Buchla Frequency Shifter 285t

The Frequency Shifter 285T, originally from Buchla is the latest module to get the Eurorack treatment. It’s part of the 200 series project which aims to bring a bunch of classic Buchla modules over to the 3U masses.

So what does it do? Well, in essence you get a frequency shifter and a ring modulator housed in one module. It is great for creating complex timbres with metallic qualities while offering you plenty of modulation options to go with that.

Frequency shifters are different from pitch shifters in that they shift the entire input signal by a fixed amount, disregarding the relative relationships between the fundamental and the overtones as a pitch shifter would. This is also the main reason for its metallic sonic quality. The more harmonics your source sound contains, the gnarlier it gets. Pitch shifters on the other hand operate in a more melodic fashion, harmonious if you will.

The top of the 285T the frequency shifter section lets you shift frequencies up or down. You’ll also find two outputs here, Sum and Difference as well as bipolar CV in and linear FM.

At the bottom of the device you have the balanced modulator section, a.k.a. – the ring modulator. This part mixes the upward and downward shifted frequencies. There’s a variable control that lets you blend in the amount of ring modulation to taste. For those who prefer to mix these two externally, fret not – there are outputs for that as well.

Quick history digression: Ring modulation is one of the oldest sound manipulation methods, dating back to the 1930s. It was first used to combine and separate multiple frequencies so they could share a single line in early telephone systems. Who would have thought it would eventually contribute to this wonderful world of fascinating electronic instruments we live in today?

Anyhow, where was I? Ah yea — Buchla, Tiptop, 285T! The frequency shifter and the balanced modulator of this module combines some of the oldest synthesis techniques in electronic music, dating back to a time when the only way to achieve this was through the use of old test equipment. What’s not to love?

Features:

Frequency Shifter Section:

• Sum and Difference Outputs: Upward and downward frequency shifting
• Internal Oscillator: Up to 1kHz of shifting
• External Reference Input: Use an external signal for shifting
• Bipolar CV Inputs: Control for the Reference oscillator
• Linear FM Inputs: Further modulation options

Balanced Modulator Section:

• Combining Components: Blend sum and difference outputs.
• Balanced Modulator: Ring modulation with variable blend control.
• Control Voltage: Dynamic morphing of timbres.