A little more information

The two main activities in my life: Helping the hungry in the late hours of the night and helping guitar players sound better one amp at a time.

I always try to remember that in order to do good one has to take action and actually do something.

I was born and raised in Los Angeles. I have watched the city and Southern California change for well over half a century.

I can be found on facebook at www.facebook.com/mylesr or on twitter at www.twitter.com/myles111us or on my own Guitar Amplifier Blueprinting website at www.mylesrose.com

Los Angeles Architectural History

Los Angeles Architectural History
1935 Art Deco at some of its finest: No. 168 - Griffith Observatory- (click on the photo for information)

Wednesday, October 20, 2010

Vacuum Tube Series - 5751 Tung Sol, RCA, GE

Vacuum Tube Series

I updated this to add the link to the RCA version as a second data sheet set.

This will be a continuing series on vacuum tubes and amplifiers.

Some folks do not realize that the 5751 vacuum tube produced today is little more than a 12AX7 that did not make the grade as a 12AX7. .....

The 5751 of the past was intended for rugged use in place of a 12AX7.  It was designed for use as a phase inverter (meaning the two sides of the tube were intended to be closely matched).  It is a great tone generator in any amplifier that uses a 12AX7 in a tone/gain stage where a touch less gain is desired or if one wishes to alter the ratio of front end to back end (output section) distortion.  You will generally obtain a bit more clean headroom over the use of a 12AX7.

Not a lot of physical microphonic issues with NOS versions of these tubes to say the least.  This cannot be said of new production versions.

The 5751 was a tube used by Stevie Ray Vaughn in the front end of some of his Fender amplifiers.

The link to the Tung Sol datasheet

The RCA version datasheet

The General Electric 5751 datasheet

Myles Rose is the founder of Guitar Amplifier Blueprinting which provides support services and training for touring bands and individuals as well as blueprinting services.   I offer consulting services to various amplifier designers and manufacturers.  The link www.guitaramplifierblueprinting.com has links to music industry forums which I moderate and direct email contact information.  My shop is located in the complex at www.65amps.com.  If you wish a tour of 65 Amps please feel free to contact me directly.  When I am not doing something related to music I do what I can to support the homeless of Los Angeles either directly on the streets at night or through my good friends at Union Rescue Mission.


  1. I thought the 5751 would result in less headroom than a 12AX7 tube because the former has lower gain. It takes less to push the tube to distort. I am not a tube person but this is what I was taught/told.

    Thanks for posting the topic.

  2. You have more headroom because the front end is driven to distortion later. The ratio of front end to back end distortion has changed.

  3. http://www.guitaramplifierblueprinting.com/Tube/5751WA.pdf

    On the SRV questions, Fender has produced an amp for years that was pattered after one of his amps along with the lower gain mod in the front end.

    Lots of info on the net and on my GAB website.