By Barry Rudolph
RV-1 Real Reverb From Demeter
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.
Ease of Use: 5
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!
James Demeter took a long look at solving the problems and came up with the all-analog, RV-1 Real Reverb spring reverb.The Real Reverb is a one rack-space unit boasting a pair of Accutronics six-spring reverb tanks.
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.
Channel 1 and Channel 2 are identical except for decay times: Channel 1 offers around 1.5 seconds; Channel 2, about 3 seconds. You can operate the RV-1 as two separate mono reverbs or tie the inputs together with the Input Link control so that signals coming into either channel are mixed and sent to both springs. In this mode, the two outputs would be panned left and right in your mix. Instead of trying to adjust reverb time (which is not possible with spring reverbs), I lowered the level of the longer right channel to match the length and level of the shorter left.
The Output Link switch mixes the two outputs together for an extra thick mono reverb. I used this mode when I wanted the richest possible sound in mono only. If you are monitoring in stereo with the two outputs split left and right, you’ll hear the sound image swing to the center, a dramatic effect. You can maximize headroom with careful use of the Input level control, minding the red LED overload indicator; the manual says that you’ll get maximum level in and out when this indicator blinks a bit.
Each channel also offers a high-pass Filter switch for rolling off rumble and low frequencies below 100 Hz. I used this to prevent muddiness when adding reverb to bassy instruments. The Mix control governs the ratio of wet-to-dry sound (important when using the Real Reverb as an insert effect). I found the Phase switch, which flips the phase of the reverb signal output, to be a clever and unique feature. You might think that since all reverb is out of phase anyway, the Phase switch would have little impact, but reversing the phase actually added a bright sparkle to the overall sound.
The Real Reverb in Action
I used the Real Reverb in many instances where I use reverb, and even in a few places where I usually would not. The best sounds came with guitars, keyboards, and voice. I liked that I had a couple of reverb channels to place in specifically panned positions. In one mix, I used Channel 1 panned hard left for a guitar track whose sound image I wanted fixed (as opposed to spread out across the speakers). The longer Channel 2 was panned dead center for the lead vocal. Using a mono reverb “locks” the singer’s sound into a defined space without the dissipation effect you get with stereo effects.
If you like surf guitar sounds, the Demeter offers the ultimate reverb with a much fatter, smoother, and cleaner sound than any old Fisher Space Expander or Fender reverb. You also get the option of real stereophonic reverb, whereas those older units are mono.
With excellent sound quality and a decidedly vintage flavor, the Real Reverb is a great addition to any studio where a good alternative to digital reverb is desired.
Input Impedance 10kOhms
Signal to Noise Ratio >90dB
Total Harmonic Distortion (THD) 0.1%
Frequency Response: 20Hz-20kHz
MSRP $699 (US)