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Old 5th April 2013, 05:45 AM   #41
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It is difficult to see from the pic, but drivers and VAS tranies seem to be 2SB649/2SD669. These are good parts, and I would keep them. Not so low Cob as some, but still good overall.
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Old 5th April 2013, 07:01 AM   #42
sajti is offline sajti  Hungary
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Quote:
Originally Posted by Evenharmonics View Post
For 1815, I found this http://www.mouser.com/ds/2/149/KSC1815-59515.pdf Spec is just about the same except for the middle lead is base instead of collector. I suppose I can just bend it to fit the board.

Try KSC1845 instead of 1815

Sajti
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Old 5th April 2013, 08:34 AM   #43
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Quote:
Originally Posted by Evenharmonics View Post
For 1815, I found this http://www.mouser.com/ds/2/149/KSC1815-59515.pdf Spec is just about the same except for the middle lead is base instead of collector. I suppose I can just bend it to fit the board.
I thought there was something odd about that datasheet. look at this, also from Fairchild......KSC1815 Pinouts , KSC1815 Pin out,KSC1815 pin diagram
Also, I should have posted the complement to 2SA970, ie. 2SC2240 and that is almost the same as satji's suggestion, KSC1845. These are all listed in Greg's chart, #39
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Old 5th April 2013, 08:41 AM   #44
sajti is offline sajti  Hungary
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Quote:
Originally Posted by Ian Finch View Post
I thought there was something odd about that datasheet. look at this, also from Fairchild......KSC1815 Pinouts , KSC1815 Pin out,KSC1815 pin diagram
Also, I should have posted the complement to 2SA970, ie. 2SC2240 and that is almost the same as satji's suggestion, KSC1845. These are all listed in Greg's chart, #39
The 2SC2240 2SA970 is not manufactured any more, unfortunately. Only smd version is available. It's not easy to get original Toshiba version now.
KSC1845/KSA992 is available from Mouser for peanuts. I have ordered 1000pcs each.

Sajti
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Old 5th April 2013, 08:50 AM   #45
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Thanks, sajti. I checked this earlier this year and the "not suitable for new manufacture" was still showing. Well, it seems to happen to every good thru-hole part.
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Old 5th April 2013, 08:59 AM   #46
sajti is offline sajti  Hungary
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Quote:
Originally Posted by Ian Finch View Post
Well, it seems to happen to every good thru-hole part.
Unfortunately I was the bad guy, who ordered the whole 2SC3423/2SA1360 stock from Mouser (300pcs each), and get the last stock of 2240/970 from Newark. It looks, that we have to make our own stock for the future, to keep our hobby up, and running...

Sajti
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Old 5th April 2013, 03:58 PM   #47
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Originally Posted by Ian Finch View Post
I thought there was something odd about that datasheet. look at this, also from Fairchild......KSC1815 Pinouts , KSC1815 Pin out,KSC1815 pin diagram
I noticed that after posting my finding yesterday. I was going to check the pinouts with DMM before installing anyway.

Thanks Ian and sajti.
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Old 17th April 2013, 05:46 AM   #48
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Bump.

Also replaced 5401 and 1815. Now DC offset is 2 mV. It was a cheap (they are 10 - 15 cents each) and fun learning experience.
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Old 19th April 2013, 09:24 PM   #49
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Good, I honestly thought you would have more difficulty getting a match there. Was it the current mirror pair that made the difference?
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Old 20th April 2013, 12:54 AM   #50
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It was 5401 pair (Q15 & Q16) that made the main difference. When I replaced 1815 pair (Q11 & Q13, Q17 & Q19), DC offset still remained at 14 mV.

So here's the DC offset track record:
1) -24 mV out of the box stock.
2) 15 mV when I replaced 1015 pair (Q6 & Q8).
3) 14 mV when I replaced 1815 pair (Q11 & Q13, Q17 & Q19)
4) 2 mV when I replaced 5401 pair (Q15 & Q16)

Click the image to open in full size.

Last edited by Evenharmonics; 20th April 2013 at 12:57 AM.
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