Audio Op-Amps

[Paul Schreiber]

>From extensive Audio Precision testing, the LM8xx series from National
suffers from
large THD at frequencies above 1.2Khz, which the 5532 does not. I would
never consider
them.

Also, you have to watch the Icc of the 553x parts. If you have 20
replacements, your
cheesy 3-terminal regulators will get toasty.

For price/performance ratio, still hard to beat TL07x parts. We use OP275s
in the MOTM
synthesizer with great results. Must bypass: alot (read....most) synths I've
worked on had
ZERO bypass caps on the op amps (includes the $$overpriced$$ Moog modular
with the
741 op amps in the 921 VCO summers!). TL07x may be the best overall
"generic" choice.

Lastly, there is another bipolar dual op amp called a RC4558 that JRC made.
Used EXTENSIVELY in early
Yamaha synths, mixers, cd players, and car stereos. Not a bad part, was
about 1/2 the price of the TL07x
in 1984. Makes a difference: JRC rep told me Yamaha used 125,000 a WEEK!

Paul Schreiber
Synthesis Technology
www.synthtech.com