Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: rdrgtr on November 21, 2010, 04:26:08 pm
-
If a person wanted to wire a tube socket to handle the most common output tubes (6l6,6v6,el34,and 6550) without changing, how would it be wired? I sometimes get confused about pins 1 and 8 and 4 (7027). A friend was telling me about an amp that is plug and play for all of these tubes.
-
Tie 1 and 8 together. Don't connect anything to pin 6.
-
7027 is -special-. It has G2 (+400V!) where other tubes have G3 (normally cathode) or Metal Shell/Base (should be at chassis ground).
Are you sure you must allow 7027? They are now uncommon.
If you must: jumper 1 and 8 with a 470K 1 Watt resistor. This will pull EL34 G3 to cathode well-enough, and keep metal bases near ground, yet allow 7027 to pull pin 1 to G2 voltage with only minor waste heat.
-
I thought that a 6l6 and a 7027 was basically the same thing? If they are the same under the glass why is it different? The 7027 is really not a consideration, I guess, for the socket wiring. I thought is was the same so I threw it on the list. So I can put a 6L6 in the place of a 7027 (altec-ampeg) but not a 7027 in a fender type amp?
-
http://www.mif.pg.gda.pl/homepages/frank/vs.html
http://tdsl.duncanamps.com/tubesearch.php
-
I thought that a 6l6 and a 7027 was basically the same thing? If they are the same under the glass why is it different? The 7027 is really not a consideration, I guess, for the socket wiring. I thought is was the same so I threw it on the list. So I can put a 6L6 in the place of a 7027 (altec-ampeg) but not a 7027 in a fender type amp?
http://www.triodeel.com/7027.htm