The phase splitter valve while it is a pre-amp type valve is really not part of the pre-amp chain at all. It is actually part of the output stage. When an amp has two or more valves then it operates in a mode called push pull. Its job is to invert the signal so that one of your two output valves is driven at any one time. This is a an oversimplified description but I […]
Phase Splitter Valves they do influence your amp tone Read More »
We were asked to have a look at an Ampeg B200R bass amp. This is a Chinese built amp and is known to have a few challenges. Faults include badly fitting chassis in the case resulting in the chassis being damaged and known to fail when the speaker is switched from ” no horns” to “horns” jack socket. This failure mode is caused by the panel which is mounted in the chassis with the speaker
Over the weekend I had the pleasure of doing a quick service on and Orange Rockerverb MkIII. The amp is just coming up on two years old and gigged at least every week. The owner reported that the amp was creating murky distortion and it sounded so horrible it was no longer useable. So this amp is experiencing a lot of lugging around and used at giigs lasting 3 hours or more. He was leaving
Unexpected Valve wear in an Orange Rockerverb 50 MkIII Read More »
Its a couple of weeks since I wrote about fixing amps and I had not seen a Fender amp to fix for a few weeks and then along comes four all on the same day ! In the cover picture we proudly present four broken amps -At the Top a Fender Blues Jr III -Underneath is a Fender Supersonic 40 watter -to the left is a Princeton Reverb re-issue -to the right is a Hot
The Howl and the Hum fixing four Fender amps in one day Read More »
This is essentially a solid state amp so before I get shot down in flames, my defence is that there is one valve in this amp which is there to warm up the sound. This Ashdown Evo II 300 is a 300 watt amp with twin 12 inch speakers. It is very well constructed with great access to the key parts of the amp This Ashdown Evo II 300 was distorting and sounded terrible. When
The Fault A nice Tone King Imperial Mk1 ( http://www.toneking.com )arrived with a strange fault. When you turned up the reverb control there was this horrible buzzing sound which increased as you tried to increase the wetness of the reverb. Faults like this are usually the reverb cables, plug and sockets not being earned correctly or even a faulty reverb pan. Not this one! Read on ….. Background on the Tone King Imperial Amp Mk1 and
A two rock Gainmaster 35 arrived for a service. It is manufactured by the Premier Builders Guild LLC. A fancy name! The amps are made in California and are around £2000.. They are built on a printed circuit style board which looks very like tagboard . See in the picture below. This amp is extremely well made and is a relatively simple straightforward design having two pre-amp valves, one phase splitter driving the two 6L6GC