high voltage input opamp

[sunrise]

hi guys....
i need op-amp that has high voltage input - up to 40V plus and 40V minus - total 80Vpp that has high input resistance and that is unity gain stable....
i need it as a voltage buffer - with unity gain folower
any ideas....
i don't need almost no current driving capability but the input voltage has to be high and unity gain stable....
any ideas that are cheap and good (if cheap is possible).....

[sunrise]

o.k. - to clear things a little bit more....
i need opamp that is:
- unity gain stable
- has rail-to-rail input/output topology or at least common mode input voltage range and output swing must include the voltage range of the signal that is up to arround +/-40V......

so this opamp should be a monster kind of opamp that has very high voltage input and that will work as a unity gain voltage buffer......
help please

question - what "rail-to-rail input/output topology# really means - what is that.????

[theAnonymous1]

Extreme......

[sunrise]

this is really extreme but this design does not have more than 8V at the input - i need +/-50V swing at the input and unity gain stable.....

[jaudio]

http://focus.ti.com/lit/ds/symlink/opa445.pdf

[cliffforrest]

Originally posted by sunrise
this is really extreme but this design does not have more than 8V at the input - i need +/-50V swing at the input and unity gain stable.....

It is confusing to switch forums in the middle of a thread ... :-(

[sunrise]

i am sorry Cliff....my apologies but.....i like to hear a lot of opinions......i hope you understand ... you are helping - i appreciate this a lot and because of it THNX A LOT
so far i know how to make this thing working with interconnetc cables....only have to figure out how to make it work with speaker cables up to 50-70W power amps....

[sunrise]

Originally posted by jaudio
http://focus.ti.com/lit/ds/symlink/opa445.pdf

this one looks interesting.....

by now i have made a decision - i will try this approach with interconnect cables - if this works - i will try to make it work with speaker cables......

for interconnect cables i think that also OPA604 or OPA2604 might work nicelly too.

i would like to suggest that we continue on this part of the forum so that our friend (and others maybe too) can follow more easilly...
here is the link....
http://www.diyaudio.com/forums/showt...30#post1179330