Shadders
pfm Member
Hi,The amount of feedback is the open loop gain divided by (subtracted from in dB) the closed loop gain. The figure you calculated from the global feedback resistors is the closed loop gain.
The Naim circuit does have fairly high feedback. The NCC200 has less open loop gain due to the emitter degeneration in the LTP.
Yes - and what is in vogue at the moment is low global feedback, in favour of local feedback. This, at this time seems to be the preference, and amplifiers stated to have this approach get the preferential subjective review.
The Naim clone has NO (zero) LTP emitter degeneration - no designed local feedback in this part of the circuit. The VAS has NO (zero) designed local feedback (no emitter resistor).
So we have a Naim clone that sounds wonderful using lots of global feedback and NO designed local feedback to achieve the relevant performance, in complete opposite to the in vogue hifi which uses local feedback and reduced global feedback.
So the folklore that global feedback is bad, or any feedback is bad, is just that - folklore, myth, utter rot.
When you referred to lots of feedback, the remark was intended to be negative against the Audiolab unit, yet the Naim clone unit is worse in its design and could be considered out of vogue.
Since people do not know about the design, they accept the folklore as is for the Naim clone. When people make statements about Audiolab as you have done, they accept it as fact, despite Naim clone being worse.
Regards,
Shadders.