Marshall Class 5 Guitar Amplifier Mods
This Marshall Class 5 Combo came in to the workshop for some mods. I was given the chance to do pretty much what I wanted to this guitar amp, so this was going to be a fun project.
I opened the amp up and found the date inside. It was made in 2009. This amp was 14 years old and was in need of a re-cap.. So, I did a full re-cap and the mods to this amp.
The amp lacked that bright top end sparkle, was muddy and lack lustre. The customer also said it was too loud for home use. So we changed the output tube to a Russian tube, 6P43P. This tube has a lower output than the stock EL84 that was fitted in the Class 5.
Watch the video to see how we modded this amp to get it sounding much better.
The gain is (7.5mA/V) on 6P43P. The El84 is (11.3mA/V)
The List of Mods for the Marshall Class 5
- R18 820 ohm
- C8 680nf
- R20 1MEG
- C20 22nf
- R28 33K
- C10 Removed
- C21 Removed and a jumper added
- C2 10nf
- C5 10nf
- C6 47uf
- C3 22uf
- C11 22uf
- R4 6,8K 2 Watt Metal Oxide
- R2 6,8K 2 Watt Metal Oxide
You can find the schematic in the link I have provided below.