The Lusithand Devices 800BM is an onboard preamp for bass guitars that takes the EQ section of the Gallien-Krueger GK800RB amplifier and fits it inside the instrument. The maker describes the tone stack as having "some serious high-frequency power and a very deep bottom end, just like the amplifier it's based on", with a sound that is always very "cut through" and clear.1
Controls
The 800BM uses two stacked potentiometers, each carrying two controls, plus a Contour switch21.
| Control | What it does |
|---|---|
| Stacked Bass/Treble | Active bass and treble control; bass boosts and cuts at around 60Hz1 |
| Stacked Hi-mid/Lo-mid | Active hi-mid and lo-mid control1 |
| Contour switch | EQ pre-shape (V)1 |
Because it is a Boost-Cut preamp, the Hi-mid and Treble controls are highly interactive, and the circuit uses lower impedance throughout for quieter operation.2
The stacked pots are not fixed in their assignments. The manual explains that the potentiometers come with connector cables and can be assigned by the user: "It is up to you if treble goes on top or bottom of the potentiometer or if you want to pair the Hi-mid and Treble on one" pot and Lo-Mid and Bass on the other.2
Power and fitting
The 800BM runs on 9 to 27VDC and draws around 3mA at 9V, according to the maker's product page. That low draw is gentle on a battery, and the wide voltage range leaves room for higher-voltage onboard installations.1
The 800BM is a rear-mount (Back/Rear Mount) design, intended to be fitted to the back of the instrument rather than through a plate, and installation means soldering and routing inside the bass.1
The 800BM and the 800BMF
Lusithand Devices points players who want more to the 800BMF, which the maker calls "a full version of the 800BM". The 800BM itself served as the Back/Rear Mount option in the range.1
Warranty
The maker's manual states that any defective product will be replaced or fixed with all expenses covered, once it has been verified that the problem is not bad handling or negligence. Damage due to negligence loses the warranty, a repair cost can occur, and shipping costs are not covered in such cases.2
Videos
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Questions
Does the Lusithand Devices 800BM work with passive pickups?
Yes. Lusithand Devices states that the 800BM preamps are compatible with both passive and active pickups, so it can be fitted to a passive bass without needing active pickups first. The preamp itself is a Boost-Cut design with lower impedance throughout, which the maker says allows quieter operation.
What voltage does the 800BM run on?
The 800BM runs on 9 to 27VDC, with a current draw of around 3mA at 9V according to the maker's product page. That wide voltage range means it can be run from a 9V battery-style supply or at higher onboard voltages, and the low current draw is easy on a battery.
What is the difference between the 800BM and the 800BMF?
Lusithand Devices describes the 800BMF as the full version of the 800BM. The 800BM served as a Back/Rear Mount option in the range, so the 800BMF is the fuller-featured counterpart for players who want more than the rear-mount format offers.
Can the stacked pots on the 800BM be reassigned?
Yes. The stacked potentiometers come with connector cables and can be assigned by the user. The manual says it is up to you whether treble goes on top or bottom of the potentiometer, or whether you pair Hi-mid and Treble on one pot and Lo-Mid and Bass on the other.
What does the Contour switch do on the 800BM?
The Contour switch is an EQ pre-shape, described by Lusithand Devices as a V-shaped pre-shape. It shapes the signal before the main EQ controls, in the spirit of the contour function on the GK800RB amplifier the preamp is based on.
Sources (2)
- 800BM - Lusithand Devices, Lusithand Devices, 2026-08-25
- 800BM-Manual.pdf, Lusithand Devices, 2024
