Amplifier power

**GregS[_3_]** · October 17th 08, 07:44 PM posted to uk.rec.audio,rec.audio.tech

In article , (GregS) wrote:
In article , "Arny Krueger"
wrote:
"Eeyore" wrote in
message
Chronic Philharmonic wrote:

"Arny Krueger" wrote
"Marky P" wrote

LM741 (pretty sure this is an op amp)

Yup and a real oldie. Slow and noisy, not to mention
power hungry and a weak output for what it does.

This was arguably the "breakthrough" IC op-amp. It was
one of the first popular devices that was actually a
monolithic design, and not a hybrid like some of the
original Burr Brown modules. It was compensated for
unity gain, which made it much too slow for anything but
a buffer for audio work. It had a slew rate of 0.5
volts/microsecond. With a +/- 12 volt power supply, 6
kHz rail-to-rail was about it for non-slew rate limited
signals. You could get 20KHz through it if you were
content with about 4 volts peak.

I think it had more applications in analog computing,
integrators, low frequency function generators, servo
controls, etc.

True but it DID get used in audio. Its companion, the 748
was uncompensated internally (like the 5534 vs the 5532)
and always seemed less noisy to me, so I used quite a few
of those.

The on-chip compensation cap for the 741 was a well-known source of noise.

LM301s were another alternative once the market matured some more.

I believe that the integrated preamp/crossover for the original Infinity
Servo-Static system used 741s.

As others have pointed out, their slew-rate limitations were not that bad if
you were running them at usual consumer levels like 1.5 volts RMS.

The more recent NHT pro monitors used RC4136's in the active stages.

I was talking about the Ken Kantor pro speakers.

greg