SAE mk XXX1B transistor sub

[ostie01]

HI, just mistype my last thread. Would like good sub transistors for the power amp SAE mk XXX1B. Service manual ask for SAE 103 and SAE 204. Number mark on transistor installed in the amp right now are 11-0064A and 11-0070A. Thanks for any advice.

 

[Mark A. Gulbrandsen]

If these are the outputs I am pretty sure they are Power Darlingtons and may be hard to find......Used to repair SAE stuff years ago at Midwest Hi-Fi near Chicago.

Mark

 

[ostie01]

HI, you're right, they are the output transistor, 2 pairs TO-3

 

[ostie01]

HI, by looking at the schematic, those are not darlington transistors

 

[MikeBettinger]

HI, by looking at the schematic, those are not darlington transistors

I worked in an SAE authorized service shop in New York when these were new. The outputs were definitely darlingtons.

I'll have to look at the schematic to see if I can suggest a replacement.

Mike.

 

[ostie01]

Hi, thanks, here my address, just e-mail with a subject and I send you the schematic since I can't sent you personal message.

cubitus_61@hotmail.com

 

[djk]

Original parts were probably house branded 2N6059/2N6052, a 12A 100V 150W part, hard to find.

first choice:

Mouser

2N6284 TRANS DARL NPN 20A 100V 160W TO3 $3.84
2N6287 TRANS DARL PNP 20A 100V 160W TO3 $3.88

second choice:

Digi-Key

MJ11015 TRANS DARL PNP 30A 120V 200W TO3 $3.65
MJ11016 TRANS DARL NPN 30A 120V 200W TO3 $3.65 (non stock)

 

[macka]

SAEXXX1B issues:

ostie01,

Thanks for sending the schematic of the sae xxx1b

It would appear ths amp was blown up and one point and repair.

The actual fault I fixed was hum in one channel and I replace some electro capacitor on the input which helped.

However, some of the input diff transisters were odd types and I have replaced them with generci equivalents..

I note however one channel has odd bias of the darlington output stage of 0.01 while the other is 0.04 as stated in the schematic.

The voltage of the Q5 & Q 6 collector is 1.1 volt on one channel and about 0.114 volt on the other channel.

Both channel work functionally but I am stumped why these odd voltages and bias exist.

Any thoughts much appreciated

macka

 

[macka]

Okay,

I found out why the odd voltages from the drivers, one channel has a blown bias sensor SAE402.

I pulled apart the heatsink and what it is is a 17 pin UA3086PC transistor array. However I am not sure of that is the original part.

The original drivers the SAE801 and SAE 902 are also gone and it has 2n3440 and 2n 5416.

If anyone can advise what the badged pats were it would be appreciated

macka

 

[ostie01]

Hi, the parts number of this transistor array on mine is CA3086. Just bought some of these parts from syracusesemiconductors on ebay, not expensive, only 0.40 each, I have one of these not working so still waiting for them, Jeff

 

[Burnedfingers]

The original drivers the SAE801 and SAE 902 are also gone and it has 2n3440 and 2n 5416.

If memory serves me correctly they were the MPS u56 and MPS u06 vintage belonging to the u56,u57, and u60 and u06,07, and u10 family. These will be hard to find and expensive.

The 2N3440 and compliment 2N5416 will work fine as drivers. Use a heat sink on them.

 

[macka]

Thanks for your assistance.

Macka

 

[macka]

This keeps getting better.

I just looked at the input differentials and they are also odd

The original 2n 3565 are still in there but the 2n4250's have been replaced with 2 C2N 4249 on one channel and FPN 4249 EBC on the other channel.

I have looked for the 2n 4250 and they appear no longer available.

(I have thought of using a generic replacement PN100 (2n3565 ) and PN200 (2n4250) but I am not sure if this is correct.

Aby suggestions much appreciated

macka

 

[Burnedfingers]

Match some MPS A06's and MPS A56's or 2n5401's and 2n5550's

 

[macka]

Thanks,

I have some of those so I will give it a try.

I managed to order the CA3086 from Farnell.

Thanks again for your help

Macka

 

[macka]

Hi everyone,

I ironed out most of the bugs and got the bias working. The CA3086 were damaged when it was last blown up and who ever repaired it did not change them.

I got hold of some 2n6052/2n6059 darlingtons and put them in both channels so everthing is matched

I still have the PN100/PN200 in the diff pairs and will change them out tomorrow for either MPSA56/MPSA06 or the other alternative. I have plenty of those from my Doug Self advanced pre amp I built about 30 years ago!!

The PN100/PN200 appear to have limited the HF bandwidth somewhat.

I must say repairing something more complex than a Zen that has been blown up and butchered is a real challenge🙂

 

[mgm31]

Hi all,

I found a SAE mark XXXIB to fix : one channel, already repaired (output transistor changed and bias (?) variable resistor changed.

This channel have a DC of +36V and a very bad smelling.

Could someone kindly send me the schematic or service manual ?

I found output transistors on e-bay but would you recommend me 2N6059/2N6052 or 2N6284/2N6287 pair ?

Do you think this amp is a good value and I could spend some money to fix it ?

Thanks a lot