19-04-2013, 12:20 AM
I remember when these transistors came out. A fascinating idea, and a valiant attempt to improve thermal tracking, which of course is most important with class B amplifiers. But sadly, including the emitter resistor was a step too far, as this often fails before the transistor. Sanken dropped the family a while back - but do similar products that are sans the resistor...
The first amp that I came across with these in was the Arcam A85. This was a lovely thing, and would be well-worth fixing.
Then there is this one
As Al wisely says, walk away. This amp was made to a price - a pretty low one - and has woefully inadequate heat sinking.
In case you haven't see it, the service manual is attached. The negative terminals are earthed - it's a conventional single-ended design. Of course, signal earth and chassis might be two separate things. It seems that they are 47 ohms apart, thanks to R267.
The motorised pot might be worth rescuing though...
The first amp that I came across with these in was the Arcam A85. This was a lovely thing, and would be well-worth fixing.
Then there is this one
As Al wisely says, walk away. This amp was made to a price - a pretty low one - and has woefully inadequate heat sinking.
In case you haven't see it, the service manual is attached. The negative terminals are earthed - it's a conventional single-ended design. Of course, signal earth and chassis might be two separate things. It seems that they are 47 ohms apart, thanks to R267.
The motorised pot might be worth rescuing though...
