The Rikstone H140 is a power amp including two identical power amps with separate power supplies. The inputs can be connected together with a switch. The amps can be used both for guitar and bass. As power tubes at least 6550,  KT88,  EL34 and 6L6 can be used. The amps have been built in a 4U rack.

Technical data (values per amp):

Inputs: 1 input
Outputs: 16, 8  and 4 Ohm with Speakon jacks + 8 Ohm with 6.3mm jack
Controls: VOL, STAND-BY
Tubes: 1 x 12AX7, 2 x 6550
PT: Uraltone TS30
OT: Hammond 1650RA
Rectifier: Semiconductor diodes
Schematic: Power amp/power supply