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#1
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MOSFET transistors
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 |
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#2
Posted to rec.audio.tech
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MOSFET transistors
"François Yves Le Gal" wrote: wrote: any idea where i can get the following MOSFETs? They're bipolars. As Francois has indicated. Graham |
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#3
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MOSFET transistors
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#4
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MOSFET transistors
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 |
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#5
Posted to rec.audio.tech
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MOSFET transistors
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 |
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#6
Posted to rec.audio.tech
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MOSFET transistors
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. |
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#7
Posted to rec.audio.tech
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MOSFET transistors
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#8
Posted to rec.audio.tech
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MOSFET transistors
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#9
Posted to rec.audio.tech
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MOSFET transistors (2nd take)
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 |
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#10
Posted to rec.audio.tech
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MOSFET transistors
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 |
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#11
Posted to rec.audio.tech
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MOSFET transistors
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/download...%20/%20A5.html You'll need (Win)rar though. Trial versions are available. http://www.rarlab.com/download.htm Graham |
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#12
Posted to rec.audio.tech
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MOSFET transistors
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 |
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#13
Posted to rec.audio.tech
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MOSFET transistors
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/download...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 |
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#15
Posted to rec.audio.tech
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MOSFET transistors
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. |
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#16
Posted to rec.audio.tech
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MOSFET transistors
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 |
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#17
Posted to rec.audio.tech
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MOSFET transistors
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-MU...QQcmdZViewItem All of £8 in P&P Beware of pin-out issues. Graham |
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