optimizing LF353s

[Gus]

they sound good in guitar and bass effects. they sound better that TL072 to me but I would not use them for a Hi Fi circuit. Are they NS

 

[SonsOfThunder]

[quote author="buttachunk"]how do you optimize LF353s for audio use.[/quote]

Pull 'em!

They just suck! THD is too high. They are of course FET input so... You know what to do.

HTH!

 

[hitchhiker]

hey Butta,

I had a circuit designed for these and popped in a OP275 and never bothered to try anything else. I got the 275's just to check out and they sure worked here. I think they are a low draw too if I remember right.

Lance

 

[SonsOfThunder]

I have yet to hear of anyone that doesn't like the OP275 and there is a lot of commercial stuff that uses it!

Peace!

 

[zmix]

Read the data sheet on the OP-275 very carefully. The distortion increases dramatically if they see a load of less than 2K. This can happen easily in an EQ circuit... Thomas Grafey(sp?) designed the thing, and designed it specifically to sound good. He fixed the design in the OP-176, which is a single op-amp.

 

[Gold]

The Neumann SAL 74 Amplifier rack which is commonly found with a VMS70 or 80 is littered with LF353's. Those racks sound pretty good. I think I have a schem of an elliptical eq. I'll see if I can dig it out.

 

[Gold]

I just looked at the schem for the elliptical EQ. The studio that this schem came from replaced the opamps with TL074 and MC 34084. It doesn't exactly make my case. If anyone still wants to see it let me know.

 

[rafafredd]

Yes, schematics are alwys welcome! Please, if possible, post it here!

 

[Jonathan Hayward]

[quote author="buttachunk"]how do you optimize LF353s for audio use. i recieved a sidecar full of them (72 of them). they sound very eq'd to me,,, with no eq on.

i looked for some info on THAT's site and found that "oscillation... can occasionally result when using op amps with limited gain-bandwith product (like the LF353) which exhibit inductive output impedance at relatively low frequencies".

is there anything i can do but replace them ?[/quote]

Kinda odd that, given that a load of their design notes employ them all over.
My Amek EQ uses three of them as amps/buffers/ gyrators and I can never tell the difference between it set flat and bypassed, I auditioned other (mostly BB) chips with no real audible advantage, I'll send a scan if you like.

Jonathan

 

[Gold]

http://photobucket.com/albums/v357/plushmore/QE712/Elliptical%20EQ/


Here is the EE77 which uses IC opamps and the EE66 Which is a discrete LC design. I use the EE66's. I'm not so good with the graphics apps so I can't stich them together.

 

[Jonathan Hayward]

Hi Paul, I'm getting this at photobucket, is the URL right?

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[PRR]

> The Neumann SAL 74 Amplifier rack... 80 is littered with LF353s.

The dbx 160 dual RMS limiter, a hot-ticket on eBay, and WIDELY used in many audio paths in the 1980s, is also stuffed with 353s.

It isn't the sword, it is who waves it.

 

[AMZ-FX]

I seem to recall that the LF353 had some kind of problem with asymmetrical drive capabilities if loaded down too much. I have typically avoided using them for high-end audio apps, though they are adequate for stompbox use.

regards, Jack

 

[Gold]

Try this.


http://img.photobucket.com/albums/v357/plushmore/QE712/Elliptical%20EQ/EE66_1.jpg

http://img.photobucket.com/albums/v357/plushmore/QE712/Elliptical%20EQ/EE66_2.jpg

http://img.photobucket.com/albums/v357/plushmore/QE712/Elliptical%20EQ/EE77D_1.jpg

http://img.photobucket.com/albums/v357/plushmore/QE712/Elliptical%20EQ/EE77d_2.jpg