Sound — 10
6550's are harder sounding to me, gives a good kick to the head. Have had the opportunity to hear it on stage and pegged (lent it to a guy, Randy Hanson, who used to do a Hendrix tribute round here)in an average little club (200 peeps maybe), all controls on '10' from straight guitar to phaser and fuzz a single 4x12 cab used (top cab, lower cab used for looks) he could make it moan and screech on cue, man this amp is LOUD. Likes front end slammed with more gain, still cleans up nice with guitar volume(with right pedal). Want to get rid of rehearsal rat's? Set master to 10, preamp to 4, spank the guitar hard, HEAD CUTTER! This amp's sound = Rock
Overall Impression — 10
Kick a-se amp. The sound that 800 buyers thought they were getting. They came with less headroom and less CHUNK! Have played metal, hard rock, blues, classic rock, punk, power pop and other junk and it works for all of it. Turn the Master above the pre volume and it slices 'bout as good as a twin. Plug in a tele and country the crap's out of it! Freak the goober's out ("Hey, Zeke, that ain't no Fender! That one o them devil music makin Marshillz!") then cut their head's clean off. Show then it ain't just fer "rawk".
Reliability & Durability — 10
Played hundreds of gigs with no backup. Sloshed beer into to vent at a party, amp must have been on standby or just turned off, I discovered next day it didn't work and found the far left power tube shattered (it smelled like beer in there). Good thinking Marshall - we sell to rock musicians! Never known to indulge in drinking! Or excess. I Taped over that vent now. Still has plenty of airflow. Before I bought it I blew it up during a Jam at my bud's place, That was around 1983 or so. Paid for half of re-tubing (dude took us for $200 for four 6550 and three 12AX7 tubes and biasing. 1983! At least they were all USA made groove tubes. The shattered tube was replaced by me around '89 or '90. 2 months ago I replaced the power tubes with Tung-Sol reissue units from Russia have a good supply of NOS preamp tubes (25+)so this re-tubing cost me $140.00, it's 2013. I did just what an official Marshall repair center does, open back - replace power tubes - close back. Did not need re-biased. Heck of a reliable workhorse. Just them plastic bit's mentioned above. Blame the British economy and Thatcher.
Features — 9
Made in '78 or '79. 6550 power tubes. Mass headroom, less gain than later 800's with EL34's. Two (one, really) inputs, 6 knobs, 4 speaker out, the most perfect layout ever created. If I have a complaint - it's with the 1/4" jacks and cabinet corners - they are all plastic. In the '70s? If I was going on the road with it I would replace the jacks that I use with metal ones. No pots or jacks are connected on the pc board, it's guts are Neat and clean with a small pc board, just a step beyond point to point. Ya don't need more than 2 sounds a nite anyway, you clean, you dirty.