"APR" I_don't_Want_Spam@No_Spam wrote in message


I have A20's which I use in my home audio system and
cannot fault them. I have no issues with them that would
make me say the IC's should be changed.

Some people say they are too forward, some have said they
are too bright for their liking. I am quite happy with
them.

Both the A10 and the A20 were well-received on the professional market when
introduced, and still seem to be holding their value in the used equipment
market.

What difference would you expect a different IC to make
over the 4558's?

Why the NHT designers used 4558s would be an interesting question. As a
group, they were very well-informed engineers with any number of sucessful
designs for speakers and amplifiers already under their belt.

If you avoid very high and very low signal voltages, 4558s can work out just
fine. I wonder if the NHT engineers were making a statement against the sort
of bias that makes so many fly off the handle when they see 4558s in an
audio signal path.

Personally, my bespeak audio designs are mostly based on 5534s. and 5532s. I
think some LM353s snuck in a few places where impedances were high.