

Studio/Stage Head
Custom Hiwatt 20/40W Head
The SS20/40 is the flagship of our Custom Shop Studio range, packed with powerful, intuitive features like power scaling, footswitchable reverb and boost, and a wide gain spectrum. Designed for professional session players seeking versatility without option paralysis, the 2025 update brings higher headroom in Stage mode, a Bright switch, footswitchable Boost, and enhanced reverb control—available in both combo and head formats. The circuit begins with High and Low impedance inputs to tailor gain response—Low impedance is ideal for high-output pickups or players wanting less preamp compression. The new Bright switch works across both inputs, adding sparkle to clean tones or tightening higher-gain sounds. The Boost adds preamp gain for harmonic richness and interacts with both the Bright switch and input impedance. It’s now footswitchable for on-the-fly dynamics. A traditional 3-band EQ shapes tone before hitting a quad of EL84s, delivering 40 watts in Stage mode or just over 20 watts in Studio mode via smart power scaling. As one of our few Custom amps with reverb, we’ve refined the onboard spring tank for lush, versatile sound. A new Dwell control adjusts input to the tank, while the Reverb control blends it back in—offering everything from subtle ambiance to expansive textures.
FEATURE OVERVIEW
- — NEW Footswitchable Transparent Boost via Push/Pull Gain Pot
- — NEW Bright Switch for sparkling cleans
- — Independent Hi and Low inputs. Versatile and intuitive, perfect for bringing life out of dark pickups or taming shrill high end in bright pickups.
- — Push/Pull Gain potentiometer providing extra preamp gain at a touch.
- — Volume for any gig — Switchable wattage allows switching from 40W down to 20W for smaller venues and practice spaces. Furthermore, this gives the option of more clean Headroom in the 40W ’Studio’ mode, or natural tube breakup in the 20W ’Stage’ mode.
- — A fantastic Pedal platform, with natural tube saturation and True-Spring Reverb on tap when you have to leave your board behind.


Specs
wattageSwitchable — 40W or 20W
inputs
- Hi
- Low
output
2 x 1/4" Speaker Out
preamp valves3 x ECC83 (12AX7), 1 x ECC81 (12AT7)
output valves4 x EL84
controls
- Master Volume
- Reverb Level
- Reverb Dwell
- 3-Band EQ — Bass, Treble, Middle
- Gain (Pull Potentiometer for Boost)
- Bright Switch
- Standby — On/Off
- Mains — On/Off
impedanceSwitchable using Impedance Selector on the rear panel — 4 Ω, 8 Ω, or 16 Ω
height255mm (~11")
width630mm (~25")
depth280mm (~12")
weight16.1 Kg (~36 lbs)
- Road Ready — Rugged 18mm Birch-Ply Construction
- Band Ready — ’Soak Tested’ by our Custom Shop Technicians
- Touring Ready — World Voltage and Impedance Selectors
- Original Partridge spec English transformers.
- Meticulously hand-wired to Harry Joyce’s exacting military standards.
- 🇬🇧 Proudly manufactured in the Hiwatt Custom Shops.