anyone experienced in comparing these (or LM13700) ?
TNX
Haven't compared them but I have a Korg compressor (Ross clone with a 13600) and that puppy is dead quiet.
I made the first PAiA/Anderton dual limiter that appeared as a project in Modern Recording some 20 years ago. The audio path was essentially a 570 and nothing else. No transistors or other op-amps on the way out or in. I suppose that is as direct a test of noise levels as one could get. I don't have it any more, and the article and schem (with specs) is in a binder at home, but I recall that noise levels were so-so. Something like a 60db S/N ratio, although I'm sure you realize that knowing what input signal level that refers to is critical and missing information. In contrast, the 3080-based Anderton Volume pedal retrofit is spec'd at about 70db S/N.
On the other hand, it is worth considering that the limiter was using the two sections in compressor mode only (i.e., boost with momentary sidechain-directed gain-reduction), so one is listening to noise at the output from boosting thermal noise at the input. I have no idea what it does when used as a VCA.
I should also point out that the penalty in terms of signal handling (if one uses a 3080) might be greater than the noise penalty in using a 570 or 571. I'm sure Jim Patchell would suggest using a 3280 and being done with it. (http://www.oldcrows.net/~patchell/archives/archives.html) Much better signal-handling than a 3080.
Hey Mark: thanx for the Patchell link: interesting!
I need some "gain-cells" for a project, using them as var. resistors,
and want to use the opportunity of the built-in "env.-followers";
For the rest, I usually think the 13700 to be ok for me -
it`s the low pin-count which the 570/71 offer including
the rectifier section, that intrigues me,
just don`t wanna trade that for higher noise figures than what is
possible with 13700s.
BTW.: the Philips counterpart NE5517 has been discontinued in Feb.`04.