[1] While there are several string machines and vocoders, a single device combining the two is rare, despite the advantage of paraphonic vocoding, and the VP-330's synthetic choir sounds are unique.
Despite the VP-330's electronic string and choir sounds being less realistic than those of the tape-based Mellotron, touring musicians used it as a lighter and more robust alternative.
[3] The Roland SVC-350 is a similar vocoder in rack-mount form designed to accept external inputs.
[2] Like Roland's other string machines of the era, such as the RS-202, it features a BBD-based ensemble effect that thickens the strings, and optionally the choirs and vocoder.
In 2016, Roland made a digital recreation of the VP-330, named the VP-03, as part of their Boutique range.