Although the electric guitar era officially began in the late 1920s, it wasn’t until the early 1950s that the electric guitar fully established itself as an instrument of major popularity. Manufacturers and retailers realized the electric guitar represented a sales bonanza—not just as far as selling the guitars themselves, but also in selling the accompanying amplifiers. As retailers began to ask for amps, many companies that built guitars were happy to comply. (Some companies, like Fender, came from the opposite direction, too.) Guild was no exception.

Guild Guitars Inc. was formed by guitar and accordion retailer Alfred Dronge and ex-Epiphone manager George Mann in New York City in late 1952. The first guitars to bear the Guild brand were made at Guild’s lower Manhattan factory by a group of workers that consisted in part of ex-Epiphone employees, with some Gretsch expatriates sprinkled in. Epiphone had recently de-camped from New York in favor of Philadelphia because of labor issues, something that would affect Guild as well. The first Guild guitars reached the market in early 1953. In the spring of 1954, Guild printed its first catalog, which featured a new line of acoustic archtops to go along with the acoustic flattops and electric archtops already available. Business was brisk, and approximately one year later Guild released its second catalog. The 1955 catalog featured jazz great Jimmy Smith on the cover and was packed with stellar guitars—including the sublime new Aristocrat M-75, a low-production Les Paul killer with mahogany back and sides, a spruce top, and P-90-style pickups. The new Guild catalog also presented the company’s maiden foray into the wild and woolly world of guitar amplification with the Masteramp line.

A 1955 Guild Model 200 Double-Twin combo with “TV-front” cosmetics.

Shooting for the Moon
The amp business in 1955 was still a fairly open field. Fender was the leader, but not yet the all-ruling juggernaut it would become. Gibson ran a distant second, although it was introducing new models at a rapid pace. Smaller brands such as Premier, Epiphone, Multivox, and Magnatone were either looking for their niche or rapidly falling behind. While the majority of amps available on the market were still relatively small and low-volume, with minimal features and weak output, Guild made an attempt to take a place in the higher end of the market. But while the new Guilds were built a bit more sturdily than most amps and offered good controls and speaker options, they lacked a truly robust circuit design.

The initial line of Masteramps dripped ’50s style, with chunky “TV” front plywood cabinets and a two-tone vinyl covering of fabric-textured tan on top and dark faux wood grain on the bottom. Staying to the industry-standard price-point formula of low, medium, and high, Guild offered three models. The smallest of the ’55 Masteramps was called the 66. Standing a foot-and-a-half tall, the relatively compact 20-pounder offered 15 watts through a single 12" RCA hi-fi speaker. Next up in size, price, and power was the 99, a 25-watt amp with a 12" Jensen and two Jensen tweeters.

Guild shot for the moon with its top-of-theline amp, the Double-Twin. It was stocked with two 12" Jensen P12P Concert-series drivers and two switchable Jensen 4" tweeters. By adding the tweeters, Guild aimed squarely for the high-end market. An amplifier with two 12" speakers was big stuff for any company in 1955, much less a startup. The few other 2x12 amps of the time came from major manufacturers like Fender and Gibson. The 1955 catalog billed the Double- Twin as “perfect for small combos.” That pronouncement may seem odd or obvious unless you know that, at that time, all the players in a group usually shared one amp. Guitarist, singer, and even a string bass player would plug into the same multi-input amp.

Each of the three ’55 Masteramp models had top-mounted controls on a chrome panel with screened white lettering. They all had two channels, with a single input for the Accordion/Mike channel and three inputs for the Instrument channel. One of the instrument inputs was labeled “Recording,” and according to the catalog, this input was modified with a “Filtertone” buffer for use specifically in recording situations. The Recording input ran through a separate filter network and, unlike the two other instrument inputs, was not wired at the jack with 68k resistors. Each Masteramp had the same set of controls: Volume for each channel, plus master Bass and Treble controls. Also on the panel were controls for the tremolo feature, including an on-off slider, knobs for Strength and Speed levels, and a jack for the optional trem-control footswitch.

From 50L6s (and No Transformers) to 6L6s Tube selection is where the Masteramp story gets weird. The catalog mentions that the 66 has a six-tube chassis—RCA tubes at that. The 99 had a seven-tube chassis, and the Double-Twin had nine. What the catalog doesn’t say is that the power tubes on all three amps are of the 50L6 variety. Mention the 50L6 to any amp old-timer and they’ll guffaw and roll their eyes. In the 1950s, the 50L6 was not used as a high-fidelity tube. Rather, it was used when the goal was to push volume through a speaker. The benefit of the 50L6, at least in 1954 and 1955, was that it had enough voltage to eliminate the need for a power transformer and allow the use of a weak (read “cheap”) output transformer. This type of construction would, at least in theory, lower the price of the amp. Using the 50L6 involved wiring the filaments of three tubes in series, creating a trio. The Masteramp 66 had a single trio of 50L6 tubes. The Double-Twin and 99 had two sets that ran push-pull. The Double-Twin also used dual selenium rectifier units that are similar to today’s diode rectifier. Preamp tubes on all three were 12AX7 and 6SN7.

In addition to the aforementioned problems with 50L6 tubes, heat issues were a real concern. Today, many amps that came equipped with 50L6 tubes show signs of heat damage to the chassis. Guild certainly became aware of the issue, because at a certain point during the run of the first Masteramp series, 50L6s were ditched in favor of the more stable, more powerful, and—above all—more musical 6L6. While the transformerless 50L6 circuit was a money-saver early on, glass-tube 6L6 and 6V6 tubes were rapidly coming down in price enough to make up for the expense of a power transformer. It was an added bonus that these tubes also offered a much more toneful solution. Consequently, Guild amps from that point on used a more standard circuit design and tube complement.