The simplistic Salas low voltage shunt regulator

[Tham]

Hi everyone, not much of listening the last week as I was experimenting with xover points and level matching for my FR/supertweeter speaker system. I had also changed the smoothing caps to 2 x 10,000uF KMGs and letting them to run in.

[iko]

Yes, when I compare regulators this is one of the tests I do. It's almost magical to see that wiggly trace across the screen.

What do you mean by noise output?

I should add, at the end of the day it is still your own subjective impression of the sound that will matter to you. So best will be to listen to all of the alternatives that tickle your imagination, and decide what you like.

Regarding the output impedance of simulated models, I'm not as naive as to think that we'll see any such results in reality. Hopefully someone with good measuring equipment will do a shoot out of all these regulators one day.

[jkeny]

Originally Posted by ikoflexer

What do you mean by noise output?

Iko, I meant the added or generated noise, I guess. Batteries have been shown to produce noise associated with generating current so I guess this would be what I'm wondering about but I'm thinking that it's not going to be too easy, so as you say listening is the final arbiter.

[iko]

Originally Posted by jkeny

lab results give 4 mohm

In no way I'm going to argue with professional results.

Any idea how to measure noise output?

Using the same fixture as I described above, if you don't apply a sine to the load, i.e. if the load is constant, whatever ripple you see on the output will be noise. But that gets complicated, because on most oscilloscopes the most sensitive setting is 5mV/div. At that setting, I could see no ripple on the scope using salas' v1. I use an old tube scope with 100uV/div sensitivity. But at such noise levels it's hard to say what is picked from the environment and what is dut noise. There are some interesting application notes on this subject (look up app notes by Jim Williams from Linear Technology).

It's good that you're a skeptic, you'll learn a lot this way.

Edit: btw, the only reason why I ever do these tests is to satisfy my own curiousity. I don't claim my tests are worth a penny, and definitely I'm not trying to convince anyone of anything.

[Salas]

Jkeny:

Will not the batteries add up impedance since you have to chain several of them in series to get up to about 13V for the T amp?

[jkeny]

Yes, Salas, you're correct - 4 in series (13.2) will add the impedances - 16 to 32 mOhm which could be detrimental? (BTW, these are the batteries of choice being used in the electric vehicles, GM's Volt, etc. - just thought this might be interesting info)

Iko, it's not that I'm sceptical - I believe the great results attested to here - I'm just interested how it will fair against a great battery as it's ultimate test. As Salas said, it would be impressive if it matches or surpasses some of these better (expensive) ones - Soundcheck, I believe, runs all his kit on NorthStar NSB 90 batteries internal R of 2mohm.

As I said, don't mistake my questions as anti-regulators; I'm a user of John Swenson's high voltage series regulators based on Gary Pimm's self biasing CCS and believe it offers excellent sonics.

[Salas]

I am actually much interested in comparisons with everything and subjective results. What is best goes, that is my motto. Ease of making, cost, reliability and functionality included in the mix. A member is using HV Swenson on tubes now that you mentioned, and he is experimenting with my HV simplistic as well, maybe soon he will tell us if there is any subjective gain or not comparing it.

[jkeny]

One point favouring your reg is that it scales; the Swenson is only for high voltages & doesn't scale down. A sonic comparison between them would be excellent!

[Salas]

Not directly equivalent to what you gonna make for your T-Amp, its the ring of two, resistor Vref ultra simple HV.

The simplistic LV's scaled from 10V on DC B1 to 250V on Iko's HV high bandwidth version, and from 70mA to 2.5A by now on actual builds.

[jkeny]

A member is using HV Swenson on tubes now that you mentioned, and he is experimenting with my HV simplistic as well, maybe soon he will tell us if there is any subjective gain or not comparing it

Not directly equivalent to what you gonna make for your T-Amp, its the ring of two resistor Vref ultra simple HV.

So what he's using wouldn't be a fair comparison then with the SWenson HV?

The simplistic LV's scaled from 10V on DC B1 to 250V on Iko's HV high bandwidth version, and from 70mA to 2.5A by now on actual builds.

That's quiet a range, Salas and goes to show that it doesn't rely on a particular device's performance in a limited range for it's operation - something to commend it highly!