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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Anybody know what the output transistors are in a Peavey PV-1.3K high power
slave amp ? House codes 70484200 and 70474200 TIA Arfa |
#2
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Arfa Daily wrote:
Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 TIA Arfa -- 70484200 = MJ-15024 70474200 = MJ-15025 Dave M |
#3
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![]() "Dave M" Arfa Daily wrote: Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 -- 70484200 = MJ-15024 70474200 = MJ-15025 ** Probably true enough - but PV use the codes for reason. Motorola ( or "ON" ) select devices from regular stock to meet particular customer's requirements and supply them with a code number that is confidential. With output transistors that are to be used in parallel sets, devices are selected that have near identical Base Emitter voltages for given collector currents. This is a parameter that varies quite independently from simple Beta. I recall seeing a test rig and procedure described by PV that allows service techs to select output devices in this way. Since they were released in 1977, MJ15024/5 devices have undergone several major revisions of the chip design and along with batch and sample to sample variations this renders older and newer examples incompatible for parallel operation. Also and not least, these same devices are on the very top of the list for counterfeiters so you MUST know that the ones you buy are from authorised sources. Farnell and RS Components are safe sources - almost no-one else is. .... Phil |
#4
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![]() "Phil Allison" wrote in message ... "Dave M" Arfa Daily wrote: Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 -- 70484200 = MJ-15024 70474200 = MJ-15025 ** Probably true enough - but PV use the codes for reason. Motorola ( or "ON" ) select devices from regular stock to meet particular customer's requirements and supply them with a code number that is confidential. With output transistors that are to be used in parallel sets, devices are selected that have near identical Base Emitter voltages for given collector currents. This is a parameter that varies quite independently from simple Beta. I recall seeing a test rig and procedure described by PV that allows service techs to select output devices in this way. Since they were released in 1977, MJ15024/5 devices have undergone several major revisions of the chip design and along with batch and sample to sample variations this renders older and newer examples incompatible for parallel operation. Also and not least, these same devices are on the very top of the list for counterfeiters so you MUST know that the ones you buy are from authorised sources. Farnell and RS Components are safe sources - almost no-one else is. ... Phil Thanks for that. It would be Farnell that I would be getting them from. I don't think that I've currently got any in stock, but if I have, it will be Farnell that they came from. I suppose that there are several alternatives here. I could just go for it, and look at the voltages across the emitter resistors to see how close a match that I've got to the others. Or I could replace the whole set, which would be an expensive option, or I could leave the bad pair out altogether, and maybe take a pair out of the other channel to balance it up, if the owner doesn't use it at anywhere near the kilowatt per channel that it claims to be. |
#5
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![]() "Arfa Daily" Thanks for that. It would be Farnell that I would be getting them from. I don't think that I've currently got any in stock, but if I have, it will be Farnell that they came from. I suppose that there are several alternatives here. I could just go for it, and look at the voltages across the emitter resistors to see how close a match that I've got to the others. Or I could replace the whole set, which would be an expensive option, or I could leave the bad pair out altogether, and maybe take a pair out of the other channel to balance it up, ** Huh ?? That last one is plain crazy. BTW: PV released the 1.3K twenty years ago - the 4 digit date codes on the TO3 device will tell you when they were made. Recent MJ15024/5s I have tested show slightly higher Vbe readings than old ones - so will draw less current when operating in parallel. I only get worried if new devices draw more. .... Phil |
#6
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On 01/10/2013 20:17, Arfa Daily wrote:
Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 TIA Arfa my exploration of Peavey PV 2000, 2 x 1KW, 30Kg, 2001 http://www.divdev.fsnet.co.uk/repair2p.htm "70474200 replaced with MJ15025 and 70484200 with MJ15024" |
#7
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![]() "Phil Allison" wrote in message ... "Arfa Daily" Thanks for that. It would be Farnell that I would be getting them from. I don't think that I've currently got any in stock, but if I have, it will be Farnell that they came from. I suppose that there are several alternatives here. I could just go for it, and look at the voltages across the emitter resistors to see how close a match that I've got to the others. Or I could replace the whole set, which would be an expensive option, or I could leave the bad pair out altogether, and maybe take a pair out of the other channel to balance it up, ** Huh ?? That last one is plain crazy. BTW: PV released the 1.3K twenty years ago - the 4 digit date codes on the TO3 device will tell you when they were made. Recent MJ15024/5s I have tested show slightly higher Vbe readings than old ones - so will draw less current when operating in parallel. I only get worried if new devices draw more. ... Phil Fair enough. Option 1 then ... Arfa |
#8
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![]() "N_Cook" wrote in message ... On 01/10/2013 20:17, Arfa Daily wrote: Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 TIA Arfa my exploration of Peavey PV 2000, 2 x 1KW, 30Kg, 2001 http://www.divdev.fsnet.co.uk/repair2p.htm "70474200 replaced with MJ15025 and 70484200 with MJ15024" Ta ! Arfa |
#9
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![]() "Arfa Daily" wrote in message ... Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 TIA Arfa Here's a Peavey semiconductor cross reference sheet worth keeping on file: http://www.slideshare.net/modestogui...cross-ref-2009 Gareth. |
#10
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![]() "Arfa Daily" wrote in message ... "Phil Allison" wrote in message ... "Dave M" Arfa Daily wrote: Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 -- 70484200 = MJ-15024 70474200 = MJ-15025 ** Probably true enough - but PV use the codes for reason. Motorola ( or "ON" ) select devices from regular stock to meet particular customer's requirements and supply them with a code number that is confidential. With output transistors that are to be used in parallel sets, devices are selected that have near identical Base Emitter voltages for given collector currents. This is a parameter that varies quite independently from simple Beta. I recall seeing a test rig and procedure described by PV that allows service techs to select output devices in this way. Since they were released in 1977, MJ15024/5 devices have undergone several major revisions of the chip design and along with batch and sample to sample variations this renders older and newer examples incompatible for parallel operation. Also and not least, these same devices are on the very top of the list for counterfeiters so you MUST know that the ones you buy are from authorised sources. Farnell and RS Components are safe sources - almost no-one else is. ... Phil Thanks for that. It would be Farnell that I would be getting them from. I don't think that I've currently got any in stock, but if I have, it will be Farnell that they came from. I suppose that there are several alternatives here. I could just go for it, and look at the voltages across the emitter resistors to see how close a match that I've got to the others. Or I could replace the whole set, which would be an expensive option, or I could leave the bad pair out altogether, and maybe take a pair out of the other channel to balance it up, if the owner doesn't use it at anywhere near the kilowatt per channel that it claims to be. Farnell have recently set a minimum order price of £20, othrwise you have to pay £3.95 +VAT postage. Bummer, I used to order on a daily basis so every spare arrived next day, Now I'm having to save them up and order weekly., and my customers wait longer. Cuh, its a sign o' the times. Gareth. |
#11
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On 02/10/2013 14:32, Gareth Magennis wrote:
"Arfa Daily" wrote in message ... "Phil Allison" wrote in message ... "Dave M" Arfa Daily wrote: Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 -- 70484200 = MJ-15024 70474200 = MJ-15025 ** Probably true enough - but PV use the codes for reason. Motorola ( or "ON" ) select devices from regular stock to meet particular customer's requirements and supply them with a code number that is confidential. With output transistors that are to be used in parallel sets, devices are selected that have near identical Base Emitter voltages for given collector currents. This is a parameter that varies quite independently from simple Beta. I recall seeing a test rig and procedure described by PV that allows service techs to select output devices in this way. Since they were released in 1977, MJ15024/5 devices have undergone several major revisions of the chip design and along with batch and sample to sample variations this renders older and newer examples incompatible for parallel operation. Also and not least, these same devices are on the very top of the list for counterfeiters so you MUST know that the ones you buy are from authorised sources. Farnell and RS Components are safe sources - almost no-one else is. ... Phil Thanks for that. It would be Farnell that I would be getting them from. I don't think that I've currently got any in stock, but if I have, it will be Farnell that they came from. I suppose that there are several alternatives here. I could just go for it, and look at the voltages across the emitter resistors to see how close a match that I've got to the others. Or I could replace the whole set, which would be an expensive option, or I could leave the bad pair out altogether, and maybe take a pair out of the other channel to balance it up, if the owner doesn't use it at anywhere near the kilowatt per channel that it claims to be. Farnell have recently set a minimum order price of £20, othrwise you have to pay £3.95 +VAT postage. Bummer, I used to order on a daily basis so every spare arrived next day, Now I'm having to save them up and order weekly., and my customers wait longer. Cuh, its a sign o' the times. Gareth. And that is before Royal Mail privatisation |
#12
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![]() "Gareth Magennis" wrote in message ... "Arfa Daily" wrote in message ... "Phil Allison" wrote in message ... "Dave M" Arfa Daily wrote: Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 -- 70484200 = MJ-15024 70474200 = MJ-15025 ** Probably true enough - but PV use the codes for reason. Motorola ( or "ON" ) select devices from regular stock to meet particular customer's requirements and supply them with a code number that is confidential. With output transistors that are to be used in parallel sets, devices are selected that have near identical Base Emitter voltages for given collector currents. This is a parameter that varies quite independently from simple Beta. I recall seeing a test rig and procedure described by PV that allows service techs to select output devices in this way. Since they were released in 1977, MJ15024/5 devices have undergone several major revisions of the chip design and along with batch and sample to sample variations this renders older and newer examples incompatible for parallel operation. Also and not least, these same devices are on the very top of the list for counterfeiters so you MUST know that the ones you buy are from authorised sources. Farnell and RS Components are safe sources - almost no-one else is. ... Phil Thanks for that. It would be Farnell that I would be getting them from. I don't think that I've currently got any in stock, but if I have, it will be Farnell that they came from. I suppose that there are several alternatives here. I could just go for it, and look at the voltages across the emitter resistors to see how close a match that I've got to the others. Or I could replace the whole set, which would be an expensive option, or I could leave the bad pair out altogether, and maybe take a pair out of the other channel to balance it up, if the owner doesn't use it at anywhere near the kilowatt per channel that it claims to be. Farnell have recently set a minimum order price of £20, othrwise you have to pay £3.95 +VAT postage. Bummer, I used to order on a daily basis so every spare arrived next day, Now I'm having to save them up and order weekly., and my customers wait longer. Cuh, its a sign o' the times. Gareth. Funnily enough, I sent their customer liason an email about just this, only today. I told them in no uncertain terms that I didn't think it was very sporting of them to start doing this to their long-standing small customers who have helped them build their business over the last 30 years into what it is now, and have loyally stuck with them through the recent bad times. I blame this decision in no small part on the fact that they insist on using UPS to ship just about everything. I don't care how good a deal they have with them, it's never going to be cheaper than Royal Mail for small packets. Another contributory factor is the warehouse that they have in Belgium, and from which they often ship all or part of an order. That always requires them to use a UPS international service. I don't see why I should be penalised for that. Just in the last week, I have had, all from the same order, an item out of stock, and two others shipped separately from Belgium, each of which took UPS two days to get to me. So, not only do I now have to pay for the shipping, I am actually getting a worse delivery service for it. The trouble is that it's not just £3.95 either. It's that plus VAT making it £4.75. That's enough in a lot of cases to make the difference between a repair going ahead, and the item being scrapped. Much of the general stuff, I now order from UK eBay suppliers, who often offer free postage, or very reasonable postage charges based on what it actually costs to send a 100 gram JIffy package. Farnell, unless they change this policy, have been relegated to only supplying stuff that really does need to come from them. Arfa |
#13
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![]() "Gareth Magennis" wrote in message ... "Arfa Daily" wrote in message ... Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 TIA Arfa Here's a Peavey semiconductor cross reference sheet worth keeping on file: http://www.slideshare.net/modestogui...cross-ref-2009 Gareth. Cheers mate. Very useful Arfa |
#14
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![]() "Arfa Daily" wrote in message ... Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 TIA Arfa We have stopped slavery about 60 years ago; get with the program. How would you like to be a slave? Shaun |
#15
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"Arfa Daily" wrote:
Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 TIA Arfa I have a 1.3K, it is usually on the floor. I was trying to think where I got the transistors. ? I have not tested it after the flood, but I hosed it out good ! I think I should check the connectors. Greg |
#16
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![]() Shaun wrote: "Arfa Daily" wrote in message ... Anybody know what the output transistors are in a Peavey PV-1.3K high power slave amp ? House codes 70484200 and 70474200 TIA Arfa We have stopped slavery about 60 years ago; get with the program. How would you like to be a slave? You are a slave, if you pay taxes you didn't vote for. -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge. |
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