Transcendent Sound       Vacuum Tube OTL Audio Amp Kits

Tubes And Circuits

by Bruce Rozenblit

Join Transcendent Sound’s Bruce Rozenblit as he takes you on a journey from the basics of tube circuitry, through advanced designs.  Tubes and Circuits is a condensed engineering manual that teaches the theory and operation of vacuum tubes—as well as circuit design.  In addition, five projects are included that you can build.  Projects provide step-by-step design procedures, equations, schematics, parts lists, and photos to assist the hobbyist in construction. 


●   The Son of Beast OTL:  A state of the art, very low cost OTL amplifier that outputs 15W per channel.

●   The 300B OTL:  The most glorious 1.5 watts in all of audio.  Pure single-ended, Class A sonic heaven.


      Change driver tube to 12AU7 and feedback resistor R15 to 2.2K.  Connect R15 to positive end of C5.  Connect 36V-5W zener from positive

      end of C5 to ground. 


●   A Tube Tester:  Tests virtually all current production audio and guitar amp tubes—can be user modified to test any tube.

●   A Rectifier Tube Tester:  A simple device used for testing most octal based rectifier tubes.

●   A Tube Analyzer:  Used for manually determining tube constants and bias currents. 


Chapter 1:  Basic Circuit Science:  Essential physics required to understand circuits.  

Chapter 2:  Electricity:  Explains in detail what electricity is and how it works. 

Chapter 3:  DC circuits:  Shows how current flows and behaves through resistive elements.

Chapter 4:  AC circuits.  Detailed information on AC circuit theory, reactive elements, and how they affect signals. 

Chapter 5:  Inductance:  What it is and how it is created. 

Chapter 6:  Networks:  How components are used to create networks and interact with each other— includes transformer theory.

Chapter 7:  Feedback Theory:  Shows how feedback works and how best to use it.

Chapter 8:  Vacuum Tube Construction and Chemistry:  Reveals in detail the chemical and physical processes of how vacuum tubes function, generate current, age, and deteriorate.

Chapter 9:  Vacuum Tube Fields and Function:  Shows how the electric fields inside vacuum tubes cause them to work.

Chapter 10:  Tube Characteristics:  Demonstrates what tube constants are and how to use them.  Shows how to use tube characteristic charts to derive the tube constants used in design equations.  Explains load lines and their application.

Chapter 11:  Tubes Circuits:  Detailed operation and all design equations for virtually all of the tube circuits used in high-end audio.  Includes single-ended and push-pull transformer coupled output stages. 

Chapter 12:  Power Supplies.  Basic information on power supply design and function.

All of the theory is put to use and made practical in the project chapters.  Learn how to design OTL amplifiers.       

Tubes and Circuits provides all design procedures and equations necessary to allow readers to create their own designs.  Practical methods are revealed—all built upon a solid theoretical base.  Bruce Rozenblit shares his decades of experience designing hi-end tube audio equipment.  Nothing has been held back. 

Anyone that uses vacuum tubes, the hobbyist, the musician, to the design professional, would benefit from Tubes and Circuits.


Buy it now.  Available worldwide on  Only $34.95.

268 pages.  6” by 9” format.

ISBN   978 1477532867

LCCN  2012910148