Regulate the high voltage making better sound? (Preamp)

[9999]

Sorry about the basic question.

I heared a statement: Regulate the high voltage making better sound. (Preamp)

there is 2 questions:

1.If it's ture, why the most preamp circuits using C-R-C or C-L-C ripple filiter circuit, not regulate circuit ?

2.How does the sound different?

Thanks for your answer

[SY]

Proper regulation (note the qualifier!) can be beneficial to preamp circuits that operate at low levels and/or have mediocre power supply rejection. Unlike simple filter circuits, regulators maintain their low source impedance right down to DC and have outstanding line rejection. On the downside, doing a proper low-noise design is not always trivial.

As with everything else.... tradeoffs.

[analog_sa]

1.If it's ture, why the most preamp circuits using C-R-C or C-L-C ripple filiter circuit, not regulate circuit ?

The above is only true for diy projects; most commercial designs use regulators.

2.How does the sound different?

It's difficult enough to design a good-sounding low votage regulator

In tube preamp circuits line regulation is not very important and i doubt if low impedance is also that useful. So, traditional regulation virtues are not really required.

What is really important is low ps noise.

And low noise is easy to achieve with a passive CRC or LCL type of filter. Even if you have to use many cascaded filters. Yes, active regulation achieves the same but only by introducing NFB and even worse - solid state devices.

There is of course the old VR type of tube which is quite benign in sonic signature and even die-hard tube lovers seem to accept it.

So, how does regulation sound? It really depends upon the regulator design. Most SS regulators, even topologies which sound acceptable in SS circuits, seem to clash in sonic character with tubed circuits. They often sound sterile, overdamped, flat.

Over the years i've been searching in vain for that elusive regulator circuit, which while being cheap, light and simple to make could replace the piles of chokes and separate power supplies for each stage.

The search is still on.

[sajti]

I made some regulators for line, and phono preamp. My experience is that non feedback regulators sound better.
I prefer BJTs over mosfets as series pass device, and some additional load makes the sound better. For line amplifier with 20mA, I recommend to use resistive load (simple resistor), which results additional 20mA at least.
For very low current, simple zener regulator do the best.
Some insulator filter helps too. 10-100ohms series, and 10-47uF paralell at the output of the regulator makes the sound closer to the fully passive filtering. With this filter I found no difference between the mosfet, and bjt series pass elements.

sajti

[Zen Mod]

in any case ,for preamp (and other low(er) level stages ,only shunt type of reg is good .
gas tube , or active (with tube or SS device as shunting element ) circuit -its up to you .
gas tube is more than good enough even for phono stage .

[rdf]

Has anyone experimented with capacitive multipliers instead of true regulators?

[SY]

Yes, I have, back in the '70s. All the unreliability, expense, and complication of a good regulator but with much worse performance.

[DigitalJunkie]

I've always heard that gas VR tubes are kinda noisy,and shouldn't be used in things like phono amps..although I suppose zener's are probably about as bad?
Most VR tubes also cannot have alot of capacitance in parallel with them,something on the order of 0.1uf max.

[Zen Mod]

Originally posted by DigitalJunkie
I've always heard that gas VR tubes are kinda noisy,and shouldn't be used in things like phono amps..although I suppose zener's are probably about as bad?
Most VR tubes also cannot have alot of capacitance in parallel with them,something on the order of 0.1uf max.

try it ,properly ;
then you'll know

[DigitalJunkie]

Hey ZM,

I've played with VR's in a small stereo SE power amp I built up,didn't notice any noise issues there.I havn't used them in any preamp circuits yet.

Perhaps I'm not worthy,Shall I send all my gas VR tubes to you for proper disposal?