A vocoder controlled by a keyboard.
The cheapest effect unit with the vocoder patch that be had for about $65 is the Behringer DSP Pro 1000.
Beh doesn't make that particular model anymore, but this unit can be purchased off e-bay and some music retailers etc.
Their are other signal processors out their that offers higher bit rate and superior A/D/A converters with adjustable parameters to
fine-tune the vocoder function(along with other efx such as reverb,pitch,chorus etc) that are more pricier, but you can produce the same "Troutman Flow" with the DSP1000 at a small
price.
