Of course I don't just do Marshall repairs on Mondays but what a great way to start the week; a gorgeous 4502 JCM900 50W Dual Channel Reverb on the bench. There's nothing too wrong with this amp. It just came in for a re-valve and a tune-up (bias check) after the customer complained that it sounded a bit dull and lifeless.
In my humble opinion, the JCM900 Dual Channel Reverb was the last 'proper' Marshall. Personally I'm a 100W head freak but the 50W heads and combos do sound sweeter. Put a 50W through a 4 x 12 and you get a whole lotta' beef underneath that sweetness.
HEAR AND FEEL THE DIFFERENCE
I ALWAYS USE PREMIUM MATCHED VALVES AND I ALWAYS RE-BIAS
I get a lot of people ask me about impedance matching valve amps and speaker cabs so sometime over the next couple of weeks, I'll be posting some bumf on how it all works and best practices. Stay tuned!
UPDATE - 12th June 2020: A little more than a couple of weeks 🙁 but here's my post on guitar amp and cab impedance matching.