So how bad is the bad transistor list really... shoot on sight or more check here first if trouble shooting?

[larryleezard]

I am refurbishing an SA-8500ii and love it. My gosh I really like this amp. I am just finishing up with the amp boards and looking at the sca798 double transistors that are currently working and wondering if I should swap them out for some matched A992's or let them ride? Thoughts? Insights? Pros/cons?

 

[painttoad]

shoot on sight

 

[larryleezard]

shoot on sight

Really! Have you found any sound difference between the sca798's and the matched AA92's? Now you got me thinking I should just do it while I have it all torn down.

 

[painttoad]

Really! Have you found any sound difference between the sca798's and the matched AA92's? Now you got me thinking I should just do it while I have it all torn down.

nope but i have found better dc offset and piece of mind by getting rid of the 2sa798 and replacing with closely matched ksa992s

 

[larryleezard]

nope but i have found better dc offset and piece of mind by getting rid of the 2sa798 and replacing with closely matched ksa992s

Cool, OK. I am gonna do it. Good thing I have a pile of them.

 

[Ray66]

I'm assuming the OPs reference to 'SCA798' is a typo. @larryleezard, if you want to avoid the hassle of finding matched pairs theres the option of using SMT replacements described here.

 

[larryleezard]

I'm assuming the OPs reference to 'SCA798' is a typo. @larryleezard, if you want to avoid the hassle of finding matched pairs theres the option of using SMT replacements described here.

Correct! 2SA798! Opps. I got two nice KSA992 pairs out of what I had, coupled them thermally everything worked really well! Thanks for the info though for the future.