The Gibson RD Guitar
Series
In 1977 Norlin owned several companies including Moog which
manufactured synthesizers designed by Robert Moog.
Due to the popularity of personal synthesizers during this era, Gibson
partnered with Moog to design the RD Guitar (research
and development) which brought electronic circuitry to Gibson instruments for
the first time.
RD Custom |
Many of these guitars were fitted with a Bob
Moog designed compression and expansion preamplifier. Gibson soon discovered
that many players did not like the advanced electronics.
RD Standard |
The guitars shape could be described as a weird
looking reversed firebird with a Les Paul head stock.
The Gibson RD standard had a double cut solid body, 2
humbuckers, stop tailpiece, rosewood fingerboard, dot inlays, chrome parts,
large back plate, and were made in natural, walnut or sunburst finishes.
(Note
the 2nd and 3rd guitars have an extra toggle switches on the bottom that engages the
active circuitry.)
The Gibson RD Custom had basically the same specs like the
rd standard but with active electronics and was made with maple fingerboards.
1978 Gibson RD Artist |
The RD Standard was not as fancy and was not equipped with active circuitry.
The
Gibson L-6S was really a nice instrument. It was a cheaper descendant of the
L5S jazz solid body electric guitar. It was the same shape - very much like a
wide Gibson Les Paul. It was the first Gibson to sport a 24 fret two-octave
neck.
The L-6S was designed by a young Bill Lawrence in 1972, who had been given the task of designing a "multi-sound system" under a very tight budget. The final production guitar was somewhat different from the Guitar he had in mind but as he stated, "even with these changes, the early production L6-S was still an excellent performer.”
The guitar had a small following and at the time
was favored by Al DiMeola, Keith Richards and Carlos Santana among others.
The L-6S came in three variants; all were
maple-bodied with twin super-humbucking Lawrence designed pickups.
The L-6S Custom was the best known version with
total production of over 12,000 instruments. It featured a Maple body, and set
neck with a choice of maple or ebony fingerboard. Controls include a six
position pickup selector, master volume, mid-range and treble roll-off
controls.
The first production models were simply called the L-6S. Later Gibson renamed the guitar the L-6S Custom and added a badge on the truss rod cover.
The first production models were simply called the L-6S. Later Gibson renamed the guitar the L-6S Custom and added a badge on the truss rod cover.
The
L-6S Custom is noted for its six way rotary selector switch, complete with
"chicken head" pointer knob. Starting with switch position #1, in the
most clockwise position, the available pickup switching options are as follows:
1 Both pickups, in series
2 Neck pickup, alone
3 Both pickups, in parallel
4 Both pickups, parallel out of phase, with the
neck pickup's bass response restricted thought a series capacitor*.
5 Bridge pickup, alone
6 Both pickups, series out of phase.
• The capacitor in the #4 position gives a
fuller tone than the otherwise very nasal out of phase tone. The capacitor
serves to limit the low end response of the neck pickup, and also phase delays
the signal from that pickup, resulting in a fuller tone, not too unlike the #2
and #4 switch positions on a Fender Stratocaster guitar.
In the L-6S's mid-range control, the resistance
is variable, while the capacitance is a fixed value. The result is one which
allows decreasing of the middle tones, while retaining a large degree of "sparkle"
or "brilliance" to the tone of the instrument. The volume and treble
roll-off controls work as they do in most other electric guitars.
There were two versions of the L-6S produced
without the sophisticated tone swithing control. One version was The L-6S called The Midnight Special with total production of around 2000
instruments Maple body, and bolt-on maple neck with a maple fingerboard.
Controls include a pickup selector, master volume, and tone control. This guitar was strung through the body.
Controls include a pickup selector, master volume, and tone control. This guitar was strung through the body.
The
L-6S Deluxe was less popular than the Custom with total production around 3500
instruments The Deluxe had a set maple neck, with a rosewood fingerboard.
Controls include a pickup selector, master volume, and tone control. Strung
through the body. The guitars production was ended in 1979.
The
Gibson Mark Series aka MK Series
This effort was initiated by collaboration
between Dr.
Michael Kasha, a physics professor at Florida State University and Richard Schneider,
who at the time was an apprentice of Mexican Luther Juan Pimentel. The
collaborative result was the Gibson Mark series.
Dr. Michael Kasha had been working on improving
the classical guitar circa 1965. Encouraged by the classical guitar
establishment he began to measure the sound response of great classical
guitars. He had already been aided in his effort by Richard Schneider.
By 1971, Kasha was publishing many of his conclusions. Kasha loaded weight in or near the headstock to increase the transmission of string vibration down through the neck. (Many of us as young guitarist had discovered that placing the headstock of your guitar against a wall or the headboard of your bed resulted in transferred vibrations and increased sound.
In fact there is a company that builds a flat piece of metal called the Fathead that is designed to fit on the rear of a guitars head stock for this purpose.) Kasha counterbalanced this by adding a weight in the tail block.
The soundboard received a radical revision to the bracing system.
MK Series top bracing |
X bracing was used on the upper bout and fanned bracing on the lower, with braces get graduating from thick to thinner as they moved from bass to treble sides. FYI, steel string guitars normally use X bracing and classical/flamenco guitars use fan bracing. So this design was very unusual.
Kasha also came up with an impedance-matching bridge
that was basically wide on the bass side and tapered on the treble.
Ironically in 1972 Kasha and Schneider signed an
agreement to sell classical and steel string instruments through the Baldwin Piano and Organ Company,
owners and builders of Gretsch and Baldwin/Burns guitars.
That arrangement lasted only about a year, perhaps due to the financial problemsBaldwin was experiencing at the
time due to their purchase of Burns.
That arrangement lasted only about a year, perhaps due to the financial problems
Kasha and Schneider then signed with Gibson in
1973 to develop a line of scientifically designed acoustic guitars, with Norlin
picking up the development tab.
The Gibson Mark line consisted of five
steel-stringed models. All were jumbo-bodied, with more rounded shoulders and
lower bout than a typical square-shouldered Gibson dreadnought. They could be
had in either natural or a sunburst with dark upper bout and a fairly thin band
of stain around the lower.
All sported 25 1/2" scales and had a
plastic ring around the sound hole. The top of the line was the Mark 99 in
spruce and rosewood with an ebony fretboard, gold hardware, and bow-tie inlays
($2,199). These were basically custom-made by Schneider.
The Mark 72, a plainer rosewood
model with less binding, chrome hardware, rosewood fingerboard, and dots ($749).
The Mark 35 had a mahogany
body with rosewood 'board and dots ($569). Cases were an extra $109. Two
12-strings were briefly offered, the Mark 45-12, probably made of maple
(two made in '79), and the Mark 35-12 (12 made in '77).
The Mark guitars were only offered for four
years, until 1979. Only one custom Mark 99 was ever produced and sold. Of the
Mark 81s, 431 were produced. The second most popular was the Mark 72 clocking
in at 1,229 units. The maple Mark 53 saw 1,424 produced. The most popular was
the mahogany Mark 35, with 5,226 made
I have played a Gibson Mark 53. It is a fine American-made, solid wood, extremely well constructed instrument.
I am of the opinion that despite all the scientific research that went into producing and designing the Mark Series guitars produced an excellent instrument, but when it is compared with a Gibson Hummingbird or a Martin D-28 the Martin and Hummingbird produce a better tone.
©UniqueGuitar Publications (text only)
1 comment:
"Tone" is a subjective matter. I own a MK-81 which in my opinion is the best sounding acoustic guitar I ever had my hands on, rich and musical, not to mention balanced response. So one man's poison is another's medicine. It's the way it is.
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