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Recommended dual OPAMPS

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hardcore misery

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for high-gain pedal users here..

can you recommend some dual OPAMPS with lower noise and greater gain...

i have TL072 now, and so far its good, but i'm still looking for a greater one...

anyone?
 
hardcore misery said:
for high-gain pedal users here..

can you recommend some dual OPAMPS with lower noise and greater gain...

i have TL072 now, and so far its good, but i'm still looking for a greater one...

They are already very low noise, and have massive gain - why do you want anything different?, what are you trying to do?.
 
You can run pretty well any opamp off a single supply, just use a pair of resistors to generate a virtual midpoint - check Audioguru's famous opamp graphic!
 
It is possible to power any op-amp from a single rail supply.
opamps_832-gif.4587
 
The TL072 dual opamp has lots of voltage gain:
1) 200,000 from DC to about 20Hz.
2) 100,000 up to 32Hz.
3) 10,000 up to 316Hz.
4) 1000 up to 3160Hz.
5) 100 up to 31.6kHz.
6) 10 up to 316kHz at low levels.
7) 1 up to 3MHz at very low levels.

An OPA2134 dual opamp also has FET inputs and has less noise than a TL072. Its open loop voltage gain is typically 2,000,000 from DC to 3Hz. It has a gain of 1 at 10Mhz at very low levels.
 
An OPA2134 dual opamp also has FET inputs and has less noise than a TL072. Its open loop voltage gain is typically 2,000,000 from DC to 3Hz. It has a gain of 1 at 10Mhz at very low levels.

..and therefore, it will be much better that TL072?
 
I would recommend the lm6132 for dual and the 6134 for quad. I have been using them recently and they perform pretty much rail to rail, which is great for single-ended low voltage supplies. I am currently using 4 6134's in a Single-ended supply IR circuit. They are not cheap but you get what you pay for.

EDIT: Hero, won't the voltage divider you have shown in the 2nd circuit for the Virtual Ground get screwed up from the parallel cap and resistor? I always use an extra op-amp set to output .5Vcc for my Virtual Ground, cause it needs to be able to sink current.
 
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hardcore misery said:
..and therefore, it will be much better that TL072?

There's a fair price difference though, $3.90 for the OPA2134, and $0.55 for the TL072. Prices from www.futurlec.com

Guess it’s a bit like graphics cards - would you pay the extra $$ to see that drip of water roll down a blade of grass?
 
Ambient said:
I would recommend the lm6132 for dual and the 6134 for quad. I have been using them recently and they perform pretty much rail to rail, which is great for single-ended low voltage supplies. I am currently using 4 6134's in a Single-ended supply IR circuit. They are not cheap but you get what you pay for.

EDIT: Hero, won't the voltage divider you have shown in the 2nd circuit for the Virtual Ground get screwed up from the parallel cap and resistor? I always use an extra op-amp set to output .5Vcc for my Virtual Ground, cause it needs to be able to sink current.

The LM6132 is actually cheaper than the OPA2134, its $1.75 from futurlec.com.

From what I've heard in the past, the OPA models are no toys. Infact, comparing the two outputs in the datasheets can verify that - Look at the time scale for the settling times, 200nS in the first, and 1uS in the second for each edge.

The LM6132 has ~2uS settling time on each edge.

Datasheets;
https://www.futurlec.com/Linear/LM6132AIN.shtml
https://www.futurlec.com/Linear/OPA2134PA.shtml
 
ah. You guys are looking for really high performance stuff then. NM my suggestion. But they are till great if the "settling time", which I assume is the fall time, is not critical. I would think for audio that 2us would be fast enough, since it would only influence signals way way over audio frequencies. 2us -> 500,000Hz. Am I way off in assuming that?
 
Why use a very good opamp for a lousy fuzz-making pedal for an electric geetar?
 
hardcore misery said:
..and therefore, it will be much better that TL072?

Well, "better" is entirely relative to the task!
High bandwidth can bring about stability issues and is pointless if this an audio circuit. Likewise, I've no idea why you think you need more gain.

For audio, the noise is important. The + and - input and output range are important (be really sure you look these up and understand them!). In some cases the output current and offset error is important, but usually not.
 
hardcore misery said:
how does the slew rate of opamps affects the tone? is it a factor for Volume? the higher the slew rate, the higher the clean headroom?

The higher the slew rate the higher the frequencies it will pass, a lower slew rate will reduce high frequencies, particularly at high signal levels.
 
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