Where to find original: Ssc2525/26 and 2sa1075/76?

[USMC Spike]

Hi

For Pioneer SA-7800, SA-8800 series, anyone know where I can
find pairs in 2, 4, 6, or 8 of these devices.
I'm needing at least one 2sc2525/26//2sa1075/76 pair but would
like to have a spare set or two.

I'm kind of stuck with the original configuration, because with MT-200s
I'd have to cut the end of the device or removed and drilled the heat sink.
The heat sink was originally drilled crooked and the originals are just up
against the vertical parts.

Using some of the later parts 2sa1386/As in MT-100 is more drilling to
fit.

Any ideas appreciated.

 

[sregor]

I don't know if you can do it with your units, but there is at leas one case where the tech ended up lowering the PCB to accommodate the MT-200s. Depends on how the board is mounted and where. FWIW I do believe it was a Pioneer unit, also. I would guess it would involve spacers or modified mounting brackets.
Another option would be to drill a plate with the same hole spacing, then use it to mount a TO-264 type transistor. I know somewhere there is a 1980 thread where this was done to replace the b706a / d746a outputs. Good luck with this.

 

[sregor]

pic of 1980 outputs Credit to @markthefixer )

 

[USMC Spike]

OH wow, I see the initials "IMG" in a box "[ ]", It's a joke right?

 

[markthefixer]

no, i am a subscriber and the only way i can get that boxed img is to log out.

the transistors are "ring emitter" and are no longer made. Thus they are reproductions and counterfeits.
Counterfeits will die spectacularly under load.

Go with modern transistors from a reputable industrial source and use hold down bars to mount them.

 

[redk9258]

I'm also a subscriber. The picture is not shown. Maybe a link to the original thread would be better?

 

[larryderouin]

Subscriber or NOT, you have to LOG IN to see Pic's in the posts. It came up when I Logged in as i originally saw "IMG" in the [ ].

 

[sregor]

Picture in this thread http://www.audiokarma.org/forums/index.php?threads/sx-1980-back-from-markthefixer-wow.337619/
post #6
you still have to be logged in to see the picture....

 

[merlynski]

I right clicked on the IMG[ ] box, selected 'Open in new Tab' The new tab said 'You must be logged in to do that' and showed a login screen , so I did. Now the image is visible in the original post (after page refresh).

 

[redk9258]

Subscriber or NOT, you have to LOG IN to see Pic's in the posts. It came up when I Logged in as i originally saw "IMG" in the [ ].

I AM logged in.

Edit. opening the other post in a new tab, I have to log in. Refresh this thread and I can see the picture.

Weird that I have to log in again for the other post.

 

[merlynski]

I AM logged in.

I was too, but I had to Log In again to see the image. I have had that occur with other links on AK before this time.

 

[petehall347]

the larger ones can be made to fit in the sa-8800 but i dont recommend it as not the best way to do it . the pcb can be filed down but not so pretty really .

 

[markthefixer]

I AM logged in.

Edit. opening the other post in a new tab, I have to log in. Refresh this thread and I can see the picture.

Weird that I have to log in again for the other post.

I think that's a browser setting.

 

[redk9258]

I think that's a browser setting.

I wouldn't know which one. I do have my browser to clear history on exit. This doesn't happen on newer posts. It only happens when opening older posts.

 

[USMC Spike]

Thanks Mark,
Hear are a couple of images. I didnt' want to 90 degree mount the 1386s type even though
I probably can do that. For anything deeper it will run into the left most 8DA, which are real
unobtainium.

The head sink is at a slight angle also, trying to use two matched pair of outputs...well just look
at the interference of the 2sa1075, lack of head room. No I haven't purchased replacements
to see if they'll fit. Maybe I'm just being a repair woosie because I don't want holes all over
the head sink....

Was hoping someone might have a spare pair, or two as they could PM me.

Anyway here is the image of the heat sink side with two fried devices removed.

 

[redk9258]

How about mounting Toshiba 2SC5200N(S1,E,S) / 2SA1943N(S1,E,S) TO-3P(N) style transistors sideways? Then use short leads to connect to PCB.

 

[petehall347]

How about mounting Toshiba 2SC5200N(S1,E,S) / 2SA1943N(S1,E,S) TO-3P(N) style transistors sideways? Then use short leads to connect to PCB.

are those ring emitter transistors ?

 

[redk9258]

Or maybe these SanKens would be better?...
2SA1386A / 2SC3519A

 

[redk9258]

are those ring emitter transistors ?

I don't know. Are there any ring emitter transistors produced? They are a smaller version of the popular 2SA1943 / 2SC5200 output transistors. They are current parts that can be procured from a reliable source.

 

[Watthour]

Perforated emitter devices should do nicely there. Some of the later die BJT power trannies use the technology and don't even bother to advertise it as a feature. Their operating specs tell the tale.