All signal path coupling caps were removed and replaced w/ Jentzen .022uf PIO and then by-passed with a cap we have made especially for us by Southern Capacitor. Now out of Business. You would know their caps since they are used by many manufacturers. They are yellow cylindrical or oval shaped. A good sounding polypro cap, but not in the same league as a $20.00 Paper in Oil capacitor. Southern capacitor had the market for many years. CAT, Audio Research, most of the higher end companies used their caps..
Our custom cap was made in the style of a multi-cap, designed especially for signal or critical area by-pass.
All of the "signal cable" was replaced w/ our type 1895 hook-up wire. This is the wire used in our S-X Ltd series cable assemblies. Very open, airy and transparent.
The Power supply capacitance was beefed-up and the electrolytic caps discarded and replaced w/ Solen hi-uf and by-passed again w/ our coupling capacitor. There was one Audio Professor electrolytic left in the power supply. I'm not sure why, but my tech said it should stay, so it stayed. Apparently Audio Professor was the Black Gate of the day.
That's it for the up-grades.
The EL34's are RAM matched especially for this amp.
Tube Complement 4 x 6CA7/EL34
2 x 12AU7, 1 x 12AT7, 2 x 5AR4
Frequency Response 20Hz - 20kHz +/- 1dB (36W)
Input Impedance 100k Ohm
Signal to Noise 100dB (IHF-A weighted, Input -shorted)
Input Sensitivity 1 V RMS for full output
Output Power Stereo: 36 watts x 36 watts (8 Ohms)
Total Harmonic Distortion