The Linear Solution Reference 1 Linear Power Supply: Viable Alternative to a Paul Hynes SR7?

[auricgoldfinger]

Background

 

If you are reading this review, then you probably already appreciate the key role that power plays in the sound quality of an audio system.  I own or have owned a JS-2, two LPS-1, two LPS-1.2, and two sPS-500.  I have also heard the benefit of a double regulated SR7 powering my OCX-10 master clock. 

 

With one exception, all of my DC cables are Audio Sensibility Signature Silver DC cables.  The Audio Sensibility cables are made from cryogenically treated Neotech twisted pair 16 AWG solid core silver wire and terminated with cryogenically treated Oyaide connectors.  The exception is a Linear Solution DC cable made from Neotech twisted pair 16 AWG solid core silver wire and terminated with Oyaide connectors.  I have not had time to compare the Audio Sensibility and Linear Solution cables.

 

Earlier this year, I decided to start migrating to double regulated power supplies for their superior performance.  The obvious solution was to buy a second Paul Hynes SR7.  However, from my perspective, the SR7 is no longer a practical alternative.  I am now in the 14th month of waiting for my first order, and there is still no hint of a delivery date.

 

One day, while looking at The Linear Solution website, I noticed that the LPS-912 power supply specifications were remarkably similar to those of the SR7.  Was Adrian using the same transformer as Paul Hynes?  Were these numbers even real?  I knew some trusted sources had found the power supply that shipped with his OXCO switch to be lacking.  Was Adrian capable of building a power supply equivalent to a double regulated SR7?  I decided to find out.

 

I had numerous exchanges with Adrian discussing my objectives and expectations while doing my best to assess his ability to build a power supply meeting his published specifications.  Ultimately, I decided to take a chance and placed an order.

 

Once Adrian began work, I found his commitment to be exceptional.  He went through several design iterations until he was completely satisfied with the sound quality.  One of his key goals was to create a circuit that worked equally well for both digital and analog devices.  He delivered the power supplies only after he felt that they met his objectives and designated them as Reference 1.

 

I took delivery 5 months after placing my order.  The final build is as follows:

 

Single rail 12v/6A with dual regulators

Cryogenically treated transformer

Class A circuit

Parallel super diodes

Quad rectifier diodes

Neotech 16 AWG stranded silver internal wiring

Mundorf capacitors

Furutech FI-06 NCF IEC

Ground post

Black case

Dimensions - L: 16”  W: 12”  H: 4” (ground post adds another 1.75” to overall length)

 

As you can see from the photos, there is a large heat sink attached to the case.  Consequently, it is always cool to the touch.

 

 

 

 

Impressions

 

Back in August, I had the opportunity to meet with @austinpop and @limniscate for a master clock comparison.  One protocol was to determine the best power supply for my modified OCX-10.  Listening to The Chain by Fleetwood Mac (96-24 version) on Eric’s Magnepan 3.7i speakers with dual Rythmik F12G subs, we compared the JS-2 and SR7.  The SR7 was unanimously declared the clear winner.

 

I am very familiar with The Chain, but with the SR7 powering the OCX-10, I heard elements of the music that I never knew existed.  When I returned home, I was naturally disappointed to find my JS-2 powered OCX10 was unable to reproduce virtually all of those elements through my HE1000 v2 headphones.

 

After the Reference 1 was burned in for a few days, one of the first songs I played was The Chain.  Now, I can hear all of the missing elements just as I remember them on Eric’s system.  Am I claiming that my headphones now sound like Eric’s speakers?  Certainly not.  I am simply saying that to the best of my memory, the previously missing musical elements are now all present just as I heard them in August.

 

More generally, detail and dynamics are enhanced, with a better sense of space and image separation.  The bass is tighter and more well-defined, extends deeper, and sounds more natural overall.  The texture of instruments and voices is richer and more complex.  For example, I have been enjoying and appreciating the vocalizations of Mark Knopfler and Robert Plant more so than in the past.  It is as if the microphone feed goes directly to my headphones. 

 

Overall, the music has more energy and is more palpable.  Limehouse Blues from Jazz at the Pawnshop (192-24 version) has always sounded dynamic and lifelike on my system, but now I seem to be present in the room, a mere 15 feet in front of the musicians, and surrounded by others in the audience.  I also have experienced Jimmy Page’s guitar in a new way.  There are now times when I can feel the speed and energy emanating from it.

 

I have made a few tweaks that have yielded varying results.  First, I connected the ground post to my Synergistic Research ground block via a Synergistic Research HD grounding cable.  Grounding the Reference 1 in this way had a surprisingly noticeable and positive effect.  The primary enhancement was to further extend the bass with even better definition.

 

Second, I replaced the stock fuse with an Audio Magic ultimate beeswax SHD fuse.  I could hear a small improvement, but I believe Adrian did a good job of selecting a fuse.  I would recommend first applying those funds to a better power cable.

 

Finally, I replaced my Audio Sensibility statement power cable with a Synergistic Research UEF blue high current 10 AWG power cable.  This cable had a dramatic effect in terms of lowering the noise floor while improving the soundstage and dynamics.  I highly recommend it.

 

At some point, I will compare a Synergistic Research blue quantum fuse to the Audio Magic fuse.  The blue quantum fuse produced a startling improvement in sound quality with my Auralic Vega DAC.  I will also place some EMI paper on the inside of the case.  Adrian has endorsed EMI paper as long as it is applied in moderation.

 

In conclusion, the Reference 1 is an excellent product worthy of consideration by anyone who is interested in a bespoke, custom linear power supply as a means of extracting the best performance from their audio system.  It is clearly head and shoulders above all of the other power supplies that I have owned.  Until I am able to hear one side-by-side with an SR7, there is no way to conclusively state that they are truly equal.  Hopefully, @austinpop, @limniscate, and I can find a time and place to perform such a comparison.

 

For perspective, my chain at the time of these listening impressions can be described as follows:

 

FMC > switch > sMS-200ultra > tX-USBultra > DAVE > HE1000 v2

 

The OCX10 re-clocks the sMS and tX, which in turn re-clock the switch and both FMCs.  (The FMCs and switch were modified by SOtM.)  The OCX10 and tX are each powered by a Reference 1, the sMS and switch are each powered by an LPS-1.2, and the downstream FMC is powered by a JS-2 rail.  I utilize a Synergistic Research ground block and HD cables to ground various components and cables, as well as a Gutwire HD cable to ground the DAVE.

[auricgoldfinger]

2 minutes ago, Johnseye said:

Nice review.  How much was it?  Does Adrian have a breakdown of cost per custom component?

 

Thanks!  I'd rather not publish an exact price, but the cost is comparable to an SR7.  Adrian hasn't updated his website to show the Reference 1 even exists, so you would have to contact him directly to discuss options and pricing.  He can give you cost per component.

[auricgoldfinger]

3 hours ago, taipan254 said:

Thanks for the review! Does Adrian have detailed specs on the power supply? Is the regulation discrete or does he use LDOs?  

 

It would be best to ask Adrian.  I'm really not able to answer your questions.

[auricgoldfinger]

5 hours ago, Forehaven said:

I was getting excited until I saw the price is similar to the SR7.

 

I think it's roughly $200 less than an SR7DRXL, if that makes a difference.  Still very expensive no matter how you slice it.

[auricgoldfinger]

My impressions weren't detailed enough for you lol?  Seriously, I haven't gotten around to applying the EMI absorber or comparing the Audio Magic and Synergistic fuses.  ?

 

Nothing is currently in the works for a comparison to the SR7. 

 

 

[auricgoldfinger]

@limniscate recently brought his dual rail, double-regulated SR7 to Houston for a Boxing Day shoot out with my two single rail, double-regulated Reference 1 units.  We were both hoping that the Reference 1 would be a true equal of the SR7; however, the SR7 reigns supreme.

 

I am using one Reference 1 to power my OCX10 master clock and the second to power an AL NUC endpoint.  Initially, we focused on the OCX10.  When I substituted the SR7 for the Reference 1, the improvement was immediately obvious to both Eric and me.  We confirmed by switching them out a second time.  The SR7 has a blacker background with better dynamics.  Individual sounds and instruments are more separate and distinct from one another, so there is more space between them.  Edges are sharper and more focused.  They sound fuzzier with the Reference 1.

 

Next, we left one rail of the SR7 powering the OCX10 and focused on the NUC.  Once again, the difference was easily discernible.  The sound was cleaner and clearer.

 

Finally, we left one rail of the SR7 powering the OCX10, returned the Reference 1 to the NUC, and used the second SR7 rail to power the Hugo M-Scaler.  The improvement we heard over the stock HMS power supply was much more subtle than with the OCX10 and NUC.  To my ears, the change was so minimal that I feel no need to upgrade the stock HMS power supply.

 

The HMS finding was surprising to me.  A couple of HMS owners whose ears I trust heard a notable improvement from upgrading the power supply, while others whom I do not know have heard no difference.  Thus, I was biased toward hearing a benefit and confounded to hear so little change. 

 

I ground a BNC input on the HMS to my SR ground block.  I also ground both of the Habst BNC digital interconnects between the HMS and DAVE to the ground block.  Perhaps the reason for hearing so little improvement is the “noise” from the HMS stock power supply is being shunted to ground.

 

In conclusion, in my estimation, the Reference 1 achieves 85-90% of the performance of a DR SR7.  Immediately after removing the SR7 from my system, I was still able to listen to music with the Reference 1 without experiencing any buyer's remorse.  It is an outstanding power supply, and my system sounds amazing with it.  The SR7 is clearly more refined, but the gap is not so large that I feel my listening experience is diminished.

 

For those who may be contemplating their next steps, I offer the following perspective.  I have been waiting almost 15 months for an SR7 that was supposed to be built in 50-60 working days.  At this point, I'll be happy to have it by the 24 month anniversary of my original order date.  There is the obvious financial risk due to the indefinite delays, plus there is the opportunity cost of putting a key part of your audio system on hold for 1-2 years.  I believe there is a strong argument for getting the best PSU that you can find and enjoying it now rather than waiting years for the Holy Grail which conceivably could never arrive on your doorstep.

 

Addendum:

 

Subsequently, I added EMI absorber on the inside cover above the transformer.  The midrange and treble are now noticeably cleaner.  For the first time, I can clearly make out John Bonham’s spoken words on the introduction of The Ocean by Led Zeppelin.  On other tracks, the tambourine zills sound crisper and more distinct.  I am now comfortable stating that the Reference 1 achieves 90% of the performance of the SR7.  The most obvious remaining differences are in dynamics and bass.

 

 

[auricgoldfinger]

7 minutes ago, LTG2010 said:

I believe it has mundorf caps ? These I have been advised take three months to burn in and start performing in terms of dynamics and bass power. So hopefully it will improve further.

The other point is that its 6 amps vs 10 amps? SR7 the larger transformer will IMO always have an edge in dynamics, but 90% is great, I don't think I would stress waiting so many months for 10%.

 

I haven't noticed any recent change in SQ.  They have been running 24/7 for 2-3 months now, but I'll keep my fingers crossed for further improvement.  🤞

 

[auricgoldfinger]

1 hour ago, elan120 said:

Are these test done with Reference 1 stock stranded silver DC cables? 

 

Yes

[auricgoldfinger]

The SR7 used one of Paul's silver DC cables which has a Switchcraft DC connector on the equipment end and an Oyaide 5.5mm x 2.1mm on the device end.  @limniscate  Do you recall which flavor of DC cable you bought?  Paul offers several.

[auricgoldfinger]

1 hour ago, TheAttorney said:

 

What EMI absorber did you use?

I'm thinking of doing the same for my SR7 - there's no reason why it couldn't also benefit.

 

I'd also be interested to hear how you got on with your fuse upgrades. I got an interesting result when adding an SR Blue to my SR7 - more of that later in the SR7 thread.

 

I used this one:  https://www.digikey.com/product-detail/en/3m/AB5100SHF-210X297/3M155949-ND/5823559  The key is to use it sparingly.  Too much and you won't be happy with the result.

 

I used the Audio Magic Beeswax SHD fuse for a long time.  Eventually, I decided the sound was too soft, so I substituted an SR blue fuse that I had on hand.  I let it burn in for an hour, and I knew immediately that it was my preferred fuse.  Whenever a blue fuse has worked in one of my components, I have noticed improved dynamics and greater focus in the music.  It sounds as if the AC power is cleaner.

 

The wonderful thing about the SR blue fuses is the 30-day return policy.  The primary risk in trying one is the return shipping cost.

 

I'm looking forward to hearing about your results with the SR7.

 

[auricgoldfinger]

Just to be clear, we're talking about my experience with the Reference 1.  I didn't take a photo, but I placed the EMI absorber directly above the transformer.  It extends about an inch beyond the perimeter of the transformer. 

[auricgoldfinger]

20 minutes ago, str-1 said:

I was thinking of trying some of this paper with my Zenith SE and SR4, and eventually also the SR7 I hope to get at some point this year.  Do you have any tips on how to approach finding tne right amount of paper to use and where to try it?

 

I try to place the paper in the areas where I would imagine EMI emissions are greatest.  For the power supplies, start by placing some above the mains transformer.  If the diameter of the transformer is 3", maybe use a 4" piece of absorber.  For the Zenith, I suggest you begin by placing some above the microprocessor.  I'm not sure what would be the next best candidate on the motherboard or elsewhere (such as the SSD, etc.).  You could also consider placing some near the internal power supply. 

 

It's really all about experimentation, but as I mentioned above, you want to err on the side of too little rather than too much.  I put an entire sheet of thin paper inside my former DAC, and it was overkill.  I had to remove most of it.

 

If you happen to have an EMF field tester, you could try moving it around inside the case and see what you find.

[auricgoldfinger]

7 hours ago, Superdad said:

 

Given that the 3M material absorbs emmisions mainly up in the GHz range, putting it around an AC mains transformer won’t do a darn thing.  Sorry. 

 

I was hoping someone knowledgeable would chime in.  🙂

 

Fortunately, the size and location of the EMI paper inside the case is still able to a make a difference by absorbing emissions from other parts.

[auricgoldfinger]

3 hours ago, str-1 said:

In what range does an AC mains transformer generate emissions?  Are there consumer products suitable for placing inside audio devices, power supplies etc that would deal with that without impacting negatively on sound quality? 

 

Maybe other EMI paper absorb different frequencies?  If @Superdad responds to your question, we can look into it.

[auricgoldfinger]

Given the lack of response,  there must be some doubt regarding the statement on transformer emissions.

[auricgoldfinger]

You can find the actual data here on page 2:  http://multimedia.3m.com/mws/media/960849O/3mtm-emi-absorber-ab5000-series-tds.pdf

 

My observation is that this EMI absorber has been used successfully by others here on CA in various audio components, including at least one SR7.  So, the perceived improvement in SQ is either an example of mass delusion or yet another example of a real audio phenomenon whose mechanism is not well understood.

 

Also, IIRC, many Chord Blu Mk.II owners (as well as Rob Watts) found the most effective ferrite in reducing perceived glare operated in the 2.5GHz range.

[auricgoldfinger]

51 minutes ago, Johnseye said:

 

I use the 3M EMI absorber in my SR7 with positive effect.

 

That makes 2 confirmed users in an SR7.