sound like a bad opamp? i built these test circuits..

[danelectro]

well im trying to determine if my LM308 is to blame for my new Rat build not working..

i built a voltage follower and an inverting amplifier on a breadboard and wired up guitar jacks to the inputs and out puts.. the output to an a small guitar amp

w/o power the guitar plays through the circuit.. odd i thought

with power i get a loud buzz..

im pretty sure i wired em up right, ive done it a lot in school on these boards (im a EE) and i consulted diagrams to double check.

sound bad to you guys? the guitar shouldnt play thru w/o power should it?

[danelectro]

god dammit while checking pin voltages w/ my volt metere i accidently touched pin 3 and 7 together.. thats 9vs on the input and it fried.. doh

[freebird1127]

sound bad to you guys? the guitar shouldnt play thru w/o power should it?

Sounds bad to me, nothing above a few microvolts should go thru w/o power.  Never heard of this problem before, sounds like shorted I/O, doesn't it?