tl082 power supply

[tomwarrior]

can i just connect a 9 volt battery to pins 8 and 4 or do i have to use a bipolar power supply. if i have to use a bipolar power supply how would i connect it? i will be using 5 tl082's in my current project. thanks in advance.---tom

[The Tone God]

Can it run off just 9v ? Yes.

Will you need a bi-polar supply ? Depends on your circuit. Need more information about the circuit in question.

How you will connect the bi-polar supply ? Depends on your circuit. Need more information about the circuit in question.

Andrew

[niftydog]

yes you can use a battery, but you then need to bias the op amp to half supply so that it works properly. There's a decent amount of discussion on this topic here already, searching around a bit might help you understand the concept.

A bipolar supply has three connections to be made, +ve (positive), -ve (negative) and ground. Typically +ve is pin 8, -ve is pin 4 and for a standard inverting amplifier the non-inverting terminal(s) (pins 3 and 5 on a dual op amp) is(are) grounded.

[tomwarrior]

the circut im building is the mashall preamp sim;
http://hem.passagen.se/amps/
i hooked up my 9 volt power supply the same way i did when i built my mxr phase 45(pins 4 and and all i get out of my first opamp stage is a farty distortion. i tried shorting pins 1 and 2 and it didnt help. i also tried running 16 volts and it didnt help. i had origanaly built this circut using lm324's and had the same problem. thanks in advance.---tom

[niftydog]

i hooked up my 9 volt power supply the same way i did when i built my mxr phase 45

how exactly was that?

I'm convinced you have overlooked signal biasing.

[Prive]

Sorry but there is more than 5 tl082 in that proyect, or you are thinking in a part of it???
A single battery will not give you lots of time of 9v and you will still need two for the entire power supply.
That circuit is amazing, i'm starting it too, will be cool share some experiences in a new topic maybe.

Saludos, Marcelo.

[tomwarrior]

niftydog, like this;
http://www.geocities.com/j4_student/mxrdodphase.gif
pins 4 and 8.

prive, im only building the preamp. there are 9 opamp stages in the preamp. im going to do it using 5 tl082's. heres the schematic;

[tomwarrior]

i figured it out!!!

i got the first 4 opamp stages completed on my breadboard. sounds good so far!!!!

[niftydog]

don't leave us hanging! What was the problem?

[tomwarrior]

i didnt hook up the batteries correctly. it needed a bipolar power supply.
i havent had alot of time lately but i managed to build up to opamp 7 so far.
ive been checking the sound of each opamp as i wire it and it sounds great out of opamp 7.
if you build this preamp be aware that unlike all the other opamps in the circut that opamp 5 is wired so that the non-inverting input is grounded. if you mess up the two inputs the presence control will not work correctly. if i have time i will finish it tonight and hopefully record some sound clips.---tom