RV-1 Real Reverb From Demeter
Part 1: Reverbs of Old / Not Your Father's Boing Box
James Demeter has revisited a glorious analog effect and come up with an alternative to digital reverbs. The RV-1 Real Reverb offers excellent sound quality and genuine vintage characteristics -- without the problems inherent in vintage reverb units.
Back in the olden times, before the days of digital anything (other than fingers), there were only three ways to add reverberation to vocals or instruments: The echo chamber, the plate, and the spring reverb. Echo chambers are essentially large, reverberant rooms with a loudspeaker playing the source material and microphones picking up the echoes; the plate is a long piece of sheet metal energized at one end, with the reverberating vibrations picked up by a transducer at the other; spring reverbs use the same principle as the plate, though they're considerably smaller and more affordable.
Spring reverbs are a big part of the sound of Hammond organs and Fender Reverb guitar amps, and they've proven to be essential tools for surf rock and dreamy mood music. But previous attempts at making the spring a viable, professional studio effect have yielded mixed results: The springs and surrounding components are burdened with many inherent mechanical and electronic problems that are not easily fixed.
Not Your Father's Boing Box!
One of the traditional problems with spring reverbs was the huge difference in sound between individual tanks. Demeter solves this by testing every tank that goes into his units; only closely matched pairs are used. (I can vouch for this personally: I saw a pile of rejected tanks at the Demeter factory.) Another problem was the poor frequency response of the drive and receiving transducers at each end of the spring units. Demeter solved this by using Analog Devices' OP176 operational amplifiers, in "constant-current mode," for the transducer drive amplifiers. This flattens out the frequency response of the transducers, revealing the full sound of the spring tank.
Other factors add to the RV-1's impressive sound quality. The fully regulated + or - 18-volt power supply insures maximum audio headroom and +28dBv output. Analog Devices 2142 and 2143 chips are used for input/output line amplifiers. The age-old noise problem common to "boing boxes" has been taken care of by careful circuit design, component layout, and the extensive use of mu metal shielding for both the tanks and the custom toroidal power supply transformer. Emplying the RV-1 within a 24-bit digital mix, I immediately noticed the unit's quietness. I heard no extra noise or hum even during the quietest moments in my mixes -- moments that would surely reveal any noise problems.