Spectro Amplifier
All Tube Amplifier for Bass and Guitar
New: Spectro B400
The Spectro series amplifiers have been around since 2015 and have built up a small community of fans and enthusiasts, particularly as bass amplifiers. So it's time to expand and improve the concept with a few new features, based on various suggestions and proposals. The basic concept remains the same, as this is where the Spectro stands out with its tonal characteristics and unique look. New features include a mute switch and expanded tap functions for the DI output. In addition, a bass amp model with 400W output power has been available since June 2025, which makes this amplifier even more impressive with its increased power reserve. Due to current occasions, the photo gallery shown above will only feature this amplifier model until further notice. More photos can be found on the ‘Showroom’ and ‘Photo Gallery’ pages.
Specifications and Features - Overview
Power-Amplifier in Ultralinear connection 100W (4 x EL34); 200W (4 x KT88); 400W(8xKT88) r.m.s. output
Flexible preamp configurations to optimize the amp for bass or guitar. (2 kinds of Boosters and a various Tone-Control designs)
The Spectro B400 is only available as a bass amplifier with active 3-band tone control and 3 power levels: 150, 250 and 400 watts.
Modifications and Extensions:
3-Position Impedance-Switch
Weight:
Size:
iluminated (RGB) fullcolour acrylic glass frontpanel
Output Power-Switching 50/100W; 100/200W; 150/250/400W
switched speaker-emulation at Di-Out
single or dual tonestack
active 3-band-tone-control (specially for bassamplifiers)
4 - 8 - 16 Ohm (prefered for guitaramplifiers)
2 - 4 - 8 Ohm (prefered for bassamplifiers)
Spectro GB100 ca. 17,5Kg (39lb)
Spectro GB200 ca. 24Kg (53lb)
Spectro B400 ca. 30Kg (66lb)
Spectro GB100 610 x 240 x 230mm (Width, Depth, Heigth) 24"x 9,5"x 9"
Spectro GB200 610 x 285 x 230mm (Width, Depth, Heigth) 24"x 11,2"x 9"
Spectro B400 610 x 300 x 230mm (Width, Depth, Heigth) 24"x 11,8"x 9"
Tolexcover and colour at your choice
Flightcase available
Lettering in English or German
Customizing the spectro amplifier
Controlpanel
Preamplifier with 3-band passive tone-control
Preamplifier with 3-band passive, dual-tonestack
Preamplifier with 3-band active tone-control and 2 switchable frequencies each band (only available for 200W Amps at the moment)
Preamplifier section for bass amplifiers with active tone-control. The mute switch is standard there since June 2025
Booster selection
Bass-Booster
Guitar-Booster - identical to the 'Hornet Tube Booster'
Both Bass- and Guitar-Booster are looking identical at the controt-panel. But they sound different and do have different circuitdesigns
Rear connecting panel
Backview of a 200W Guitaramp with additional controlknobs for plexi-panel-light, speaker emulation switch and output-power switch Output-connectors = phone jack Speaker-Selector-Switch = 4-8-16 Ohms
Backview of a 200W Bassamp with additional controlknobs for plexi-panel-light, speaker emulation switch
Output-connectors = Speakon Speaker-Selector-Switch = 2-4-8 Ohms
Backview of a 200W Bassamp with additional controlknobs for plexi-panel-light, speaker emulation switch and output-power switch
Output-connectors = Speakon Speaker-Selector-Switch = 2-4-8 Ohms
Since 2022 all bassamplifiers were fitted with this back-controlpanel. This one here is a 200W Amplifier.
Speaker Emulation
The switchable speaker-emulation delivers an output signal corresponding to the frequency response of a single loudspeaker in a cabinet. There are different emulated models for both guitar- or bassamplifiers available.
Illuminated Frontpanel
Adjustment of all 'Rainbow'-Colours within one 300° Potentiometer turn. The right (max.) position will set the colour 'white'.