Op-amp: TL072 vs. 4558

[Wounded Paw]

I know this has been covered but I wanted to get fresh opinions on using different op-amps in non-overdriven uses.  For example in a blender circuit like ROG's Splitter-Blend, or Sean. M's B.Blender or just in simple buffers or boosters, is it possible to notice a difference in sound quality and output level when swapping in different op-amps.  I'd like to use TL072s in everything but I also have a pile of various makes of 4558s hanging around that'd I'd like to use up.  I'm going to do my own comparisons but thought I'd get some thoughts from the pros around here.

[plankspank]

For non-overdrive applications, I prefer the TL072's. they are quieter and have JFET inputs. But hey swap them out in the circuit and let your ears be the judge.

[Wounded Paw]

Kinda what I thought.
How about NTE778A?  Got a cupla those hanging around too.

And for single op-amps, TL071 vs. NE5534? I'm guessing the TL071 would be superior for the same reasons.

[petemoore]

 View data sheets.
  Particular interest is the title and first blurb.
   TL072's a good opamp.
  There's better, but only if you 'think' so, or can find a real reason why.
  Somehting that draws more current [NE5532 ?] might be better or worse, and might give more voltage swing to the signal output before the rails matter being in a socket where a low current opamp [TL062].
  Notice how the discussion has drifted, become generalized and non-specific.
  For a specific application, more relevant comments might be easier to come up with...
  Low noise ne5532
  Low current  Tl062
  rail to rail outputs ...I forget the numbers
  Near rail to rail outputs  ...
  Desirable internal distortion LM 741
  and..
  They all have their characteristics, which tends to equate to trade-offs, high current draw/low noise...or low current draw for low noise...depends on the application.

[StephenGiles]

At 9v, very little difference.

[plankspank]

Another factor to consider when choosing op amps is slew rate. One of the reasons the LM308 sounds good for distortion (i.e. the RAT) is the slew rate distortion it produces.

[Rocket Roll]

There are some interesting (although HiFi) remarks to be found here:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=97507
http://www.diyaudio.com/forums/showthread.php?s=&threadid=49442

[ayayay!]

Another factor to consider when choosing op amps is slew rate. One of the reasons the LM308 sounds good for distortion (i.e. the RAT) is the slew rate distortion it produces.   

That. 

Right there. 

Slew rate: what to consider, and how to consider it.

Please.

A link is fine if no one wants to type all night. 

Thanks! 

[flo]

Compare the slew rate of the 741 (0.5 V/microsecond) and the LM308 compensated with 30pF like in the Rat (0.15 V/microsecond) with the slew rate of a "modern" fast opamp like the TL072 (13 V/microsecond).
Low slew rate => Can not cope with high frequencies in combination with high gain => Nice for (opamp) distortion with reduced (harsh) high frequencies.

See also:
General Guitar Gadgets - Rodent
https://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=92&Itemid=26
"Opamp Selection
...

The datasheet for the LM308 states that the special characteristics of this opamp are very low input bias current, low supply current, and guaranteed drift characteristics, characteristics not normally important to audio. Further checking of the datasheet shows the slew rate of the LM308 (0.15 V/microsecond) is dismal compared to a typical audio opamp, like a TL071, which I think is the key to why it sounds great in the RAT circuit.

I compared the LM308 to both the TL061 and the TL071. The TL opamps sound OK in the RAT circuit, they are brighter and more of a heavy metal type of tone, and there is some "plinking" to the attack. The LM308 gives a warmer tone, less treble, and with a smoother, more tube-like attack, no "plinking". I theorize the dismal slew rate is responsible for this - the opamp simply cannot reproduce the pick attack at high gain. "