On the advice of several friends who have tried this combination and the somewhat over the top feedback at
www.eurotubes.com, I rebiased and switched tubes for my '85 JCM 800. *I replaced the Sovtek 6550s I had with JJ KT88s and the pre-amp tubes were replaced from Ruby Tubes (which are most likely Svetlanas OR Sovteks) to JJ 12AX7s.
Wow....really! *It has a much more musical quality to the sound. *I don't particularly drive my amp heavy and I've only had the JCM for under a month. *I've loved the Boogie sound (used to have a mini Boogie stack) but my playing style and sound with the new band had a tendency to veer back to Marshall. *I started using my JTM-45 a lot more often and got a new appreciation for the sound it delivers (especially with
Les Pauls)..so I picked up a JCM800 for that saturated heavy sound that its known for. *The tube change itself just opened the amp more (as it squarely stated at the Eurotube site)....much more responsive to harmonics, the crunch that it has is still heavy but more musical (think Satriani's Crushing Day type crunch). *
Just thought other JCM 800 owners may appreciate this info. if you didn't have it.
Oh..the other big notable difference..it actually gives a much better 'clean' sound at higher levels (if you use your Marshall for clean).
Go JJ Tubes....
