All-Tube Bass Preamp

All-Tube Bass Preamplifier  $2,640 CND, approx. $2,100 USD 

All-tube Bass Preamplifier (ATBP) is an evolution of London Power's Spectrum bass amp design, creating classic bass tones with ease yet capable of much more. ATBP accommodates active and passive basses easily, 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.

London Power Bass Preamp - rearAll-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 have 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 compatability
• 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"

For our price list, see Studio Gear Ordering.


About London Power

London Power was founded in 1990 by Kevin O'Connor, after two decades of research into innovative audio amplification techniques. Kevin is an audio designer, author and speaker, known for his proprietary methodology called Power Scaling, and for his eleven books on audio subjects. Whether you seek amps, kits or information, you'll find useful answers here on not just the "how" but the "why" of audio amplifier design. Please enjoy the information on this site, and don't hesitate to contact us with questions.

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PO Box 10012, Thunder Bay, ON P7B 6T6 CANADA