help identify Crown driver transistor

[angelothewolf]

Hi there,

im working on a Crown Macrotech 600, canīt find the schematics.

BTW I got a hole set of C8187/C8188 Crown output transistors (originals are C4751/C6492)

This amp came with a few output and driver transistors shorted, So I decided to replace all of them. My problem is that I coudnt identify the original driver transistor Itīs a TO220 Motorola device marked "84-8"

I have another Macrotech that has 2sa1837/2sc4793 as drivers, I imagine that something like that (230v 1A) will work, but it would be good to know wich the original transistor was, to match pinout and specs.
SOmebody has idea, or the schems??

thanks!

[oc disorder]

Bm Amps have a few including the 600. Here's just the 600.

http://bmamps.com/Schematics/Crown/C...ice_Manual.pdf

I'm reduced to a snails pace on a 800. Never cleaned for years and years and ended up a block of felt ..(compressed dust !)

Transistors .. resistors destroyed... caps seem ok.

Found this on line.... going through forums. May be inaccurate... then again maybe another clue to the wild and wacky in house
numbering system!! Seems like you already know this.

C6492 = Mj15016/Sj4092 Pnp C4751 = Mj15015/Sj7443 Npn ( I presume Mj15024/25 are the usual replacements.)

HERES SOME INFO, HOPE IT HELPS IN SOME WAY.......

103285-1 = SJ7195
103286-1 = SJ7196

C8188-2 = SJ7147
C8187-4 = SJ7148

AND THE REST IS ANYBODY'S GUESS!

Crown now grade the transistors in just 2 types, 1 and 2, if you
have grade 3 or 4 fitted then you must change the whole set.


EDIT: attached a jpeg

[lowell]

Just want to add, since I'm working on one of these, that the power transistors C4751 and C6492 are MJ15015 and MJ15016 by Motorola. Crown emailed me back with this info and said they all must be matched as well since they're directly paralleled.

[lowell]

Was about $80 including shipping.

[J M Fahey]

Was about $80 including shipping.

*What* was about $80 including shipping?

[lowell]

The transistors - matched, 4 of each, and from Crown directly.

[angelothewolf]

I ended up repairing this Crown ( macrotech600) with the transistors of a Macrotech 3600 that I have from waste. I use C8188/87 output devices and to220 2SA1837/2SC4793 as Drivers
After replace some shorted diodes (1n4007) and adjusting bias and "ODEP" voltages properly it work very very well!