I have used this amp both live and in the studio. It has been serviced, with new tubes, in 2020, and only used once live since then, then I moved from Paris (France) to Järvsö (Sweden). It has hardly been used since.

Serial #J10023 (mid-to-late 2000s)
HIWATT Custom Shop SSP103 100W Head Class A/B Made in England Signature Series
This model is unique to the Hiwatt catalogue and unlike any other guitar amplifier models it is based upon the amplifier used by Pete Townshend (The Who) 
This 100W amplifier boasts more gain and a more responsive treble and bass control network. 
You will notice the absence of middle in the EQ and the presence of four channel volume controls as well as the master volume. 
The four independent pre-amp channels mean that this amp has 5 x ECC83 (12AX7) instead of the usual 4. 
This amp is very loud, but it is possible to use it at home, even without attenuator.

This head is powered by 4xEL34 in the power stage and employs the original Partridge designed transformers. 
Switchable to 4, 8 & 16 ohm output impedance, the SSP103 allows you to select from 100, 115, 230 and 240 volt sources. 
The amp features 4 individual inputs: 1-2 normal, 3-4 brilliant. 
It can be used for keyboards as well. Add your favorite pedals to create your own personalized sound. 

FEATURES
Front Panel Controls: INPUTS 1-4, VOLUME 1-4, BASS, TREBLE, PRESENCE, MASTER VOLUME, STANDBY SWITCH, MAINS SWITCH
Back Panel Features: VOLTAGE SELECTOR, OUTPUT IMPEDANCE SELECTOR, SPEAKER OUTPUTS
Output Power: 100W. Please note this is an All Purpose (AP) amplifier, which can be used for guitar, bass and even keyboards.
Valves: 4 x EL34’s, 5 x ECC83/12AX7’s

Dimensions (Unboxed) L x H x D: 63 x 28 x 28 cm
Weight (Unboxed): 21 kg

Comes with a Roqsolid padded ampcover.
Can also be bought with a 4x12 Hiwatt Cab (SE4123C - Celestion), that I also sell on Vintage & Rare, see my other adds, total price to be discussed then.

Shipping with UPS.