All Kits & Mods

A master list of all kits, mods and building supplies from London Power

QRK-DIP - Four-way DIP switch

QRK-DIP - Four-way DIP switch

$4.00

QRK-DIP is a high-quality four-switch DIP package used on various QRK-series switching cards. .....

QRK-JFT - N-jfet with Gate Diode

QRK-JFT - N-jfet with Gate Diode

$4.40

QRK-JFT combines an n-jfet and its gate diode on a small PCB to make series-switch wiring easy. L.....

LIC - Technology Licence (per unit, for commercial builders and installers)

LIC - Technology Licence (per unit, for commercial builders and installers)

$5.00

NOTE: Installations and constructions using London Power kits are inherently licenced, and no add.....

CARD - Circuit Card Refill

CARD - Circuit Card Refill

$7.00

6" x 12" x 1/16" thick glass-epoxy card stock. Rigid material - can be cut to size by the user. .....

MOS - Replacement Mosfet + Thermopad

MOS - Replacement Mosfet + Thermopad

$8.00

Did you damage the mosfet in your London Power kit installation? It always saves time to follow t.....

EYELETS-100

EYELETS-100

$9.00

Order 100 or 1000. Bulk eyelets for your building needs. Two hundred eyelets is typically en.....

QRK-FSW - Push-button for Foot Switch

QRK-FSW - Push-button for Foot Switch

$9.00

QRK-FSW is a high quality Switchcraft momentary-action push-button suitable for use as a foot swi.....

LP-MV - London Power Master Volume

LP-MV - London Power Master Volume

$10.00

We don't normally brag, but this is the best master volume on the planet! Truly transparent. No t.....

SEM - Single-Ended Mod

SEM - Single-Ended Mod

$10.00

The SEM allows the tone of a single-ended amp to be produced by any push-pull fixed-bias or catho.....

QRK-SR - Single Relay Controller Interface for QRK

QRK-SR - Single Relay Controller Interface for QRK

$11.00

QRK-SR allows up to four voice control lines to interface with a a group of relays switched in ta.....

QRK-LED - Four LEDs for Amp Panel

QRK-LED - Four LEDs for Amp Panel

$12.00

QRK-LED is an assembly of four LEDs on a PCB. This can be supported atop QRK-SW for a clean, mode.....

RLY - Mechanical Relay

RLY - Mechanical Relay

$12.00

RLY is comprised of a miniature 12Vdc relay on a PCB to make wiring easy. Mechanical relays p.....

SUS-2 - Sustain & Compression Enhancer for Cathode Bias

SUS-2 - Sustain & Compression Enhancer for Cathode Bias

$12.00

The SUS-2 is suitable for cathode-biased amps. It can be used in single-ended or push-pull amplif.....

SUS-3 - Sustain & Compression Enhancer for Fixed Bias with Power Scaling

SUS-3 - Sustain & Compression Enhancer for Fixed Bias with Power Scaling

$12.00

The SUS-3 is specifically designed for fixed-biased amplifiers fitted with Power Scaling. The.....

QRK-VX - Voice Selection Expander

QRK-VX - Voice Selection Expander

$14.00

 QRK-VX is required when more than four system "voices" must be controlled in a guitar rig, .....

FPM - 2-Channel Fender Preamp Mod

FPM - 2-Channel Fender Preamp Mod

$15.00

FPM converts the preamp channels in a vintage Fender amp to those of the "LPSP" London Power Stan.....

GND - Ground Link Isolator

GND - Ground Link Isolator

$15.00

GND replaces the old-fashioned ground 'lift' switch "of old" with a modern automatic ground-link .....

PSX - Power Scale Control Switch

PSX - Power Scale Control Switch

$15.00

PSX provides an easy interface between ERK Electronic Relay Kit and multiple Power Scale controls.....

TREM - Tremolo Level Tracker

TREM - Tremolo Level Tracker

$15.00

TREM provides automatic tremolo modulation depth control with Power Scale control adjustment for .....

PSW - Toggle-style Latching Panel Switch

PSW - Toggle-style Latching Panel Switch

$16.00

PSW is a high-quality latching toggle switch made by C&K, that can be used as a front panel s.....

FSW - Alternate-action Foot Switch

FSW - Alternate-action Foot Switch

$18.00

FSW is a large-body push-on/push-off alternate-action foot switch with a chrome actuator. Popular.....

QRK-LDV - Four-LED Driver

QRK-LDV - Four-LED Driver

$18.00

The QRK-LDV four-LED driver is optimally suited as a voice indicator in a QRK-style system. The s.....

QRK-SF - Single Jfet Controller Interface for Multi-Voice Control

QRK-SF - Single Jfet Controller Interface for Multi-Voice Control

$19.00

 QRK-SF allows multiple voice control inputs to interface with a set of jfet control lines, .....

SL-MV - Splitter Limit Master Volume

SL-MV - Splitter Limit Master Volume

$19.00

Techs and amp designers have used various methods to control the gain of the Schmitt splitter as .....

PA66-CR - Cathode-Bias Switching Relays

PA66-CR - Cathode-Bias Switching Relays

$20.00

PA66-CR provides the relays that fit onto our PA66 or PX66 power amp projects for easy and/or rem.....

QRK-SW - Four-way Panel Switch Assembly

QRK-SW - Four-way Panel Switch Assembly

$20.00

QRK-SW is a set of four momentary-action push switches mounted on a PCB. This mounts to the front.....

RBX-BLT - Pre-assembly of RBX

RBX-BLT - Pre-assembly of RBX

$20.00

If you would like to receive RBX Raw Bias Auxiliary Supply pre-assembled, add RBX-BLT to your RBX.....

TX364 - 150H Choke

TX364 - 150H Choke

$20.00

Hobbyists and amp builders can now use the same high-quality transformers and chokes found in Lon.....

TX365 - 3H Choke

TX365 - 3H Choke

$20.00

Hobbyists and amp builders can now use the same high-quality transformers and chokes found in Lon.....

BMK2 - Bias Mod Kit for 2 Tubes

BMK2 - Bias Mod Kit for 2 Tubes

$24.00

Bias Mod Kits allow easy checking of output tube bias currents, regardless of whether those tubes.....

TBS - Tracking Bias Supply Kit for Fixed-Bias

TBS - Tracking Bias Supply Kit for Fixed-Bias

$28.00

The TBS provides an easy installation of a tracking bias supply for fixed-biased amplifiers. The .....

ERK - Electronic Relay Kit

ERK - Electronic Relay Kit

$29.00

ERK Features: A, B exclusive selection ground-referenced jfet shunt switch elements.....

PA66-S1 - Global Bias Switching for PA66 or PX66

PA66-S1 - Global Bias Switching for PA66 or PX66

$30.00

PA66-S1 provides a panel switch plus the relays that fit onto PA66 or PX66 for easy and/or remote.....

BMK4 - Bias Mod Kit for 4 Tubes

BMK4 - Bias Mod Kit for 4 Tubes

$35.00

Bias Mod Kits allow easy checking of output tube bias currents, regardless of whether those tubes.....

T5S - TUT5 Standard Project: Semiconductors only

T5S - TUT5 Standard Project: Semiconductors only

$36.00

For the hobbyist who can source most parts but wants the semiconductors from one source. This kit.....

BFX-PCB - PCB only

BFX-PCB - PCB only

$38.00

BFX is the Best All-Tube Effects Loop, and BFX-PCB is the printed circuit board and kit notes for.....

D-PRE-PCB

D-PRE-PCB

$38.00

D-PRE-PCB is just the printed circuit board and notes for our D-PRE Mini-Marshmallow Style Tube P.....

F-PRE-PCB

F-PRE-PCB

$38.00

F-PRE-PCB is the printed circuit board plus assembly notes for F-PRE Fender-style Tube Preamp. .....

LP-PRE-PCB

LP-PRE-PCB

$38.00

LP-PRE-PCB is the printed circuit board and assembly notes for our LP-PRE London Power 2-Channel .....

M-PRE-PCB

M-PRE-PCB

$38.00

M-PRE-PCB is the printed circuit board and assembly notes for M-PRE British-style Tube Preamp. .....

PA66-PCB - Octal Push-Pull Power Amp: PCB only

PA66-PCB - Octal Push-Pull Power Amp: PCB only

$38.00

The London Power PA66-PCB Octal Push-Pull tube power amplifier can be used with any of the common.....

PSU-PRE-PCB

PSU-PRE-PCB

$38.00

PSU-PRE is a low-power supply to support tube preamplifiers. PSU-PRE-PCB is just the printed circ.....

PSU-TPA - Power Supply for Tube Power Amp: PCB Only

PSU-TPA - Power Supply for Tube Power Amp: PCB Only

$38.00

Tube power amplifiers require various voltages for the plate circuit, bias and heaters. PSU-TPA p.....

PX66-PCB - Card for Extra Power Tubes

PX66-PCB - Card for Extra Power Tubes

$38.00

PX66-PCB allows additional pairs of output tubes to be added to a London Power PA66 project, for .....

REV-PCB - LP-Style Reverb Loop: PCB only

REV-PCB - LP-Style Reverb Loop: PCB only

$38.00

This is the London Power style reverb loop, using a push-pull reverb driver and two-stage recover.....

S-PRE-PCB

S-PRE-PCB

$38.00

S-PRE is our Sprectrum bass preamp and S-PRE-PCB is just the PCB and kit notres. If you would.....

SUS-1 - Sustain & Compression Enhancer for Fixed Bias

SUS-1 - Sustain & Compression Enhancer for Fixed Bias

$38.00

SUS-1 is suitable for non-Power Scaled, fixed-bias amps. The signal envelope has three parts:.....

V-PRE-PCB

V-PRE-PCB

$38.00

V-PRE-PCB is the printed circuit board and assembly notes for V-PRE Vox Top-Boost-style Tube Prea.....

Z-PRE-PCB

Z-PRE-PCB

$38.00

Z-PRE-PCB is the PCB and notes for the Zen-style High-gain Tube Guitar Preamp. See Z-PRE for .....

BFX-BLT - Pre-assembly of BFX

BFX-BLT - Pre-assembly of BFX

$40.00

Add BFX-BLT to your order for BFX - Best All-Tube Effects Loop Kit to have the BFX pre-assembled......

CH-8 - Insert Panel for 8" Deep Chassis

CH-8 - Insert Panel for 8" Deep Chassis

$40.00

This 6" (152mm) aluminum sub-chassis can be mounted inside an 8" deep (203mm) or deeper chassis, .....

PRE1-BLT

PRE1-BLT

$40.00

PRE1-BLT can be added to your order for any Tube Preamp that has a single tube, including: &n.....

PSP-BLT - Pre-assembly of Simple PSUs

PSP-BLT - Pre-assembly of Simple PSUs

$40.00

Add PSP-BLT to your order of PSU-PRE Power Supply Kit for Tube Preamp if you would like to receiv.....

VCK-BLT - Pre-assembly of VCK

VCK-BLT - Pre-assembly of VCK

$40.00

Add VCK-BLT to your VCK order if you would like to receive this kit pre-assembled. The assemb.....

BFX-HP - PCB + Tube Socket only

BFX-HP - PCB + Tube Socket only

$42.00

BFX-HP is the PCB plus tube socket for the BFX - Best All-tube Effects Loop. .....

PAF - Power Amp Front-end

PAF - Power Amp Front-end

$42.00

PAF is the classic power amp front-end used by London Power in all of its amps, and in hifi amps .....

QRK-MNR - FX Loop Controller + more

QRK-MNR - FX Loop Controller + more

$42.00

QRK-MNR is the "heart" of London Power's QRK-MINI amp switching system - the 'MN' in MNR - design.....

BMK6 - Bias Mod Kit for 6 Tubes

BMK6 - Bias Mod Kit for 6 Tubes

$44.00

Bias Mod Kits allow easy checking of output tube bias currents, regardless of whether those tubes.....

F-PRE-HP

F-PRE-HP

$44.00

F-PRE-HP is the "hard-to-find parts" for our F-PRE Fender-style Tube Preamp, including the printe.....

V-PRE-HP

V-PRE-HP

$44.00

V-PRE-HP includes the "hard parts" for V-PRE Vox-Top-Boost-style Tube Preamp, including the print.....

QRK-RLY - 4-way Relay Controller

QRK-RLY - 4-way Relay Controller

$45.00

 QRK-RLY provides interfacing for four relay groups. QRK-RLY is the equivalent of four QRK-S.....

SV84 - Super-Versatile Super-Value Power Scaling Kit for Single-Node

SV84 - Super-Versatile Super-Value Power Scaling Kit for Single-Node

$48.00

Most guitar amplifiers have separate power supply nodes for the the screen and plate of the outpu.....

TX316 - Push-Pull Reverb Driver Transformer

TX316 - Push-Pull Reverb Driver Transformer

$48.00

Hobbyists and amp builders can now use the same high-quality transformers and chokes found in Lon.....

PX66-HP - Power Expander: includes hard parts

PX66-HP - Power Expander: includes hard parts

$49.00

PX66-HP allows additional pairs of output tubes to be added to a PA66 project, for more power, fu.....

QS-LV - Quiet Supply for Low-Voltage Tube Amps

QS-LV - Quiet Supply for Low-Voltage Tube Amps

$49.00

The QS-LV provides a large reduction of supply-borne noise and hum - typically 60dB from 50Hz to .....

RBX - Raw Bias Auxiliary Supply Kit

RBX - Raw Bias Auxiliary Supply Kit

$49.00

The RBX provides a high-voltage low-impedance raw bias supply when one is not readily available i.....

CH-13 - Insert Panel for 13" Deep Chassis

CH-13 - Insert Panel for 13" Deep Chassis

$50.00

This 11" (280mm) aluminum sub-chassis can be mounted inside a 13" deep (330mm) or deeper chassis,.....

D-PRE-HP

D-PRE-HP

$50.00

D-PRE-HP is the "hard-to-find parts", essentially the printed circuit board and the tube sockets,.....

LP-PRE-HP

LP-PRE-HP

$50.00

LP-PRE-HP is the printed circuit board, tube sockets and assembly notes for LP-PRE London Power 2.....

M-PRE-HP

M-PRE-HP

$50.00

M-PRE-HP is the "hard-to-find parts" for our M-PRE British-style Tube Preamp, including the print.....

PSU-OPA - Opamp Supply Derived from Heater

PSU-OPA - Opamp Supply Derived from Heater

$50.00

PSU-OPA provides a transformer-isolated +/-8Vdc supply for opamps derived from the 6Vac heater su.....

S-PRE-HP

S-PRE-HP

$50.00

S-PRE-HP is the "hard parts" form of S-PRE, inlcuding the PCB and tube sockets and kit notes. .....

VCK - Voltage Clamp Kit

VCK - Voltage Clamp Kit

$50.00

VCK Voltage Clamp Kit stabilises voltages in a tube preamp, helping to keep tone consistent with .....

Z-PRE-HP

Z-PRE-HP

$50.00

Z-PRE-HP is the PCB plus tubes plus kit notes for the Zen-style High-gain Tube Preamp. See Z-.....

QS-HV - Quiet Supply for High-Voltage Tube Amps

QS-HV - Quiet Supply for High-Voltage Tube Amps

$52.00

The QS-HV provides a large reduction of supply-borne noise and hum - typically 60dB from 50Hz to .....

BMK8 - Bias Mod Kit for 8 Tubes

BMK8 - Bias Mod Kit for 8 Tubes

$53.00

Bias Mod Kits allow easy checking of output tube bias currents, regardless of whether those tubes.....

PA66-HP - Octal Push-Pull Power Amp PCB + Hard-to-Find Parts

PA66-HP - Octal Push-Pull Power Amp PCB + Hard-to-Find Parts

$54.00

The London Power PA66-HP Octal Push-Pull tube power amplifier can be used with any of the common .....

SV3 - Super-Versatile Tracking High-Voltage Regulator

SV3 - Super-Versatile Tracking High-Voltage Regulator

$54.00

The SV3 Is a Tracking High-voltage Regulator used as part of a Power Scaling solution in tube amp.....

CCK - Circuit Card Kit

CCK - Circuit Card Kit

$62.00

200 eyelets one piece of 6" x 12" x 1/16" thick glass-epoxy card stock hand staki.....

SV2 - Super-Versatile Super-Value Power Scaling Kit for Cathode Bias

SV2 - Super-Versatile Super-Value Power Scaling Kit for Cathode Bias

$64.00

SV2 + our VCK Voltage Clamp Kit comprise the Power Scaling solution for 99% of all cathode-biased.....

VCK-HV - High-Voltage Clamp Kit

VCK-HV - High-Voltage Clamp Kit

$65.00

VCK-HV stabilises the supply voltage against variations of incoming voltage. using an active regu.....

DFC - Dual Function Controller

DFC - Dual Function Controller

$68.00

DFC - Dual Function Controller allows independent control over two functions or features in an am.....

PX66-COMP - Card for Extra Power Tubes with Components

PX66-COMP - Card for Extra Power Tubes with Components

$70.00

PX66-COMP allows additional pairs of output tubes to be added to our PA66 series of power amp kit.....

QRK-FET -  Quad Jfet Interface for Series and Shunt Switching

QRK-FET - Quad Jfet Interface for Series and Shunt Switching

$70.00

QRK-FET interfaces London Power's QRK-LATCH (or similar control circuitry) with four groups of jf.....

QRK-LATCH - Quad Voice Controller for Guitar Amps

QRK-LATCH - Quad Voice Controller for Guitar Amps

$73.00

 QRK-LATCH is the heart of the QRK Quad Relay Kit amp switching system. provides a 1.....

SV-TT - Super-Versatile 2/3rds Power Scaling Kit for Tube Amp

SV-TT - Super-Versatile 2/3rds Power Scaling Kit for Tube Amp

$74.00

SV-TT is a truly universal Power Scaling solution for 100% of guitar and bass amps. SV-TT is .....

SV1 - Super-Versatile Super-Value Power Scaling Kit for Fixed Bias

SV1 - Super-Versatile Super-Value Power Scaling Kit for Fixed Bias

$78.00

London Power's SV1 Power Scaling Kit, along with our RBX Raw Bias Auxiliary Supply Kit, make up t.....

DFC-BLT - Pre-assembly of DFC

DFC-BLT - Pre-assembly of DFC

$80.00

If you would like to receive your DFC Dual Function Controller kit pre-assembled, add DFC-BLT to .....

PA-BLT - Pre-assembly of Power Amp

PA-BLT - Pre-assembly of Power Amp

$80.00

Add PA-BLT to your order of a power amp kit, to receive that kit pre-assembled. This applies to: .....

PRE2-BLT

PRE2-BLT

$80.00

Add PRE2-BLT to your order of a Tube Preamp that uses two tubes, to obtain that kit pre-assembled.....

PSU-BLT - Pre-assembly of Large Power Supply

PSU-BLT - Pre-assembly of Large Power Supply

$80.00

Add PSU-BLT to your order, to have the following products shipped pre-assembled: PSU-COMP.....

QLTCH-BLT - Pre-assembly of QRK-LATCH

QLTCH-BLT - Pre-assembly of QRK-LATCH

$80.00

Add QLTCH-BLT to your order of QRK-LATCH if you would like to receive a pre-assembled board. .....

SV-BLT - Pre-assembly of Power Scaling Kit

SV-BLT - Pre-assembly of Power Scaling Kit

$80.00

Add SV-BLT if you would like to receive your Power Scaling kit pre-assembled. This applies to: .....

EYELETS-1k

EYELETS-1k

$84.00

Order 100 or 1000. Bulk eyelets for your building needs. Two-hundred eyelets is typically en.....

F-PRE - Fender-Style Preamp Kit

F-PRE - Fender-Style Preamp Kit

$88.00

F-PRE is the classic North American style of clean preamp: two gain stages with an EQ and level c.....

V-PRE - Vox Top Boost Preamp

V-PRE - Vox Top Boost Preamp

$88.00

V-PRE is the famous Vox "Top Boost" channel of their classic AC-30 amp from the 1960s 3-w.....

GMX-KIT - Transconductance Multiplier

GMX-KIT - Transconductance Multiplier

$89.00

The "GmX" effect is the difference of sound between a 50W amp with two power tubes and a 100W amp.....

REV-HP -  LP-Style Reverb Loop: PCB + Hard-to-find Parts only

REV-HP - LP-Style Reverb Loop: PCB + Hard-to-find Parts only

$92.00

This is the London Power style reverb loop, using a push-pull reverb driver and two-stage recover.....

BFX - Best All-Tube Effects Loop Kit

BFX - Best All-Tube Effects Loop Kit

$98.00

BFX can be incorporated into any tube amp, providing a tube solution to active effects loop requi.....

PSU-PRE - Power Supply Kit for Tube Preamp

PSU-PRE - Power Supply Kit for Tube Preamp

$98.00

PSU-PRE can support up to five12A_7 tubes - enough for a 3-channel preamp with effects loop, cons.....

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.

Contact Us

(807) 473-0952
11 am - 6 pm, M-F
amps@londonpower.com
PO Box 10012, Thunder Bay, ON P7B 6T6 CANADA