An AM modulation station, the 285t is perfect for expanding a 258t!

The 285t features an analog frequency shifter and a ring mod with variable "depth".  Frequency shifters are a bit like pitch shifters only instead of shifting overtones by multiplication, it shifts by addition, which means as the inherent pitch rises the overtones lose their relationship to the fundamental and start to sound a bit "ring modded".  It's sort of like a ring mod but instead of the tones being based on the ratio of an external oscillator, it can be set by amount with an internal one, and instead of both upper and lower side bands you have separate outputs for the apparent pitch rising or falling.  They are great for expanding an oscillator and super fun on the feedback path of delays.  Tiny amounts of shifting can be used to stereo-ize a mono signal sort of like a clangy chourus.

The bottom half of the 285t features a "balanced modulator".  Based on the serge ring mod, the circuit is special because it has a control to crossfade between the clean carrier and the ring modded signal, giving you a depth control.  Halfway between the clean carrier and the ring mod provides balanced modulation, which is a bit like ring mod but with more fundamental/bass.

285t features our favorite ring mod circuit and a great analog frequency shifter, super fun module.

Specifications:

18HP

Depth: 45mm

Power: +12V 50mA / -12V 44mA