DSM & Humboldt Simplifier Bass Master bass guitar pre-amplif

Centre positive/negative	centre negative
Power supply plug	barrel 2.1 mm (inner diameter)
adapter included	no
Complete	~
Original packaging	~
Condition of product	~

DSM & Humboldt Simplifier Bass Master bass guitar pre-amplifier
Product no: 9000-0140-5982 Bax Music Warranty: This product comes with a 3-year warranty.

General

Meet the Simplifier Bass Master from DSM & Humboldt. An all-in-one solution for bassists looking for a powerful and versatile sound. This high-quality preamp is the result of years of development and in-depth research into everything that makes a bass sound great. With three characterful modes (Clean, Comp and Hot), a parallel signal chain with adjustable low-pass filters for extra depth, and a comprehensive 4-band EQ, the Bass Master offers unprecedented sound freedom for every style and situation.

Simplifier Bass Master: Seamless integration into your setup

As we have come to expect from DSM & Humboldt, the Simplifier Bass Master is full of smart connection options. Think of a dual effects loop with separate Pre-FX and Main FX routes, where you can freely assign effects to the preamp, the parallel signal or both at the same time - without fussing with splitters or extra cables. There are also separate XLR outputs for reamping or driving a subwoofer, a headphone output with AUX-in for silent practice sessions, and two TS outputs with options like cabinet simulation bypass.

Tips or comments about this product

Note: A power adapter is not included.

Specifications

Product features

Sustainable product	not specified
Guitar preamp functions	boost / gain / level, tone control, DI, cabinet simulator, ground lift, phase switch, fx loop
True bypass	no
Mini pedal	no
Voltage	9 V, 12 V
Can be powered by battery	no
Centre positive/negative	centre negative
Power supply plug	barrel 2.1 mm (inner diameter)
Adapter included	no

Weight and dimensions including packaging

Weight (incl. packaging)	435 gr
Dimensions (incl. packaging)	14,0 x 9,0 x 7,0 cm

Product specifications

bass guitar preamp
3 voicing modes: clean, comp and hot
4-band active equaliser
parallel signal chain with low-pass filter options
dual effects loop: pre-FX and main-FX
pre-FX loop assignable to preamp, parallel or both
separate XLR outputs for main and parallel signal
suitable for reamping and subwoofer routing
headphone output with aux-in
2 TS outputs: parallel-thru and main with cabinet sim bypass
full analogue signal path
compact and robust design
developed and built by DSM & Humboldt in Chile

connections:

input: 6.3 mm jack
main output: 6.3 mm jack
parallel output: 6.3 mm jack
DI parallel: XLR
DI main: XLR
pre FX send & return: two 6.3 mm jacks
post FX send & return: two 6.3 mm jacks
aux input: 3.5 mm stereo jack
headphone output: 3.5 mm stereo jack
power connection: barrel connector 5.5 x 2.1 mm, centre negative
power consumption: 100 mA
operates on 9-12 V DC adapter (not included)
dimensions (w x d x h): 115 x 65 x 55 mm
weight: 430 g
made in Chile

controls:

preamp: gain (comp), preamp level
parallel: main mix
cab: master level, porting, tweeter
equaliser: low, low mid, high mid
phones level

switches:

preamp drive mode: clean / comp / hot
parallel LPF: 500 / off / 100 Hz
pre FX assignment: drv / both / parallel
cab size: 4x10 / 8x10 / 1x15
speaker colour: warm / bright / modern
main output: main / cab / bypass
parallel output: parallel / thru
parallel phase
ground lift

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Reviews from other countries

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Steve L. December 9, 2025

Wrote the following about DSM & Humboldt Simplifier Bass Master bass guitar pre-amplifier

Excellent Preamp, Cabsim and DI.

The reviews are right: the tonal possibilities and the different setups are enormous with this device. The EQ controls are quite subtle, so even relatively big boosts and cuts sound reasonable.

I bought this as a backup and even smaller alternative for my usual setup that uses a Tonex One pedal into a Radial J48 DI. I was able to find the warm but clear tone I like after a bit of experimenting using the headphone output. From what I've heard at rehearsal, the sound quality of the DI outputs is excellent too, but I'll see what my usual FOH engineer will have to say about that.

One caveat : the Preamp and parallel signals are not blended but added, meaning that you double the gain. You have to be careful with your gain staging to avoid clipping when adding a lot of the parallel signal.

The build quality seems excellent. It's well finished and feels study, even tough it's not overly heavy. The pots and switches feel solid too.

It's not cheap, but given all it can do, it's actually quite reasonable. For example, a good DI and a preamp or ampsim pedal would cost at least the same amount.