I didn't understand exactly what the 'speakers were. The earlier post
says ILP TL4, but I can't find any references for these. I know of ILP
as amplifier module manufacturers, but not for 'speakers. I also haven't
seen anything from Arnie casting doubt on the metal faculties of the
builder. Possibly my News server misses the odd post.

S.

My typo -------- the speakers are IPL Acoustics STL4's
Re Arny K, his suggestion that I'd screwed the design up and that National
had idiot proofed the new LM4562's gave me the impression he thought I was
the idiot, maybe I read too much into his comments. I still say though,
these sound much better than the 5532's.

Quote
" 2. a few yrs back I got samples from Analog Devices of a
low noise audio switch and a dc controlled vol chip (
0.002% thd ) I knocked them together with a couple of
5532's and have been enjoying them since ( from tv/dvd or
Technics CD into 4 x 75wrms mosfet amps and onto a pair
of ILP TL4's, ground/door and window shaking stuff and
very clear, or so I thought..... last week I got hold of
samples of National's LM4562 and replaced the 5532's, the
attack on drums is now much better and everything sounds
tighter.

Anybody who thinks that a LM4562 sounds better than a NE5532, both in
well-designed circuits, is suffering from specificaion-induced
constructor's ear. They are both free of audible distortion unless someone
screws up the design.

As it was chucked together I used 7815 & 7915
regs, I had a trouble with rf on the -ve rail which could
be heard as a faint hiss, so I thought whilst it's in
bits I'll go over the power supply , no need! it's now
silent, better rejection ?

More than likely you screwed up the design by not properly bypassing the
5532 power pins in the origional design. Conventional wisdom is that a
suitable cap (classic 0.05 uF ceramic for example) between the power supply
pins will settle them down.

More than likely National idiot-proofed the 4562s."