Hi!
I'm still about to repair an old Yamaha A400 for a friend of mine. It had completely lost one channel, so i ordered a replacement for the voltage driver chip, a stk3042-II. This one's not available any more, but i was lucky to get a 3042-III which should work out fine. In order to make a safe repair, i decided to change all transistors in the dead channel as well, thinking 42volts gone wrong from the stk might have easily harmed follow-up-parts.
I got them all very quick, but the 2sc2579 took four weeks for delivery. But now, the company's logo doesn't say anything to me. I'm no pro, but shouldn't this one be Toshiba or Sanken?? The complementary is, but the 2579? What company is that???
It's rather cheap amp with only about 40watts. Should i change the second channel to transistors of the same (unknown) manufacturer?
Thanks for any comments!
Matthias
I'm still about to repair an old Yamaha A400 for a friend of mine. It had completely lost one channel, so i ordered a replacement for the voltage driver chip, a stk3042-II. This one's not available any more, but i was lucky to get a 3042-III which should work out fine. In order to make a safe repair, i decided to change all transistors in the dead channel as well, thinking 42volts gone wrong from the stk might have easily harmed follow-up-parts.
I got them all very quick, but the 2sc2579 took four weeks for delivery. But now, the company's logo doesn't say anything to me. I'm no pro, but shouldn't this one be Toshiba or Sanken?? The complementary is, but the 2579? What company is that???
It's rather cheap amp with only about 40watts. Should i change the second channel to transistors of the same (unknown) manufacturer?
Thanks for any comments!
Matthias
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Both devices are absolutely fakes
In my oldest Sanken catalog, dated September 1998, both A1104 and C2579 were already in the discontinued devices list, so these transistors have no longer been manufactured by Sanken for the past seven years [or more]
Sanken suggests the newer 2SA1694 and 2SC4467 as replacements. You should have looked at Sanken catalogs before ordering obsolete parts, because when you order discontinued parts you allways receive fakes
This is how genuine Sanken TO-3P [MT-100] transistors look like, note that the case style and the letter markings have nothing to do with the fakes you received :
In my oldest Sanken catalog, dated September 1998, both A1104 and C2579 were already in the discontinued devices list, so these transistors have no longer been manufactured by Sanken for the past seven years [or more]
Sanken suggests the newer 2SA1694 and 2SC4467 as replacements. You should have looked at Sanken catalogs before ordering obsolete parts, because when you order discontinued parts you allways receive fakes
This is how genuine Sanken TO-3P [MT-100] transistors look like, note that the case style and the letter markings have nothing to do with the fakes you received :
Attachments
Yeah, thanks... it was what I expected 
But it might get uneasy to find original replacement parts, don't you think? I use to buy at Segor's, a shop with a fine reputation. But when i browsed their catalogue for the recommended replacements, the pic of the sc4467 doesn't seem to show any sanken either
:
http://cgi.segor.de/user-cgi-bin/sidestep2.pl?foto=1&Q=sa1694&M=1
This is how an old original sc2579 in the a400 looks like:
But it might get uneasy to find original replacement parts, don't you think? I use to buy at Segor's, a shop with a fine reputation. But when i browsed their catalogue for the recommended replacements, the pic of the sc4467 doesn't seem to show any sanken either
:http://cgi.segor.de/user-cgi-bin/sidestep2.pl?foto=1&Q=sa1694&M=1
This is how an old original sc2579 in the a400 looks like:
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