|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: Why Build a Regulated Tube Power Supply? posted by megasat16 on July 10, 2016 at 16:29:37:
Regulation in general seems to have gotten a bad reputation here but there's a lot more to the story.First, linear pass style tube regulators are big, hot, and expensive. Some circuits need two or more isolated filament windings. And in addition to all that they are not very stable. Morgan Jones has a few paragraphs on this subject and he advises to use SS for high voltage regulation. The only reason the engineers of the golden audio era didn't use MOSFETS is because they didn't exist yet! IMO, if you can't do it with an 0Bx tube due to current limitations, use a SS approach.
Next, it is generally agreed that regulation is not desirable on any power amp, be it tube or solid state. I have confirmed that myself with regulated power supplies on PP tube amp in the 40-60w watt range. I went back to good old CLC supplies with SS rectification.
Then we come to small signal circuits. These are typically class A, especially in tube circuits. Here regulation is a good thing if nothing more than to lower the ripple to virtually immeasurable levels.
While there is legitimate engineering evidence that the impedance varies across the audio band a lot of that talk is taken out of context in audio circuits. Just how audible is it with standard LM78xx and LM317/377 parts?
Case in point, I am restoring two broadcast video tape recorders made in 1980 (Ampex VPR-2). The analog video circuits go form DC to 4.2mhz. The FM circuits go from 7-10mhz. Yet this machine is chock full of 78xx regulators and the main power supply is a classic 723 design with a stack of pass transistors. And even in 1980, the Walter Jung regulation papers were alive and well.
In my early career, all broadcast video, audio and RF equipment used regulated power supplies. That includes recording studio equipment. Ditto that for test equipment across the entire electronics industry.
Audio is not high bandwidth!
And when you consider the the above examples I question the sub performance audibility of reasonable regulation circuits in line level audio circuits.
Edits: 07/12/16 07/12/16
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: Why Build a Regulated Tube Power Supply? - gusser 12:51:27 07/12/16 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
