+/- 15V OR +/-12V for opamp circuits?

[diydidi]

Hi.
I'm busy building some opamp circuits, and it occurred to me that most of the circuits/ schematics I see, run the opamps from dual +/-15V supplies.
I have dual +/-12V for this project. Will it degrade the performance in any way?
I'm using JRC4558 IC's.
I know that headroom will be diminished somewhat, but my project will be for line level signals only.
Why is it more common to see 15V dual rails????

[km6xz]

12 volts will be fine, only p-p 6 volts less swing. Are you talking about line level +4 or -10? For consumer -10 line level a swing of almost 24 volts will be more than enough for lots of headroom but more limited headroom if 0 is +4. What are you building?

[Mick Bailey]

Remember too that most common opamps can't swing rail-to-rail. With a 4558 that means a loss of around 1v in either direction.

[J M Fahey]

Why is it more common to see 15V dual rails????

Because 99% Op Amps can easily stand them and that gives max easy to get output.
Of course they work perfectly with +/-12V , just a little less headroom, which often is not needed .

[diydidi]

12 volts will be fine, only p-p 6 volts less swing. Are you talking about line level +4 or -10? For consumer -10 line level a swing of almost 24 volts will be more than enough for lots of headroom but more limited headroom if 0 is +4. What are you building?

Thanx for the reply.
I'm building a DI box and its inverse, all in one box for my second test bench. Will be used for servicing mixer and/or taking balanced signal, converting to unbalanced for my bench test amp and speakers.

[tedmich]

For this application check out the excellent line divers and receiver chips from THAT Corp.

THAT IC Datasheets

available at Mouser

[Mark Hammer]

There's what an op-amp can handle, and there's what an op-amp needs for the job it is being asked to do. Many op-amps are perfectly fine with +/-18V, for that matter, but as so many effects pedals richly illustrate, often +9V (essentially +/-4.5V) is sufficient to do the job. The 12 and 15V designation is really more a function of how widely available 3-pin regulators are at those voltages, than anything else.

Given how many DI units run on less than +/-12V, I think your supply is more than adequate. Whatever supply voltage you go with, make sure that any and all relevant electrolytic caps are voltage-rated appropriately for a comfortable margin of error. Use 25V ratings and you'll be fine.

A DI box assumes one is directly feeding a mixer or other similar input. You can likely find much better op-amps to use than a 4558...unless the master plan is to exploit the weaknesses of the chip in some manner.