The GR Bass DUAL Pre is a preamp pedal for bass from the Italian maker GR Bass. GR Bass describes it as offering "the best compromise between portability and versatility for the modern bass player", and its defining feature is right in the name: two completely independent channels that you can use simultaneously, each with its own complete compressor1. It sits among preamp pedals and, with its built-in dynamics control, overlaps with what players use compressor pedals for.
Channels, compressor and overdrive
Each of the two channels carries a complete compressor with Volume, Ratio, threshold and a two-mode release control1. Channel 2 adds a complete two-mode overdrive on top, giving the pedal a clean or compressed path on channel 1 and a driven option on channel 21.
The DUAL Pre draws 500mA at 9V DC and no power supply is included1. That is well beyond what a typical shared pedal supply delivers per outlet, so it needs its own capable power source.
Outputs, monitoring and practice features
For playing out or recording, the pedal provides two separate professional DI outputs with what GR Bass calls GR Bass quality1. For quiet practice and monitoring, it has headphone outputs with a separate EQ dedicated to them, which GR Bass says is there for perfect monitoring, plus an aux input for your media player1.
Build and origin
GR Bass designs and produces the DUAL Pre completely in Italy1. The company notes that its products are assembled manually and may differ slightly in aesthetics, weights and sizes, with differences it describes as minimal1. The pedal measures W28 x D13.5 x H6.5 cm1.
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Questions
Can both channels of the GR Bass DUAL Pre be used at the same time?
Yes. GR Bass describes the DUAL Pre as holding two completely independent channels that you can use simultaneously. Each channel carries its own complete compressor with Volume, Ratio, threshold and a two-mode release control, so you can shape two different bass sounds and switch or blend between them on the same pedal.
Does the GR Bass DUAL Pre have a DI output?
It does. The pedal provides two separate professional DI outputs, which GR Bass describes as carrying GR Bass quality. With two DI outputs alongside the two channels, you can send more than one signal path to a mixing desk or recording interface at the same time.
Where is the GR Bass DUAL Pre made?
GR Bass states that the DUAL Pre was designed in Italy and is produced completely in Italy. The company also notes that its products are assembled manually, so individual units may differ slightly in aesthetics, weights and sizes, with differences it describes as minimal.
How much current does the GR Bass DUAL Pre draw?
The DUAL Pre runs on 9V DC and draws 500mA, according to GR Bass's product page. The power supply is not included with the pedal. Because of the 500mA draw, a standard low-current pedal power supply or daisy chain may not be sufficient, so plan your board power accordingly.
Does the GR Bass DUAL Pre have a headphone output?
Yes. The DUAL Pre includes headphone outputs with a separate EQ dedicated to monitoring, which GR Bass says is there for perfect monitoring. There is also an aux input for a media player, so you can play along with backing tracks through the headphone output.
Sources (1)
- DUAL Pre, GRBass, 2026