[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]

My assessment, between a GaN versus LPS power supply. LPS wins hands down!

[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]

You would be correct,
I did buy it used from a studio that was doing renovations.

[genjamon]

Can you remind us how many amps yours delivers?

[NXSTUDIO-DRUMMER]

Answer,
I have multiple LPS's, two of them are 8.5 amps, another has 10 amps of current.

Acopian model -A48HT850 -
48 volt, 8.5 amps

Acopian model -A24H850 -
24  volt, 8.5 amps

Acopian model- V28PT10AFHMP
28 volt, 10 amps

[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]

Based on my experiences between the various Acopian LPS's, the A24H850 is the most practical for those on a budget. Even though I obtained a remarkable deal on a 28 volt 10 amp LPS. Lot of LPS options, for people to choose from.

 


I don't advise anyone buying this one, it requires modifying the terminal block, adding a larger one on the backside. Even though I did it, it's not a turnkey configuration. It also requires adding grills to the two outer most oposing area's on chassis.
 

[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.

[genjamon]

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

[NXSTUDIO-DRUMMER]

Your Welcome!

I’ve used three Acopian models now with excellent results.
Here are the three:  A24H850, A36HT800 and A48HT850
You can find these models on Ebay used, for very reasonable prices.

They do not require modifications, but you may need to buy a cover plate for the terminal blocks, from either Acopian or make your own.

Ring terminal connectors are a good option too. Now a days, there are some really high quality ones online for sale.








The bottom of all three LPS's  have 8-32 Screw holes on bottom of chassis. They have no rubber footing support, since their used primarily for rack mounting. Here are two options, budget rubber feet, or audiophile grade sorbothane rubber feet.

https://www.amazon.com/Adjustable-Rubber-Bumper-Levelers-Thread/dp/B00WZRPL4G   

The AV3 Model
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=6421&pn=AV5

[goggle1824]

NXSTUDIO-DRUMMER,

Why have you already have sold the A24H850 ?

[NXSTUDIO-DRUMMER]

Answer, I have multiple LPS's, therefore selling it.

_______________________________________ _______________________________________ _______________________________________

Selling one of my GaN power supplies, including a upgrade Figure 8 cable.

Here is the link posted on AC's trading post.
https://www.audiocircle.com/index.php?topic=192791.0

[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.

[NXSTUDIO-DRUMMER]

I've basically completed my objective obtaining a LPS. I may experiment with other Op-amps down the road at some point. I couldn't be more pleased with taking on the project.
 
The Douk A5 class D amp really benefits connected to a preamplifier.

Having multiple pre-amp’s to switch back and forth, I’m thoroughly enjoying the different sound presentations, with the A5 / Acopian LPS combinations. Regardless of what pre-amp used with the A5, one must set the A5’s volume to maximum setting. This bypasses the budget attenuator circuit Douk incorporates on the amp.

My passive pre-amp, provides higher resolution with the ultimate transparency, basically straight wire with source material. Obviously, fewer components in the signal path, will preserve the original signal cleanly. Input impedance is very important using a passive pre-amp. With the A5 it’s not a problem though, as long as your using a DAC and music source with high output. Dynamics are not as strong compared to my tube pre-amp, but the what it lacks in a slight loss in dynamics, it more than makes up in detail, being very transparent. With out doubt more analytical, alongside a class D amp. If your speakers are on the warmer side, and efficient, this may be a nice option, for consideration.

Using my tube pre-amp, with the A5, it actively shapes the sound, adding the characteristic warmth, rich harmonics, and a smoother musical presentation. I notice a more three dimensional, holographic sound stage, with greater imaging and depth. Because of additional output voltage provided my tube pre-amp, delivers more dynamics, versus the passive pre-amp. Bright sounding speakers may be a good choice with a tube pre-amp.

Audiophile grade passive pre-amp / attenuator manufactures, typically won’t vary as much in sound signature’s, versus, tube pre-amplifier manufacturers, IMO. I definitely notice more distinguishable differences among tube designed preamplifiers. Usage of different tubes, design philosophy with active circuitry creates very differnt audible outcome among tube preamplifier manufacturers

Summed up, if one wishes to improve upon the A5 audio performance, this is an excellent additional add on, to your existing set up.

Let's put some perspective on the Acopian LPS's, if Recording studio's, NASA, DOD, Hospitals and many other big corporations are using their linear power supplies, they're obviously measuring up to a higher standard. For the price's I've paid for these units, I'm seriously impressed.

Now it's up to others to share their input, with their experiences upgrading to a LPS.

I'm Done Here!