The simplistic Salas low voltage shunt regulator

[HiFiNutNut]

Iko and Salas,

Thanks for the information.

I am pressing on now and am trying to order the parts. All are available except the ask170.

It can't be found in Farnell, RS Components, WES Components, 3 of the largest in Australia. I also searched Digi-Key in the U.S. and the part is still not found.

Where can I get them? Does any Aussie forum members know where to get it within Australia? I prefer to source it locally, as the shipment fee is about $9, vs anything from $35 to $70 if I get it from the U.S.

Regards,
Bill

[quanghao]

All the guys who want a DAC 5V version may refer to this. Endorsed for visual clarity and optimum Vref. The 100R in series with two leds is a trimmer.
The resistor in the CCS IRFP9240 is the 470R.[/QUOTE]

Thank Salas!
QuangHao

[Salas]

Originally Posted by HiFiNutNut

Where can I get them? Does any Aussie forum members know where to get it within Australia? I prefer to source it locally, as the shipment fee is about $9, vs anything from $35 to $70 if I get it from the U.S.
Regards,
Bill

Spencer is the man that supplies our NJFET habbit. Have $37 in your hand and he will fix ya for 100mg pure Toshiba BL. Err sorry, 100 pieces.

Spencer's thread

[Salas]

Originally Posted by quanghao

Thank Salas!
QuangHao

Can you post it 25% bigger, and with CCS IRFP9240 symbols as in the middle one? On the other two they look like Jfets and maybe someone will be questioning. Plus put the word trim in the middle 100R above 2 leds too? What Sala, means in Chinese? There is a tune by Pupils aswell. Make it Salas if you can on the scematic.

[HiFiNutNut]

Originally Posted by RCruz

Hi Bill

I apreciated your comment about the caps because due to the lack of BG I might need to use Silmic in future mods.

I experimented with Ruby ZA and ZL and find these to have extraordinary high freq responce (enhancing sounstage with and transients) but loosing bass presence.

In V1 shunt, C2 affects tone very effectively. (Here I found 680u a good compromise between bass presence and detail)

Please let us know your findings regarding the best caps here.

Regards

Ricardo

Sorry I am unable to give you an answer.

I believe that there is no way that the different good quality electrolytic capacitors would change the fundamental frequencies. They don't, or they are not capacitors. So basically, I don't think that the Elna or Panasonic caps are richer in bass while the Rubycon ZLs are lack of bass. But I confess that they do sound like what you describe, and I had the same subjective findings. I think the reason behind it is, instead of changing the fundamentals, they perhaps are unable to produce the rapid transients at higher frequencies therefore producing their distortions, possibly in a way like injecting harmonics. In psychoacoustic, we know that it is the harmonics that make us perceive instrument sound, rather than the fundamentals. I guess that the sort of good caps are those that produce "better" harmonics, such as perhaps BG or Elna Silmic, and the bad caps are those that produce "bad" harmonics. I guess the Rubycon ZL produces less harmonics except some higher frequency harmonics.

On a very clean system, the Rubycon ZL produces absolutely no less bass than the Elna, just the sound has har less distorted harmonics. So it is cleaner bass. But I agree that The Elna is less bright comparing to the Rubycon at the higher frequencies.

I hope one day people can measure these effects. Before that happens, we will continue having fun playing with capacitors, being "audiophiles", i.e. sometimes playing with magic. It is interesting that human psychic likes magic. If we take out magic from HiFi, HiFi may have less fun. I like to have that sort of fun, but realized that in order to obtain ultimate audio, I need to step out of the subjective territory, believe in no magic but science, and follow what the engineers telll me...

Have fun.

[Salas]

SY will buy you a beer.

''They don't, or they are not capacitors.''

[HiFiNutNut]

Originally Posted by HiFiNutNut

So Salas recommends using a string of LED instead of zeners above 6V. For 12-15V, if I use 8 x 3mm LED1.7 or even 4 x 3mm LED3.2, would the noise be reduced enough to ditch C2?
Regards,
Bill

Salas,

Would you please give an answer on this?

Regards,
Bill

[HiFiNutNut]

Salas,

Thanks for your great work. I like it (v1). It is so simple to implement it, given it is a shunt regulator.

Correct me if I am wrong. The same circuits / parts will work with different voltages and current demands, and only D1, R1 and R5 need to be altered to suit specific requirements, but nothing else.

I am sure the information has been given before, but considering that this is a long thread I have not had the time to read through the entire posts, would you mind giving the formula to calculate the required voltage and current, a formula of just D1, R1 and R5?

Regards,
Bill

[Salas]

Originally Posted by HiFiNutNut

Salas,

Would you please give an answer on this?

Regards,
Bill

I recommend leds in critical or perfectionistic builds, yes, but losing the capacitor presents all the Vref noise to the driver BJT for amplification, even if little. You can check in your application. For OPA627 member Marinos have found a big improvement over battery supply with the V1 shunts in older posts, even if he had the zener + cap plain vanilla.

Originally Posted by HiFiNutNut

Salas,

Thanks for your great work. I like it (v1). It is so simple to implement it, given it is a shunt regulator.

Correct me if I am wrong. The same circuits / parts will work with different voltages and current demands, and only D1, R1 and R5 need to be altered to suit specific requirements, but nothing else.

I am sure the information has been given before, but considering that this is a long thread I have not had the time to read through the entire posts, would you mind giving the formula to calculate the required voltage and current, a formula of just D1, R1 and R5?

Regards,
Bill

Forget R5 & R3, its a lift that does something transiently.

ICCS=(Vf3Leds-Vgs)/R1 Decide target current, derive needed R1.

Vref=VfD1+0.6V=Vout Can be Zener or Leds. Measure their Vf at about 6mA
add them up in two matched strings for +/- regs

[ikoflexer]

Originally Posted by HiFiNutNut

No cap is better than any cap. But then I must trust the experts who examine it with a scope and at least model it using Spice.

I'm not an expert, but the noise at the output of the regulator I measured with and without the cap across the zener. With the cap the "grass" was no longer there. Measured various cap values, and the noise was inversely proportional to the value of the cap. But I've said it before, trust your ears rather than my scope. Just because it shows on the scope it doesn't mean the sound is bad; or good.

To avoid confusion I usually say explicitly when I talk about simulation.

I also agree with you, I'd rather not have a capacitor in a circuit, but there are times that it makes sense to have it.