Pc2002m with mis-matched outputs

[Ziricote1]

I recently picked up a nice pc2002m from a fellow member here in barter town. I went through and recapped it, DC offset is good and bias dialed in easily. Only slight issue is that one channel has a single pair of replacement outputs that are not original and do not match the rest. Should I be looking for a matching set to replace these or is it no big deal? I know that on phase linear amps they specifically say that all outputs must match.

 

[avionic]

What pairs are installed ie 2SAxxxx,2SCxxxxx ? Or MJxxxx ? or what ever ?

 

[Ziricote1]

Can't remember exactly, but I think they are Motorola's. When I looked them up they seemed to be the previous generation of whatever MJxxx is recommended for replacement now.

 

[N8Nagel]

Can't answer your question, but Bryan was so impressed with this guy that he posted a pic of it on the local Facebook group

 

[avionic]

Can't remember exactly, but I think they are Motorola's. When I looked them up they seemed to be the previous generation of whatever MJxxx is recommended for replacement now.

I need to know what they are, all 4 pairs.

 

[Ziricote1]

OK, just found the photo I took earlier. I've got the original 2SC2607 and 2SA1116 - 7 pairs. And then one pair of motorola 70483180 and 70473180.

 

[Ziricote1]

 

[petehall347]

MJ15015
MJ15016

 

[petehall347]

makes me wonder why they were swapped

 

[avionic]

Me too.

 

[Ziricote1]

Me 3... rest of the amp is pristine and this one definitely lived an easy life.

 

[avionic]

The schematic says 2SC2608 and 2SA1117. The difference between a 2SA1116/C2607 and 2SA1117/C2608 .... 15A and 17A...probably a typo in the schematic.. I know the PC5002M uses 2SA1117/C2608.

 

[avionic]

MJ15015
MJ15016

Those are not very good subs........for the 200 volt Vceo -- 2SA1116/C2607. The onsemi's/motorola are 120 volt Vceo .

 

[Ziricote1]

I think they are peavey part numbers for MJ15024 and MJ15025. Found some NOS 2SC2607 and 2SA1116 from a US seller on ebay so I'm going to swap those in.

 

[avionic]

I think they are peavey part numbers for MJ15024 and MJ15025. Found some NOS 2SC2607 and 2SA1116 from a US seller on ebay so I'm going to swap those in.

FYI Those OEM transistors from ebay have a real good chance of being fake.

 

[Ziricote1]

Here's what they look like:

 

[avionic]

Here's what they look like:

Hopefully there legit..

 

[swanng]

I'll have to check my databooks to see if there is a currently manufactured replacement-I know there are substitutes, but most have the wrong package. Avionic-if you happen to read this-do you have any ideas about suitable subs for the 2SC2608 and 2SA1117 in TO-3 or suitable packages? I think the MJ-15022G comes close to the 2SC2608 and it's in the T-204-2 package, but the gain bandwidth product is only 4 MHz. Can't find anything (yet) for the 2SA1117.

 

[swanng]

Hmmmmmm...................maybe the MJ-15023G? It's the PNP equivalent of the MJ-15022G.

 

[avionic]

Can't find anything (yet) for the 2SA1117.

Good luck pretty much unobtainium.
MJ21193G and MJ21194G but still these are 16A devices.