LHZ Custom Potentiometers

We are pleased to announce that we have contracted a manufacturer to produce custom potentiometers for our Bass and Treble controls to be paired with our LHZ Preamps. The new potentiometers will be available by the end of September, and will replace the Bourns potentiometers currently being sold with the LHZ preamps.


Spector basses made in Europe present two challenges that make finding potentiometers challenging:

  1. Use of metric potentiometers with a small M8 (approximately 5/16″) thread diameter. As a result, the 3/8″ threads on the common “guitar potentiometers” in the US are too large to fit into European Spector basses.
  2. The unique contour of a Spector Bass requires the control cavity to be set deeper than most other basses. Spector used custom potentiometers with a 9.5mm thread length to ensure the potentiometer would have enough thread to fit through the deep mounting hole.

Two additional factors make it even more difficult to find to EQ potentiometers. The LHZ preamp is a component-level HazLabs clone and requires potentiometers with a 100K Linear Taper as were used in the original HazLabs preamp. We also wanted to provide a center detent that easily indicated the “flat EQ” setting.


The Bourns PDB181 series are high quality mini-potentiometers with a small diameter M7 thread that easily fits in the European Spector potentiometer mounting holes. This is a readily available model renown for its long life, durability, and a pleasing amount of rotational torque.

The downside is that the threaded shaft is only 6.5mm long. While Bourns pots fit most Spector basses, there is often only enough thread to get one rotation of the nut onto. There is also a small percentage of basses that have a deeper mounting hold that requires a longer thread.

The following image is a comparison of the Spector OEM potentiometer, the Bourns potentiometer, and the new LHZ custom potentiometers.

Spector OEN vs Bourns vs LHZ Custom pots

As noted in the above photo, the LHZ custom potentiometer (far right) is nearly identical to the Spector OEM potentiometers.

The LHZ custom potentiometer provides OEM specification fit and finish. Using the same 18mm shaft length as the original Spector OEM pot, knobs sit closer to the surface as compared to the 20mm shafts used on EMG controls and Bourns pots.


Our manufacturer utilizes modern automated production equipment and quality control systems, maintains current ISO certifications, and currently supplies potentiometers to well-known corporations such as Yamaha, Panasonic, Ibanez, Siemens, GE, and others.

Early sample potentiometers have passed internal testing and found to meet or exceed Bourns build quality, and have been shipped to selected clients for comparison. All customers uniformly report that the potentiometers fit perfectly, are quiet and perform identically to the Bourns units, and had “just the right amount” of rotational torque to provide a robust and high-end feel.


We expect to transition all sales to the new potentiometers no later than the end of September. Clients who prefer the Bourns potentiometers can still request those at any time, however we are confident that the new potentiometers will provide a superior fit, finish, and performance for clients with European Spector basses.