Marshall JCM 900 2501 50w Hi Gain Master Volume MkIII → 2 thoughts on “ Marshall JCM900 4100 Hi Gain Dual Reverb ”. 4100 - Poweramp 2: 4500 - Preamp: 4500 - Poweramp: 4500 - Poweramp 2: 6100 - Poweramp: 6100 Clean Crunch Cct: 6100 Lead Master Cct: 6100 Psu Cct: 8040: Jcm 2000 - Bias: Jcm 2000 - Preamp: Jcm 2000 - Poweramp: Jcm 2000 - Rear Out: Jcm 2000 - Reverb Main In: Jcm 2000 - Channel A: Jcm 2000 - Channel B: Jcm 800 2203: Jcm 800 2204: Jcm 900 - 100. Marshall JCM900 2100, 2101, 4100, 4101 and 4102 power supply and output section schematic. About the Marshall JCM900 4100 amplifier: The JCM900 4100 was the next logical step on from the JCM800 Series. This particular amp is an authentic re-issue of the original JCM900 4100 which first made its debut in the early 1960s. This is a two-channel, high gain plus reverb, 100W head with no solid state components. Marshall Diagrams, Schematics and Service Manuals - download for free! Including: 5x02 new, 18w new, 18wr new, 30thanniv new, 87x 60 02 1 new, 87x 60 02 2 new, 100w 67 new, 200w new, 1917 new, 1930 new, 1959 01 60 02 new, 1959mk2u new, 1959prem new, 1959pwrm new, 1959sprm new, 1959spwm new, 1959t 66 new, 1959tu new, 1959u new, 1962ri89 new, 1962ri93 new, 1963 70 new.
Early 90s JCM900 with two channels and reverb on both. A lot of opamps in this amp. They are used for the input and first gain stage, reverb drive and recovery, and for the boost circuit. It essentially has an overdrive pedal inserted into the front of the amp before the V1 12AX7 drives the tone stack. It is a cathode follower in the typical fashion. V2 is a gain stage and V3 is phase inverter.
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Somehow I lost my chassis image of this amp and all I have is a pic of the crappy re-soldering job someone did in the past. This thing had intermittent crackle and it would cut out occasionally. After re-flowing many solder connections like these ones it worked reliably. It was also extremely dirty. I’m sure cleaning the pots and tube sockets helped too.
Jcm900 Head
Marshall JCM900 2100, 2101, 4100, 4101 and 4102 power supply and output section schematic