Hi!OK, folks. Coming back just to update.
The regulators I need are to be used on a phono preamp, so you will need a very low noise supply.
I could simulate plenty of them, some of the best were measured by John Walton on Linear Audio.
https://linearaudio.nl/sites/linearaudio.net/files/v4 jdw.pdf
I am working on opening another thread with the simulations I did, compared to the actual Walton results.
Now you can find the LT3045 in a small version that you can use to replace a fixed voltage 3-pin regulator. Price is reasonable.
https://pt.aliexpress.com/item/1005003282538515.html?spm=a2g0o.detail.1000013.5.37d34f8bH6JwOn&gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.291025.0&scm_id=1007.13339.291025.0&scm-url=1007.13339.291025.0&pvid=d20ab2ab-4027-4f4e-b332-f90cca465e0f&_t=gps-idcDetailBottomMoreThisSeller,scm-url:1007.13339.291025.0,pvid:d20ab2ab-4027-4f4e-b332-f90cca465e0f,tpp_buckets:668#2846#8109#1935&pdp_ext_f={"sku_id":"12000025008751691","sceneId":"3339"}&pdp_npi=2@dis!USD!25.98!12.99!!!!!@2101d1bc16709322398561672e52ba!12000025008751691!rec
These folks, who probably also designed this 3-pin adapter, sell a V+/V- power supply, at a very reasonable price.
The LT chips excel at noise and PSRR, but they are not as good as others on impedance.
I can upload the asc files from the simulations I did, if anyone is interested.
There's a new family of regulators that use 3X7 regulators existing supplies, and you add a small pcb called "denoisator" and it improves all measured figures by a large margin.
But the most reliable high end power supply still continues to be the Jung/Didden design called Super regulator. Now you can buy the two pcbs for V+/V- regulators, buy all the listed parts, easily available in Mouser, and have a state of the art PS.
Could you please share the asc files from the simulations? Have you also simulated with "denoisator"?
Yes, of course I can include my sims. Yes, I did simulate the denoisator and nonoiser, including the recent Teleru's CCS versions.
Which ones would you like to see on the Superregulator? I have tried many chips.
Perhaps for a start I could put here the comparison tables I made between several SR IC options and the Denoisators. Denoisators, particularly the original type in their latest versions looks as the cheaper and best compromise.
Shall we star with the tables? I can include Walton original comparison, and comment on the differences I found.
IIRC the 3042 is about 90dB of noise rejection but only below ~ 100kHz. You’ll want ferrites and caps to filter higher frequency noise (ie 10MHz+). Alternatively switch to a shunt (lower impedance and larger band width). Although you may still want some ferrites for high frequency.
Just a little late in responding
I am looking for PSU with ultra low noise 1µVRMS or less, very high PSRR starting from 120db and up. Output voltage regulation from 3.3V to 15-18V and output Current 0,5A-2,5A. Very low output impedance less than 20mΩ or so. Also positive and negative regulation rails. Simple and quite cheap to make would be great. Planning to use it with DAC, OPamps, tube heaters etc.
What would be the best different scheme options to achieve it?
What would be the best different scheme options to achieve it?
Well, simple and quite cheap for those three specs you demand only with the Denoiser, I think. Try the last version of the original Elvee design. You won't find any kits around, though perhaps some pcbs to add to your 3X7, as the design is an add-on to those regulators.
Why should I worry to filter noise so high in frequency?IIRC the 3042 is about 90dB of noise rejection but only below ~ 100kHz. You’ll want ferrites and caps to filter higher frequency noise (ie 10MHz+). Alternatively switch to a shunt (lower impedance and larger band width). Although you may still want some ferrites for high frequency.
Just a little late in responding
In my case - the power supply is for a ~24Mhz oscilator. Most of the series/shunts max out at 1MHz.
For such application, a 24MHz oscillator, it's more than necessary to worry about UHF. But for an audio project that can only achieve 20KHz, as theoretical human ear limits, I don't see how it may affect things. But please correct me if I'm wrong.
UFF concerns for analog audio are not necessary, me thinks.
UFF concerns for analog audio are not necessary, me thinks.
Because ultrasonic trash can beat and alias into the audio band with varying results (hisses, whine, hash).
And because a reasonable degree of >100kHz usually only costs a few bucks (unlike what we already spent for LF regulation/filtering).
This used to be less of an issue. Now every other day I read of a problem that went away when cell or wi-fi service was killed. Or junky LED room lights. Or wall-warts: I had a used good-brand wart which killed all AM reception in the house bZZxbZZxbZZX. Before I even thought to try the hi-fi I had cut its tail off and set out for recycling.
Which you can use when you assemble something, not when you buy a kit. Which is many times the case with LT3042/3045
None of them seem to have fast start-up. And the noise-wise critical Cset capacitor is class II ceramic.
The problem with not having fast start-up is that some DAC controllers reset/initialize the DAC chip immediately at startup. But some DAC chips (e.g. AK4493) require that all voltage supplies should be powered up before reset. Without fast start-up this can take several seconds.
The problem with not having fast start-up is that some DAC controllers reset/initialize the DAC chip immediately at startup. But some DAC chips (e.g. AK4493) require that all voltage supplies should be powered up before reset. Without fast start-up this can take several seconds.
Almost better going for a cough*tantalum*cough? (For large values)
There are suggestions for set cap X7R piezo noise reduction by putting two caps on opposite sides of the board but I’m not entirely convinced. As the board is still going to transmit vibrations to other ceramics.
There are caps with end plates that allow the caps the bend them to reduce noise but that’s then making a nice antenna.
I must admit I ordered some X7Rs for the set pin but I’m considering if there’s any other option. Most of the designs probably follow the datasheet suggestions of those ceramics.
There are suggestions for set cap X7R piezo noise reduction by putting two caps on opposite sides of the board but I’m not entirely convinced. As the board is still going to transmit vibrations to other ceramics.
There are caps with end plates that allow the caps the bend them to reduce noise but that’s then making a nice antenna.
I must admit I ordered some X7Rs for the set pin but I’m considering if there’s any other option. Most of the designs probably follow the datasheet suggestions of those ceramics.
OK... if you where to change them.. for what (type, value)?
Startup times are OK for me so no worries there...
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I normally have 22uF at Cset. Depending on output voltage and size I have used e.g. these:
TPSB226M020R0400
TF08A226M16APE200
TPSA226K010T0900
With 22uF at Cset lack of fast start-up may become more of a worry.
One thing to note however is that the microphony of class II ceramics at Cset is most probably not audible. I have only seen them cause increased noise with DAC Vref supply.
TPSB226M020R0400
TF08A226M16APE200
TPSA226K010T0900
With 22uF at Cset lack of fast start-up may become more of a worry.
One thing to note however is that the microphony of class II ceramics at Cset is most probably not audible. I have only seen them cause increased noise with DAC Vref supply.