Akai AA-1150 Need Transistor Substitutions Please

[TubeJunkie]

Hi. I have an Akai AA-1150 with some burnt components on the main amp board. I'm looking for transistor substitutes for
2SD600K (TR5 on schematic) main amp board,
2SB631K (TR6 on schematic) main amp board
2SB618 (TR6a, b on output board) batwing style mounts
2SD588A (TR7 a ,b on output board) batwing style mounts


I have the service manual pdf, but it's too large to upload. Link below. Thanks in advance.

https://www.hifiengine.com/manual_library/akai/aa-1150.shtml

 

[quaddriver]

IIRC the 2SB618/2SD588 pair are the outputs in a kenwood KR4070. and IIRC in a thread I started about one, I worked those out...lemme check....this is what I wrote:

Outputs:
Q15, Q16 Outputs 2SD588 NPN t0220 batwing? bce 150v 7A 80w 8Mhz hfe min 40
replace with: 512-FJP5200RTU npn tp220 bce 230v 15a 80w 30mhz hfe 55-110 $1.60

Q17, Q18 Outputs 2SB618 PNP t0220 batwing bce 150v 7A 80w 8mhz hfe min 40
replace with 512-FJP1943RTU pnp to220 bce -230v 15a 80w 30mhz hfe 55-110 $1.82

Thems mouser part numbers. HOWEVER, I happen to have another set of batwings, condition unknown (sometimes even bad trans give an hfe on the meter, and pass diode checks, but just suck due to thermal damage) and you can have them...

the replacements I dialed up are available in heavier currents but they are NOT batwings. If you locate a thread I did on a KR4070 that went silent, you see pics of how I modified the sink to mount them.

are the others the drivers? look at KAS1220/KSC2690 pairs

 

[TubeJunkie]

Thanks quad driver for your help. I ordered parts and found more bad parts. lol. I want to replace the diodes marked GP300. Looks like a standard 200v 3A rectifier. Would 1N5402G work?

 

[quaddriver]

cant find the recovery time for the 5402 at mouser, but sure, I have those in stock - this for the power supply?

 

[TubeJunkie]

Yes, power supply. I had found a website, that listed 1N5402G as a replacement.

BTW, I mounted the new transistors on the heatsink with the metal backs off of the old ones. With a little deconstruction, that worked good. Thanks

 

[rotco]

If you locate a thread I did on a KR4070 that went silent, you see pics of how I modified the sink to mount them.

Hi @quaddriver
i also have the exact problem with the exact Akai model.
i need to replace those 2SB618, 2SD588

thanks for the adequate substitutes.
i looked for your post about the KR4070 and couldnt find pics for reference how to work around the batwing issue.
(only find PDF for how you fix any switch there)
this is the post i found (maybe im not in the correct place) please help if you can
http://audiokarma.org/forums/index.php?threads/good-news-for-kenwood-owners.105429/

 

[quaddriver]

Hi @quaddriver
i also have the exact problem with the exact Akai model.
i need to replace those 2SB618, 2SD588

thanks for the adequate substitutes.
i looked for your post about the KR4070 and couldnt find pics for reference how to work around the batwing issue.
(only find PDF for how you fix any switch there)
this is the post i found (maybe im not in the correct place) please help if you can
http://audiokarma.org/forums/index.php?threads/good-news-for-kenwood-owners.105429/

in the kenwood forum find 'kenwood kr4070 went silient...' as the title. Its about a 4070 amp rebuild BUT, it has the output subs and how I fit them on a KENWOOD heat sink....ymmv