Upgrading OpAmps in Iffy OEM Preamps Advisable?

[12bass]

For years I've been tracking the available op amp chips for use in onboard pres. There are very few out there that can beat the On Semi MC33178 for low noise AND long battery life, AND maintain a reasonable gain bandwidth (GBW). Other chips can beat the 33178 on one or maybe two of these scores, but I don't know of any that can beat all three.

The OPA1642 suggested by other posters has better noise and GBW, but will drain the battery 3x as fast as the 33178.

The TL062 is ridiculously noisy and fairly slow, but its power consumption is very low.

If you find anything better... I want to know!

LT1352 sounded better than LF442 in my EMG BTS, with lower quiescent current than MC33178. OPA1641x2 sounds better yet, IMO, and I consider the higher draw a worthwhile tradeoff.

 

[chucko58]

After getting better light and magnification, I got some crud off of it and sure enough, it IS a 062!

The question is "why?"

This board is perhaps the most overpriced circuit I've ever seen at retail, so couldn't they pony up another eighteen cents or so for a better OpAmp?

Battery life and cost are the only conceivable reasons for picking a TL062. I suspect battery life was the deciding factor. Given 12bass's comments, you might want to try a Linear LT1352, which should give about the same battery life but lower noise. It won't be cheap though!

 

[UncleFluffy]

After getting better light and magnification, I got some crud off of it and sure enough, it IS a 062!

The question is "why?"

This board is perhaps the most overpriced circuit I've ever seen at retail, so couldn't they pony up another eighteen cents or so for a better OpAmp?

Probably a long supply chain with everyone trying to scrape a little extra as the $ train goes past.

The money's in the margins ...

 

[aborgman]

Free engineering samples are your friend. B-B is part of Texas Instruments these days, and T-I and National are both pretty liberal about giving away samples in small quantities IME.

Analog Devices is REALLY great about free samples also.