Pete Cross wrote:
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.


I've looked up the STL4s, I'm rather a fan of transmission line
'speakers. Generally, they need plenty of power, but I should think you
would have good reason to be happy with them.

As to the sound of different chips, I'm rather with Arnie on this one.
If the design is reasonably sound, and you get low distortion and noise,
then I don't think there would be any audible difference.

There are well accepted thresholds for the minimum noise, distortion and
frequency response variations which are audible. Once two amplifiers are
each below the threshold, whatever differences there are between them
will not be audible. For example, one amplifier having 0.05% distortion
and another having 0.01% won't sound any different, as it is generally
accepted that the threshold for distortion on programme material is at
least 0.1%. Analogue tape machines' output were rated as standard at the
3% THD level. Typical values were 1% at 0dB and 2-3% at 8dB above 0dB
which was considered peak level. At the time, few people complained that
the tape machine's distortion was ruining the music, and even today,
some artists like the analogue tape sound.

My two turntables both had 741s in the RIAA equaliser, which I replaced
with TL071s, only because I couldn't stand the idea of 741s. The TL071
is a direct plug-in replacement and the equalisers have their ICs on
sockets, so the replacement was easy. I didn't even have to solder
anything. I suppose the distortion of the TL071-equipped equaliser could
be lower than before (I didn't measure a before and after) but any
reduction would be swamped by the inherent distortion of vinyl and the
cartridge. I certainly haven't noticed any improvement, I just feel
better not having 741s in the signal path.

S.