Arny Krueger wrote:
"Eeyore" wrote in message
Arny Krueger wrote:
The 4558 that Trevor decries is even widely used in professional gear
that is highly regarded.
No it *isn't* Arny. At least not in any respectable kit.
I guess you'd be amazed where I've found them.
Perhaps not entirely. I did hear that Otari used a load. Standard mod is to bin
the lot of them.
The 4558 ( originally Raytheon's 1558 ) is no more than a dual '741 class'
op-amp.
That was the 558.
Now you're making things up ! Here's the original Raytheon 1458/4558
http://www.datasheets.org.uk/search....458&sType=part
http://www.datasheets.org.uk/specshe...?part=RC1458DE
And here's JRC's current 4558.
" The NJM4558/4559 integrated circuit is a dual high-gain
operational amplifier internally compensated and constructed on a
single silicon chip using an advanced epitaxial process.
Combining the features of the NJM741
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
with the close
parameter matching and tracking of a dual device on a monolithic
chip results in unique performance characteristics "
http://semicon.njr.co.jp/njr/hp/file...o?_mediaId=148
The NJM 4558 that is currently used is a far different chip. It does things
that the orgional 4558 could never do, like swing +/- 12 volts at 30 KHz.
Do tell how it does that with a slew rate of 1V/us please !
The only pro gear I've normally seen it in is low-end budget Asian kit.
Notably DJ gear.
It shows up in more highly-regarded places.
Such as ?
Even the modest change to the 4560 provides very real benefits.
A better device for many apps, true.
However, DVD players with 4558 line drivers don't seem to have any technical
or audible failings because of them.
I'm rather less convinced than you about that.
Graham