Zorko El Basso Model 1030 Model Piggyback Tube Amplifier, c. 1961, made in Chicago, Illinois, dark grey with sparkles finish.
The story of the Zorko El Basso amplifier begins with a now-obscure effort to electrify the upright bass in the 1950s. Pioneering Slovak-American brother luthiers Rudy and Ed Dopyera had been involved with National String Instrument Company and the subsequent Dobro company ("Dobro" being both a contraction of their last name and the word for "good" in Slovak) which merged an evolved into Valco in the 1940s. Working independently from Valco the brothers introduced their unique electric upright bass in 1958, dubbed (for reasons lost to history) "Zorko".
The Zorko bass featured a small hollow fiberglass body with a slightly scaled-down head and fingerboard and was marketed as a "mini bass". The 1958 Zorko sales brochure trumpeted it as "the first electric nylon or gut string bass fiddle." A unique double bridge pickup system used one bridge to reduce downbearing force on a second bridge that activated a magnet and coil beneath, allowing for the use of gut strings instead of metal. The vibration of the strings was transmitted mechanically into the magnet, which in turn induced a current in a stationary coil in the body. The design was successful enough that it was sold to the New Jersey based Ampeg company in 1961 where it was developed into the much better remembered "Baby Bass".
And thus we finally arrive at this "El Basso" amplifier! When the Zorko bass was introduced, a specialized amplifier was marketed alongside it. This is an early example of the separate head and cabinet layout Fender adopted a couple of years on, and was specifically designed by the Dopyera brothers for the unique bass concept. Neither the bass nor the amp were produced in any significant quantity, only available for a few years prior to the Ampeg sale. While Zorko basses are uncommon the accompanying amp is far more rare; obviously Ampeg did not continue their production and few have survived to the present day.
The "El Basso" is a fairly early example of a dedicated bass amplifier, a very clever piggyback design featuring two channels, each with dedicated tone and volume controls. One is marked "Standard Bass" and the other "Zorko Bass". The preamp section has two 12AX7 triodes feeing a pair of matched 6L6GT tubes, all mounted horizontally in the open-back head. These in turn drive a 12" speaker housed in a cleverly designed closed-back cabinet that locks to the head via clips on the sides. The head features an additional speaker output alongside that meant for its accompanying cabinet and small round vents in the top.
The unit is covered in a dark grey fabric with silver specks scattered around, the speaker aperture is a shield-like shape mirroring the logo plated pinned on both head and cabinet. These proclaim "ZORKO" with a somewhat ironic (considering it was a bass-oriented company) "atomic treble clef" logo. This is a historically interesting unit that is also well engineered and good sounding, although its original purpose is gone. Still, it is a cool and fun amp and a great conversation piece, even if just for the "ZORKO" logos!
Height is 30 in. (76.2 cm.), 20 in. (50.8 cm.) width, and 9 1/2 in. (24.1 cm.) deep.
This is the first Zorko amplifier we have had the pleasure of offering. Cosmetically, both the head and cabinet are in surprisingly good condition given the age. There is a repaired rip on the left side of the amp head and general wear on corners and at edges but the delicate fabric covering is largely intact. The metal "Zorko" badges on both the head and speaker cabinet are also intact and remarkably clean. The control panel features the original switches and knobs and shows minimal corrosion; the original lettering is clean and crisp. The speaker grill is free of rips or tears but does have some moderate staining and yellowing with age. The handle on the amp head is original but its sister on the speaker cabinet has been replaced with a similar vintage handle from the same era.
Electrically, both head and cabinet are remarkably original. The output and power transformers are original, as is the 12" Electro-Voice speaker in the cabinet. The speaker has been re-doped by our in-house professionals to improve tone and durability. The volume and tone pots were manufactured by Chicago Telephone Supply and date to the 34th week of 1960. The amp head has seen our standard in-house maintenance, including the installation of a 3-prong power cord, replacement of electrolytic and wax paper capacitors, cleaning, re-biasing and testing. It is a solid, cool sounding tube amp for low-volume bass, and also a pretty nifty guitar amp if not super versatile. Overall Very Good + Condition.
