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This is John Lam. I was the founder of JE  Audio, which designed and produced high-end audio products employing solid-state and vacuum tube devices. Many of the JE Audio products were in fully balanced configuration. After my retirement from the audio industry, I have written a book in the field of analog audio amplifier design.  

The Book introduces all the fundamental principles of analog audio amplifiers, alongside practical circuit design techniques and advanced topics. Covering all the basics of amplifier operation and configuration, as well as high-end audio amplifiers, this is a comprehensive guide with design examples and exercises throughout. It will help audio enthusiasts, students and engineers to acquire skills and circuit techniques in audio amplifier design. Check out the Book web page for details.

Speaking from my own experiences, I believe the best way to learn audio amplifier design is to actually build some amplifiers yourself. These hands-on experiences together with the working principles learned from the Book will ultimately form a solid foundation to your audio amplifier designing skills.

Given with this in mind, I am now offering free PCB layout design for some selected circuits from the Book. A complete PCB layout is given in the Gerber format. What you need to do is simply sending the Gerber file to your favorite PCB company for production. All Gerber files can be downloaded for free. 

To kick off this work,  let us start with a low noise dc regulated power supply below. 

The schematic of a dual ±24V power supply is shown in Figure 1 above. This is a series type dc regulated power supply similar to the one appeared in Figure 14.28 of the Book, which is a dual ±15V version. This dc regulated power supply offers very low noise floor (10μV). It is an excellent power supply for low level amplifying applications such as phono-stage and line-stage amplifiers. The component values shown in Figure 1 are designed for dual ±24V. However, this power supply can be easily modified for output voltages from dual ±15V to ±30V. For applications that require output voltage over ±30V, the use of floating type dc regulated power supplies is recommended. For example, Figure 14.29 of the Book is for dual ±45V, and Figure 14.33 for 250V.

Two versions of PCB layout are given. The first (Rev A) requires two heat-sinks. The second (Rev B) does not require heat-sink and power transistors (Q3 and Q6) are mounted directly onto the chassis of the amplifier.