 (NPN) and MJ-15025 (PNP) to be good general
replacements. The basic specs are 250 volt, 16 amp, 250 watt. Remember
that you should replace ALL the outputs in the channel that is bad, and
that you should try to get MATCHED transistors if possible. (It is most
important to match the ones that are in parallel, such as all of the NPN
output transistors in a channel. It is LESS important that the NPN's
and PNP's match.)
If you have no access to matched transistors, or a curve tracer, then
at least try to get devices with the same date code for each type. (IE
the same code on all of the MJ-15024's )
Best of luck,
Tim Schwartz
Bristol Electronics
P.S. There are others who will debate which output transistors SOUND
best. I can't help you there. I use these because I've found them
reliable.
Terry DeWick
>Hi guys, I'm looking for output transistors for an SAE model 31B power
>amplifier. I have the originals here, marked SAE 103 and SAE 204, and
>those are no longer available. I tried Motorola's web page, even tried
>to look for an E-mail address for recommendations on Motorola devices,
>and all I see is their corporate bullshit. Can anyone recommend
>replacements for these output transistors without all the corporate
>crap? Sorry for the attitude, but I'm kind of disgusted with these
>websites anymore, all they care for anymore is sucking the board of
>directors' asses and their bottom line. What I want is a no-bullshit
>website that can give me the info I need, without all that useless
>corporate crap. International Rectifier was very good, they
>recommended MOSFET's I needed for a UPS that I'm rebuilding, the
>originals are no longer available for the UPS. This SAE amp is in
>beautiful condition and I'll be damned if I am going to shitcan this
>amp, because of crap like this. Please help!:)
>
>A very disgusted (with these crap websites) Joe
Warning SAE103 and SAE204 are Power DARLINGTON transistors, general
replacementes will NOT work.
SAE101 = MJ802
SAE202 = MJ4502
SAE402 = CA3086
SAE204 = PNP power darlington
SAE103= NPN power darlington
Sorry I do not have a cross for the 103 and 204 but found some in ECG
with larger leads that would work, the originals are Obsolete.
Last batch I bought I found at the Dayton Hamfest, bought the guy out
and used them all in one MK III CM amplifier.
Good Luck,
Terry
http://www.esper.com/macaudio
Chris Johnson
devices are considered to be the best bipolar T0-3 (or whatever they call it now)
cased audio output devices available. Companies like Krell Industries
and Mark Levinson Audio Products, who both build Very High End audio
amplifiers costing up to fifteen thousand dollars or even more
apiece use these transistors as their standard outputs.
These amplifiers are built for those people who are willing to spend
a lot more money to get that last bit of performance out of their equipment.
So they use the MJ 15024 and MJ 15025 outputs (which you can get for
3 bucks each) because they're the best available, yet plentiful enough to
be dirt cheap.
(I own a pair of Krell monoblock power amps myself, and they're
worth the money. They use those Motorola devices.)
I've found these devices to be such a good choice for replacing bad
TO-3 case audio ouputs that I use them in everything, no matter what
the original device was. In each case, the unit sounded noticeably
better with the Motorola devices installed.
Chris Johnson
wjoh...@palmnet.net
Mr. Steven L. Bender
Last week, I heard a pair of new $16K Krell amps driven by a new Krell
$20K CD Player / Preamp into very expensive british speakers, costing
in the same range < about another $15K >.
Unfortunately the system sounded inadequately bad. Crappy even, as
some of my friends who also attended dictated. Bad in ways I would
expect for a $200 jap receiver. The Krell amps built now no longer use
the TO-3's, but the even more vastly inferior TO-220 Plastic Pak
devices, I think he said it had 216 per amp channel. Fact is that is
likely inferior to the prior thirty odd - pairs of MJ15024 / MJ15025
output transistors and frankly, neither really cuts it for high end
dollars.
Fact is you hit the nail on the head, Chris - no matter how high priced
or heavy to lift the equipment, "dirt cheap" output transistors sound
dirty and sound... dirt cheap...
And, that's the reason my under $700 vintage amp rebuild kits makes an
ancient and lowly regarded 1962 Dynaco Stereo-120 power amp, rebuilt
with my proprietary single pair of Ultralinear [ ULT ] Transistors
better sounding than $16K worth of Krell monobloks.
My ULT Output Transistors cost from $150 to $200 per pair... depending
on level of matching and polarity. But the fact is, when compared to
whatever number of $6 per pair devices, or even a hundred pairs of $2
Plastic Pak power devices, the quality difference can be heard.
Differences that can easily be heard. And the ULT's Sound is just
about the best that can be had with solid state technology today - - -
even a 1962 vintage Dynaco Stereo-120 becomes a Krell Killer...
Steven L. Bender, Designer of Vintage Audio Equipment
Email: buq...@prodigy.com <or> SLBe...@juno.com
*** The BENDER-2pp. a Transistor to Tube Amplifier Rebuild -
Nuts&Volts Magazine. February / March / April 1997 ***
BENDER VINTAGE AMP REBUILD KITS INFO PAGE:
http://pages.prodigy.com/BUQU35D <- use CAPS
" If we're not supposed to eat animals, how come they're made
out of meat " ??? -Tom Snyder
Chris Johnson
Mr. Steven L. Bender wrote:
> Fact is you hit the nail on the head, Chris - no matter how high priced
> or heavy to lift the equipment, "dirt cheap" output transistors sound
> dirty and sound... dirt cheap...
>
> And, that's the reason my under $700 vintage amp rebuild kits makes an
> ancient and lowly regarded 1962 Dynaco Stereo-120 power amp, rebuilt
> with my proprietary single pair of Ultralinear [ ULT ] Transistors
> better sounding than $16K worth of Krell monobloks.
>
> My ULT Output Transistors cost from $150 to $200 per pair... depending
> on level of matching and polarity. But the fact is, when compared to
> whatever number of $6 per pair devices, or even a hundred pairs of $2
> Plastic Pak power devices, the quality difference can be heard.
>
> Differences that can easily be heard. And the ULT's Sound is just
> about the best that can be had with solid state technology today - - -
> even a 1962 vintage Dynaco Stereo-120 becomes a Krell Killer...
>
> Steven L. Bender, Designer of Vintage Audio Equipment
Uh, you might want to move this discussion to rec.audio.opinion at this
point, because you have said something that deserves a good flame.
"Krell killer", my @!#!!
I've heard one of your warmed over Dynacos, and it sounded like a
busted transistor radio. Those hack jobs (and, yes, they LOOK
like a hack job, even! Try looking at some equipment which is designed
by someone with an eye for tecnical elegance some time and take notes!
Your workmanship is "U-G-L-Y I ain't got no alibi!")
are, in my opinion, a waste of a perfectly decent but common Dynaco.
They are of no interest unless you feel you just HAVE to do some sort
of homebrew/modification.
"You can't polish a turd." When will you learn that, Steve?
And now would be quite soon enough to transfer this to rec.audio.opinion.
I will flame no more on this board.
CJ
Krell: Anything else is just a gadget.