1 ohm biasing resistor: how to connect?

[nee]

Greetings!

Considering pins 1 and 8 of the EL34s are tied, can I leave them tied and install a permanent 1ohm cathode resistor, or do I need to untie them, install the resistor to pin 1, bias, and then remove the resistor and re-tie pins 1 and 8?

Thanks!

[johnny riff]

Tie pin 1 g3(sepressor)and pin8(cathode) with 1 ohm resistor to ground.Or tie 1 ohm between test tips for easy cathode current bias check.
jr

[nee]

Thanks jr. So it's OK to leave pins 1 and 8 tied, AND have the 1 ohm to ground? It's just that at Duncan's Amps site he says to disconnect the tie and insert the 1 ohm to check the bias.

[johnny riff]

I'm no amp guru but I've done that on amps(el34)with no problems.It's safer and easier to bias IMO than the shunt bias method.Or why couldn't you ground g3 and bring the cathode to ground through the 1ohm.
Happy NewYear
JR

[nee]

Oh I think I get it now: pin 1 is unused in both EL34 and 6V6, so it's just used as a convenient spot to connect the 3 protection diodes and then take them to ground.

[Jana]

Pin 1 is used on an EL34. It is grid 3, the suppressor grid. DO NOT use that as an extra, freebie terminal. Check your data sheets.

[johnny riff]

Oh I think I get it now: pin 1 is unused in both EL34 and 6V6, so it's just used as a convenient spot to connect the 3 protection diodes and then take them to ground.

pin#1/g3 should be tied to cathode pin#8(el34)as jana said refer to tube data.then bring to ground through 1ohm.I've seen were its been(g3)tied to bias supply.in some Taylor curcuits I think.

[drz400]

If you are using a 1 ohm resistor this is not a problem, at least according to Randall Aiken to use a 1 ohm between 1 & 8 and take 1 to ground.

[nee]

Pin 1 is used on an EL34. It is grid 3, the suppressor grid. DO NOT use that as an extra, freebie terminal. Check your data sheets.

Right - I see. I was looking at a KT77 data sheet, which I assumed would be the same. Assume nothing!

[jaysg]

If you are using a 1 ohm resistor this is not a problem, at least according to Randall Aiken to use a 1 ohm between 1 & 8 and take 1 to ground.

This is what I have done.