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General => Open Discussion => Topic started by: jessenator on June 17, 2024, 03:08:52 PM

Title: dual OTA circuits
Post by: jessenator on June 17, 2024, 03:08:52 PM
Curious about this

I'm tinkering with a couple of OTA circuits and it got me thinking:  anymore it's more economical to use the LM13700/NE5517 dual OTA chips, and just terminate one of them.

Wondering if there are circuits that can take advantage of both amps.
Title: Re: dual OTA circuits
Post by: jimilee on June 17, 2024, 03:19:19 PM
See if you can find a Ross phaser schematic. I can't remember if it does or not.


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Title: Re: dual OTA circuits
Post by: Aleph Null on June 17, 2024, 03:37:43 PM
I'm working on a multi-band compressor that would use both sides of the LM13700, but I haven't had much luck getting it to work yet. Other than that, I can't think of any circuits that use both sides. 
Title: Re: dual OTA circuits
Post by: jessenator on June 17, 2024, 06:06:18 PM
Quote from: jimilee on June 17, 2024, 03:19:19 PMSee if you can find a Ross phaser schematic. I can't remember if it does or not.

nope, sadly (https://experimentalistsanonymous.com/diy/Schematics/Phasers/Ross%20Phaser.png) :/  thanks for the suggestion, though

edit: ope, my b, looks like this could be? Translation says LM13600 (slightly different spec, but basically LM13700)

(https://guitar-gear.ru/wp-content/uploads/2016/04/ross_phaser_mychanges.jpg)
(https://guitar-gear.ru/wp-content/uploads/2016/04/ross_phaser_mod.jpg)

Quote from: Aleph Null on June 17, 2024, 03:37:43 PMI'm working on a multi-band compressor that would use both sides of the LM13700, but I haven't had much luck getting it to work yet. Other than that, I can't think of any circuits that use both sides. 

Interesting. Yeah, keep us posted on that. sounds neato


Title: Re: dual OTA circuits
Post by: jwin615 on June 18, 2024, 02:52:11 AM
Supposedly the top half of this circuit acts as a noise gate.
Could be useful in noisy fuzzes
(https://i.imgur.com/KFBL7Xa.jpeg)