I took a few voltage measurements with the 6П14ПEВ (EL84M) in my Simple SE. The socket adapters make for very easy voltage checks, since the legs of the 9 pin sockets are slightly exposed above the chassis. I have a two part cathode resistor - 250 ohms in series with another 510 ohms. Tonight I jumpered out the 510, leaving only the 250 ohms.
B+ is 329 VDC. Cathode voltage is 10.9 V on one channel, and 10.8 V on the other. This works out to 13.9 watts total dissipation in the tube, which might be a little higher than I'd like. Oh well. I think it does sound better than it did the previous night, before I jumpered the cathode resistors.
Thank you for the kind words, Neon. I started out building wooden stuff with framing lumber, a circular saw, and deck screws. It looked like hell. Just keep building stuff. Take care in your work, but never worry about how it will turn out. Consider every project a learning experience to help you practice new techniques. Kinda like building amps. I think I still have a lot of room for improvement, but I'm still happy with what I can do today. Anything you build yourself will (almost) always sound better.
B+ is 329 VDC. Cathode voltage is 10.9 V on one channel, and 10.8 V on the other. This works out to 13.9 watts total dissipation in the tube, which might be a little higher than I'd like. Oh well. I think it does sound better than it did the previous night, before I jumpered the cathode resistors.
Thank you for the kind words, Neon. I started out building wooden stuff with framing lumber, a circular saw, and deck screws. It looked like hell. Just keep building stuff. Take care in your work, but never worry about how it will turn out. Consider every project a learning experience to help you practice new techniques. Kinda like building amps. I think I still have a lot of room for improvement, but I'm still happy with what I can do today. Anything you build yourself will (almost) always sound better.
Yes, too hot. Before I shut it off last night I peeked in through the plates holes. Some small sections of one of the grids was glowing slightly. Guess I need to go with a larger cathode resistor.
If you are so inclined try JJ EL84's. THey are the abuse king in my Simple P-P's. They sound good too. I run them on 350 volts of B+ with a 270 ohm cathode resistor. No plate or screen glow. They are wired in pentode with screen voltage = B+, so triode or UL should be OK.
I have another set in another Simple P-P with the screens at 320 volts and the plates at 430 volts! I get 30 watts out of a pair and still there is no glow!
I've been watching eBay for a cheap set, but haven't found them yet. I think I've got a lone JJ EL84 in my pile, but only one doesn't do me much good. Someday I'll get at least a pair, preferably a full quad.
I eased back on the cathode resistors and jumpered for 510 ohms. Cathode voltage is 13.8 volts, which gives a nice and easy 8.5 watts total dissipation. I think it might sound better than it did last night, too. I'd better be careful, or I might get used to these little tubes in my Simple SE.
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