Orange is auctioning off a “graphics only“ OR50 amplifier head, signed and used by Biffy Clyro, in aid of Cancer Research UK

Orange has listed a 50-watt “graphics only“ OR50 guitar amplifier – signed and stage-played by Scottish rockers Biffy Clyro – on eBay, with all proceeds from the sale going to Cancer Research UK.

The amp was owned by Biffy session guitarist and Orange Ambassador Mike Vennart, who describes the single-channel head as a “workhorse beast.“

“This was my amp,“ says Vennart. “I toured it for about four years. It’s signed by Simon Neil, James Johnston and Ben Johnston of Biffy Clyro, and myself. It’s an absolute classic workhorse beast of an amp. Never let me down. Goddammit I miss it!!“

Listed on eBay yesterday, the current bid for amp is £1,750, with six days of the auction left to run. Biffy fan or not, whoever gets the amp will have a seriously powerful amp on their hands, and a sound that evokes the classic British rock of the early 1970s.

Inspired by Orange's 1972 80-watt Graphic Valve Amplifier, the OR50's power stage might seem a little more practical but it's still capable of moving some air about the room. A single-channel design, it has a three-band EQ, three-stage gain section and HF Drive control. 

There is a switchable master volume that allows you to bypass the master volume and control volume via the gain knob.

The HF Drive feature controls the power section's presence and gain. Dime it and you've got a bright, effervescent attack. Between eight and 10 on the dial, Orange designer Adrian Emsley says “negative feedback is added to really make it scream.“

You can read our review of the 40th Anniversary OR50H here, and bid on the auction at the Orange Amps eBay page.

Learn more about Cancer Research UK and make a donation here.