A novel way to massively improve the SQ of computer audio streaming

[paulhynes]

Hello Hols,

 

That was a while back. I had forgotten about the two old SR9 power supplies I custom designed and built for the Trinity and 10M. I just recently allotted the designation SR9 to a design under discussion with Roy (Romaz), without realising I had already used it once before for your custom power supplies. Woops!

 

For clarity, these two SR9 power supplies were totally different to the current SR5 and SR7 type power supplies I currently provide. They used one of my older shunt regulator topologies with a back biasing current source that reduced the standing current after the 10M start-up surge. I only made two of these SR9 and they are in no way comparable to the SR5 and SR7 power supplies or my current shunt regulator circuit topologies regarding performance.

 

The following is a general statement regarding equipment comparisons and not aimed at you, Hols. For the record, over the years, I have noticed references to power supply comparisons using my power supplies. They usually state “the Paul Hynes Power supply”. Well which one? I have a very wide range of power supply options, so a vague comparison like “the Paul Hynes Power supply” is absolutely meaningless as there is no specific power supply reference. Also, many of my power supplies have had multiple performance improvements as time goes by, so older Paul Hynes power supply versions compared to current competing power supplies are once again rather meaningless. The marketing boys often use this vague statement presentation to give the impression their products are better than their competitors. If you are going to do a comparison with my power supplies (or other manufacturers products whether or not they are power supply related) make it current and specific like Roy has recently done in this thread.

 

Regards

Paul

Paul Hynes Design

[paulhynes]

Hello Greenleo,

 

I agree that the SR7 is not a piece the majority can afford. So I have designed a lower power version of the SR7 to fit into an elongated SR3 chassis and this will be designated the SR4. This is a single rail supply and the continuous current rating will be 2A with a transient current rating of 20A. The SR4 has switched outputs of 5/7/9/12V, which should cover most of the digital interface equipment power requirements and the 2A output is available at all the voltage settings as the elongated chassis allows for the extra heat dissipation at lower voltage settings.

 

A new manufacturing facility is currently in preparation here in South Uist and I expect this to start operating in September/October.

 

The SR4 is in production engineering at present and I plan to have this available “Off the Shelf”, as a standard version to replace the SR3 in small quantities initially, from September/October to coincide with the new manufacturing facility start. Price will be circa £330 (currently $421) for all countries excluding Europe where VAT (Value Added Tax) will have to be added to comply with local tax legislation. Customisation outside the range of 5/12v is possible but this will be a made to order option and additional cost may apply for this depending on the level of customisation.

 

Regards

Paul

Paul Hynes Design

 

 

[paulhynes]

Hey Guys,

 

Give me a break. You requested a custom build service to provide a bespoke product that is not generally available off the shelf and certainly, according to all reports, not available elsewhere at this high level of performance. Custom build is completely different form ordering an off the shelf item which can be shipped out as soon as the packing and paperwork is completed.

 

Firstly my products are very popular (I guess this is my fault for designing products people like) and this also guarantees there will be a queue often with long lead times. Secondly, my ordering terms do state that lead times are estimates and unforeseen circumstances can affect lead times. How many unforeseen circumstances occur in any given time frame is unpredictable and they do happen, hence the inclusion in my ordering terms. I mean you no disrespect but I have to say that if you are not able to accept such terms of ordering, please do not order products from me. In future buy something off the shelf and accept the resulting performance level you will get from such sources.

 

ElviaCaprice, you forgot to mention that when ordering you did not inform me you would be leaving for Costa Rica by a certain time and in fact it was in August when you let me know. Disregarding that lead times had drifted this was very short notice and, at the time you notified me, it would have been impossible to get the power supply ready in time for shipment to your leaving date, as others were before you in the queue. It was fortunate that one of my other customers who was not in a hurry agreed to swap lead times with you which allowed me to finish your power supply early enough in theory to ship for delivery before you left for Costa Rica. But guess what, another unforeseen circumstance arose to delay the shipment when the parcel carrier managed to loose the shipment documentation. Sorry the parcel did not arrive in time, but due to the special circumstances involved, I did make a sincere effort to try to ensure it did.

 

John Zei, I guess you are one of the lucky ones and your life runs smoothly. I made no excuses but just explained why delays were occurring. Granted my remote location does cause complications. Trips to the mainland to deal with family medical issues are at least a three-day round trip for just one appointment. If there is more than one appointment for several screening tests and this can extend trips by several days. This year both my wife and daughter have had cancer screening tests on the mainland, and I have also had a variety of health tests to ensure I am healthy enough to continue with my planned business expansion. Regarding incoming materials and outgoing products, delivery times in both directions are often extended due to the complicated transit path shipments take just to get to and from the mainland which can easily be disrupted by bad weather events that prevent ferries from sailing. As there are no electronics or machinery suppliers on the islands these have to be ordered in from the mainland or in the case of the bar cutting band saw, to replace my damaged saw, from Germany. It was unfortunate that the one I ordered was too small to allow machining of the mains transformer reinforcement plates by literally 2mm and I ended up ordering the plates from the mainland with another delay due to the suppliers lead time, which was extended due to their holidays. I tend to design with discrete electronic components because it allows me to control circuit parameters that are important for high performance. Designing with integrated circuits can be rather limiting without access to adjust the actual chip circuitry. Unfortunately, component manufacturers are dropping discrete component inventory in favour of mass market integrated circuit solutions with their attendant limitations, so I have had spend considerably more time this year sourcing components than in past years. Lead times for chassis and mains transformers have also been extended through summer. The cumulative effect of all these sourcing issues can create alterations in the customer queue depending on what has to be sourced. Your request to convert rail 1 to DR operation has also delayed lead times by the time required to build and test the additional regulator module as well as installing it in the power supply. Also spending several hours composing this post has extended lead times. People also have holidays and I am no exception. All these events all add up to extended lead times with my products.

 

It would appear that custom build is in disfavour due to the long lead times. Perhaps it is time for me to follow the path of other manufacturers and just have a few fixed products available off the shelf. No customisation, no alternative options on chassis, no adaptation for alternative applications future proofing the products, no hassle from people when things do not go according to plan. Now there is a plan.

 

Regards

Paul

[paulhynes]

I have to admit I am impressed by the tenacity of purpose displayed by CA members in searching out the highest level of performance, and I also have to say that I think your heroic efforts are having a profound effect encouraging manufacturers to raise their game. Once a topic is raised there is a concerted effort to understand the topic more fully and to put the resulting conclusions into practice.

 

For those currently investigating power supply issues here is some information you may find useful.

 

The articles I wrote for Common Ground magazine during the mid 1990s explain why separate power supplies are required for each individual stage of signal processing for the finest performance. Yes I did say each individual stage of signal processing and not each individual item of equipment. Breaking this down to its logical conclusion does require a large number of power supplies in the average system. If you have an item of equipment with say 6 signal processing stages, the requirement is 6 separate power supplies to remove any power supply cross modulation between the processing stages. Scared yet? Think how many signal processing stages there are in your system. You might also consider that separate mains power feeds back to your consumer unit would also be a must to reduce mains interaction. For most enthusiasts this is about as far back on the power system as you could go without incurring a redesign of your local power grid.

 

I originally suggested in the articles that separate transformer windings were required for each power supply to provide galvanic isolation, and this is certainly an improvement over one common master power supply for all the stages, but further work on this proved that separate mains transformers were essential to avoid core interaction artifacts.

 

The Common Ground articles were written it three parts which Chris C kindly agreed to re-publish in the CA forum a while back. For those that have not read the articles I have added the link to the first part. The three articles are reproduced in three consecutive posts so scroll down to read them all.

 

https://www.computeraudiophile.com/forums/topic/28538-the-importance-of-power-supplies-generally/?page=2&tab=comments#comment-560512

 

To answer a few questions that have popped up since I last checked this thread.

 

The SR7MR Multirail power supplies were designed as a result of customer requests for high quality multiple power rails in a single chassis rather than having separate power supplies. This also reduced the overall cost as only one chassis was used and one mains transformer core. Of course there is a compromise running up to four rails on separate windings, on one mains transformer, in one chassis, but to follow the purist path gets expensive. And, just like the quality of design and implementation of any piece of equipment is important, the quality of the power supply is also important.

 

As an example, I designed the power supplies for a system commissioned by a client of Russ Andrews in the early 1990s. Each accessible signal processing stage in the system had its own power supply back to the separate windings on mains transformers to reduce power supply inter-modulation to as low a level as we could at that time. There were no regulator chips good enough back then for use in this system so all the regulator modules were my discrete component design that was the forerunner of the SR4 and SR7 regulator circuitry. All the resistors in the system were Vishay Bulk Foil and the printed circuit boards were manufactured from Teflon board. BHC slit foils were used throughout for energy storage. This system was tri-amped and the power amplifier output stages used six1000VA mains transformers. The power amplifier voltage gain stages each had their own 500VA mains transformer, as did all the stages in the preamplifiers, vinyl record deck and the analogue stages in the DAC on the laser vision player we used as the digital source. The mains transformers were custom manufactured on oversized cores of the highest quality.

 

This system was the centre of attention at one of the HiFi News audio shows at the Penta Hotel, London, and was regarded as best sound at the show by many. HiFi Reviewer Paul Messenger brought his own personal test records for audition and described the system as being all things to all men as it provided exemplary performance with all types of music. The system filled half of the demonstration room and cost around £80,000 back in the early 1990s. I guess you could quadruple that figure to reproduce the system nowadays. Whilst there are HiFi enthusiasts able to cope with such costs they are few and far between. So we manufacturers have to work in the real world for most people and the design brief for products is to provide the best performance we can for a given level of cost.

 

The regulator circuitry and component quality used in the SR4 is the same as used in the SR7. The SR4 also uses a balanced mains isolation transformer (smaller of course due to the finite chassis size) and the same amount of energy storage as used in the HD and EHD rails. This is why the performance of the SR4 and SR7 are close. The single rail SR7 will out perform an SR7MR Multirail but the cost escalates when you start separating the supplies into single rail power supplies.

 

I am currently finishing off orders 8 and 9 ready for shipment, Order 6 was delayed due to a specification error with one of the mains transformers. I have tried to contact you via e-mail, number 6, but my e-mail keeps being rejected by the mail system. Perhaps you have an alternative e-mail we can use. I am expecting a replacement mains transformer next week and will progress this as soon as the transformer arrives.

 

I will also be starting Limniscate’s order number 10 next week.

 

Regards to all,

Paul

[paulhynes]

Imitche,

 

No need to be embarrassed. You are moving in the right direction with your power supply applications. How many signal processing stages do you have in your system? That’s the number of power supplies you are going to need.

 

One of my old customers has taken this to the extreme using one of my SR1M shunt voltage regulator modules for each stage in his system, each with its own LIPO battery as power source. He also has a lot of battery chargers. He now lives in Singapore. I hope he has a large listening room and good air conditioning to keep the room cool.

[paulhynes]

Austinpop,

 

Nice choice of music for your listening test. I have the first Proprius Jazz at the Pawnshop recording on vinyl and CD. It is one of my test records of choice for testing vinyl equipment. There is tremendous presence and dynamic scale in this recording.

 

Str-1,

 

There are several cancelled order SR7 power supplies available that may be suitable for the applications you were considering. E-mail me and I will endeavour to help if possible.

 

Regards

Paul

[paulhynes]

Hi Elvia,

 

There are AC load currents passing through the DC leads so I would suggest you treat them in the same way that you treat your signal leads. This is also why the voltage regulator circuit topology, and of course the rest of the power supply support system, are so important as the load currents are circulating around the power supply.

 

Regards

Paul

[paulhynes]

16 hours ago, ElviaCaprice said:

Paul, I have applied the JS 360 to all my DC cables consisting of Canare 4S6 star quad cable.  I have placed the SR7 MR4 as close as possible to my needed components so as to maintain the shortest length possible.  The results have been outstanding to say the least and only enhance the results of your top of the line design.   

But my thoughts are that the JS 360 is preventing any external leakage from seeping into the DC conductor.  When you say AC load currents passing through the DC leads, I would assume your talking about just this kind of external leakage?  Otherwise if that AC current is already within the DC conductor from the power supply, how would any cage such as the JS 360 prevent it?

 

Loving the SR7 MR4, thanks again.

 

Hi Elvia,

 

The AC load currents are the varying currents the equipment load draws from the power supply during signal processing. They are nothing to do with external interference leakage picked up from around the DC lead from various external sources. A cage such as the JS360 should not prevent the varying load currents in the DC lead. If it did it would disrupt the operation of the equipment. However there could be some interaction between the DC lead cores and the surrounding cage and indeed the insulation material, which could affect the AC load currents and consequently the signal processing. To what degree any interaction would affect the perceived sound quality of the sound system is dependant on many factors. Investigation requires much work and CA members are rising to the occasion admirably.

 

I am pleased you like the SR7.

 

Regards

Paul

[paulhynes]

48 minutes ago, Em2016 said:

An interesting post by Rob Watts here about linear PSU's vs SMPS. I don't know if we have any PSU experts here, other than @JohnSwenson

 

Obviously Rob couldn't have possibly inspected/measured every linear PSU on the planet but I assume he has good experience with a variety.

 

"And before anybody starts saying LPS, these devices provide no rejection from 10 MHz and above, as they do not employ RF filters- but a SMPS must employ filters, both on the OP and back to the mains.

As you know, RF noise creates noise floor modulation, as the intermodulation distortion from random RF noise is a white noise modulated by the wanted signal. This then results in noise floor modulation, and is very very audible. It accounts for the things sounding brighter and less smooth; additionally, when you reduce RF noise, things sound considerably warmer and darker, and one consequence of this is perception of tempo - more midrange gives the impression of a slower tempo, as individual instruments have much more body.

Now if somebody prefers the brighter sound from more noise floor modulation, then fine - that's their taste and preference. But it's not accurate."

 

https://www.head-fi.org/threads/chord-electronics-hugo-2-the-official-thread.831345/page-934#post-14445774

 

 

 

 

 

Actually that statement regarding LPS by Rob Watts is not entirely true but it could be applied to most of the integrated circuit voltage regulator solutions currently available.

 

Nowadays there are a few integrated circuit voltage regulators with exceptional supply line rejection, however their load current transient response is usually quite slow and the settling time after a load current transient is also usually slow and less than ideal for audio power supply use. Such voltage regulators react to fast load current changes by adding signal related noise spikes and low level ringing to the noise floor. This noise floor modulation is one of the causes of brighter sound (noise spikes) and false ambient reverberation (low level ringing) and can be high enough in level to mask the natural transient response and ambience of the musical event.

 

As Rob says, some people like the resulting bright airy sound of noise floor modulation. It is not something I can live with and I much prefer to hear the music unadulterated.

 

 

[paulhynes]

49 minutes ago, austinpop said:

 

I couldn't agree with you more, Paul.

 

But the mystery here is that Rob seems to be attributing the noise floor modulation (and resulting brightness) to LPSes - like yours - whereas most of us here have had the opposite experience. It's the SMPSes that cause the bright, fatiguing sound, and once you replace with an SR4 or SR7DR, the resulting sound is so much more relaxing, effortless, and open.

 

I don't understand this.

 

Linear power supplies are not exempt from being the cause of bright fatiguing sound. Signal processing currents in your audio equipment also flow around the power supply so anything that disrupts the current flow within the power supply is going to imprint itself on the signal is some way. Both types of power supply can have aberrations that can imprint on the current flow but the SMPS also has the added problem of dealing with the high frequencies used for timing switching. Filtering attempts can give mixed results as they often shunt noise pollution into other areas of sensitivity. Some imprints are relatively benign but others are highly fatiguing.

[paulhynes]

Hi Sunny,

 

I am afraid you are many years out of date with Gavin’s old dual rail custom built SR7 serial number 28 (18v 2A and 9v 2A). Gavin purchased this second hand from one of my old customers. If you are comparing this old SR7 to your own power supplies, and finding them equivalent in sound quality, you still have much work to do on your own power supplies.

 

Much has changed since this SR7 serial no 28 was made with the early PR3 regulator boards. The latest boards used in the SR7 (and the SR5) have several circuit improvements, some component changes to improve the audible performance plus increased energy storage capacitance and the new Turbo upgrade (substantial) as well as electronic shutdown in the event of overload or excessive temperature. Not to mention the new SR7 chassis configuration with improved thermal capacity allowing the use of two 12v 16A supply rails.

 

Regards

Paul