The simplistic Salas low voltage shunt regulator - Page 529 - diyAudio
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Old 4th September 2012, 07:34 AM   #5281
Salas is online now Salas  Greece
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The 0.1uF decoupler is across the Zobel effectively shorting the 1 Ohm damping higher band. The small resistor you put there is a proper move that I recommend also in difficult interfacing cases. Scope it and if still not well damped a 100uF cap across the sense out wires can be of further aid.
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Old 5th September 2012, 08:41 PM   #5282
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Reflecting back to the Reflektor when I chanced on this Kon San's account in his Japanese blog. Its about a +5V one for his DAC as attached. Google translation of the parts selection and his impressions is:

"I increased 0.47uF to 0.1uF were conventional ones Zobel circuit placed in the immediate vicinity of the IRF640 which circuit (2) shunt. I made this because there is no hand in the measures listed in Diyaudio, 1uF, but it seems really good too.

Was in 8200uF 2 of (generally from Kemi Sun) 10000uF conventional electrolytic capacitor that is connected in parallel with the semi-fixed resistor and 1KΩ 1S1588 that make up the reference voltage (3). In the LE series of Nichicon, which is similar to what is referred to as Sanyo (Panasonic) and OS configuration.

The results.
I can hear without aging, the effect is enormous. Throb feeling overflows, and listen to the live recording version of "Tannhauser" Wagner, it sounds as if the singer is singing at the position of 3 meters in front of me. Sound is clear and vivid. Descriptive power is a masterpiece majestic panorama seen the stage to take in hand. It is the impression that "sang" all anyway.

The sound is so different from what the regulator, I was nothing but surprised. I came out a sound that was really worried about it until now and can not afford lightly. No one was feeling stiff and sound before. Without having to worry about anything, just be soaked to the hilt with music. This is not a happy thing. It's enough that I think it is not necessary to make an amp anymore, no reason to make is to have disappeared, and I wonder if anything was lost, it becomes a little anxious to reverse.

It has been decided that the bug is to turn out to mess with, I would like to thank and I was able to meet the regulator in any case also a really good anyway.

Due to the small number of parts, I will work with no trouble using the MOS-FET specified, if you take even a decent pair of tiger to use a current mirror circuit.

Noise is minimal. Not only can hear the sound of the noise that it is difficult simply, it is also in the sense that I feel is very small dynamic noise that occurs incidental to the music signal. I feel a high sense of transparency that is probably to blame.

Only one point, where unlike conventional regulators is that the output voltage drift. It is probably to blame running on a different operating principle and the general negative feedback regulator. Until the output voltage becomes stable immediately after switch on, take a few minutes.

If you can only point to note, this circuit is recommended by all means."

Kon San if you are visiting here we will be happy to know more about your mod adventures with Reflektor or help you with any questions.
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Old 6th September 2012, 05:55 PM   #5283
RCruz is offline RCruz  Switzerland
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Quote:
Originally Posted by Salas View Post

"I increased 0.47uF to 0.1uF ......*

Was in 8200uF 2 of (generally from Kemi Sun) 10000uF conventional electrolytic capacitor that is connected in parallel with the semi-fixed resistor..... **

If you can only point to note, this circuit is recommended by all means."

Kon San if you are visiting here we will be happy to know more about your mod adventures with Reflektor or help you with any questions.
* So he found 047uF a better choice for the output zobel (my choice too)
** Does he use 2 x 8200uF (16400uF) for vref ? I did not go so far but found that the reflektor is uF ungry in the vref area also

PS: Kon San... please visit here and let us know your opinion.
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Old 6th September 2012, 06:10 PM   #5284
RCruz is offline RCruz  Switzerland
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Also found that to be true: "1) to 3 ohms resistance provided for entire current constant current circuits from conventional 5.2, increasing the current.
This is already listed in the Diyaudio measures, and the reported system began singing in the increase of the current. "

"Without worrying about anything, just soaked and immerse yourself in music."
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Old 7th September 2012, 01:35 AM   #5285
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You could use a simple Cmultiplier in place of those 2 x 8200uF caps - not sure what effect they would have, but simple to try ...

... another 2 cents!
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Old 7th September 2012, 07:59 AM   #5286
Salas is online now Salas  Greece
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There is a contradiction in text to Kon's schema showing 2x 820uF in parallel, not 2x 8200uF which would be really big. If true it could take some time until they come up to target Vout with 4mA available from the mirror.
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Old 7th September 2012, 08:12 AM   #5287
Salas is online now Salas  Greece
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Ta da! Mystery solved, found the Nichicon LE datasheet. Those are a solid Alu series in low voltage that don't come bigger than 1500uF. Not bigger than 820uF at 6.3V J code type anyway. So its 2x 820uF as in Kon's schema, the text has a typo.
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Old 7th September 2012, 02:05 PM   #5288
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Thanks Salas, is there a negative version of the Reflektor?
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Old 7th September 2012, 02:25 PM   #5289
Salas is online now Salas  Greece
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Yes there is. Only that was the beta test post, has some differentiated stopper resistor values, zobel values, that we experimented on subjectively later. Maybe you could follow Cruz and Kon suggestions. The input should be decoupled to ground with 0.1uF to 1uF if the rectification and filtering is wire connected and not integrated. Around the input CCS must be tight layout and add a base stopper that's missing from the original post schema. Vin must be no less than 5V higher than Vout in worse mains conditions, better have 7V or more margin.
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Old 7th September 2012, 02:36 PM   #5290
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Thanks Salas
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