The head has a 12AX7 tube installed in it, straight from the Marshall factory in England. These are the same tubes that go in La2a compressors, etc. If you haven't heard an La2a, they make the signal sound big and fat. Same in these amps. The amp head has both tube and analog solid state gain stages, which they labeled the Valvestate VS100 design in Bletchley, England where this amp was made -- it has a tube gain stage to get the warmth and fatness of a tube, and it also has analogue diode overdrive clipping stages which sound really good.
TUBE & Transformer:
This amp sounds great at low levels, but also sounds incredible when turned up. I think the head is either 100 or 150 watts, so it is really powerful. You can hear the warmth of the analogue circuitry in the clean channel and the 2 overdrive gain stages, which make this amp sound huge. Great distortion channels as well as clean.
The original reverb unit in the Marshall was really sprongy in a bad way (I love sprongy spring reverbs -- i like everything from the fisher spacexpander (THE king tubby reverb)) to the re-201 spring reverb sounds... but the original reverb tank in this Marshall was it's weakest component... it sounded small and thin. I put about 300 dollars into getting a hand-wired Accutronics reverb tank put into the head. (These are the units that Universal Audio mapped and re-created for their spring plug-ins). They are some of the best sounding spring reverbs... I put in the best and most expensive one -- a 19" tank. Now this amp sounds even warmer and bigger. You can still dial in the sound of the short original reverb, or make it sound like you are playing in warm, amazing technicolor sounding hall spaces. Really, really awesome sounding, rich sound.
The cabinet for the amplifier has 4, 12" speakers inside. Nowadays, all Marshall amps are made in China with cheap components... however, this amp was made in Bletchley, England. Both the head and cabinet were built there using all original Marshall components... and you can hear the difference between the harshness of the new Chinese models vs the warmth and depth of this older British made one.
You can dial the guitar legends into this British amp and get the signature Marshall crunch that you hear on lots of records.
Sad to sell my amp, but hope it can get to a good home.
Accepting offers on it... If you are serious about the amp and live in the los angeles lands, would be happy to drive it over so that you could play through it and hear the tone. Would be willing to ship it too.