[SoCalWJS]

Finally found a Linear Power Supply for my A5, time to enjoy~

What did you get? How is it working?

[Jon L]

Definitely giving up a little bit in ultimate clarity and pinpoint imaging but the fullness and weight of images are back with the Jolida.

Nothing wrong with adding a little bit of NOS tube flavor to the signal chain of A5..

[nlitworld]

Holy opamp rolling Jon! I've read your posts comparing a bunch of them, but seeing them all on display is just cool. Definitely makes you curious on "season to taste " with some good ones. 

[Jon L]

It's all for fun.  I'm glad I found the good ol' OP2604 to work so well in the Aiyima tube preamp despite all the discrete opamps I tried.  In this hobby, one simply has to try things in the specific setup 

[NXSTUDIO-DRUMMER]

Added a linear supply to my A5, here are my initial thoughts after listening for a week.

Although, It didn’t surprise me though, here are some of the improvements thus far. 

1. Improved lower noise floor, no surprise.

2. Imaging is even better compared to the GaN power supply. The amp also operates at much cooler temperatures, no where near GaN temps.

3. Low level detail, has more blackened background

4. Tonality appears more natural as well.

5. Transient response, is quicker, enabling large reserves to be delivered on demand with high dynamic changes in source material playback.

6. Sound-stage is more expansive, also the veil is now removed delivering even better transparency.

7. Bottom end, this is where it excels, no running out of gas, versus a GaN. There is no comparison really IMO. This huge 26lb linear power supply may be overkill. I know better than to overdrive it. I probably wouldn’t suggest it for others. Perhaps a model or two lessor in power.
I’m really enjoying the combination. These subs hit harder with this LPS!  To think I only paid $35 for this linear supply to make this amp truly sing! I’m thrilled needless to say with the results, considering how little I have invested in it.

8. The amplifier's ability, improved to accurately follow both large and small changes in volume (dynamics), preserving the energy and flow of the musical performance. The pace overall is more musical and natural.

These combinations of using the new LPS and various preamps, will truly hold it’s own, compared to more expensive audio amps, on the marketplace. Giving the A5 a hybrid like quality, with a little tube flavor, leaning more towards a relaxed solid state amp feel. That is used with a tube preamp. The latter, passive amp, is more analytical and more revealing, still pleasant, with a different delivery approach.

By the way, I tried experimenting, connecting up my Reference Line Preeminence One Passive, and it held nothing back. Having so much power on demand, with the linear power supply, the combination is impressive. Without a doubt the micro-details are better compared to a tube preamplifier.

Thoroughly enjoying the different preamp combinations. The tube preamp IMO, still provides the best synergy alongside the class D amp. Make no mistaken, the Reference Line Preeminence One sounds great too with the A5, used with this larger LPS!

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Interesting observation I’m experiencing with the set up, the amp is actually running cooler listening between the levels of 75 to 85 decibels. At idol, I used to touch the amp and it would be pretty warm, now however, it’s not at all now. The linear power supply appears to be enabling the Douk audio A5 amp to run cooler. This is a huge bonus, I was worried about not having a large enough heat sink on the A5, therefore shortening the lifespan of the amp significantly from excessive heat. Linear supplies pushes most of its excess heat out of its own casing, rather than passing it on to the audio amplifier. In contrast, a GaN power supplies being highly efficient, can generate more high-frequency noise that requires filtering inside the A5, creating extra heat in the process.

I’m using the dual discrete SX52B’s Op-Amp’s. Typically dual discrete op amps run warmer than the stock 5532 op amps do. So this is another bonus for the individuals wanting to hot rod the amp with dual discrete op amps.

In summary,
This has met my objective and some, improving the Douk Audio A5 performance capability.

FINALLY FOUND A EXCELLENT LPS TO WORK IN TANDOM WITH THE A5!

I did make a power cable, haven't added the texflex yet. I'm not noticing any noise interference coming through. 






Paid $1.00 including shipping for the one meter of OCC Wire.


One could use the copper ring connectors too, staying on a budget.

[nlitworld]

So... do you have a link or some info for that LPS where to buy? You can't tease like that! Or at least specs if you built one out from an Antek toroidal  unit.

[genjamon]

His original post said he got a used Acopian unit from an IT center or something for $35. Looking at their new 48V 5A or 10A units, they go for around $1k or more. So $35 is a steal, even used. There are some similar used items out there for around $200-400 it seems. Unknown condition or reliability gives me pause, though.

[NXSTUDIO-DRUMMER]

His original post said he got a used Acopian unit from an IT center or something for $35. Looking at their new 48V 5A or 10A units, they go for around $1k or more. So $35 is a steal, even used. There are some similar used items out there for around $200-400 it seems. Unknown condition or reliability gives me pause, though.

You would be correct,
I did buy it used from a studio that was doing renovations.  I was at the right place at the right time. Normally this would sell for $775.00.
For $35.00 It truly was a bargain.
 

[genjamon]

Can you remind us how many amps yours delivers?

[NXSTUDIO-DRUMMER]

Painted all but the front black on my Acopian linear power supply. Still deciding if I'm going to paint the front or not. I'm also going to make a terminal cover plate, providing a safeguard, as well as looking little better concealing the cable and terminal block.


Time to put some Sorbothane support under the LPS.






Considering a Douk audio A5 Class D amplifier? Enjoy simple tweaks, taking this amp to another level of fidelity? Based on my experimentation, I had excellent results upgrading the following: 

Upgrading to higher quality power cords and connectors

Upgrading to dual discrete op-amp’s

Buy a linear power supply

Use with a tube preamplifier

I’ve chose to keep the amp & power supply in a separate chassis’s, keeping cost down.

Under $200 dollar invested, this truly is an excellent amp combination. 

[WGH]

His original post said he got a used Acopian unit from an IT center or something for $35. Looking at their new 48V 5A or 10A units, they go for around $1k or more.

Acopian power supplies are always available on eBay, I have bought a couple. Yes, the supplies are built like tanks and for all practical purposes will work forever. Acopian power supplies have exposed AC and DC connections and need to be tucked away from small children with forks.

First I look up the model number based on the volts and amps needed then look it up on eBay.
https://www.acopian.com/power-supply-voltages/powersuppliesbyvoltage.aspx?min=48


A 48 volt 8 amp Acopian W48MT8 is $200 including shipping on eBay.
https://www.ebay.com/sch/i.html?_nkw=acopian++W48MT8&_sacat=0&_from=R40&_trksid=p4432023.m570.l1313

A 48 volt 5 amp Acopian 48PT5 rack mount with meters is $110 - $160
https://www.ebay.com/sch/i.html?_nkw=acopian+48PT5&_sacat=0&_from=R40&_trksid=m570.l1313&_odkw=acopian++W48MT8&_osacat=0

[NXSTUDIO-DRUMMER]

Heads up comparing two, Acopian Linear Power Supplies. A 48 volt 5 amp, versus a 24 volt 8.5 amp, LPS.

If your looking at a Acopian 48PT5 LPS, take this into consideration. Comparing a A24H850 versus, a
Acopian 48PT5 LPS.

Output voltage:
While the 48PT5 has a higher voltage output, the A24H850's much higher current capacity is the more important factor for musical peaks. Dynamic power for these transient events is more dependent on the instantaneous delivery of current than on voltage. The A24H850
can deliver more than 1.5 times the current of the 48PT5.

Analogy: The "bucket" of current
Think of the power supply as a water bucket (capacitor bank) for your amplifier.

• The A24H850 is a large bucket with a wide spigot (higher current). It can deliver a lot of water very quickly to satisfy a sudden demand.
• The 48PT5 is a smaller bucket with a narrower spigot (lower current). It can't supply as much water as quickly.
• During a musical peak, the amplifier suddenly needs a large "gulp" of current. The A24H850's greater current capacity and likely larger energy reserve enable it to provide that power burst more effectively, resulting in more dynamic headroom.

Conclusion:

The Acopian 48PT5 will only provide a marginal increase in power and thus a negligible increase in perceived loudness over the Acopian A24H850.
Wattage difference: The 48PT5 power supply provides the Douk Audio A5 with approximately 120 watts per channel, versus an estimated 100 watts per channel from the A24H850 (at 4Ω impedance).

• Loudness difference: This 20% increase in wattage equates to a loudness increase of less than 1 dB.

You should expect to hear almost no difference in loudness between these two power supplies. If you already own the A24H850, it is not worth upgrading to the 48PT5 for the purpose of getting more volume.
This A24H850 operates safely within the parameters of the specifications Douk Audio A5 specifies. What a difference in how much cooler the A5 operates, night and day difference!


Sold Acopian A24H850 Linear Power Supply
 

[genjamon]

Cool that there are other good options! Can’t tell if you’re saying one sounds better than the other, or if they both sound equivalent. Can you clarify if you hear a sound quality difference between the two?

[NXSTUDIO-DRUMMER]

Cool that there are other good options! Can’t tell if you’re saying one sounds better than the other, or if they both sound equivalent. Can you clarify if you hear a sound quality difference between the two?

They have the same sound qualities, with the exception of one having more amperage, delivering more headroom, for dynamic peaks. Other than that, both sound as I've described on a earlier thread above. Listing eight audible improvements.

Douk should seriously market a LPS for the amp, it's a no brainer. I never have to take the lid off the top, it run's that cool! Now I don't have to add heat sinks, worrying about burning up the amp either.

[genjamon]

Thanks for clarifying - awesome that it works just as well!

[NXSTUDIO-DRUMMER]

Your Welcome!

[goggle1824]

NXSTUDIO-DRUMMER,

Why have you already have sold the A24H850 ?

[NXSTUDIO-DRUMMER]

NXSTUDIO-DRUMMER,

Why have you already have sold the A24H850 ?

I have three Acopian LPS's, using them for different applications. They all happen to be compatible with my A5. However, I've decided to sell the A24H850. It is truly a perfect fit for the class D amp. Highly recommend it for anyone owning a Douk Audio A5, It's a serious upgrade.

I wasn't expecting it to sell so quickly, really wasn't pressed whatsoever to sell. I was more than willing to keep it and use for other purposes.
I'll say this, I believe in the product, by how it improves the A5 so much, I wanted someone else to benefit, enjoying what I'm experiencing too, by owning a Acopian LPS.

I can vouch personally in experience, using these four models testing them with the A5. I've used all four, and now own three.

Acopian  A48H850 Regulated Linear Power Supply, use this one responsibly, it's rated up to 404 watts! A5 is only rated up to 300 watts.
Acopian  A24H850 "                                          "
Acopian  48PT5     "                                          "
Acopian  V28PT10AFHMP REGULATED POWER SUPPLY

Note: I suggest purchasing the bottom three, they don't go beyond the capacity rating of the A5. Also worth mentioning, the 48PT5 and the 28PT10 have Galvanic Isolation incorporated in their design.

_______________________________________ _______________________________________ _______________________________________ _

Galvanic isolation is an electrical engineering technique that completely separates two functional sections of a circuit to prevent current flow between them, thereby blocking electrical noise and ground loops. Information or power can still be transferred across the barrier, but only through non-conductive means, such as magnetism, light, or electric fields.   

This technology is a significant feature in high-end audio and other sensitive electronic equipment because it purifies the signal path, which results in cleaner, more accurate sound reproduction.

How galvanic isolation benefits audiophile electronics

Breaks ground loops:
A ground loop is an unwanted current that flows through the shared ground connection of two or more pieces of electronic equipment. It is often the cause of audible humming or buzzing noise in an audio system. By providing a complete electrical separation between components, galvanic isolation breaks the path of these currents and eliminates the associated noise.

Isolates components from external noise:  Modern homes are filled with noisy appliances, lighting systems, and computers. Electrical noise from these devices can travel through the power lines and other cables, contaminating the audio signal. A galvanically isolated circuit acts as a barrier, preventing this external noise from reaching sensitive audio components.

Isolates components from external noise: In a complex audio setup, different components may have slight differences in ground potential. This can lead to transient voltage spikes that degrade performance or even damage sensitive circuits, such as digital-to-analog converters (DACs). Galvanic isolation protects delicate internal electronics from these harmful electrical events.

Ensures signal integrity: Digital signals, particularly from USB connections, can carry high-frequency electrical noise from a computer's power supply and processors. Many high-end DACs incorporate galvanic isolation on their USB input to prevent this noise from corrupting the digital audio signal before it is converted into an analog wave.

Creates a "blacker" sonic background: By eliminating a wide range of electrical interference, galvanic isolation ensures that the audio signal is heard against a "black," or silent, background. This provides a clearer soundstage, enhances the detail and dynamics of the music, and allows for more accurate reproduction of the original recording.

Methods of implementing galvanic isolation

Audiophile electronics employ several techniques to achieve galvanic isolation in both the power and signal paths.

Transformers: Signal and power transformers use magnetic coupling to transfer energy between windings without a direct electrical connection. This is a common and effective method for both power supplies and audio signal lines.

Optocouplers: Also called opto-isolators, these components transfer signals using light. An LED on one side of the barrier transmits a light signal that is received by a photosensitive transistor on the other side, completely isolating the electrical circuits.

Capacitive and magnetic isolators: Modern integrated circuits (ICs) use tiny capacitive or magnetic elements to achieve isolation in a compact form. These solutions are highly effective for high-speed digital data transfer, such as in USB or Ethernet ports.

_______________________________________ _______________________________________ _______________________________________

So which one is my favorite?

They all sound excellent, but if I had to choose in ranking. Keep in mind, these are all used models, not new. You can find good deals on Ebay, as WGH mentioned on a earlier thread posted here.

1. Acopian  V28PT10AFHMP REGULATED LINEAR POWER SUPPLY

2. Acopian A24H850, most bang for the buck! impressed for so little money

3. Acopian A48H850, ranking it lower, only because it's over the capacity of what the A5 can handle. Therefore, don't suggest others buy!

4. Acopian 48PT5

The Acopian  V28PT10AFHMP REGULATED LINEAR POWER SUPPLY, meets all the criterial perfectly to suit the A5. It has over voltage protection, volt  and amp meters. Has on/off switch, Galvanic isolation to provide even lower noise floor capability. Handles for maneuvering a 22 lb. power supply definitely helps. I like the fact it stays within Douk Audio A5's specification requirements. 28 volts, 10 amps. Delivering 280 watts. Whenever I see a manufactures spec's, I always account for fudging the numbers. Bloating them more than what they actually provide.



Listening to the 28PT10 powering up the A5, The dynamic headroom,  The synergy mates perfectly with my A5.
Purchase was just a good a deal as my A48H850.


_______________________________________ _______________________________________ _______________________________________

VERY IMPORTANT, PRIOR TO BUYING OR BUILDING A LINEAR POWER SUPPLY!
FACTOR THIS SIMPLE EQUATION, FOR PROPER COMPATIBILITY USAGE WITH THE DOUK AUDIO A

Keep in mind the magic number not to exceed on a Douk Audio A5 amp. 300 watts output maximum!
Regardless of what LPS manufacture your choose, including making you own as a DIY project.

Use this simple formula, Volts (V) x  Amps (A) = Watts (W)

For example: Acopian  V28PT10AFHMP REGULATED LINEAR POWER SUPPLY

28 Volts x 10 Amps = 280 Watts total maximum output for this particular LPS.
Approximately 6.8 % less than the 300 Watt rated maximum output Douk specifies.

I personally practice the safe route, in the event the manufacture marketed their product
specifications higher than what they actually bench test.
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Genjamon 

Thanks for addressing that very important detail. When shopping     Referring to thread by Genjamon below.

Acopian website indicates, here is a example.
https://www.acopian.com/power-supply-voltages/powersuppliesbyvoltage.aspx?min=28

[genjamon]

Just an additional note of caution that not all Acopian units are linear power supplies. Some use SMPS - even ones that have regulated outputs. A lot of the Ads will say regulated, but not mention whether it’s a linear power supply (ie, uses a transformer) or is an SMPS. As mentioned a lot of the benefit from linear power supplies is their inherent galvanic isolation through use of transformers. While SMPS often measure cleaner than linear supplies, my theory of why a lot of us still prefer linear supplies has to do with this inherent rejection of grid noise.