Peavey transistors

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi to anyone who can help,
A Peavey Heritage has 2-6465 T0-3 case NPN and 2-6531 T0-92 case NPN transistors in the output circuit..
Tell me this is a 6465 a 6465 no matter who makes them.
Is the number on a transistor is a standard throughout the transistor world.
A Sylvania 6465 and a Motorola 6465 is the same transistor, RIGHT?
Thanks to who ever can guide me here.
 
PM sent. The last time I saw this it was just one 6L6 per driver transistor - and they were TO-220. One side was still ok, and it just looked like a run of the mill transistor. I used a TIP41C and it was fine. Currents are just plate current, and cathode voltages just don't get that high - especially in pentode. I'd just need to confirm whether or not it needs a darlington or just a regular one. The circuit was just a current source, modulated by the audio with an op amp referred to the negative bias rail.
 
6465, or SJ6465, is just a Peavey part number, NOT an industry number. SO you won't find them in Moto or Sylvania catalogs. the part is a Moto MJ4247 as someone pointed out. Even if the part is not available, you can still look up its data sheet.

The MJ4247 is a 120v 8A part, cinsiderable overkill. As is the TO3 package. But later Peavey models like the Classic VTX used a more modern part in a TO220 in the same application, as did Music Man in many models as someone pointed out. The Peavey house nunber was 5884, but those were MJE15030.

MJE15030 is a 150v 8A part with plenty of dissipation. MJE15032 is a 250v 8A, and MJe15034 is 350v 8A, if you want to goose the specs a little. You would have to mount them where teh TO3 was, but that should not be mich of a challenge.




And as someone noted, the 6531 is an MPS6531. PV also lists the 2N3642 as a sub. MPS6531 is available at Mouser for 7 or 8 cents each.


Cathode voltage on the 6L6 will be about 90VDC at idle. The control grids are set at about +15VDC. Idle current is about 10ma. These run at close to class B.
 
Peavey Heritage

Man you guys, I've never had so much info. Thanks to you all!
This amp was brought to me with a couple of problems.
First he took it to someone on the south side of OKC. This person replaced the 2 original speakers saying that was the problem. He removed the originals and put in one different Peavey speaker and one Eminence Alpha. That wasn't the problem....duh! The real problem was that someone had removed either one or all four 6L6's and ended up breaking the guide pin on a couple of them and I believe that someone installed them a hole or two off and it caused the two 6465's and two 6531's to blow.
I spoke with a tech at Peavey and they said that's most likely what took them out..I have been testing the caps in the power circuit and so far everything checks out okay. So that's is the problem...now I'm waiting on the parts from Antique Electronic Supply.
I tested the original 12's, cleaned the dirt out and they are fine. After I cleaned the speakers I attached two pieces of plastic screen (cross-hatch) on the open hole of the magnet structure. I'll take a couple of pics and post them for all to see.
Peace to you all and keep looking up!
Ron in OKC
 
Peavey MPS6530 & 6465 Transistors

Ron,

How did those parts from Antique Electronics work out for you? Repair went OK?

I just fixed one of these Heritage VTX 212 combo amps. It had blown two transistors, one 6465 (SJ6465) and one MPS6530. Got replacement parts at Newark Electronic's (element-14.com) web store.

Peavey's cross says MPS6530 is an MPS6531. Newark shows the exact replacement for the MPS6530 as a 2N4401 (9 cents ea). They also have the MPS6531 for 12 cents ea. I got some 2N4401s and replaced both Q6 & Q8 with them.

For the 6465, I used a 2N3442 ($1.43ea). The gain (hfe) of the 2N3442 can be a little low so you might have to hand-select higher gain parts to match the 6465, or match two 2N3442s. I did the former and the amp works great. Had I seen this thread before placing an order, I would have bought the AES old stock parts. But now, the water's under the bridge & I feel comfortable with my device substitution.

My Heritage VTX is a real nice, near-museum piece. Even has the original vinyl cover & footswitch. Check it out...
 

Attachments

  • img_0978-1.jpg
    img_0978-1.jpg
    180.5 KB · Views: 81
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.