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The rule of thumb was...

A class A/B power amp assuming it's a high current design with a very stable power supply can potentially operate on the Class "A" bias around 10-15% of its power output before it'll slide into Class "B" bias operation. For example, if a Class A/B power amp has a power output of around 100 watts/c the first 10 watts/c of its power output would be on a Class "A" bias operation. However, there are some exemptions to the rule for example Krell, Mark Levinson, Pass Labs just to name a few power amps designs are known to exceed the 10-15% rule as some can output up to 40% of their power output on Class "A" bias operation.

What this means is if you have very efficient speakers with sensitivity at around 105dB and you happen to drive them with a Krell power amp you'll always going to be listening on a Class "A" bias operation. Unless you decided to unfurl Krell's sails then all bets are off as you're reliably be catching one of the woofers on your lap.

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Follow Ups Full Thread
Follow Ups
  • The rule of thumb was... - kootenay 02/2/2220:37:16 02/2/22 (1)
    • Quad II? - fredtr 15:39:07 02/4/22 (0)


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