Register / Login
Home
AudioAsylum Trader
Tube DIY Asylum

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

For Sale Ads

FAQ / News / Events

 

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


Login to access features only available to registered Asylum Inmates.
    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

RE: Choke or CCS loaded ECC83 in phono stage?

Posted by Paul Joppa on February 6, 2025 at 07:13:13:

For a choke load, you're going to need at least 2000 henries; when Magnequest made one - I believe it was from a Freed design - it was rated >4000H at 1mA. They are now very hard to find.

But a choke will (approximately) double the plate voltage and current, which would call for adjusting the other resistors and capacitors. Plus, any choke not double-mumetal shielded against magnetic fields would likely pick up hum if used in the first stage.

The gain is set by the feedback network, not the stage gains, so current source loads would increase the feedback, not the gain.

The posted circuit appears to have voltages indicated, but the values are illegible so I can't offer much more. And the feedback network is partially cut off, so it's hard to guess the feedback-adjusted gain.