Hi there. I've been doing a lot (too much!) hacking on UA5's lately.
I fixed a failed digimod unit.
Then I played with all kinds of opamps in my own unit. I finally settled on an AD712 input stage followed by a pair of AD8620's for the ADC driver stage. I would have went with all AD8620's except that I only had two of each type (samples from Analog Devices
). The chips are real expensive to buy as well. (AD8620 is something like $10-15!, AD712 is $5-10 I think.)
OK, I'm thinking, how about putting a pair of INA217 opamps in there (samples from Texas Instruments this time
). They are 8pin DIP, so they would need a small board added in there, but it seems like it should be possible. There is a +/-5V power supply. And the INA217 chips each take only 10mA each. So either disconnect the some of the other opamps, or just load another 20mA, which is not too much IMO.
Hey, I think what I'm going to do is leave my unit the way it is and put a switch to swap out an INA stage for the existing AD stage.
I can't keep my hands off of this puppy!!!
Richard