Krohn-Hite Model 3550 Variable Filter Delay/Echo Here's a quick demo of

Here's a quick demo of another HE-2150 we posted to our Instagram:

manual and PSU

Input is on a mini-jack socket

It has a few scuffs and scratches - mostly to the top and around the rack ears - which have been touched-up and are barely-discernible when racked

Use both knobs with both hands and create your own filter effect

Krohn-Hite Model 3550 Variable Filter Delay/Echo Here's a quick demo ofThe Krohn Hite 3550 Variable Filter is a multifunction filter that offers band pass, band reject, low pass or high pass operation in a single piece of equipment. The mode of operation can be selected by a front panel switch. The cut off frequency is continuously adjustable from 2 Hz to 200 kHz.