Class A Amplifier

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Hi,
how many mA can the 5534 give in ClassA before moving to ClassAB?
Why select a 5534 and then add a compensation cap to convert it to unity gain stable?
What is the 338 supposed to be doing? It certainly does not look like a CCS load for a single ended Sziklai follower.
 
Hi Andrew,

I´m writing a short specification. Posting it still sunday! Have to finish the specification of the PSU for tube amplifier posted in an other thread.

3 stage:
- voltage amplfier,
- current amplifier,
- and current source (LM338K).

You can use LF351, but I like the original PHILIPS NE5534.

Take a look at the LM395, is not a standard transistor. TO3 case is obsolete, we have to use the TO220 case.
 
a screenshoot of the EAGLE PCB: only amplifier!
 

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'cause of your drawing errors the amplifier doesn't work.
Compare it against the original natsemi circuit!
What do you think?
I don't like the old datasheet application either. It looks to me like a 'nailed together' circuit, which only purpose seems to be to utilise as much expensive national semiconductor parts as possible.
Hopefully they pulled this circuit from a reliable piece of equipment and not just published some first work from their lab trainee.
Nevertheless the idea of taming an emitterfollower with currentsource inside the feedbackloop of an opamp is not bad and worth some experiments.
I just think, that this old application is a bad starting point!
regards
 
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