Discrete or IC regulation power supply

[smithomo]

Hi Friends,
I'm would like to ask your opinion what is the best thing between discrete devices regulation compare with regulator IC.
We know that the good power supply brings very good sound and black background. So what do you think which one best power supply for lower signal amplifier like pre amp and input stage power amplifier.

 

[AndrewT]

For low power use the Salas Shunt Reg is gaining a very good reputation.

 

[KatieandDad]

It depends on what you are trying to power with the regulator.

Voltages higher than about 25V will require discrete components - unless you use specialist ICs.

However at lower voltages the LM317/LM337 can offer very good performance, especially if augmented by a Shunt regulator.

 

[Jay]

Shunt regulator is best if you can accept high voltage dropout. Mosfet one is my favorite.

78XX IC (LM7812 etc) is a big NO NO.

LM317 is acceptable and is very useful. It is not as quiet as LM78XX but it doesn't kill the dynamics. If better regulation is needed, then add a good discrete regulator after the LM317 (shunt one). I sometimes use 2 equivalent LM317 regulators in series. For higher voltage than 25V, add another high power transistor. For higher current than 1.5A, you can parallel LM317s.

 

[MagicBox]

LM317s can be 'stacked' onto one or more zener diodes as well, the current through the zeners is that of the LM317 sense current through the voltage programming resistors. Each zener needs a decoupling cap. This allows you to reach higher regulated voltages. If you're going above aproximately 30V, you can add a 33V zener between the input and output of the LM317. This ensures that it will never see more than 33V during startup. An 1.3W zener could handle the charge spike of the small decoupling caps used in the fed circuit. It works well if you only feed the driver stage and give the output stage of a power amp its own supply.

 

[jez]

For best possible performance you can't beet a discrete regulator.

 

[discrete]

For sensitive circuits, or circuits with limited PSRR, I vote for the Salas shunt:

http://www.diyaudio.com/forums/atta...-dc-power-supplies-fft-shunt-power-supply.png

 

[smithomo]

Thanks to All, I'm actually want to have about 15-24V for pre amplifier.
I'm ever measured the ripple voltage and noise from LM317, and this one Finesse Voltage Regulator Noise! can help improve it.
Because of listen the Moon I3.3 integrated amp, it was very quiet background. Really want to know how they have done it.

So now I plan to have 2 stage regulator. LM317-->Low drop out regulator. hope it would better performance.

 

[qusp]

lm317 type regs can handle MUCH higher voltage than 30v, what they cant handle is more than 30v input to output voltage differential. you can have 200v input and 190v output without any problem. i use them at 50v daily and they hardly get warm. if you can spring for the LT version its considerably better and the lt1085/1033 an even better drop in replacement.

 

[jez]

lm317 type regs can handle MUCH higher voltage than 30v, what they cant handle is more than 30v input to output voltage differential. you can have 200v input and 190v output without any problem. i use them at 50v daily and they hardly get warm. if you can spring for the LT version its considerably better and the lt1085/1033 an even better drop in replacement.

Yep
In fact I think it's 40V in-out differential... I've used them for regulation of supplies for valved equipment!
It's a pity most of the better regulators are going out of production these days. I see the LT1033 is "not recommended for new designs".
Manufacturers seem obsessed with low standby current, high efficiency and low voltages these days, most of the requirements for high quality audio are going by the wayside