Of course I know there are an additional measures which can be taken for clipping protection - in particular your very interesting and unusual input stage described here: YAP Front End The idea in schematic I proposed is not mine - it's an excerpt from a well know book which I happen to find circulating the Web (actually I believe that "If we can see further it is because we stand on the shoulders of giants"). Of course you're right about the purpose of the Baker clamp and this is well known. Hi Ovidiu (if you allow me to call you this way), This can be avoided by bootstrapping the Baker clamp, making the diodes to have a rather constant reverse bias voltage. It is true that a Baker clamp has an impact on the circuit distortions, because a nonlinear capacitance (the diodes) is added, and the reverse bias voltage swing is rather large. So while the circuit is technically a Baker clamp (in the generic sense) it does not play the role of clipping protection, as usual in audio amplifiers, but more like avoiding the amplifier to self destruct. That's the diode clamping I was talking above in #407, to avoid the VAS output to exceed the output stage power supply voltage. The diodes in your schematic have the role to avoid the emitter follower saturation due to the possible excess voltage from the VAS output. In audio, a Baker clamp is usually wrapped around the VAS transistor(s), avoiding their saturation and hence avoiding the ugly transient response (since the loop gain collapses and the recovery from saturation is rather slow for bipolars), when the amplifier input is overdriven. In general, a Baker clamp is a circuit that avoids transistor staturation.
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