Recommendation for inexpensive fet inout opamp

[zerodigit]

I'm building quite a few portable preamps for my friends recording room and need some fet input opamps that can operate with a single 9v battery. I tried the opa2134 but need something a bit cheaper since most of the portable units will be lent out to various people and probably beaten to hell. Thanks for suggestions.

 

[jcx]

opa2134 is about as cheap as good op amps come, but they are limited in not swinging very close to the rails so they are a poor choice for single 9V battery supply

AD823 is a little pricier but does have r-r output and is often mentioed in lists of op amps for audiophile apps

but I don't understand worying about saving $2 on op amp price, surely connectors, pwb, assy time cost several times that

 

[adrome00]

If size/space allows, I find it well worthwile to use two 9 volts. You'll get better headroom and won't need to use devices to establish a ground at 4.5 volts which would probably involve additional current usage and go out of balance as the battery fades. (Downside is that there goes the single-pole power on)
The TL072 is economical and often seen in high-quality commercial audio products. It has low noise and a slew rate of 13 v/us.