Advice sort on quad opamp upgrade . . .

[strangeandbouncy]

I have just snaffled two Alesis microlimiters for less than the postage to get them from Germany. 18 euros each. i absolutely love them. One has TLO84's, and the other has LM347's. I cannot really tell any difference between them, and they both sound great into 10kOhm inputs. However, they both sound piss-poor driving some of my 600 ohm gear. Not to surprising really, especially considering the chips in question and the reduced headroom, which I guess is +/-12V since wall wart is 9vac, and the curtiss vca has +/-12v absolute max! Now I don't want to spend a fortune on trying to improve something so cheap that already gives me the horn, but do any of you worthy gentlefolk have any opinion on posibly upgrading the quad op-amps? LM837's which certainly can drive 600 ohms with an adequate power supply, MC33079's which always seem to sound good in applications of mine that have 'em, ie Maselec SSL eq cards . . . opa4134's, ad713's, op470/471's? - do any of them measure up/sound good? or should i just be extremely greatful for what I've got and leave well alone? Perhaps a +/- 15v supply for the op-amps, leaving the vca to it's existing +/-12v?

Any suggestions will be most welcome!


Many thanks,


ANdyP

 

[gyraf]

I've been very happy with MC33079-upgrade for most quad-type opamps - it seems to behave really nice in cases when the low input offset current of the FET-inputs of TL0x4 and LF347 is not needed.

On the other hand, if the low offset current is needed in your circuit (because of missing input DC-decoupling), you may - over time - run into scratchy pots or switches..

Jakob E.

 

[bcaust]

Would it be possible to tack a SSM2142 on its tail somehow- beyond my expertise but spec sheet shows 10k input impedence

 

[mbrebes]

You could always try a TL054, which is like the TL074 but can drive a 600 ohm load.

 

[strangeandbouncy]

All good stuff, guys,

thanks! I guess suck-it-and-see is the order of the day. I didn;t even know that there IS a tlo54! Nice! I had thought about SSM2142, especially as it would give me balanced outs. Cool! 33079's are new to me (in building things), but I have always been impressed by the Maselec ssl type eq, and also the humble Aphex 109 eq which ahve 'em.



all the best,


AndyP