Chapter 20

Schematics & Troubleshooting

Circuit schematics and troubleshooting guides for the Electrocompaniet amplifiers and preamplifiers, from the original 1973 Otala design through the EC production schematics, the 1982 preamplifier, and the later NRF/Special Version modifications.

Ported from Legacy/: evolution of the schematics, original 1973 schematics, the real EC schematics, 1982 preamplifier schematics, transformers, wiring & mechanical assembly, troubleshooting the amplifier, troubleshooting the preamplifier, the NRF modifications, calculations on the 25W amp, and the regulated 25W power amplifier.

Not ported: distortion_calculators.htm and SingleCalc.htm (an ActiveX distortion-calculator control — only ever worked in old IE, and the control binary itself isn’t something to carry forward) and a_strange_one.htm (linked from the old site as “a further schematic variant”, but the actual page content is just a generic “site under reconstruction” placeholder — no real schematic survives there).

One gap filled in during migration: the old site’s schematics page said “SCHEMATIC 5 is coming later” for the Special Version schematic and never delivered it, but the scanned image (ASpecial_SpecialVersion.jpg) existed unlinked in the old site’s files — it’s now included on the evolution of the schematics page.