Tube Amp Kits & More

Tube Amp Kits & More - Designed by Kevin O'Connor

London Power's tube amp kits and tube amp mod packages allow the hobbyist or tech to add cutting-edge features to existing musical instrument amplifiers, or to build complete amplifiers from scratch. Have fun, while learning and adding desired functionality to your amp! Do keep in mind that if you build or mod an amp you should have a basic understanding of electronics, safety procedures and circuit theory. Also, please see our Safety page.

What's Included


Each kit or mod package contains the electronic components relevant to the circuit. For example, the LP-PRE London Power Preamp Kit contains the electronic components that make up the audio path of this style of guitar preamp, including: resistors, capacitors, potentiometers, tube sockets and a printed circuit board (PCB). This kit does not include the power supply components, the switching components, tubes, wire or a chassis. When additional circuits are required - such as the PSU-PRE Power Supply for Tube Preamp for power and the ERK Electronic Relay Kit for switching - the product page on this site will indicate the complementary kits required.

Power management kits, preamp kits, power amp kits, switching circuits and power supplies have a PCB. Wire connections are made from the PCB to pots, jacks, switches and power entry sockets. The PCB carries the essential circuit portions, including the tubes (if applicable), so that the overall layout will be noise-free if wired according to the diagrams. Since mid-2012, pots also have their own small PCBs to make wiring to them easier.

Modification packages such as the SEM - Single-Ended Mod supply only the "extra" components that must be added to an existing circuit to change or enhance its function. These generally do not require a PCB (except for pots) as the quantity of components to be added is low and/or the components are to be chassis-mounted.

Descriptive notes are included with each package, which should make assembly straightforward. The kit notes are designed to facilitate assembly and are not meant to be tutorials of circuit operation. If you need more infromation on amp design in general, please refer to our "The Ultimate Tone" (TUT) series of books for explanations of circuit methods and theory.

Parts Quality


The components used in the kits are the same ones London Power uses in their amplifier and sound accessory products. These include: low-noise metal-film precision resistors, flame-proof metal-oxide resistors, high-quality plastic capacitors, low-leakage long-life high-temperature electrolytics, custom toroidal power and output transformers, and safety-agency approved mains elements (fuse-holders, switches). Semiconductors and tubes are used well within their ratings. All kits that use pots are supplied with high-quality 16mm types.


We have made every effort to assure that the kit notes are error-free. There is no warranty on kits or the parts contained in them. London Power is not responsible for misinterpretation of kit notes, mis-installation, or for any damage such errors may cause. Alternate values or component types may be substituted according to component availability and/or for product improvement.

If you have questions about your kit or its application, don't hesitate to contact us by phone or email - we're happy to help.

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