...at what cost silence (i.e. reduced ripple)?

[sandyk]

5 minutes ago, Audiophile Neuroscience said:

 

5mV

(sorry couldn't resist)

 

I think the answer will depend on who you ask. Apart from the ways you mentioned there are very inexpensive ways to reduce ripple such as with JLH shunt regulators which I have heard and believe do make a difference. The expert is @sandyk who will likely comment soon.

Good luck Doc

 

Many members in other areas of the forum, are reporting very worthwhile improvements when using PSUs with ripple in the low MicroVolt area. For powering lower current demand devices, the LT3045 Voltage Regulators and their parallel higher current versions which have a noise level of 0.8uV (!) are getting a lot of rave reviews for their performance improvements.

 They can often be used in conjunction with PSUs like the OP mentioned.

 

Also check out the Uptone area of the forum for example.

[sandyk]

35 minutes ago, the_doc735 said:

thank you, please elaborate, I'm not an expert!

 

I don't claim to be an expert either, but well respected E.E. John Swenson has presented several well received Low Noise PSU designs that are available from Uptone.

 I suggest that you read the numerous reports in this area in the Uptone section of this forum, as well as checking the supplied performance specifications.

[sandyk]

1 hour ago, the_doc735 said:

Can't find anything in a search for seasonic Prime Ultra Titanium 650 Watt MPSU/ shunt regulators. No references found? I wouldn't have a clue regarding how to use a shunt regulator with the seasonic Prime Ultra Titanium 650 Watt MPSU. And if they are such a good idea, why didn't seasonic incorporate this into the PSU design? Cheers! 

 Shunt regulators are mainly used with DIY and Scientific applications where low noise and a highly stable voltage is needed. They add more cost and are normally used in conjunction with the main PSU to power more sensitive areas. 

 You can also use a series regulator inside a PC (room permitting) to derive a much lower noise, and isolated) +5V supply for items such as an internal SSD from the main +12V SMPS.

Attached is a photo of an inexpensive ebay regulator used for this purpose by several members.

 

https://www.radio-electronics.com/info/power-management/linear-power-supply-psu/shunt-voltage-regulator-theory-circuit.php

[sandyk]

38 minutes ago, the_doc735 said:

 R U saying that I can use the LT3045 Voltage Regulators to improve the seasonic Prime Ultra Titanium 650 Watt MPSU's performance? I can't find any like your picture? These are on ebay: https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=LT3045+Voltage+Regulator&_sacat=0&_oac=1&LH_PrefLoc=2

...these on ebay look like they need to be soldered somewhere inside SMPS (seasonic)? Not connected in line to the SSD (mine are M.2 NVMe format B.T.W./not SATA plug), also the optical drive, i2s card, and graphics card power supply cables etc? These cables consist of 4 - 8 conductors (not 2 +/-). Sounds intriguing, but I'm still puzzled regarding the connections/wiring/installation process? Many thanks for this suggestion! Could use a video tutorial right now!

 No, they can't be used directly due to only having a maximum current of .5A. They are designed mainly to replace existing Linear voltage regulators in consumer gear, and also in VERY low noise specialised applications. They do have " big brothers" (several parallel LT3045)capable of higher currents but they take up quite a bit of room due to needing relatively large heatsinks to dissipate excess heat..

 The ebay voltage regulator that I showed has only 40uV noise and could be powered from an existing larger PSU for use with low current devices such as SSDs and USB internal cards etc. It can make a small but worthwhile SQ improvement even when powering the OS SSD in a P.C.

 To use it, you would need to connect it to a +12V supply for example,) and adjust it's output to +5V using a DMM.

 A 4pin Molex to SATA PSU lead can be cut in half to connect it.

 

However , that is not possible in your case due to the type of SSD etc. that you are using.

[sandyk]

31 minutes ago, the_doc735 said:

yes I get the idea now, many thanks! However reading reviews like this: https://www.kitguru.net/components/power-supplies/stefan/seasonic-prime-750w-titanium-power-supply-review/   ....it seems hard to believe that the voltage regs. can improve on these seasonic titanium ultra's performance. That's like saying that these 'bypass' voltage regs. are superior to the ones fitted inside the seasonic itself? would the sata & molex be the 12v input and output plugs or do you need to 'tap' into a 12v wire? Cheers!

 These new LT3045 regulators when used within  their current ratings are S.O.T.A. with the lowest noise ratings normally available.

 Unlike standard voltage regulators where high frequency SMPS ripple virtually sails straight through due to their much lower bandwidth, the LT3045 has a bandwidth of over 1MHZ

 

With the ebay 40uV voltage regulator, if you use a cut in half lead as shown, it's input  plugs directly into a spare 4pin Molex connector, and it's output directly into the SATA device to be powered with +5V. You can do a little better than the LT1963 ebay regulator, but not at such a low price. If you aren't happy with the results then you won't be much out of pocket.

 

LT3045

Ultralow RMS Noise: 0.8μVRMS (10Hz to 100kHz)

nn Ultralow Spot Noise: 2nV/√Hz at 10kHz

nn Ultrahigh PSRR: 76dB at 1MHz

nn Output Current: 500mA

nn Wide Input Voltage Range: 1.8V to 20V

 

[sandyk]

2 hours ago, the_doc735 said:

many thanks, most grateful to you for staying with me on this issue! ...do you have a URL for that regulator. still can't find it? I know it's not useable with my M.2 NVMe SSD's, but their are other devices that may benefit from a voltage reg. I NOTE: There are some that are adjustable/variable voltage, and both +/-, whichever you require. Cheers!

 

 

https://www.aliexpress.com/item/Ultra-low-Noise-40uV-Adjustable-Voltage-Regulator-Module-1-25-20V-1-5-Amp/1977595044.html

[sandyk]

4 hours ago, Abtr said:

That's a big cap (1000μF) across the output. The datasheet of the LT1963 says 10μF is enough at 40μVRMS output noise. Could this large value improve transient response? The LT1963 datasheet says it is optimized for fast transient response, and also protection diodes are not required.

 

Just because the Data sheets say that protection diodes are not needed, does NOT mean they shouldn't be used.

In this suggested application, Ultra Fast transient response is not needed due to the numerous other smaller value capacitors used, and that the incoming +12V from the SMPS will already have acceptably low ripple

The main advantage that this PSU gives is the further improved isolation between the SSD and other areas via the +12V supply .

 If you want a further improvement in Input filtering when used for a +5V output with a 12V input you can also use my modified schematic, as A.C. input is not needed.  

The additional 100uF is readily mounted under the PCB and could be something like a 100uF Panasonic FC or FM.

 

In any event, several members have already used this voltage regulator to power an SSD and reported an improvement.

[sandyk]

37 minutes ago, the_doc735 said:

Great! ...many thanks! I think I'll be waiting until I can find someone who builds these power supplies! Any ideas? (LOL). Cheers!

 

...this is what I have:

 

 

 

Have you any idea how large a 650W Linear PSU would need to be ?

 

[sandyk]

2 minutes ago, the_doc735 said:

No! ...but I know the size of the HD Plex 400W LPSU

 

Putting it another way. 

Try finding room inside a PC to replace the existing SMPS with such a beast.

 Imagine the total weight too, with the extra heatsinks needed to dissipate all that additional heat when working hard.

[sandyk]

24 minutes ago, the_doc735 said:

...would the teddy LPSU considerably improve this figure?

https://www.teddypardo.com/powersupplies.html

 

You do realise that many of the PSUs on that page are only around 30W ?

[sandyk]

41 minutes ago, the_doc735 said:

no I didn't, thanks!

 

where does it say that?

 Power = Voltage x Current

The top 2 on the page are 24W and 30W. The Naim Unitiserve is 54W. The Teddy USB is only rated at 10W.(5V @ 2Amps)

 Many of the others give only the voltages .  None of them appear to be high current supplies, although some have several voltage supply rails.

[sandyk]

3 hours ago, Abtr said:

If the objective is output noise reduction, then according to the LT1963 datasheet 40uV is obtained with 10uF output capacitance; not 1000uF.

 Get real !

 I didn't design this PCB, and it has been reported to work well in practice, which is something you appear to have very little of, judging by your previous comments about fuses always being able to protect against supply rail short circuits !!

 Every device to be powered already has an Input capacitor across it's D.C. input of a value  that we have no control over.

 This means that the optimistic figures that many voltage regulator manufacturers quote is highly unlikely to be achieved in the real world unless the voltage regulator is an integral part of the original design and it's requirements for highest performance are fully taken into account.

A 100uF Panasonic FC or FM electrolytic across the input , and using the series bridge rectifier diode instead of the D.C. input terminals as I have shown, will help to reduce the amount of SMPS HF rubbish going into the voltage regulator.

 

[sandyk]

52 minutes ago, the_doc735 said:

???

 

Hi Doc

 The attached diagram from the LT1963 Data Sheet shows that a 10 x higher value Tantalum (100uF) capacitor plus extra parallel on board  low value capacitors can further improve ripple rejection at >100KHZ over just a 10uF Tantalum.

 In addition, the 3 x  1,000uF capacitors used are Rubycon YXF 35V types which have a Low ESR (100KHZ)

(Effective Series Resistance)

 

Regards

Alex

 

 

 

[sandyk]

5 hours ago, Abtr said:

How and why? There are already 3 caps at the input and reducing (HF) rubbish is what the LT1963 is supposed to do.

 The LT1963 is not only used with SMPS. The extra filtering will also reduce mains frequency related ripple before it gets into the regulator.

 You appear to be confusing noise out with the slew rate of the regulator.

 A single strand of stray wire IS sometime capable of blowing up a regulator or associated components, especially the lower powered voltage regulators. BTW, You previously stated WILL not WILL/SHOULD blow the fuse. Even Ralf11 disagreed with you there. .

5 hours ago, Abtr said:

Cout=100uF may slightly reduce HF ripple rejection but will most likely increase output noise relative to Cout=10uF.

Are you even able to fully understand Data Sheets and terminology ?

 The last paragraph of your previous reply where you also mentioned ESR  suggests otherwise.

B.TW., using a series diode with a DC supply is an old trick to further isolate sections of the PSU

 

 I have better things to do than play silly games with you ! 
 

[sandyk]

As Ralf11 agreed, a fuse does not blow instantaneously. This is especially so when the  PSU is not capable of far greater current than actually needed.

The 100uF FM  Panasonic will further reduce SMPS ripple before it gets into the regulator section, and may also help a little for other devices which may be connected from the same group of Molex 4 pin connectors in a P.C.

In addition, the forward resistance of the conducting Bridge Rectifier  diode, plus the 2  parallel 1,000uF Low ESR Rubycon YXF capacitors will also act as an additional RC filter when used with a D.C. supply as I described .

This will make life easier for the LT1963 with HF rubbish.

 

 With say a relatively low powered Stereo amplifier, (e.g. I.C. type) the use of a series diode will prevent one channel of the amplifier which may have a sustained low frequency note from also dragging down the voltage of the other channel , assuming adequate value filter capacitors are used.

 

Perhaps the Asian guy who designed this ebay Regulated PSU put a lot more thought into it than at first glance, with his choice of the YXF electrolytics and the carefully chosen values of the smaller parallel capacitors ?

 If the voltage regulator hadn't been designed for such a wide variation in Voltage output, he MAY  have further refined the ease of voltage adjustment by replacing the 330 ohms with say 120 ohms, and the 10k TRIMPOT WITH A 2kOhm 20turn type as I have done with mine ?

[sandyk]

 

I basically agree with everything Barrows has said here, but as I stated originally, this LT1963 PSU from $30 ebay can give a modest, but worthwhile improvement when powering an OS SSD for around only $30 when used in conjunction with an existing +12V SMPS supply in the computer, or further improve the power from a big Linear PSU such as the HDPlex for .areas such as an  SSD or internal USB card.. 

 

 Yes, there is far more to it than simply throwing  .8uV noise  LT3045s at the problem areas as some members are trying to do.