The top-cut network on the springline output is another afterthought.Īnother 12AX7 is the vibrato phase-shift oscillator and cathode current modulator for the second effected preamp stage.įootswitching for vibrato and reverb is provided on a cast metal pendant (attached).Īnother 12AX7 as the cathode coupled 'long-tailed pair' phase splitter and feedback summer.įinally a pair of 6DQ6A's in fixed bias driving an A+R OT2700 (3k3 plate-plate) for 40W, or OT2701 (2k6 plate-plate) for 60W, output transformer with 360VDC on the centre-tap, into 7.5 ohms (40W) or 3.75 ohms (60W). The 6GW8 pentode is a class-A driver for the reverb springline, with the triode section used as reverb recovery amp. The reverb input is anode mixed with the reverb return before some high-pass filtering and mixing with the normal channel. Most of the modifications seem to be to make the reverb channel brighter and more toppy. ![]() On some units the individual 1M input resistors were replaced with a single 470k at the grid.Įach channel preamped then tone and volume controlled using both sections of a 12AX7 each and a passive 2-way Baxandall tone circuit. High and low sensitivity sockets for each of the effected and normal channels. ![]() Formal circuit updated from informal tracings, 5/1/05.)
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