SX1250 Transistor Repalcements

[Ultimatt]

About to tackle a 1250 and was wondering about transistor replacement. Per the specs the unit contains the following transistors some of which which are on the 10 worst list (bold underlined) -

2SA628
2SA684A
2SA720
2SA725
2SA726
2SA733
2SA750
2SA850
2SA858
2SA872A
2SA899A

2SB507P
2SB630

2SC710
2SC869
2SC945A
2SC1166
2SC1312
2SC1313
2SC1318
2SC1342
2SC1384
2SC1439
2SC1735
2SC1775A
2SC1904

2SD313P
2SD325R
2SD610

2SK30AW

Two Questions -

1. For the ones on the worst list are any in locations where the replacements should be matched? For example should the 4 - 2SC1312's on the tone amp be matched?

2. For the others not on the list should any be replacement with modern equivalents for improved performance or longevity?

Thanks.

 

[Watthour]

2SA628 =>
2SA684A =>
2SA720 => KSA992F or E
2SA725 => KSA992F or E
2SA726 => KSA992F or E
2SA733 => KSA733G
2SA750 => KSA992F
2SA850 => KSA1013Y
2SA858 =>
2SA872A => KSA992F
2SA899A =>
2SB507P =>
2SB630 =>
2SC710 =>
2SC869 => KSC2383Y
2SC945A => KSC945Y
2SC1166 =>
2SC1312 => 2SC2240 / KSC1845
2SC1313 => 2SC2240 / KSC1845
2SC1318 => KSC2690AY
2SC1342 =>
2SC1384 => KSC2690AY
2SC1439 =>
2SC1735 => KSC2316Y
2SC1775A => KSC1845F
2SC1904 =>
2SD313P => MJE15032G
2SD325R => KSD526Y / TIP41C
2SD610 =>
2SK30AW => BF256B (conditionally)

 

[Watthour]

Not all those devices need to be replaced. Those you have underlined are the common suspects. I've included some other equivalents in case you need to replace some of them.

The 2SC1312s do not need to be gain-matched.

 

[avionic]

2SA733 => KSA733G

KSA733CG

 

[kevzep]

KSA733CG

Centre collector right?

 

[avionic]

2SC945A => KSC945Y

KSC945CY

 

[avionic]

Centre collector right?

Yep

 

[Watthour]

Is there also a suffix for your favorite color? That blue seems to be pretty popular.

 

[avionic]

Is there also a suffix for your favorite color? That blue seems to be pretty popular.

Blue is definitely better than green.

 

[Watthour]

That "MultiSIM BLUE" seems to be the hot ticket. They're a little tougher to solder, however.

 

[kevzep]

Blue is definitely better than green.

Blue? Well not sure it will turn into a McIntosh, but worth a shot!!

 

[avionic]

Blue? Well not sure it will turn into a McIntosh, but worth a shot!!

Lets hope not..Be a funny looking SX-1280.Or a damn fugly Mac.

 

[tsd71]

Everything you need is here;

http://audiokarma.org/forums/index.php?threads/pioneer-sx-1250-recap-and-restoration-thread.420950/