Bob Carver
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Bob Carver is an American designer of audio equipment based in the Pacific Northwest.
Educated as a physicist and engineer, he found an interest in audio equipment at a very young age. He applied his talent to produce numerous innovative high fidelity designs since the 1970s. He is known for designing the Phase Linear 700, at 350 watts RMS per channel the most powerful consumer audio amplifier available in 1972. He went on to found the Carver Corporation in 1979 and Sunfire in 1994.
Carver is especially noted for his accomplishments in demand-regulated amplifier design (Magnetic Field Coil and Tracking Downconverter) and his ground-breaking (and now heavily copied) Amazing Loudspeaker and True Subwoofer.
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[edit] Innovative technologies
- Auto-correlator noise reduction (Phase Linear 1000)
- Sonic holography (Carver C-4000)
- Magnetic field coil power amplifier (Carver M-400)
- Transfer function modification (Carver M1.5t)
- Asymmetrical charge coupled stereo detector (Carver TX-11) — In 1982 Carver created a tuner whose FM stereo detector allowed noise-free reception of much weaker than normal signals. The AM tuner of the TX-11a version employed a notch filter that demonstrated an AM broadcast can exceed the 15 kHz bandwidth of FM stations without objectionable interference.
[edit] Notable products
- Phase Linear PL-700 (1972)
- Carver M-400 (1980)
- Carver TX-11 tuner (1982)
- Carver Silver Seven
- Carver Amazing Loudspeaker (1986) 60 inch full range ribbon plus four 12 inch woofers
- Sunfire Stereo Amplifier
- Sunfire True Subwoofer (1994) 2700 watts and two 8 inch woofers in an 11 inch cube
[edit] Controversy
Carver caused a stir in the industry in the mid-1980s when he challenged two high-end audio magazines to give him any audio amplifier at any price, and he’d duplicate its sound in one of his lower cost (and usually much more powerful) designs. Two magazines took him up on the challenge.
First, The Audio Critic chose a Mark Levinson ML-2 which Bob acoustically copied (transfer function duplication) and sold as his M1.5t amplifier (the “t” stood for transfer function modified).
In 1985, Stereophile magazine challenged Bob to copy a Conrad-Johnson Premier Five (the make and model was not named in the challenge but revealed later) amplifier at their offices in New Mexico within 48 hours. The Conrad Johnson amplifier was one of the most highly regarded amplifiers of its day, costing in excess of $12,000.
Of note that in both cases, the challenging amplifier could only be treated as a “black box” and could not even have its lid removed. Nevertheless, Bob, using null difference testing, successfully copied the sound of the target amplifier and won the challenge. The Stereophile employees failed to pass a single-blind test with their own equipment, and in their own listening room. He marketed “t” versions of his amplifiers incorporating the sound of the Mark Levinson and Conrad Johnson designs which caused him some criticism by those who failed to understand the true nature of the challenge — that it was possible to duplicate an audio amplifier's sound in two completely dissimilar designs. In light of this criticism, Bob Carver went on to design the Silver Seven, the most expensive and esoteric conventional amplifier up to that time and duplicated its sound in his M 4.0t and later models which sold for some 1/40th the price (around $600-$1500).
Carver also later sued Stereophile magazine for their alleged bias against Carver products. (Stereophile had first filed suit against Mr. Carver for reprinting the magazine's copyright material without authorization.) The case was arbitrated with neither side awarded damages.
[edit] References
The information on Carver products comes from Carver product brochures and manuals. Carver's career has been extensively covered by audio industry magazines including Stereophile, Audio, High Fidelity, and Stereo Review
