Maybe some EQ fun with this…

[Schlippwhip68]

Nobsound EQ9 HiFi 9-Band Stereo EQ Preamp Analog Equalizer Audio Processor for Home/Car

Features 9-band EQ equalizer: With independent and rich frequency band control (20Hz/60Hz/125Hz/250Hz/500Hz/1KHz/2kHz/6KHz/16KHz), within -6dB to +6dB range. With 2 groups of RCA inputs and outputs, without plugging in and out cables repeatedly. High-performance: The SNR of EQ9 exceeds 111dB...

doukaudio.com

Has anyone had any fun with this?

 

[Speedskater]

There are lots of semi-pro equalizers that can do about the same thing. But with more bands and independent Left & Right band controls.