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The Arp Little Brother was manufactured between 1975-1977
The Little Brother is a monophonic synthesizer that can connect to another analog synth to become an added sound.
The Little Brother has a single voltage controlled oscillator (VCO) with selectable waveforms, and a sub-octave divider that can produce up to three additional tones simultaneously at -1, -2, and -3 octave intervals.
It also has a low frequency oscillator (LFO), vibrato, and a pitch bend knob. However, it has no voltage controlled filter (VCF), voltage controlled amplifier (VCA), or envelope generator (EG, AR, or ADSR).

When used with other Arp synths to "fatten up" their sounds, the Little Brother's audio output had to be patched into the external audio input of its companion synthesizer, essentially adding an extra VCO and LFO to the system.
The Little Brother utilizes 1v/octave CV.
The back of the unit has the following:
- 1/8" jacks for CV In, CV Out, Gate In, Gate Out, Trigger In, Trigger Out, and LFO Out.
- RCA jacks for Audio In and Audio Out."