Tube DIY Asylum

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

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

should i change the operating point ?

Posted by DAK on April 19, 2017 at 17:56:19:
I just finished building a SEP 6L6 with 6SL7GT driver tube 5V4GA rectifier. Simple 2 stage amp ala RH schematic with plate to plate fb. The B+ is 300vdc which for the 6L6, yields a Av of 286v , G2 is 242v, and with the 226 ohm Cathode resistor idle current is 57 ma.
The 6SL7 has a B+ of 220vdc with 10K plate resistor Av is 180v and its Cathode resistor is 370R which yields a current of about 1.8ma.
I am thinking i should up the driver tube current or maybe use a LED for a slight update from 1940s technology. What do you all think? cheers. Dak