Overview

This project is based off of the Sontec MEP250A 5 band EQ.



I've adapted it to use Blore-Edwards PZ style 23 step rotary switches but other switches or regular pots could be used as well.

Resources

I used the following references and resources when designing and tweaking this project:

• Original Sontec MEP250A achematic gurtosey of Gyraf
• The Don Classics 250EQ 500 series module (I've built 4 f these and they are really really great)
• Glass-Ware audio bipolar power supply I used this power supply in my build rather than design my own. You can substitute for any decent bipolar power supply that provides +/- rails around 15V - or whatever you want to use for your opamps.
• Igor's calculator for rotary switch resistor values: Igor's Calcs GSheet Link. I didn't like the rev. log taper on the Frequency switch so I added my own calculations here: My GSheet Link