opamp power supply question??

[Jason D]

I was wondering would it hurt to run an opamp ckt like the Tubescreamer off of 12vdc or so, instead of 9Vdc. Would this have any effect besides extra headroom?

[Dragonfly]

I was wondering would it hurt to run an opamp ckt like the Tubescreamer off of 12vdc or so, instead of 9Vdc. Would this have any effect besides extra headroom?

depends on the opamp, i'd guess...probably wont kill most "common" opamps though.

but...im still learning about opamps...if i were you, i'd look up the specs of the opamp youre using....

if its something like a lm386, you can go to www.nsc.com and pull up the data sheet....

you can also cross reference it at www.nteinc.com


hope this helps,
  andy

[toneman]

the NE4558, from page1 of the Philips datasheet says-

"....pin for pin replacement for the RC/RM/RV4558."
"Supply voltage plus/minus22V for SE4558 and plus/minus18V for NE4558"

So...........
Uni-polar 12V would B just fine.....
Using the resistor divider "fake zeroV" string gives U plus/minus6.
Instead of plus/minus4point5 with a 9V batt.
U could concievably take 9VDC and double it 2 18V.
Then, with resistor divider U'd have plus/minus9V.
Again,  waaaay within operational parameters.
Remember, raising voltage does *not* raise gain in an opamp.
Negative feedback determines gain.
That's the beauty about opamps....no biasing...
staypolarized
tone

[Dragonfly]

the NE4558, from page1 of the Philips datasheet says-

geez...late at night, and it didnt register that he was asking about the tube screamer ckt  :oops:

[cd]

Just be sure the other parts in your circuit can handle the extra voltage.

[Jason D]

I used a 12v 1A voltage regulator to power the dual Tubescreamer pedal I just built. I didn't change anything that I could tell.

Works better than the 9v .5A regulator (small TO-92 package) that I was using before. There was a popping sound and the LEDs would blink when switching the 2 ckt's on and off. Now, that doesn't happen.

Although the change has seemed to introduce a little more 60-cyle hum. Any suggestions?

[Torchy]

crp

[Jason D]

Oh, one important detail. The power supply on this pedal is internal. So, I don't know if there is much I can do about the noise. I guess I raised the noise floor when I raised the voltage.