K&K Audio / Lundahl Transformers

Welcome! Need support, you got it. Or share youe ideas and experiences.

Use this form to submit comments directly to the Asylum moderators for this forum. We're particularly interested in truly outstanding posts that might be added to our FAQs.
You may also use this form to provide feedback or to call attention to messages that may be in violation of our content rules.

You must login to use this feature.

Inmate Login

By default, logging in will set a session cookie that disappears when you close your browser. Clicking on the 'Remember my Moniker & Password' below will cause a permanent 'Login Cookie' to be set.

Moniker/Username: The Name that you picked or by default, your email. Forgot Moniker?	Examples "Rapper", "Bob W", "joe@aol.com".
Password:	Forgot Password?
	Remember my Moniker & Password ( What's this?)

If you don't have an Asylum Account, you can create one by clicking Here.

Our privacy policy can be reviewed by clicking Here.

Inmate Comments

From:
Your Email:
Subject:

Message Comments

Original Message

Help with CCS ?

Posted by MichaelM on June 6, 2012 at 05:19:57:
Hey all.

I'm currently working on a tube phono stage. It has a single power supply, and 4 KandK CCS's, feeding current to four C3G pentodes (wired as triodes).

As part of the setup, I configured all four CCS's using a 9V battery, and a 10ohm resistor, and configured each of them for 18ma. This will give the tubes about 180V on the plate, and a bias of about 2.5V (there's a 130ohm resistor on the cathode)

Once powered up, three of the tubes show "correct" values (they bias at 2.3V, and have between 165 - 180V in the plate, which I put down to tube variation).

The last tube, however, is biasing at 3V, with 220V on the plate.
I tried different tubes, but the problem didn't follow the tube.
I removed the CCS, and tried testing it with a battery and resistor, and it measured fine.

Can't think of what else to check ?