KSA 100 from Jim's Audio on EBAY

[neychi]

David, don't mess up with transistors of suspicious origin if you can't get the real mccoy. Get 2sa1011/2sc2344 like I told you. Mouser is no guarantee that these are the original transistors. A few years ago I ordered via RS Components Toshiba's 2sa968/2sc2238 and got Magnatec. They work fine but these were actually 2sa1011/2sc2344 transistors with polished front and re-printed logo and product labels. I've made a comparison. I even went well, but their price was pretty high and I could get a two original transistors for price of one. Just be careful.

[spurlte]

What a 2012 Olympian opening show! I have here a post from AudioKarma
Toshiba 2SC2238 + 2SA968 counterfeits? [Archive] - AudioKarma.org Home Audio Stereo Discussion Forums
It talks about 2SA1837/2SC4793 as substitutes. I see that the only difference is that the Ic=1A. The 2sa968's Ic=1.5. Is this a big difference for the KSA 100?

[Kaplaars]

I could not agree with Dean more I have very bad experiences with cloned / fake transistors. Repaired a Denon PMA-920 once. Replaced the original Sanken outputs for ISC's. 5 seconds full power at the dummy and BOOM. Sliced the trannies open, and.... well see for yourself, compaire the dies (left ISC, right good ol' Sanken):



That little joke made the repair even more costly, could replace the drivers again, and now the biastransistor and emitterresistors were broken also.

[neychi]

2SA1837/2SC4793 are not direct substitution, 2sa1011/2sc2344 are.

Semiconductor Substitution List



Edit: Michael, congratulation! Excellent Fluke

[spurlte]

Originally Posted by neychi

David, don't mess up with transistors of suspicious origin if you can't get the real mccoy. Get 2sa1011/2sc2344 like I told you. Mouser is no guarantee that these are the original transistors. A few years ago I ordered via RS Components Toshiba's 2sa968/2sc2238 and got Magnatec. They work fine but these were actually 2sa1011/2sc2344 transistors with polished front and re-printed logo and product labels. I've made a comparison. I even went well, but their price was pretty high and I could get a two original transistors for price of one. Just be careful.

Thanks.

[spurlte]

neychi, I talked to the owner of this electronic components store in New Jersey, USA
2SA1011 pdf 2SA1011 datasheet PNP Epitaxial Planar Silicon Transistor - High-voltag Switching - AF Power Amp - 100W Output Predriver Application 2.51735 Transistors Bipolar Silicon PNP Power Transistors American Microsemiconductor 2SA1011 available a as I found the 2SA1011 but not the the 2SC2344. I called and got the top man himself. He took all my information regarding the 2SA968/2SC2238 and the 2sa1011/2sc2344 and said he will get back to me shortly, at least by Monday. You guys are my guardian angels and I owe you a cold beer. And I also see the specs for the 2sa1011 where the Ic-1.5A. Nice

[neychi]

You are most welcome

Look here Beezar.com

Maybe they can help you.

[spurlte]

Started on putting the Power Supply components into the case. Boy, it is HEAVY. Now when I go to second hand stores and see used amplifiers, I just pick it up to see if it's heavy. HA-HA.

[Kaplaars]

Wow, when you see it in this perspective those transformers are really huge! I like them. Will that become the PSU-box for the KSA David?

Haha, you better prepare, it will only get heavier Mine is almost like a boat anchor when lifting it up. But hey, great excuse to quit my fitness subscription

See it from the bright side David after lifting the KSA a dozen of times you will gain the same muscles like Arnold Schwarzenegger had in his glory days

Well going to sleep now, but, to quote Arnold 'I'll be back'

[lanchile]

Wow, those transformers are HUGE!!!. How much do they weight? what are the spec for them?