The photo of the underside of the EICO HF-35 amps is interesting. The modifier has converted the amps to fixed bias rather than stock cathode bias, he is using a 12ax7 for the front end instead of the EF86, he improved the amp ground connections by using a buss bar instead of chassis connections, and he is using some very old Wonder Caps for the coupling capacitors. It’s curious that he replaced the captive AC cord with an IEC socket yet he did not connect the earth tab on the IEC to the chassis. While that will work fine electrically it means he isn’t taking advantage of the safety protection afforded by a 3-wire power cord.
All in all, the amps probably sound pretty nice but those old Wonder Caps should definitely be replaced by better sounding caps. They were quite colored—-lean, bright and “plastic” sounding. If these were my amps, I would replace the Wonder Caps with some Copper V-Caps and then sit back and enjoy the music.
All in all, the amps probably sound pretty nice but those old Wonder Caps should definitely be replaced by better sounding caps. They were quite colored—-lean, bright and “plastic” sounding. If these were my amps, I would replace the Wonder Caps with some Copper V-Caps and then sit back and enjoy the music.