Our All-tube Bass Preamp (ATBP) is an evolution of London Power’s Spectrum bass amp design. It creates classic bass tones with ease, yet is capable of much more. ATBP accommodates active and passive basses, providing clean headroom or tube compression as the player wishes. Four tubes do everything. A fully featured effects loop and two independent outputs allow many system options.
• all-tube circuitry using four tubes
• use any of 12AT7, 12AU7, 12AY7, 12AX7, ECC-81/-82/-83, 7025, 5814, 5751,6201,6072, 6679, 6680
• series-parallel effects loop with Send and Return controls
• Dual independent outputs with their own Tone
• transformer-isolated Send, Return and Outputs
• 2U, 4.3kg, 17″ x 3.3″H x 6.5″D (plus tubes)
• rack-mountable with optional kit
• rubber foot storage on rear panel when rack mounted
• 120V, 240V range switch
London Power Bass Preamp
The All-Tube Bass Preamp has a sophisticated preamp with an input stage incorporating true variable gain. This accommodates any passive or active bass with ease, allowing the player to dial in sounds from pristine clean or warm tube compression. Additional gain stages add warmth and compression as needed. Equalisation is extensive and far more versatile than traditional tube bass amp EQ. Where other tube bass preamps add a maximum of two stages of tube character, ATBP provides six tube stages between input and output, providing a tone that is more like playing through a whole vintage amp rather than just a preamp.
The effects loop can be set for either series or mixing (parallel) mode and has front-panel Send and Return controls. The loop can be bypassed via a front-panel switch or by a remote foot switch (not included). Line-level or pedal devices can be used.
All-Tube Bass Preamp has two independent outputs, each with its own Level and Tone control. These can feed separate amplifiers for zoning a stage, or one can be used as a proper DI to a PA system, or however the player wishes to connect his or her system.
The Send, Return and two main Outputs feature isolation transformers to eliminate ground-loops between equipment.
All-Tube Bass Preamp incorporates all of London Power’s standard design and construction features:
• toroidal power transformers
• worldwide mains compatibility
• fusing for all transformer windings
• Galactic Grounding
• active hum filtering
• long-life capacitors
• low-noise metal-film resistors
• metal-oxide and wire-wound power resistors
• zero wiring
• zero standby power when switched ‘off’
ATBP can be rack mounted using the optional 2U6-BRKT, sold as pairs.
“Bass of ages! I can get the sound of all my old vintage amps”
“Great touch response. My Mesa is dead”