MOSFET transistors

[[email protected]]

any idea where i can get the following MOSFETs?

1) A1102
0NY

2) C2577
09Y

3) C2578
30Y

4) A1103
38Y

The old ones in one of my amplifiers have blown....decided to have a
look into replacing them....

thanx

/\/\ad-Doggie

[Eeyore]

"François Yves Le Gal" wrote:

> wrote:
>
> >any idea where i can get the following MOSFETs?

They're bipolars. As Francois has indicated.

Graham

[Tim Schwartz]

wrote:
> any idea where i can get the following MOSFETs?
>
> 1) A1102
> 0NY
>
> 2) C2577
> 09Y
>
> 3) C2578
> 30Y
>
> 4) A1103
> 38Y
>
> The old ones in one of my amplifiers have blown....decided to have a
> look into replacing them....
>
> thanx
>
> /\/\ad-Doggie
As the other posters said, these are NOT MOSFET's. The full numbers are
2SA1102

2SA1103

2SC2577

2SC2578

The 1103/2578 are slightly more rugged than the 1102/2577, so I would
suggest using them. The most rugged version of this family are the
2SA1106 and 2SC2581, which you could use in both channels. They are the
highest voltage and current rating of the group. They will NOT give
your amplifier more power. Be aware that other parts could have failed too.

Because the amp has different output devices in each channel, I'd
assume that it has been serviced at least once before. It might make
sense to know what the manufacturer intended. also, you'll need to
adjust the bias and maybe offset, or your new transistors won't last
very long. If you reply, please include the make and model of your amp.

Regards,
Tim Schwartz
Bristol Electronics

[Eeyore]

Tim Schwartz wrote:

> wrote:
> > any idea where i can get the following MOSFETs?
> >
> > 1) A1102
> > 0NY
> >
> > 2) C2577
> > 09Y
> >
> > 3) C2578
> > 30Y
> >
> > 4) A1103
> > 38Y
> >
> > The old ones in one of my amplifiers have blown....decided to have a
> > look into replacing them....
> >
> > thanx
> >
> > /\/\ad-Doggie
> As the other posters said, these are NOT MOSFET's. The full numbers are
> 2SA1102
>
> 2SA1103
>
> 2SC2577
>
> 2SC2578
>
> The 1103/2578 are slightly more rugged than the 1102/2577, so I would
> suggest using them. The most rugged version of this family are the
> 2SA1106 and 2SC2581, which you could use in both channels. They are the
> highest voltage and current rating of the group. They will NOT give
> your amplifier more power. Be aware that other parts could have failed too.

In particular, watch out for fusible (flameproof) resistors designed to open
under fault conditions.

Graham

[[email protected]]

On Nov 21, 2:31*pm, Tim Schwartz > wrote:
> wrote:
> > any idea where i can get the following MOSFETs?
>
> > 1) A1102
> > * * *0NY
>
> > 2) C2577
> > * * *09Y
>
> > 3) C2578
> > * * *30Y
>
> > 4) A1103
> > * * *38Y
>
> > The old ones in one of my amplifiers have blown....decided to have a
> > look into replacing them....
>
> > thanx
>
> > /\/\ad-Doggie
>
> As the other posters said, these are NOT MOSFET's. *The full numbers are
> 2SA1102
>
> 2SA1103
>
> 2SC2577
>
> 2SC2578
>
> The 1103/2578 are slightly more rugged than the 1102/2577, so I would
> suggest using them. *The most rugged version of this family are the
> 2SA1106 and 2SC2581, which you could use in both channels. *They are the
> highest voltage and current rating of the group. *They will NOT give
> your amplifier more power. *Be aware that other parts could have failed too.
>
> * * * * Because the amp has different output devices in each channel, I'd
> assume that it has been serviced at least once before. *It might make
> sense to know what the manufacturer intended. *also, you'll need to
> adjust the bias and maybe offset, or your new transistors won't last
> very long. *If you reply, please include the make and model of your amp..
>
> Regards,
> Tim Schwartz
> Bristol Electronics

OK...i was told that they had blown...so i took the amp apart and took
the codes directly off the four uh..MOSFETs.....and pretty much all
else you said i didnt understand too well...(bear in mind I'm 16)...
AMP model:
Sansui integrated DC servo amplifier A-7

[[email protected]]

On Nov 21, 3:13*pm, Eeyore >
wrote:
> Tim Schwartz wrote:
> > wrote:
> > > any idea where i can get the following MOSFETs?
>
> > > 1) A1102
> > > * * *0NY
>
> > > 2) C2577
> > > * * *09Y
>
> > > 3) C2578
> > > * * *30Y
>
> > > 4) A1103
> > > * * *38Y
>
> > > The old ones in one of my amplifiers have blown....decided to have a
> > > look into replacing them....
>
> > > thanx
>
> > > /\/\ad-Doggie
> > As the other posters said, these are NOT MOSFET's. *The full numbers are
> > 2SA1102
>
> > 2SA1103
>
> > 2SC2577
>
> > 2SC2578
>
> > The 1103/2578 are slightly more rugged than the 1102/2577, so I would
> > suggest using them. *The most rugged version of this family are the
> > 2SA1106 and 2SC2581, which you could use in both channels. *They are the
> > highest voltage and current rating of the group. *They will NOT give
> > your amplifier more power. *Be aware that other parts could have failed too.
>
> In particular, watch out for fusible (flameproof) resistors designed to open
> under fault conditions.
>
> Graham

I've had a look over the amp twice before....didn't look like
anything else was blown...but i will have a look again just to double
check.

[Eeyore]

wrote:

> Eeyore wrote:
> > Tim Schwartz wrote:
> > > wrote:
> > > > any idea where i can get the following MOSFETs?
> >
> > > > 1) A1102
> > > > 0NY
> >
> > > > 2) C2577
> > > > 09Y
> >
> > > > 3) C2578
> > > > 30Y
> >
> > > > 4) A1103
> > > > 38Y
> >
> > > > The old ones in one of my amplifiers have blown....decided to have a
> > > > look into replacing them....
> >
> > > > thanx
> >
> > > > /\/\ad-Doggie
> > > As the other posters said, these are NOT MOSFET's. The full numbers are
> > > 2SA1102
> >
> > > 2SA1103
> >
> > > 2SC2577
> >
> > > 2SC2578
> >
> > > The 1103/2578 are slightly more rugged than the 1102/2577, so I would
> > > suggest using them. The most rugged version of this family are the
> > > 2SA1106 and 2SC2581, which you could use in both channels. They are the
> > > highest voltage and current rating of the group. They will NOT give
> > > your amplifier more power. Be aware that other parts could have failed too.
> >
> > In particular, watch out for fusible (flameproof) resistors designed to open
> > under fault conditions.
>
> I've had a look over the amp twice before....didn't look like
> anything else was blown...but i will have a look again just to double
> check.

You won't see a blown fusible. That's the whole point ! They're normally 'cement'
covered instead of lacquer so they don't burn and set the equipment alight and the
metal film underneath just fuses. The Japs use these a lot IME. And expect to find a
few in the last driver stage too.

Graham

[Eeyore]

wrote:

> OK...i was told that they had blown...

By whom ? Someone reliable or were they guessing ? Do you know how to test them ?


> so i took the amp apart and took
> the codes directly off the four uh..MOSFETs.....

Why did you think they were mosfets ? The Jap ones start (2S)J and (2S)K


> and pretty much all
> else you said i didnt understand too well...(bear in mind I'm 16)...
> AMP model:
> Sansui integrated DC servo amplifier A-7

Check out sci.electronics repair. You'll get good advice there and a few extra
tips no doubt. Mention your age too.

Graham

[Tim Schwartz]

wrote:
> any idea where i can get the following MOSFETs?
>
> 1) A1102
> 0NY
>
> 2) C2577
> 09Y
>
> 3) C2578
> 30Y
>
> 4) A1103
> 38Y
>
> The old ones in one of my amplifiers have blown....decided to have a
> look into replacing them....
>
> thanx
>
> /\/\ad-Doggie

Hello again,

Ok, the parts you are looking for are regular output transistors. I
would suggest that you try and get the 2SA1106 to replace both "A"
parts, and 2SC2581 for the "C" ones. One place to order them from is
MCM Electronics, www.mcmelectronics.com. They are about $5 each.

However, just soldering them in might not fix your amp, and if there
are other problems the new transistors could fail right away. Do you
have an ohm meter or a digital multi meter? Do you have a teacher at
school, relative or a friend who has some experience in electronics?

While you can learn a lot here, having some guidance from someone with
experience will make it a lot less frustrating for you. You might even
ask if a local repair shop might be willing to help you out.

Regards,
Tim Schwartz
Bristol Electronics

[jamesgangnc]

Cool that you want to try to fix it. You'll need a little patience and
reasoning but it's not brain surgery. But doing it right is more
complicated than soldering in new parts and hoping that was it. I'd suggest
you get a schematic for it. You'll probably have to spend $10 or so for a
copy if you don't get lucky and find a free one. There are a number of
sites that sell pdf copies. If you don't have a vom meter you need one of
those too. Start by making sure you've got all the voltages out of the
power supply. A little high on the output stage is ok but the rest of the
voltages should be pretty close. The schematic should show the lines going
to the different sections of the amp and what voltage to expect. Always
check the power supply first.

Then if it has no sound output as from your post I'm guessing that is the
case you can go into the output section and start checking stuff. You
probably will need to lift a few legs of the output transistors to get good
meter readings on them and the surrounding circuitry. There is info on the
web about how to check a transistor with a meter. The surrounding circuitry
should be pretty simple and you should be able to find the fusables if it
has any. If it doesn't then there will probably be some low value resistors
in the output stage that you should check closely.

Typically a stereo will have 2 pairs of the same transistor. Because the
two channels are normally identical. They are almost all class ab push pull
amps. That you have 4 different ones is unusual. That's why the other
poster thought that someone may have been in there before. The schematic
should also have part numbers for these. Make sure the parts that are in
there are the parts it was built with. If possible you want to get the same
parts even though there may be others that are suitable. If you use
different output transistors then you need to look into the bias and idle
output current and I don't think you want to get that far into it.

> wrote in message
...
On Nov 21, 2:31 pm, Tim Schwartz > wrote:
> wrote:
> > any idea where i can get the following MOSFETs?
>
> > 1) A1102
> > 0NY
>
> > 2) C2577
> > 09Y
>
> > 3) C2578
> > 30Y
>
> > 4) A1103
> > 38Y
>
> > The old ones in one of my amplifiers have blown....decided to have a
> > look into replacing them....
>
> > thanx
>
> > /\/\ad-Doggie
>
> As the other posters said, these are NOT MOSFET's. The full numbers are
> 2SA1102
>
> 2SA1103
>
> 2SC2577
>
> 2SC2578
>
> The 1103/2578 are slightly more rugged than the 1102/2577, so I would
> suggest using them. The most rugged version of this family are the
> 2SA1106 and 2SC2581, which you could use in both channels. They are the
> highest voltage and current rating of the group. They will NOT give
> your amplifier more power. Be aware that other parts could have failed
> too.
>
> Because the amp has different output devices in each channel, I'd
> assume that it has been serviced at least once before. It might make
> sense to know what the manufacturer intended. also, you'll need to
> adjust the bias and maybe offset, or your new transistors won't last
> very long. If you reply, please include the make and model of your amp.
>
> Regards,
> Tim Schwartz
> Bristol Electronics

OK...i was told that they had blown...so i took the amp apart and took
the codes directly off the four uh..MOSFETs.....and pretty much all
else you said i didnt understand too well...(bear in mind I'm 16)...
AMP model:
Sansui integrated DC servo amplifier A-7

[Eeyore]

jamesgangnc wrote:

> Cool that you want to try to fix it. You'll need a little patience and
> reasoning but it's not brain surgery. But doing it right is more
> complicated than soldering in new parts and hoping that was it. I'd suggest
> you get a schematic for it. You'll probably have to spend $10 or so for a
> copy if you don't get lucky and find a free one.

http://www.eserviceinfo.com/downloadsm/31415/Sansui_A9%20/%20A7%20/%20A5.html

You'll need (Win)rar though. Trial versions are available.
http://www.rarlab.com/download.htm

Graham

[[email protected]]

On Nov 22, 11:21*am, Eeyore >
wrote:
> wrote:
> > OK...i was told that they had blown...
>
> By whom ? Someone reliable or were they guessing ? Do you know how to test them ?
>
> > so i took the amp apart and took
> > the codes directly off the four uh..MOSFETs.....
>
> Why did you think they were mosfets ? The Jap ones start (2S)J and (2S)K
>
> > and pretty much all
> > else you said i didnt understand too well...(bear in mind I'm 16)...
> > AMP model:
> > Sansui integrated DC servo amplifier A-7
>
> Check out sci.electronics repair. You'll get good advice there and a few extra
> tips no doubt. Mention your age too.
>
> Graham

the person wasnt guessing...hes my father and hes worked on a fair
amount of electronics before...and it was his amp...so im guessing
that he blew something in it and knew about it

[[email protected]]

On Nov 22, 8:18*pm, Eeyore >
wrote:
> jamesgangnc wrote:
> > Cool that you want to try to fix it. *You'll need a little patience and
> > reasoning but it's not brain surgery. *But doing it right is more
> > complicated than soldering in new parts and hoping that was it. *I'd suggest
> > you get a schematic for it. *You'll probably have to spend $10 or so for a
> > copy if you don't get lucky and find a free one.
>
> http://www.eserviceinfo.com/downloadsm/31415/Sansui_A9%20/%20A7%20/%2...
>
> You'll need (Win)rar though. Trial versions are available.http://www.rarlab.com/download.htm
>
> Graham

well...thanx all for your help...ill have a look at it...i found the
transistors at a shop and im going to see how things go...will read
through the manual to make sure i know what im doing...but again...i
suppose my father would be the only one to know what blew because he
was the one that blew it

/\/\ad-Doggie

[Eeyore]

wrote:

> Eeyore wrote:
> > jamesgangnc wrote:
> > > Cool that you want to try to fix it. You'll need a little patience and
> > > reasoning but it's not brain surgery. But doing it right is more
> > > complicated than soldering in new parts and hoping that was it. I'd suggest
> > > you get a schematic for it. You'll probably have to spend $10 or so for a
> > > copy if you don't get lucky and find a free one.
> >
> > http://www.eserviceinfo.com/downloadsm/31415/Sansui_A9%20/%20A7%20/%2...
> >
> > You'll need (Win)rar though. Trial versions are available.http://www.rarlab.com/download.htm
>
>
> well...thanx all for your help...ill have a look at it...i found the
> transistors at a shop and im going to see how things go...will read
> through the manual to make sure i know what im doing...but again...i
> suppose my father would be the only one to know what blew because he
> was the one that blew it

Is he an electronics expert ? It's quite common for bipolar output stages to suffer 'cascade
failure'. At least check the driver transistors.

Graham

[Mark D. Zacharias[_3_]]

> wrote in message
...
On Nov 21, 2:31 pm, Tim Schwartz > wrote:
> wrote:
> > any idea where i can get the following MOSFETs?
>
> > 1) A1102
> > 0NY
>
> > 2) C2577
> > 09Y
>
> > 3) C2578
> > 30Y
>
> > 4) A1103
> > 38Y
>
> > The old ones in one of my amplifiers have blown....decided to have a
> > look into replacing them....
>
> > thanx
>
> > /\/\ad-Doggie
>
> As the other posters said, these are NOT MOSFET's. The full numbers are
> 2SA1102
>
> 2SA1103
>
> 2SC2577
>
> 2SC2578
>
> The 1103/2578 are slightly more rugged than the 1102/2577, so I would
> suggest using them. The most rugged version of this family are the
> 2SA1106 and 2SC2581, which you could use in both channels. They are the
> highest voltage and current rating of the group. They will NOT give
> your amplifier more power. Be aware that other parts could have failed
> too.
>
> Because the amp has different output devices in each channel, I'd
> assume that it has been serviced at least once before. It might make
> sense to know what the manufacturer intended. also, you'll need to
> adjust the bias and maybe offset, or your new transistors won't last
> very long. If you reply, please include the make and model of your amp.
>
> Regards,
> Tim Schwartz
> Bristol Electronics

>OK...i was told that they had blown...so i took the amp apart and took
>the codes directly off the four uh..MOSFETs.....and pretty much all
>else you said i didnt understand too well...(bear in mind I'm 16)...
>AMP model:
>Sansui integrated DC servo amplifier A-7

Junk model, and failure prone. I'm not at all convinced this one is going
anywhere...

Mark Z.

[Chris Hornbeck]

On Sun, 23 Nov 2008 04:05:12 +0000, Eeyore
> wrote:

>> well...thanx all for your help...ill have a look at it...i found the
>> transistors at a shop and im going to see how things go...will read
>> through the manual to make sure i know what im doing...but again...i
>> suppose my father would be the only one to know what blew because he
>> was the one that blew it
>
>Is he an electronics expert ? It's quite common for bipolar output stages to suffer 'cascade
>failure'. At least check the driver transistors.

Everyone's trying real hard to remain positive here, so I'm loath
to add that failure of the output stages almost always causes
failure upstream, and that simply replacing output devices, and
leaving failed upstream devices, is a recipe for instant
catastrophic re-failure.

The OP needs two things not yet mentioned: the ability to
examine the current state of both the damaged the undamaged
channels, with an ability to compare and knowledge of likely
failure mechanisms (an I/V curve tracer and a friend, fer starters).

And a way to apply power to the "repaired" amplifier that
doesn't depend on the Hail Mary principle. This could be
either a Variac (in American parlance) or the old series'd
light bulb trick, 60 watts is probably right for this case.


But, WHEN, not if, the OP finds that there's more stuff wrong
than just the output devices, (s)he will need to learn how to
examine the whole amplifier with a critical eye, and that eye
is most usefully an I/V plot on a scope.

Repair of failed modern amplifiers is a matter of cutting away
cancer. You keep cutting until you don't find any more cancer.
But you can't leave *ANY* cancer, or the patient will die.


Then, when all testable, observable failures have been repaired,
the whole amplifier must *still* be brought up to operating voltages
safely. A Variac and a quick hand is one way, and also provides
a convenient stage for bias adjustments and for reforming
antique electrolytic capacitors (a separate issue, but one that
serious hobbyists might someday see). Another way is the ancient
series-in-the-AC-line lamp.

But, either way, the unstated-but-it-seems-assumed-by-the-OP idea
that (s)he could just replace a few devices, plug up and go, is false.

This is very much a wonderful learning opportunity, so I wouldn't
want to spoil it by a spectacular early failure, when some proper
prep is both a teachable moment and economical. Cool beans.


And, much thanks, as always,
Chris Hornbeck

[Eeyore]

Chris Hornbeck wrote:

> On Sun, 23 Nov 2008 04:05:12 +0000, Eeyore
> > wrote:
>
> >> well...thanx all for your help...ill have a look at it...i found the
> >> transistors at a shop and im going to see how things go...will read
> >> through the manual to make sure i know what im doing...but again...i
> >> suppose my father would be the only one to know what blew because he
> >> was the one that blew it
> >
> >Is he an electronics expert ? It's quite common for bipolar output stages to suffer 'cascade
> >failure'. At least check the driver transistors.
>
> Everyone's trying real hard to remain positive here, so I'm loath
> to add that failure of the output stages almost always causes
> failure upstream, and that simply replacing output devices, and
> leaving failed upstream devices, is a recipe for instant
> catastrophic re-failure.
>
> The OP needs two things not yet mentioned: the ability to
> examine the current state of both the damaged the undamaged
> channels, with an ability to compare and knowledge of likely
> failure mechanisms (an I/V curve tracer and a friend, fer starters).
>
> And a way to apply power to the "repaired" amplifier that
> doesn't depend on the Hail Mary principle. This could be
> either a Variac (in American parlance) or the old series'd
> light bulb trick, 60 watts is probably right for this case.
>
> But, WHEN, not if, the OP finds that there's more stuff wrong
> than just the output devices, (s)he will need to learn how to
> examine the whole amplifier with a critical eye, and that eye
> is most usefully an I/V plot on a scope.
>
> Repair of failed modern amplifiers is a matter of cutting away
> cancer. You keep cutting until you don't find any more cancer.
> But you can't leave *ANY* cancer, or the patient will die.
>
> Then, when all testable, observable failures have been repaired,
> the whole amplifier must *still* be brought up to operating voltages
> safely. A Variac and a quick hand is one way, and also provides
> a convenient stage for bias adjustments and for reforming
> antique electrolytic capacitors (a separate issue, but one that
> serious hobbyists might someday see). Another way is the ancient
> series-in-the-AC-line lamp.
>
> But, either way, the unstated-but-it-seems-assumed-by-the-OP idea
> that (s)he could just replace a few devices, plug up and go, is false.
>
> This is very much a wonderful learning opportunity, so I wouldn't
> want to spoil it by a spectacular early failure, when some proper
> prep is both a teachable moment and economical. Cool beans.

Well said. 100% agreed. Given that BJT failure is usually terminal, devices could probably be
tested with a DMM (given the requiiste knowledge) but they must be removed from the PCB.

Or buy one of those cheap Asian meters with a transistor tester built in !
http://cgi.ebay.co.uk/PRO-DIGITAL-MULTI-METER-VOLTAGE-VOLT-TESTER-TESTERS_W0QQitemZ120337117733QQihZ002QQcategoryZ58 277QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

All of £8 in P&P

Beware of pin-out issues.

Graham