Hughes and Kettner tubemeister repair

Hughes and Kettner Tubemeister repair

I’ve wanted to do a tubemeister repair since they first came out a few years back. I guess it’s a testament to general quality that this is the first to appear on the bench. I’m a big fan of the design aesthetic. 3 channels and a midi switching amp for £550ish is a lot of bang for your buck.

However, the owner was more worried about a different kind of bang – and a flash behind V1 when he flicked the standby switch. Afterwards the amp wasn’t making any sound at all.

Hughes and Kettner service manuals are easily the most detailed of any of the modern manufacturers I’ve seen (honourable mention goes to Roland/Boss) but this wasn’t needed to disassemble the chassis and get back to the PCB. The chassis is all metal which reduces weight and size. There’s a bent metal lid, removable end pieces and a separate metal base.

Hughes and Kettner have a power tube management system called TSC. This checks tube balance and bias. Orange amps have a similar system (see orange amp repair).

I discovered that the HT fuse had blown, which accounts for the bang the player heard. The valves all tested good, but since the TSC turns on the power tubes using a FET in the cathode I strongly suspected the power valves. After replacing the valves and the fuse the amp came back to life!

If you have Hughes and Kettner tubemeister repair, please just drop me a message and I’ll get you up and running again.

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