op amp gurus

[peter purpose]

The big guns are out..!!

Gentlemen,
Maybe I've just stumbled into the right place, or am a genius.. :razz: , but having listened to the original with HAI 4741s, BB OPA4132 replacing them and my discrete version, the discrete is winning hands down.
Mind you, I do have 2520s at the front and back.

I'm going to put 2520s on the front and back of the original circuit and give it a listen.

peter

 

[peter purpose]

[quote author="cuelist"]requires some serious GBW .[/quote]

Giant breasted woman?

 

[cuelist]

[quote author="peter purpose"]

Giant breasted woman?[/quote]

Yup - like this:

http://img.photobucket.com/albums/v506/Cuelist/9561.jpg

(terribly un-PC, I know )

 

[peter purpose]

:green: :green:
We've got to be careful now... otherwise NewYorkDave will hijack the thread.

 

[tv]

What is often used as a synthetic grounded inductor is the input to a Sallen-Key unity-gain two-pole highpass. The equivalent L has an R in series and another (generally different) R in parallel, so it's a bit awkward to use. With a C in series it forms a grounded R-L-C resonator, but because of the resistance across the L the impedance at high frequencies is never as high as at low.

clitnrubber and I were looking at this one-transistor gyrator circuit variant, which is abused in boss-pedals (maybe more alive sounding than opamp versions?):
http://www.freeinfosociety.com/electronics/schematics/audio/pictures/bossmt22.gif

I did a thorough google search about floating gyrators/simulated inductors a while ago. Does anybody have a schemo how to do a simulated floating inductor/or gyrator - prefefrrably with transistor(s) ?

btw: omg huge breasts. can you imagine her playin basketball?

 

[clintrubber]

[quote author="tv"]I did a thorough google search about floating gyrators/simulated inductors a while ago. Does anybody have a schemo how to do a simulated floating inductor/or gyrator - prefefrrably with transistor(s) ?

btw: omg huge breasts. can you imagine her playin basketball?[/quote]
I realize the description a pair has gotten a special meaning recently :wink: , but yes, you can do a floating: use a pair se-ones back to back. In other words: gyrator one, then a cap, then gyrator two ('reversed').

 

[tv]

Cap between bases? But - could be bases somehow just connected directly? But how can one then calculate frequencies and Q - if this is to be for pultec.

This could be done with bs170 mosfets, too, I guess? For some more mojo.

 

[bcarso]

[quote author="tv"]clitnrubber and I were looking at this one-transistor gyrator circuit variant, which is abused in boss-pedals (maybe more alive sounding than opamp versions?):
http://www.freeinfosociety.com/electronics/schematics/audio/pictures/bossmt22.gif

[/quote]

Yes, those are e-followers as ~unity-gain buffers, and the final C to the op amp input is the resonator C of the RLC. If, conversely, you were to disconnect that C and drive it, and take the output at the emitter, you have a highpass filter.

Alive?? Well, if you like lots of second harmonic...

 

[ciminosound]

[quote author="cuelist"][quote author="peter purpose"]

Giant breasted woman?[/quote]

Yup - like this:

http://img.photobucket.com/albums/v506/Cuelist/9561.jpg

(terribly un-PC, I know )[/quote]

I wanna measure and see if they're a matched pair!

(terribly un-PC, I know) :twisted:

 

[tv]

Alive?? Well, if you like lots of second harmonic...

aha-moment: those are distortion circuits and second harmonic is supposed to be a characteristic of a hot-driven tube. I wonder how would a mosfet perform in such a gyrator.

 

[bcarso]

[quote author="ciminosound"]
I wanna measure and see if they're a matched pair!

(terribly un-PC, I know) :twisted:[/quote]

I get your drift. If well-matched, they have application as a deferential pair.

"We're having a heat wave,
A tropical heat wave
The temperature's rising
It isn't surprising
She certainly can can-can"

 

[peter purpose]

[quote author="bcarso"]
I get your drift. If well-matched, they have application as a deferential pair.[/quote]

Obscure.... yet gets a chortle chortle. :green: