Need One 2SC1079....!!!

[EchoWars]

Got an amp with 12 TO-3 output devices...only one is bad. Uses 2SA679 and 2SC1079. All are OK except one measily 2SC1079, only no one (and I do mean NO ONE!!) seems to have it.

I really hate to replace them all just because I can't find one transistor. Anybody got one they'd part with? Or maybe have a source that I haven't tried?

Thanks ya'all!!

[Sch3mat1c]

Pull one of the 679's to even things out?

Can't say I've heard of it. Check NTE or something..?

Tim

[EchoWars]

No NTE's in MY amp baby!


Gotta be one somewhere.......

[DRC]

Dial electronics in the UK

£13.50 a piece - I bet the postage to the USA will add some ...

Dave

EDIT another £6.22 for delivery, goodluck !

[pinkmouse]

EchoWars

Now, Now, mind your language or I'll have to wash your mouth out with soap and water...

[Duo]

Well, this is an interesting issue. The bad transistor in the group of good ones in the output stage.

For me, I always replace all the output transistors if possible, that is because sometimes in overdriven situations, the others may be okay on a simple test, but may be weakened in some way.

As far as replacements, there is lots of room for improvement if your amplifier is old.

I worked on a large PA amplifier (500Wpch stereo) that had six outputs per channel. It was using older transistors that were mixed up from previous repairs which is something that disgusts me and is why the amplifier blew up for the last time.

I ordered all new onsemi MJ21193\21194 pairs which have characteristics exceeding those originally in the amplifier. After putting it all together and testing it out, I gave it back to the owner, who proclaims that it sounds better than it did when he first got it.

Anyway, as far as removing another transistor to even out the balance, this will work in most cases, but will reduce the safe operating range of that channel so that the stage will no longer handle the power output that it once did. This leads to an ease of failure of other devices and a different sound from the other channel that has all its devices intact.

If you can afford it, I would replace all of them, though i know that's going far out to get it working properly. If you can't, try as you can to get another transistor as close to the originals as possible.

[EchoWars]

Originally posted by DRC
Dial electronics in the UK

£13.50 a piece - I bet the postage to the USA will add some ...

Dave

EDIT another £6.22 for delivery, goodluck !

Viewcom Electronics in London has one. Only one. About 11 pounds to ship to middle USA. If it saves me from replacing them all, it'll be worth it.

I came very close to simply putting in new Moto devices and calling it a day, but I really like the old Toshiba devices for vintage gear.

Duo...

It wasn't shorted, but leaky from C to E after it warmed up a bit. The rest of them look fine. If I had found shorted devices, I probably would have just gone with new Motorola devices.

Pinkmouse...

Had a teacher in grade school do that once...soap and all. I suspect nowadays she'd probably lose her job over it, but back in the 60's things that like were probably considered essential to keeping us little beasts in line.

[bremen nacht]

http://www.grandata.co.uk/ have them for 3 quid, shipping 'at cost'.

I've not used these guys yet but intend to; they look like a good source for Japanese transistors. Let me know if they're any good!

[halo611930]

well if your not finding them then i might not ether, but i need 2 2sc1079's. 2 are bad 2 are good.

[ostie01]

I have ordered several times from this sellers on Ebay

http://cgi.ebay.com/2SC1079-C1079-NP...QQcmdZViewItem

Hope this help, Jeff