INTERACT FORUM

Devices => Sound Cards, DAC's, Receivers, Speakers, and Headphones => Topic started by: bob on December 26, 2020, 11:01:51 am

Title: EQ upgrade
Post by: bob on December 26, 2020, 11:01:51 am
In the late 70’s I built an equalizer from a kit.
It had pretty good specs for the time but I figured it’d be fun to put in some newer higher spec parts.
I had originally soldered in the 8 rc4136 quad op amps. These have a somewhat nonstandard pinout compared to more recent offerings.
I decided to go with Burr-Brown OP4134pa op amps that have much better noise floors but have 12 of the 14 pins in different configurations.
I unsoldered the 8 original chips, did a bunch of trace cutting and jumpering (96 connections) replaced the existing disc caps with tantalum and put it all back together. It works great!
Rewiring required:
http://www.tangible-technology.com/optical/quadopamp_w72.jpg
Title: Re: EQ upgrade
Post by: mwillems on December 26, 2020, 11:05:16 am
That looks like a really fun project, bob!  You should make it a graphical skin for the MC equalizer :-)
Title: Re: EQ upgrade
Post by: bob on December 26, 2020, 11:09:22 am
For me making a skin would probably take longer than the soldering did 😆