Blackstar HT100 repair

Blackstar HT100 repair

This Blackstar HT100 repair was completed for the co owner of an exciting new Grantham based venture ‘Melody Music Rooms’ in Grantham.

Melody music rooms are a rehearsal space, recording facility and teaching space located on Westgate in Grantham . It’s the brainchild of a group of Lincolnshire and Nottinghamshire music teachers who wanted to provide better music services in the area. Not just a building, they run jam nights and busking sessions featuring local young (and old!) musicians. It’s great to have these guys raising the profile of live music in the area, so do check them out on

I’m told that this amp has played Wembley(!) as the owners of Melody Music played some high profile support gigs with their old band. It had been retired when it started blowing fuses, but the owner wanted it brought back to life for the new Melody venture.

There were a couple of valves to replace and the amp had blown the bridge rectifer diodes. Unfortunately Blackstar don’t provide schematics for their amps so it’s always a bit of a tough job repairing Blackstar gear.

Normally at this point I’d put a clip of my repair video, but here’s the repaired amp being used in the studio at Melody Music Rooms.

If you need a Blackstar HT100 repair, please drop me a line.

Peavey Classic 30 repair –

Peavey Classic 30 repair

This Peavey Classic 30 repair was a bit of a nightmare!

It arrived with a fairly basic problem – the amp wouldn’t turn on. This was down to a loose screw. It held the mains fuse holder internally. When this came loose, the fuse holder was dangling in mid air and shorted mains directly to the metal case of the unit, which caused the fuse to blow – which is a good thing!

I spent an hour on it – tested all the valves and checked the plate and other power supply chain elements – all the preamp valves are good, but the inner power amp valves no longer match so I changed these. There was no means of adjusting the bias so it’s a question of juggling valves until I find a set of EL84s that properly bias.

I then soak tested the amp. This involves running the amp at gigging voltages with a pink noise signal for a couple of hours. I do this to check that there aren’t any problems with the amp that only appear after a longer period.

In this case, the amp started making a crackling noise after the two hour soak. This turned out to have a twofold cause – there was a leaking cap in the tone stack and the HT electrolytics (IC brand) were also worn.

Unfortunately the design of these early peavey Classic 30 amps uses single wire links between the boards. It’s a nightmare to disassemble and these little wire links are a common cause of failure. This slowed down the diagnostic quite severely

If you need a peavey classic 30 repair, please do contact me.

Mesa Boogie Bass amp Repair

Mesa Boogie Bass 400+ Repair

This mesa boogie bass amp repair had the highest power valve count I’ve seen. The amp uses no less than twelve 5881 6L6 valves!

Like the recent fender amp repair this valve amp was blowing fuses. Also like the fender repair, the failure was down to a damaged power tube. Two in fact.

Much is made of Mesa Boogie’s insistence upon the use of mesa branded valves on guitar forums and these guys come in for quite a lot of stick. You can read Randall Smith’s defence of the idea here. My opinion is that the principle is reasonable for the majority of non technical users.

In this case, the amp had been fitted with Sovtek valves. Aside from the two failures many of the valves no longer matched well.

By testing mesa boogie valves in my valve tester I know what non mesa valves are within mesa parameters for use in their amps. I could tell that 4 of the sovteks were out of spec, meaning that 6 of the 12 needed replacing. After completing this simple task the amp was fixed.

If you have a mesa boogie bass amp repair please contact me via the contact page.