The ValvePower 18 Watt Cage Amp is also available as a kit for experienced builders.

A layout and circuit diagram is provided, with main components loosely mounted on the chassis for safe carriage. Kit includes everything you need to build a fully working 18 watt cage amplifier.

This kit is not really suitable for first time builders without experience of electronics or amp building. All valve amps involve high voltages and unless you are confident and aware of the dangers, choose another project to gain experience and practice.

We offer an alternative (easier to build) conventional chassis type amp with the same components and the same sound, complete with a superb hand made head box.

Please contact for details.


Chassis, base, top cage, handles and feet.
JJ Valves 2 X EL84, 2 X ECC83, 1 X EZ81
2 X transformers PT 230/240V with 290-0 290 HV @ 120mA
Two 6.3V heater connections 1 X 6.3V 2.5A CT and 1 X 6.3V 1A for valve rectifier. An Output Transformer custom made for this and other 18/20 watt push pull amps. 8K primary with 4, 8 and 16 ohm taps on the secondary.

Ceramic valve bases and retaining springs.
Pre drilled circuit board, RS original turrets (with fitting tool) and all components.
Wire and sleeving. 3 Cliff Jack sockets, rotary switch/pot for VVVR (Valvepower Variable Voltage regulator) built on turrets.
Fascia panel, switch, indicator, pots and knobs.
All screws, 4 feet and safety stickers.

The Cage Mark 5 Kit Price No longer available.

Please contact before ordering to check stock levels.


The design and components are of course identical to the ValvePower handwired amp:

2 X new JJ EL84s and 2 X new JJ ECC83s.
There's also an EZ81 rectifier valve

JJ valves are the most consistent and best sounding modern production valve available, and are used by many amp builders.

The cage amp design places the valves at the front where they can be seen through the black mesh when they are lit up, and they look hot !! (they are)
The purpose built chassis is manufactured from 1.5mm steel with an epoxy based black powder coated finish inside and out. This is applied electrostatically to get into every crevice.
The cage top is also made from 1.5mm steel with added louvres for appearance and even more structural strength. The corners are folded, welded and smoothed to give a superb finish.
The whole head weighs just under 6 Kg, so it is built like a tank and will last many years.
The chassis footprint is 12" X 8" exactly the same as a Linear Conchord of the 60's in fact the top cage will fit a Conchord !!
Please bear in mind this is a finished head and doesn't need an expensive cabinet.
Speaker jack on the back, switcheable for 4, 8 or 16 ohm speakers.
The 1.5mm baseplate and top cage are secured with threaded inserts in the chassis, not a self tapper in sight !!
The handles are metal brushed chrome.
100% point-to-point hand wired quality.

The components are mounted individually on original RS holeboard and turret tags.
This makes for lifelong easy servicing and tweaking, each component can be removed and replaced without disturbing anything else.

Cathode (self) bias design means no adjustments are necessary when changing valves.

The mains transformer is 290V @ 120mA
More than adequate for an 18 watt IIb.

The Output Transformer is a UK custom made hand finished by us and is the result of many prototypes specifically made for 18W EL84 push pull amps.The laminations are made to imperial measurements from specially selected steel, to faithfully reproduce the sonic performance of the vintage transformers which inspired them.