Why is there 34v on pin 1?

sweet & juicy SE amp for 1626 Darlings and the 6L6 family

Why is there 34v on pin 1?

Postby gavinhaley » Sat Apr 09, 2016 3:23 pm

On every pinout for every version of 6L6 I can find there is not connection on pin1 yet on the Clementine voltage sheet it shows 34v on pin1. The cathode voltage obviously, but why? I just ordered some metal 6L6s to give a try is the reason I am asking.
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Re: Why is there 34v on pin 1?

Postby Geek » Sun Apr 10, 2016 4:35 pm

Hi,

I don't have a PCB in front of me, but it is accepted practise to tie pins 1 and 8 together with this pinout series of tubes as some types, like the EL34, have their surressor tied to Pin1 and is usually held at cathode potential.

Cheers!
-= Gregg =-
Fine wine comes in glass bottles, not plastic sacks. Therefore the finer electrons are also found in glass bottles.
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Re: Why is there 34v on pin 1?

Postby battradio » Sun Apr 10, 2016 4:43 pm

To use an EL34 pin 1 & 8 would need to be connected together . With a metal 6L6 there would be 34 volts produced by the cathode current of the tube across the cathode resistor on pin one and the metal shell of the tube in this case .
A KT66 has an internal connection between pin 1 & 8 .
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Re: Why is there 34v on pin 1?

Postby TomMcNally » Tue Apr 12, 2016 10:51 am

Here is Shannon's note from the order / parts list / manual page on the forum:

Also note that some old 6L6s need pin 1 and pin 8 to be jumpered together, as they are not internally connected. Go ahead and add them to V2 and V3 after you solder the socket in place. It can double as a cathode bias test point clip and permits EL34s to be used
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Re: Why is there 34v on pin 1?

Postby TomMcNally » Tue May 17, 2016 6:15 pm

Here's what happens to Russian 6n3c-e tubes if you don't jump pins 1 and 8 together ... some music, some pops, some smoke, some smell, bright blue glow! Good reminder.
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