The Wal Bass Preamp
There's no big mystery here, but the controls do take some time to get used to. Instead of the traditional global B/M/T tone controls, the Wal preamp has a tone control for each pickup. Each is actually a variable low pass filter. Also, by pulling up on the control you get an added a 10db boost to the harmonics at the roll-off point. Dial in the sound you want from each pickup and use the balance control to adjust the overall tone. In addition, by pulling up on the volume control you get the infamous "pick attack" which is an accentuated high frequency percussive attack. Not to oversimply however, it's important to note that very small changes make a big difference in sound and it takes some real practice to find the settings that work best for you.

The preamp itself is contained on two large internal PCBs and amazingly draws less than 1 ma of power from a single 9-volt battery source. All components are mil-spec of the highest grade and all internal connections are made using polarized molex connectors. A transformer isolated DI is also provided via the 600 ohm balanced XLR output. Internal trim pots are included to allow adjustments to the low bass level of each pickup, pick attack level and master volume. The preamp circuit is activated when the standard 1/4" TS phone plug (eg. regular guitar cable) is connected, although a dummy plug may also be used if only the DI output is desired. The 1/4" jack is recessed, therefore angled plugs will not work correctly.

Wal Bass Pickups
All Wal pickups are handmade in the Wal shop. The current "Custom" instruments include bridge and neck humbucking-style soapbar pickups. However, inside each pickup casing there are actually two individual pickups per string, each with magnet, wound bobbin and adjustable pole piece. Apparently the bobbins are wound in an opposite direction so that each pair creates the "humbucking" effect.

As there are two pickup casings, there are four individual pickups for each string (4,5 or 6) on Wal Custom bass models. Extremely precise adjustments can be made to the balance and tonal output of each string. The combination of the Wal pickups and Wal preamp provides the lowest possible noise and intermodulation distortion levels with the highest possible dynamic range and optimal signal headroom.

Please note that Wal pickups and/or the Wal bass preamp were not sold seperately. They only came with the instrument.