"Eeyore" wrote in message
...
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.
Otari is pro audio gear that runs at pro audio signal levels and impedances.
IOW, not a consumer DVD player running at consumer levels and impedances.
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
The fact that Raytheon had that part does not disprove the existance of the
part I mentioned. I know about both parts, thank you.
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
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Whatever that means. Its a vague statement.
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
Been there done that, thank you very much.
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 !
Look at page 3 of the PDF you cited, upper right hand corner. Then ask the
same question of NJM. It's their document.
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 ?
Stephen's NHTPro studio monitor speakers, which he seems to be very happy
with. All of the EQ is in the signal path, no matter what settings are
chosen. Seen 'em in some Rane gear as well. Just can't remember which.
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.
You say you have AP test gear - check out your typical $39.95 DVD player.
Needless to say, I've done my homework in this regard. I'm no fan of
NTM4558s but when they cause no discernable harm, well they are what they
are.