Every field has its master. There is always some man, who from long experience and dedication, acquires the knowledge that couldn't be written down, but is somehow the real assence of his work. My interest is listening to music, and so it was in the spirit of considerable anticipation that I drove to North Reading to call on the most knowledgeable expert on the reproduction of recorded sound in this area. This man's name is Mr. B. A. Humphrey, and he has designed and built in his home the only so-called high-fidelity system I have ever heard which produces sounds that are exactly like the original musical instruments.
Bruce, as he likes to be called, is a rather unassuming, pipesmoking, Vermonter. One would find it hard to imagine him dressed in any way but in an open shirt and baggy pants.
People who are unaware of his talents often are startled to hear him absentmindedly humming a complicated passage from Bach's B Minor Mass. Bruce sings in several choirs, so his familiarity with music is greater than the average appreciative listener's.
I was surprised to find the Humphrey music system in the cellar. As I discovered later, Bruce bought his home mainly on the merits of a full basement, without giving the living quarters more than a cursory glance. A cellar in the rough with concrete walls and floor and a low ceiling, is not the ideal acoustic environment, but Bruce has experimented extensively with the room, and he employs a number of interesting devices in achieving just the right type of sound. For instance, he has hung sheet blankets a short distance from all the walls and covered the entire floor with thick carpets to soften the reverberations. The result of his efforts is still a rather "live" room, but one which is infinitely comfortable to listen in. Most listening is done at a distance of fifteen to twenty feet from the speakers. This seems to add to the illusion of live performance, since imperfections such as surface noise, tape hiss, static, etc., are blended into the atmosphere. None of this would have been possible in an area smaller than his huge basement.
A first glance at the Humphrey "control room," as we feel forced to call his tremendous bank of electronic equipment, would look impressive even to the gas meter man. Prominently displayed in his system are three professional tape machines--the incomparable Crown 800, a Viking unit, and (a relic from a bygone era) one monaural Berlant. Bruce does a fair amount of live recording and remote duplicating; in fact you many have seen him making tapes of the Harvard-Radcliffe concerts.
Recording is both business and pleasure with Bruce. Last summer he took a trip across the country visiting and taping pipe organ installations with his professional equipment. He visited a number of organ and high-fidelity component companies along the way, combining travel with his favorite pasttime--sound.
His recording equipment gets a lot of use at home, too. Of the numerous tapes in his music library only two are pre-recorded. The balance are all products of his own endeavors. Since WCRB came on the air with stereo FM, Bruce has been picking up and preserving their live broadcasts of the BSO concerts.
Tape has been pictured as the ultimate sound source in some circles and one might think that a person like Bruce, with the finest in tape equipment, would avoid records and FM as sources. Nothing could be further from the truth. His Scott 310-D tuner (one of the most sensitive FM sets ever made) in conjunction with Scott's multiplex adapter, provides the household with music most of every day and particularly on occasions such as parties, dinners, etc. On the Humphrey roof it an eight-element yagi antenna, mute testimony to his interest in long distance FM reception.
Mr. Humphrey's disc set-up deserves a gold medal for unconventionality. To begin with, his turntable is mounted on a 3/4" thick, solid mahogany motor-board, which is in turn affixed to a 1" thick slab of marble! The exact opposite of shock mounting, this insures that a chance whack by anything short of a sledge hammer will leave his needle firmly and serenely in the groove. "Firmly" isn't the right word here, though, since Bruce uses the new Audio Dynamics ADC-1 cartridge and tracks it (in his home-made professional arm) at about 3/4 of a gram! The ADC-1 is one indication of how seriously Humphrey is concerned with the problem of record-wear and surface-noise. His care for records doesn't end with use of the world's lowest-pressure commercial cartridge. The familiar Dust Bug is very much present, as it is in just about everybody's system these days. But the real clincher is yet to come.
When Bruce put the first record on to play, we noticed that it seemed wet. Bruce had removed it from a special polyethlene sleeve which he had had to peel from it like backing from one of those bumper stickers. Somewhat taken aback, we asked him about it. It seems that Bruce uses a special silicone lubricant on his records which he figures cuts record wear by about 75%. This gunk has the happy advantage of not gumming up the needle (as most record cleaners do). Although the records are somewhat sticky to handle and dust might tend to cling to the slightly tack surfaces if the discs were allowed to lie around, Bruce finds this method the best available for insuring practically infinite record life.
This stuff is available only by mail from some gentleman whose company makes exotic industrial lubricants (and who is a hi-fi bug on the sly). The turntable itself is a re-worked Rek-O-Kut N33H, the motor-board which Bruce has sawed in half, suspends the motor separately from the table to reduce the rumble even below its already low figure. A special belt had to be used to drive the table, since the one supplied by Rek-O-Kut was not adaptable for such use. A sheet of copper lies under the whole unit, grounded by special cable to the Marants Pre-amplifier. As a result of these precautions total noise in the Humphrey system has been reduced to the point where it is completely inaudible with the volume control wide open.
As we just mentioned, Bruce uses a Marants Model 7 stereo pre-amplifier. This unit in his estimation is as close to perfection as is possible, and he has never made any changes in its construction. However, two of the power amplifiers (Bruce uses three separate units, for reasons that were never quite clear to me) are almost entirely his own design. He worked out their circuitry for his company (Bruce is Chief Engineer of Audio Lab, here in Cambridge) when they needed special high power amplifiers with as low distortion as possible for a theater installation.
Probably the most interesting aspect of the Humphrey system is the speaker arrangement. Upon taking inventory, we found that Bruce has no less that FIVE KLH loudspeaker systems in his home, three of which form the core of his main listening studio. A pair of KLH model Sevens act as the two stereo channels and a Model Six provides a central speaker. Two other Model Sixes serve the living room upstairs.
The loudspeakers are to be heard, seen; Bruce has hidden his speakers hind a bamboo screen (which is acoustically transparent, of course). The illusion is perfect. Sound comes from the whole width of the basement, and it has prising depth as well.
When we did look behind the curtain reasons for this perfect illusion became evident. The two KLH's stand in the corners of the cellar, about 20 feet apart. (The third-channel speaker is between them, but Bruce tells us it wasn't in use when we were listening.) The curtain hung about five feet from the wall against which the speakers are placed. Helping the Model Sevens out are a pair of trostatic tweeters (of American origin) which Bruce has suspended from ceiling, about six feet from the floor, and tight against the bamboo. Bruce feels this staggered placement contribute the sense of depth his system imparts. The Humphrey living room is provided with special sockets which allow versatile placement of his Model Sixes and connection of a tuner to the system upstairs. This latter arrangement enables the Humphreys to both operate and listen to the tuner in the living room, though the rest of the equipment is permanently stationed in the basement. Next to the main control panel down there are jacks which allow selection of any combination of speakers. All cable between components are of a special capacitance type which prevents a signal loses or distortions between units.
The control area is arranged so the knobs, switches, and levers can be comfortably reached from a centrally placed chair. Special de-humidifiers keep cellar fit for storage of tapes and discs. In short, everything has been though and provided to make the installation complete as possible.
Bruce's whole life revolves around music. He works all day among strains of melody, he records live performance on weekends, he sings in the chior in his church on Sunday. He doesn't his own orchestra, as did the medieval princes, but the "home music hall" he has built himself probably gives him genuine pleasure than their private cians ever gave them.