Discrete 5534 5532 opa604 replacement in diy projects like gssl anyone tries ?

garp said:

Ahhhhhhhhhhhh !!! Thanks salomonander ! What was the previous ic ? 5532 / 5534 or opa familly ?  did you add bypass cap between pins 1 and 2 ? Make some adjustments ?

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Bypass caps are from +/- to ground or between +/-. Between 1 and 2 would be compensation (I guess, it depends on your circuit).

Again, you need to look at the grounding and the PSU as a whole, if this is not optimized op amps will not work as good as they can and all sound differently. I've been there too many times.

Thanks for reply ... i just spent hours reading articles about phase compensation "in" and "out" of the loop and the calculations required to achieve good results with oscillations issues and overall bandwidth (and they seems to fight each other) . In other terms for a newbie like me in electronics i think i have understand that the "environment" of the op amp and what it is asked for in the schematic is crucial when you think about "improvement" and that sometimes swapping IC considered as "replacements" can lead to more problems than effective results .  My aim with this thread was to cross experiences some could have with those discrete opamps ...  my particular cases are concerned by the gssl build the Urei 1178 mods by Jim Williams and the Pm180 mods (i will post some clips of the result with mod/unmod files)

> no clue of what a GMC is ... i am living in france

That's a poor analogy.

We joke, but the AMC Gremlin was an OK car, just ugly, and soon orphaned.

GMC is a higher-price brand of GM truck. Mostly a Chevrolet truck, but sometimes a different engine, and the GMC badge is used up to very large trucks.

The 702-709 chip opamp is our Ford Model T, which is probably remembered world-wide. Not an electronic advance in the art, but made to be MASS-produced, so became universal (though the T lasted longer than the 709).

Then the 101/741 is the 1929 Chevrolet which basically replaced the Ford T. It was sleeker, smoother, MUCH easier to drive. The '29 Chevy was novel mostly in its price. Everything on it was common in high-price cars. But it inspired cross-fertilization at all levels and brands. The BMW became a much better Chevy. Toyota made Chevy-clones in Japan. Dodge made better Chevies (four brakes!!) at similar price. Even Ford (after facing the pre-1929 Chevies) had to spiff-up the T into the A and then the V-8.

I have driven a bone-stock 1941 Plymouth to the airport this decade. On local roads it is really a fine driver, though much improved from 1908 and 1929 cars. It strains to hold today's highway speed, and sucks gas trying.

These were all good cars for their day. That day is past.