Upgrading outputs

bigerik · 24th November 2004, 03:42 AM

Hi!
A friend is working on upgrading an amp that originally used, I hope I get this right, A1106 output transistors. He was given two other recommendations: 2sd817/2SD1047's and A1368LF/C3519's. The first night be lower wattage. I am not sure. (Don't worry. He knows MUCH more than I do!

).
Does anyone have any recommendations for a better quality, lower nose, etc output that will plug right in? We are talking an amp in the 100 WPC range.
Thanks!
Erik

anatech · 24th November 2004, 12:43 PM

Hi Erik,
The 2SB817 / 2SD1047 work just fine. I use these myself to sub those originals. I wouldn't lose any sleep over a higher rated output as they are just overkill. Use whatever pair is easier for you to get.
-Chris

bigerik · 24th November 2004, 07:15 PM

Hi Chris
Thanks for the input.
Actually, we can get any of them. Just wondering which would be the best sounding/cleanest of the lot.
Thanks
Erik

anatech · 25th November 2004, 10:32 PM

Hi Erik,
There will not be a sound difference between the types. Matching the gains of the diff. pair would make a bigger (positive) difference.

Take care to clean the heatsink and insulators completely and apply new heatsink grease. I aways do a C-E and C-B leakage test on the preceeding transistors and bias transistor. If you can't do this, then just replace them. When setting the bias current, take your time while watching for excessive drift. It helps to use a variac on the first power up.

-Chris

EchoWars · 25th November 2004, 11:00 PM

Quote:

Originally posted by bigerik
Hi!
A friend is working on upgrading an amp that originally used, I hope I get this right, A1106 output transistors. He was given two other recommendations: 2sd817/2SD1047's and A1368LF/C3519's. The first night be lower wattage. I am not sure. (Don't worry. He knows MUCH more than I do! ).
Does anyone have any recommendations for a better quality, lower nose, etc output that will plug right in? We are talking an amp in the 100 WPC range.
Thanks!
Erik

If you want to upgrade the amp, the last place to be swapping out components is the outputs. The 2SA1106 (and the complement, which I can't think of right now) is a fine output device and about anything you could replace it with will be a downgrade. Sure, you can get outputs that will handle more voltage or power, but will it make it sound better? Not likely.

Changing the outputs will have about the least effect of nearly anything else you could do with the amp.

If you insist on swapping them out, send the old ones to me.

anatech · 25th November 2004, 11:29 PM

Hi EchoWars,
I'm pretty sure the outputs no longer work from the text. If the outputs are good, I totally agree with you. There ain't noth'in wrong with 2SC2581 and 2SA1106 types.
Mind you, the others aren't a downgrade so much either.
-Chris

EchoWars · 26th November 2004, 12:01 AM

2SC2581...that's it. Must be getting old and feeble.

Woodang sells the original types for a pretty fair price.

If the originals are toast, by all means, slap some MJ21193's and 4's in there and call it a day...or if you want original, get 'em from Woodang. Or use the B817/D1047's. But if the originals are good, concentrate your efforts and $$ on parts of the amp where it will make a difference.

bigerik · 26th November 2004, 04:58 AM

Ok Echo.
Not going into specifics, but what area do you figure will make the biggest difference.
Thanks!
Erik

EchoWars · 26th November 2004, 05:49 AM

Depends on the amp, and its age. If its older than, say, 20 years, get rid of the old electrolytic caps.

As far as semiconductors, the difference between a decent amp and a poor one happens at the input and VAS stages. Sure, all stages are important, but the most noticable improvements will happen at the front end of the amp, not the back.

anatech · 26th November 2004, 04:47 PM

Oh yeah. Absolutely!

24th November 2004, 03:42 AM	#1
bigerik diyAudio Member Join Date: Jun 2004 Location: Toronto	Upgrading outputs Hi! A friend is working on upgrading an amp that originally used, I hope I get this right, A1106 output transistors. He was given two other recommendations: 2sd817/2SD1047's and A1368LF/C3519's. The first night be lower wattage. I am not sure. (Don't worry. He knows MUCH more than I do! ). Does anyone have any recommendations for a better quality, lower nose, etc output that will plug right in? We are talking an amp in the 100 WPC range. Thanks! Erik

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24th November 2004, 12:43 PM	#2
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi Erik, The 2SB817 / 2SD1047 work just fine. I use these myself to sub those originals. I wouldn't lose any sleep over a higher rated output as they are just overkill. Use whatever pair is easier for you to get. -Chris

24th November 2004, 07:15 PM	#3
bigerik diyAudio Member Join Date: Jun 2004 Location: Toronto	Hi Chris Thanks for the input. Actually, we can get any of them. Just wondering which would be the best sounding/cleanest of the lot. Thanks Erik

25th November 2004, 10:32 PM	#4
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi Erik, There will not be a sound difference between the types. Matching the gains of the diff. pair would make a bigger (positive) difference. Take care to clean the heatsink and insulators completely and apply new heatsink grease. I aways do a C-E and C-B leakage test on the preceeding transistors and bias transistor. If you can't do this, then just replace them. When setting the bias current, take your time while watching for excessive drift. It helps to use a variac on the first power up. -Chris

25th November 2004, 11:29 PM	#6
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi EchoWars, I'm pretty sure the outputs no longer work from the text. If the outputs are good, I totally agree with you. There ain't noth'in wrong with 2SC2581 and 2SA1106 types. Mind you, the others aren't a downgrade so much either. -Chris

26th November 2004, 12:01 AM	#7
EchoWars diyAudio Member Join Date: Dec 2002 Location: Left of the Dial	2SC2581...that's it. Must be getting old and feeble. Woodang sells the original types for a pretty fair price. If the originals are toast, by all means, slap some MJ21193's and 4's in there and call it a day...or if you want original, get 'em from Woodang. Or use the B817/D1047's. But if the originals are good, concentrate your efforts and $$ on parts of the amp where it will make a difference.

26th November 2004, 04:58 AM	#8
bigerik diyAudio Member Join Date: Jun 2004 Location: Toronto	Ok Echo. Not going into specifics, but what area do you figure will make the biggest difference. Thanks! Erik

26th November 2004, 05:49 AM	#9
EchoWars diyAudio Member Join Date: Dec 2002 Location: Left of the Dial	Depends on the amp, and its age. If its older than, say, 20 years, get rid of the old electrolytic caps. As far as semiconductors, the difference between a decent amp and a poor one happens at the input and VAS stages. Sure, all stages are important, but the most noticable improvements will happen at the front end of the amp, not the back.

26th November 2004, 04:47 PM	#10
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Oh yeah. Absolutely!