HZD (High Z Driver)
The HZD or High-Z Driver/Boost is a clean boost originally produced by LauriePedals in small runs. With no changes to the circuit itself, the HZD is still made by LauriePedal's successor company, DingoTone.
The HZD's circuit is not a clone of, but more an homage to, the Boss FA-1 FET Amplifier, producing a similar pre-amp/boost effect. Electrically, one might say the HZD is "functionally similar to" the FA-1, although the HZD does not use FETs and it is a pedal, rather than a belt-pack device.
The HZD has undergone several changes since its conception. These changes were primarily cosmetic and usually consisted of an upgrade of the enclosure livery. The first versions were housed in white Hammond 1290A style enclosures with no external markings. These are commonly referred to as "SS" (Silver Screw) pedals in reference to Early Boss compact pedals which had a silver screw in the treadle. The next batch were housed in the same enclosures but with the addition of a hand written "Laurie" signiature of the Engineer and namesake of the original company name LauriePedals. Subsequent versions have been screen printed with the signature and also labels for the controls.
Two small runs of HZDs were completed in 2012 in metallic black housings with "block" screen printing (no signature). One of these runs contained vintage input capacitors and vintage spec (new manufacture) "DD" opamps. The other run contained vintage capacitors and genuine vintage "DD" opamps that had been harvested from vintage pedals. As part of this run, a one-off special metallic black, vintage component HZD with no labels except the Engineer's signature in silver was provided to SBZ in 2012 (this is the only black, signed HZD that exists - pictured below).
The most recent versions of the HZD (June 2013) have the new DingoTone logo and have slightly updated circuitry (flatter EQ when the knobs are set to noon).