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ricard · 24th Feb 2020, 8:42 am

Yes, 200 volts sounds way too much, 50-ish sounds reasonable for an input valve like this.

How's the heater supply for the EF804 ? I seem to recall it has a separate DC supply, whereas the rest of the valves have conventional 6.3V AC.

The head switching/direction switching relay is a nice bit of kit, there are two conventional contacts on the top of the relay, and the heads are switched by a little screened contact package at the back of the relay, which protrudes into the bottom cavity of the machine.

As a side note, I've been wondering how an EF804 and EF86 can be alternate valves in the same socket. I seem to recall the pinouts are slightly different (something about being able to get better signal integrity in the EF804).

24th Feb 2020, 8:42 am	#187
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Grundig TK 819 Any Useful Info Yes, 200 volts sounds way too much, 50-ish sounds reasonable for an input valve like this. How's the heater supply for the EF804 ? I seem to recall it has a separate DC supply, whereas the rest of the valves have conventional 6.3V AC. The head switching/direction switching relay is a nice bit of kit, there are two conventional contacts on the top of the relay, and the heads are switched by a little screened contact package at the back of the relay, which protrudes into the bottom cavity of the machine. As a side note, I've been wondering how an EF804 and EF86 can be alternate valves in the same socket. I seem to recall the pinouts are slightly different (something about being able to get better signal integrity in the EF804).