Electric Upright Bass Database

zorko^* - Zorko

• Vintage: 1958
• Number of Strings: 4
  • Double bass strings compatible
  • Tuned in: 4th
• Bowable: Yes
• Thumb Reference: D
• Playable Seated: Yes
• Balance While Playing: (8/10)
• Transportability: (9/10)
• Overall Rating: (8/10)

Zorkos were made by the Dopera Brothers and were the predecessors to the Ampeg Baby Bass.  I've owned several of them over the years and now have this one in my personal collection.  They were made for a couple of years in the late 50's/early60s after which the molds, designs, and remaining inventory of parts and completed instruments were sold to Ampeg. While a Zorko, which means "Shining Star" in the Dopera's native language, looks pretty much like an Ampeg Baby Bass, it differs greatly in construction and sound. There is a good section in the Ampeg book regarding the history and exact details if you need more information.



The Dopera's company, Valco, had been experimenting with alternative materials and designs for stringed instruments from the beginning. They brought us the resonator guitar, metal and fiberglass bodied instruments, and some of the first bridge mounted transducers. The Zorko bass follows in that tradition. It's a full 41" scale upright with a mahogany fingerboarded maple neck, a hollow molded fiberglass body, and a unique pickup design that actually makes the bass sound like an amplified acoustic upright. The pickup consists of a single donut shaped coil with a horse shoe pole piece through the center. The pole piece focuses on a magnet glued to the underside of a 1/8" thick spruce rectangle that measure about 5" low E to G by 1" neck to tailpiece. The spruce plate and magnet are suspended over the horse shoe pole piece withe rubber pads (that deteriorate and need to be replace with springs). On top of the plate sits a bridge, 1 of 2 that are employed on a Zorko. In order to allow the bridge/sprcue plate/magnet assembly to vibrate properly, a second bridge is placed behind the first between it and the tailpiece to regulate the down pressure. Both bridges are connected together at the crown with 2 long machine screws and nuts to keep the the proper distance apart and keep the vibrating bridge on the "sweet spot" of the spruce plate. On my bass, it was necessary to add an additional 2 set screws to the base of the down pressure control bridge that press against the legs of the vibrating bridge to keep it reliably on the sweet spot. When I got the bass, everything on the pickup was mechanically loose and it squealed like a pig. I potted the pickup in paraffin and shielded it in copper foil to help eliminate the single coil hum. I also added a string ground that I weave through the steel strings that I use, but these basses will work with gut. My final modification was filling the body with packing peanuts. Unlike an Ampeg Baby Bass which is filled with heavy rigid foam, these basses are hollow and feed back at high volume levels. The peanuts completely solved the problem and kept the bass light enough to pick up with 1 hand. The other mod I made was adding an adjustable end pin. Zorkos are designed to be used on stands. I could never perform with an upright that was on a stand. Enough has been written about the design and construction of the Ampeg Baby Bass such that a quick google search can fill in the details of the remaining design differences in the physical construction and Jesse Oliver pickup. I've owned several Baby Basses and found them totally unusable for my style of playing. I couldn't get any sustain out of them. In contrast. my Zorko responds almost the same as my acoustic uprights.