The input, drive, bias and thermal feedback arrangements differ notably from the norm. The output following a familiar and rugged pattern (output devices 125W, 100V, 40A, 200kHz, 25hFE), this form of design's dependence (and that of the suggested power supplies, below) on expensive, difficult to obtain, large value, high-voltage electrolytic capacitors led to it's falling out of favour. Apart from restricting the low frequency performance, multiplying these components increased expense and compromised reliability.
With a >396VA transformer (66Vac @ 6A) and line rises the supply voltages could exceed the output device's Vce (~10%).
