motorola transistor part number

contaxchen · 24th February 2005, 04:08 AM

Hi all,
I am fixing an audio research D-100B power amp. I think the output power transistors are dead. I don't know the part number printed on the transistor cover. What printed on the cover are motorola 300027 7926 and motorola 300026 7852. Apparently, they are complementary pair. I think the number is only for audio research interior reference.

Anybody knows what they are??
Thanks alot!
Lhchen

jaycee · 24th February 2005, 04:24 PM

If they are motorola in TO-3 cans you can bet they are MJ15003/04 or MJ15024/25. In any case either of these should drop right in and work identically.

contaxchen · 24th February 2005, 10:15 PM

Hi,

Thanks for the help. They use 6 pairs of pnp and npn power transistors in parallel to produce only 100 watts output at +55v -0- -55v voltage. So, it's very unlikely to be one of those that we often use. Those transistors must be out of production nowadays and long not availible.

I am looking for substitutions, still motorola ? no sanken?
Thanks for any coment.
Lhchen

Original Burnedfingers · 24th February 2005, 11:05 PM

I am looking for substitutions, still motorola ? no sanken?

Yes, still Motorola/on semiconductor. No not Sanken if you want it to live for a while.

As mentioned by jaycee either of the motorola parts will work.

Eva · 24th February 2005, 11:38 PM

Sanken and Toshiba no longer produce meatal can T0-3 bipolar output devices. Motorola is almost the only source

These three companies produce very reliable transistors, but Sanken and Toshiba suffer more from fakes in the American and European markets

contaxchen · 25th February 2005, 02:43 AM

Wait a minute!!
After I opened up the chassis, I found out 6 pairs of NTE60/61 each channel. We know NTE60/61 are equivalent to MJ15003/15004. My Audio Research D100b got only output at 100 watts at 8 ohm. At B+ as 55v-0v+55v, what would be the output rating? Where are those transistors from? Somebody put them in? For extra power?

Am I missing something here? Oh My! I bought a lemon.
Lhchen

djk · 25th February 2005, 02:46 AM

"Thanks for the help. They use 6 pairs of pnp and npn power transistors in parallel to produce only 100 watts output at +55v -0- -55v voltage. So, it's very unlikely to be one of those that we often use. Those transistors must be out of production nowadays and long not availible.
I am looking for substitutions, still motorola ? no sanken?
Thanks for any coment."

Why not use what Audio Research used?

The date codes indicate the 78~79 vintage, the MJ15022/23 was just showing up in amplifiers, that's probably what they are.

Take a dead one and cut the top off and look!

If not an MJ15022/23 they are most likely MJ15003/04.

24th February 2005, 04:08 AM	#1
contaxchen diyAudio Member Join Date: Aug 2003 Location: Indiana USA	motorola transistor part number Hi all, I am fixing an audio research D-100B power amp. I think the output power transistors are dead. I don't know the part number printed on the transistor cover. What printed on the cover are motorola 300027 7926 and motorola 300026 7852. Apparently, they are complementary pair. I think the number is only for audio research interior reference. Anybody knows what they are?? Thanks alot! Lhchen __________________ The best way to stop rust on transformers is to power them up.

24th February 2005, 10:15 PM	#3
contaxchen diyAudio Member Join Date: Aug 2003 Location: Indiana USA	Hi, Thanks for the help. They use 6 pairs of pnp and npn power transistors in parallel to produce only 100 watts output at +55v -0- -55v voltage. So, it's very unlikely to be one of those that we often use. Those transistors must be out of production nowadays and long not availible. I am looking for substitutions, still motorola ? no sanken? Thanks for any coment. Lhchen __________________ The best way to stop rust on transformers is to power them up.

25th February 2005, 02:43 AM	#6
contaxchen diyAudio Member Join Date: Aug 2003 Location: Indiana USA	Wait a minute!! After I opened up the chassis, I found out 6 pairs of NTE60/61 each channel. We know NTE60/61 are equivalent to MJ15003/15004. My Audio Research D100b got only output at 100 watts at 8 ohm. At B+ as 55v-0v+55v, what would be the output rating? Where are those transistors from? Somebody put them in? For extra power? Am I missing something here? Oh My! I bought a lemon. Lhchen __________________ The best way to stop rust on transformers is to power them up.

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24th February 2005, 04:24 PM	#2
jaycee diyAudio Member Join Date: Apr 2004 Location: Norwich, UK	If they are motorola in TO-3 cans you can bet they are MJ15003/04 or MJ15024/25. In any case either of these should drop right in and work identically.

24th February 2005, 11:05 PM	#4
Original Burnedfingers diyAudio Member Join Date: Nov 2002	I am looking for substitutions, still motorola ? no sanken? Yes, still Motorola/on semiconductor. No not Sanken if you want it to live for a while. As mentioned by jaycee either of the motorola parts will work.

24th February 2005, 11:38 PM	#5
Eva diyAudio Member Join Date: Oct 2003 Location: Near the sea	Sanken and Toshiba no longer produce meatal can T0-3 bipolar output devices. Motorola is almost the only source These three companies produce very reliable transistors, but Sanken and Toshiba suffer more from fakes in the American and European markets

25th February 2005, 02:46 AM	#7
djk diyAudio Member Join Date: Feb 2001 Location: USA	"Thanks for the help. They use 6 pairs of pnp and npn power transistors in parallel to produce only 100 watts output at +55v -0- -55v voltage. So, it's very unlikely to be one of those that we often use. Those transistors must be out of production nowadays and long not availible. I am looking for substitutions, still motorola ? no sanken? Thanks for any coment." Why not use what Audio Research used? The date codes indicate the 78~79 vintage, the MJ15022/23 was just showing up in amplifiers, that's probably what they are. Take a dead one and cut the top off and look! If not an MJ15022/23 they are most likely MJ15003/04.

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