Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics.

---

[ Follow Ups ] Thread: [ Display  All  Email ] [ Propeller Head Plaza ]

---

[ Alert Moderator ]

---

Re: This one's for E-Stat, Mkuller, geoffkait

Posted by morricab (S) on May 14, 2006 at 03:36:42

In Reply to: This one's for E-Stat, Mkuller, geoffkait posted by Dan Banquer on May 12, 2006 at 05:43:01:

Well you will get no argument from me regarding the use of "proper" voltage regulation...including the output, which is rarely done (yes I realize your amp does this, bravo!).

I read the context of this quote from Audiocircle and it seems that your argument was a counter to amplifierguru who claims a large, stiff power supply is unnessary if the amplification circuit is well designed. He also sees an overbuilt (his words) power supply as a crutch to bad designs. In this is the implict assumption that an overbuilt power supply does in fact improve a poor circuit designs performance. What I fail to grasp is his funny leap of logic where he thinks that what helps a poor circuit couldn't possibly help an already good design (his idea of a good design anyway). He seems to like the idea of "dynamic headroom" rather than having lower distortion and better overall control of the system within the amplifiers specified power envelope. I happen to think he is wrong and that at least from my experience with preamplifiers, proper regulation seems manadtory for consistently good sound.

"The distortion can go even higher under these circumstances because the feedback that is applied to the amp was based on a relatively stable supply voltage"

There are two ways to look at this: 1) One needs rock steady voltage when using feedback because the effect on how the feedback performs under load is sensitive to these fluctuations. It is likely non-linear, right Dan? Distortion can therfore likely rise very rapidly with relatively small voltage fluctuations.

2)An amp with good inherent linearity and that does not require negative feedback (inspite of what you think I know of some that exist) can get away with a large unregulated supply without a catastrophic drop in sound quality or variation in measurable parameters. However; why not regulate them anyway and therefore minimize fluctuations in the operating parameters thereby allowing the amp to perform optimally at all output levels. Like my friend, a well known tube amp designer who uses shunt regulation in his designs says, anything that needs to move must move freely and anything that needs to be tied down should be tied down tight (referring to the power supply operating parameters.)!

If what you are saying is true (and I have no reason to believe its not) then feedback amps are much more sensitive to power supply regulation (or lack thereof)than those without it. Maybe that is not what you meant to say but it can certainly be taken from the context of the discussion. I realize that you cannot imagine an design without feedback and that is why you don't consider such a thing worthy of comment. But rest assurred there are amps out there without feedback (other than simple degenerative feedback) that measure as good or better than your amps.

This post is made possible by the generous support of people like you and our sponsors:

Sonic Craft

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---