Almost the exact same amp as the Sunn Sonaro in the previous post but from 1967 instead of 1971. Same tone stack with Hi and Lo boosts, a 12AX7 for the preamp and a 6AN8 phase inverter, and two 6550/KT88s in ultralinear in the output.


Layout is nearly identical to Sonaro but instead of an unbypassed 1.5K cathode resistor for each side of V1 the 200S has the 1.5K cathode resistor on V1A bypassed with a 250uF cap. It also has a GZ34 rectifier tube instead of solid state rectifier and the B+ was only 458V compared to 585V for the Sonaro. So yeah, this thing will have more gain, less power in general, and less clean volume. It only did 40W at clipping. You can just use regular 500V caps for the power supply and don’t need the 20uF/600V Spragues like a lot of Sunns have since the B+ is lower.



You can usually tell an early Sunn because the logo has no circle R (trademark logo) after the name. I could stand to be corrected but I believe the trademark logo started getting added at some point in 1969. The Sunn font is also slightly different on these older versions.


Sunn 200S schematic