klein@ucbcad.UUCP (Mike Klein) (06/03/85)
-------------- I've been out of daily contact with opamps for a couple of years now, and I'm wondering what the choice opamp of the serious audio designer is these days. Back a few years ago, there were some nice units from Signetics (5534 or something like that), and National was in there with the LM308 and LF341 or some such number. You can tell it's been a while. Requirements: low noise, fast slew (50 V/uSec) with realistic capacitive load (.001 ?), fast closed-loop settling (1 uSec?), equal positive and negative slew, high compensated unity-gain-bandwidth (> 10 MHz), very very low crossover distortion, and no more than about $3 per amp. This is for putting together some very high-quality active crossovers, so there are going to be at least 3 opamps in the signal path. Flames about sound purity ruined by opamps will be immediately redirected to /dev/null. -- -Mike Klein ...!ucbvax!ucbmerlin:klein (UUCP) klein%ucbmerlin@berkeley (ARPA)
mohler@druxu.UUCP (MohlerDS) (06/07/85)
The state of the art in monolithic opamps are the Motorola OP27, OP37, Analog Systems ma-106, ma-332/333/336, ma-352/362/372, ma-459. There are also some ECL opamp hybrids made by ? in Florida that are absolutely incredible! In fact they are better than the majority of discrete circuits!! The ultimate is still a discrete opamp implemented with a 2N5566 front end, a bipolar cascode middle and a supertex mosfet output like what Threshold and Spectral use. I hope this helps. David S. Mohler AT&T-ISL @ Denver !druxu!mohler