Tube dynamic range expander

[Ponmarcn]

Hello to everyone!
I like to build an expander based on tube.
Is there any scheme available?
Thanks

 

[artosalo]

Radiotron Designers Handbook 4th edition has a lot of information including schematics of volume expanders. See pages 686...693.
This book can be downloaded free.

https://www.google.fi/url?sa=t&sour...8QFnoECCAQAQ&usg=AOvVaw1ShgCvl2CdkcWaI1C1px_U