Op amp suggestions for battery powered buffer

[pinkjimiphoton]

rob, get some freekin sleep, bro!!!

[Rob Strand]

rob, get some freekin sleep, bro!!!

Actually I got tired while I was drawing up the schem, then I layed down and passed out for about 1hr.

[Rob Strand]

Anyway, this pic shows how the resistive beats the current source when the output is high but loses when the output is low.   The slope of the current source is more or less constant but the resistive ckt has a variable slope depending on the level.   The parallel buffer stays symmetrical and has better drive.

Click twice to get full resolution:


Back tomorrow.

[marcelomd]

Hi,

My G&L L2500 bass' uses an LM4250 opamp.

It is just a buffer after the tone/switching controls. It does the job well. Noiseless and I think I've swapped batteries only once.

[wayfaerer]

Just wanted to report back my findings. Actually I made the buffer quite a while ago but only recently finished boxing it. Because it was so long ago (or so it seems), I forgot which schematic I used, but I'm pretty sure it was the Jerry Garcia Tiger preamp layout from tagboardeffects.

I assembled the circuit with a socket for the op amp, and tried the following op amps, testing the sound and milliamperes (of the whole circuit, not just the op amp by itself) for each one:

• TL061: 0.16 mA, ~1875 hours
• TL071: 2.11-2.12 mA, ~142 hours
• TL081: 1.96 mA, ~153 hours
• CA3140EZ: 2.73 mA, ~110 hours

Hour estimates are based on a conservative 300 mAh 9V battery, and all op amps were purchased from a reputable vendor.

To my surprise, I noticed no difference in sound between any of them. I assumed the TL061 would be noisy but I couldn't hear any. YMMV. Therefore I will happily use that one and not have to worry about battery life.

Thanks for all the responses!