Home Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

RE: phasing issue

Are both 6bq5 cathodes connected to ground through one 130 ohm resistor?

At 320 vdc plate to cathode and 8.8 volts bias you should have about 67ma per tube.

I don't get it.

If you're looking for 33.5ma per tube the common cathode resistor should be about 223 ohms. 15 volts / 223 ohms = 67ma.

If you look at the triode plate curves in the link below you will see that about 15 volts bias with 320 volts plate to cathode gives about 33.5ma of current per tube. 2 tubes, 2 times 33.5ma is 67ma.

2 X 33.5ma is 67ma flowing through the one cathode resistor.

Could your tubes be worn out/weak?

Have Fun and Enjoy the Music
"Still Working the Problem"

Edits: 06/29/17 06/29/17 06/29/17

This post is made possible by the generous support of people like you and our sponsors:
  Herbie's Audio Lab  

Follow Ups Full Thread
Follow Ups


Post a Message!

Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.