Home  |  Audio Reviews  Show Reports   Partner Mags News 


 

Enjoy the Music.com Review Magazine
Sound Practices Magazine Online!
Sound Practices Magazine Online!
Try A Screen Driven Driver Stage
Article By Rikard Berglund
From Sound Practices Issue 8, Winter 1994/1995

 

  Some output tubes (211 and 845) need a very high drive voltage with low distortion. Some tube freaks have used the 300B tube as a driver but it is very expensive. Others have tried to use a triode connected EL34 but it is not linear enough.

A pentode driven on the screen grid is very linear. I have tried this concept in a new driver stage, as shown on the accompanying schematic. The first two tubes V1 and V2 form an asymmetrical mu-follower. V3 is a screen grid driven pentode. Adjust the potentiometer R9 to 350V DC at the plate of V3. You can use many different tubes for V3.

I made distortion measurements for some different tube types with the results given in table 2. EL36 and 5881 are the two best tubes. The linearity of these two tubes in this "enhanced" mode is even better than for a 300B tube used as a driver.

The sensitivity of this driver stage is so high that it can be used direct with a CD player. Use an 100k ohm pot as volume control. Both the 400V and 700V supplies should be well filtered, maximum ripple 2mV.

You can of course use higher voltage than 700V for better linearity. The EL36 tube can withstand more than 1000V. The 6DN6 tube can also be used for very high operating voltages. Never use more than 1000V B+ supply voltage and be sure to set the anode voltage to 50% of B+ voltage. Use a separate filament supply for V2. Be careful, high voltages are dangerous!

 

 

Note: Enjoy the Music.com highly encourages our readers to buy the Sound Practices CD filled with all 16 issues in high quality format from publisher/editor Joe Roberts' eBay store by clicking here. What is below is merely a small sampling of the many great articles within the CD.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

     
Quick Links


Audiophile Review Magazine
High-End Audio Equipment Reviews

Equipment Review Archives
Turntables, Cartridges, Etc
Digital Source
Do It Yourself (DIY)
Preamplifiers
Amplifiers
Cables, Wires, Etc
Loudspeakers/ Monitors
Headphones, IEMs, Tweaks, Etc

Superior Audio Archives
Ultra High-End Audio Reviews

Videos
Enjoy the Music.TV

Columns
Editorials By Tom Lyle
Viewpoint By Roger Skoff
Viewpoint By Steven R. Rochlin
Various Think Pieces
Manufacturer Articles


Show Reports
New York Audio Show 2018 Report
Capital Audiofest 2018 Report
Copenhagen HighEnd 2018 Show Report
Australian Hi-Fi & AV Show 2018
Rocky Mountain Audio Fest RMAF 2018
CanJam 2018 Denver RMAF
KL International AV 2018 Show Report
High End Munich 2018 Show Report
AXPONA 2018 Show Report
CanJam SoCal 2018 Show Report
CanJam NYC 2018 Show Report
Click here for previous shows.

Other
Audiophile Contests
Cool Free Stuff For You
Tweaks For Your System
Vinyl Logos For LP Lovers
Lust Pages Visual Beauty

Resources And Information
Music Definitions
Hi-Fi Definitions
High-End Audio Manufacture Links

 


Daily Industry News

High-End Audio News & Information

Partner Magazines
Australian Hi-Fi Magazine
NOVO (CANADA HiFi)
hi-fi+ Magazine
HIFICRITIC
HiFi Media
Hi-Fi World
Sound Practices
VALVE Magazine

For The Press & Industry
About Us
Press Releases
Official Site Graphics

Contests & Join Our Mailing List

Our free newsletter for monthly updates & enter our contests!

Our Social Media & Video Channel
      

 

 

       

Home  |  Sitemap  |  Industry News  |  Equipment / Music Reviews  |  Press Releases  |  About Us  |  Contact Us

 

All contents copyright  1995 - 2018  Enjoy the Music.com
May not be copied or reproduced without permission.  All rights reserved.