[nlitworld]

Dudes............
Nichicon KZ for the freakin win!

Finally got around to popping these Nichicon Muse caps into the Douk. Pretty easy to wiggle these out of the old spot, suck out the solder, and wiggle the new boys into place.


Old caps all content and lazy


New caps ready to get some work done.

While I was in there, I also redid the thermal paste on the bottom. As you can see, just to the right next to the thermal transfer plate is the line of capacitors to squeeze in.



Now, these KZ caps do fit into the old pcb holes, but barely. It'll take a little wiggling and possibly a soldering iron if there's any leftover solder reminants still in the holes.


Ready to rock!

Also while I had the soldering iron hot, I popped in some Miflex 0.15 high pass caps in my preamp (between out1&out2) and they seem about the same value rolloff point as the Douk cranked but much more clarity.

So yeah, long story short get your soldering iron out and freakin go to town. Super easy mods, but SO SO SO much better. Like seriously, I'm listening to Dave Matthew's "The Gorge" and it's just amazingly huge and spacious sound. I'm here giggling to myself typing on my phone right now. 

-Lloyd

[NIGHTFALL1970]

Very cool Lloyd!😎🤟👍😊
Today I played Rush- “Subdivisions”, then popped in new SX52BS and WOW!!!🤩 Holy crap what a difference!!! Night and day! I had the volume at 47 and then had to turn it down to 40 because it was so much louder! The soundstage opened up and it sounded like a veile had been lifted. I thought that it would make a small difference at best.
Btw, how on earth did you solder those caps on? There is barely any room.

[nlitworld]

Whenever working on thru hole boards, always try to solder from underside. Easy peasy. They're the super narrow double row right next to the heat transfer plate.

I will be excited to let everything burn in for a while. I know things are only going to get smoother from here

[NXSTUDIO-DRUMMER]

My initial listening experience, with the SX52B Op-Amps:  Set up in my bedroom system 

1.  Sound stage consist of a transparent background, impressive. Texture of the instruments are clear, ever so slightly rounded, on a good note though. I find the highs aren’t shrill, nor harsh, with a nice full mid range presentation. Depth of sound stage? I wouldn’t call it a deep stage,  ever so slightly forward in presentation. Note: listening is being accessed in a smaller room environment, that has it's limitations, versus a medium to larger space.

2.  Imaging really excelled over my stock A5 NE5532 op-amps, huge improvement.

3.  On the bottom end, the bass is appealing, very responsive and detailed, with out being overly emphasized or muddy sounding.

4.  I like the fact the SX52B Op-amp delivers a well balanced frequency distribution, having a analog sound. Presenting articulation, with out being too analytical. 

To think I paid $10 including shipping, this is a no brainier people. High recommend!

I can’t currently compare to the sparkos, SS3602’s since I don’t have them on hand.
This amp, I imagine could give the sparkos a run for the money, being much cheaper too.

Note:
I was listening on a set of speakers that have dome tweeters, that are forgiving, but detailed in delivery. They also have nice midrange, and image like crazy. This first initial impressions, are with no burn in time on the op-amps. This is also set up on the pre-outs of a NAD AVR solid state receiver.

My first preference, eventually to use a tube pre-amp with the A5. This should deliver the typical, holographic sound, tube pre-amps provide. Another way to put it, they often sound more layered in the midrange. IMO, tube pre-amps can impart a desirable warmth and fullness to audio through the introduction of even-order harmonic distortion, particularly second-order harmonics. This type of distortion, unlike higher-order harmonics, is often perceived as pleasant and musical, contributing to a more "alive" or "soulful" sound quality.






------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------


Seeking to upgrade your figure 8 power cable going to your GaN power supply, this is a option to check out, for your Douk A5 amp. I took the plunge and purchased this cable. I figured for $25.12 

https://www.amazon.com/Tertullus-Audiophile-Figure-Female-3-28FT/dp/B0BDDZMJQR/ref=pd_sim_hxwPM1_sspa_dk_detail_d_sccl_3_1/131-0462536-4292765?pd_rd_w=WkDnw&content-id=amzn1.sym.3a852a98-d65f-4301-9bd0-9b589b14d1ef&pf_rd_p=3a852a98-d65f-4301-9bd0-9b589b14d1ef&pf_rd_r=BSE9FZ0KA2ZJ4902JEWM&pd_rd_wg=poXWG&pd_rd_r=1304ebbb-0249-410a-89b4-cb14cb7dc4f7&pd_rd_i=B0BDDZMJQR&th=1

[NXSTUDIO-DRUMMER]

Update,

Received my new power cable for the A5 48volt power supply. Initial impression, inner details and subtle nuances in material played, are immediately evident.
 

Listened to this song with new cable set up. Unfortunately, I can only provide a compressed version from Youtube. https://www.youtube.com/watch?v=eZiAuSwYEwk
 

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Update:

Now having some burn in time with the A5 and the New SX52B's op-amps, my impression to date, this op amp works really well with soft dome speakers. Soundstage has opened up more, being more expansive and transparent. I'm also experiencing more inner detail with more burn in time as well. With out question, this amp is superior sounding over the amp section in the NAD. In this evaluation, I'm using the NAD as a Pre-amp, FYI. Something else I'm noticing, is better distinction between the instruments, triangle, cymbals, cowbells, playing chords on the strings is more pronounced, as well as other area's within the listening source. Decay structure is better developed. Granted, if recorded material is poorly mixed and produced, no electronics can save that sinking ship.

I Imagine, anyone with Encores would be very pleased with the combination. This is using a solid state NAD-AVR receiver pre-amp section, which typically are pretty neutral in presentation. I'm playing at levels between 75-85 decibels approximately.


--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

[Solarflares]

I conducted Sade once.
It was when she stopped in her chauffeured car in 1984 to ask where the University was in Colchester, UK - where she was playing that night.
But my conducting was sharp, accurate, precise, totally commanding, and devoid of any unnecessary histrionics with arm-movements, and my performers gave me all the respect I deserved for a job well done.
They could tell I was a seasoned professional, and thanked me profusely for the experience.
I did myself proud that day.

[NXSTUDIO-DRUMMER]

I conducted Sade once.
It was when she stopped in her chauffeured car in 1984 to ask where the University was in Colchester, UK - where she was playing that night.
But my conducting was sharp, accurate, precise, totally commanding, and devoid of any unnecessary histrionics with arm-movements, and my performers gave me all the respect I deserved for a job well done.
They could tell I was a seasoned professional, and thanked me profusely for the experience.
I did myself proud that day.

Cool story, I love hearing stories from our past musical life experiences. Thanks for sharing! 

[nlitworld]

I have probably 10hrs on last weekend's modifications. Things are starting to smooth out a bit and the level of three dimensionality is freaking amazing. Running my high pass filter wired into the preamp has them really about a 160hz crossover, and running my F8 subs that high is still effortless. Took a little bit of futzing to get xo and phase right, but now it is amazing. Body to the music, clarity in spades and a nice little sparkle way up top from NXStudios being just that good. I wouldn't recommend running such a high xo unless your subs can handle it, but it's really worth trying.

Also I do like a little more body to the bass, so I have >100hz a bit elevated which keeps rising all the way down to 9hz in my room. Danny Carey kick drum does sound just awesome.

As to the mods and how those actually sound, the edge of new caps is softening and the soundstage is opening up. Everything just sounds a little more dynamic as well. I wish poly caps were an option for those coupling caps in the middle, but 10uf would be overflowing like a tractor pull racer with 4 engines... At first I claimed this was a good amp for the money. As it sits now, this is a surprisingly really nice little amp, full stop.

[Stercom]

Just added these speaker $20 extension/adapters to my A5 makes things a little less crowded back there.




https://www.ebay.com/itm/136161285499?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20250324084321%26meid%3D2cedcd407fce4b51baefa4fb57ff39fd%26pid%3D101949%26rk%3D1%26rkt%3D1%26itm%3D136161285499%26pmt%3D1%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2WithMLRPboosterAndUpdatedFeatures_BP&_trksid=p4375194.c101949.m162918&_trkparms=parentrq%3A6c640ecf1980a6b332072373fffe6654%7Cpageci%3A180f281c-6fdc-11f0-ad58-76c324469134%7Ciid%3A1%7Cvlpname%3Avlp_homepage

[Jon L]

I think that Reeti.org site is a scam. 

First, there are websites like this that just harvest listing information from legitimate online retailers and then offer at huge discounts to sucker in buyers.  Googling around, I can't find any information about Reeti as a real retailer.  And if you look at the user reviews on Amazon for the product and compare to those on the Reeti listing, they're exactly the same.  I bet Reeti just harvested product listings from Amazon for their site.

Second, based on this thread, I made a splurge purchase from Reeti of the unit.  I never received a confirmation email from them, making me suspicious, and the charge came from a Felix Sanchez Mejia rather than from Reeti - making me double suspicious.  Now, two days later, the charge was unilaterally amended by Felix to be $42 rather than the original $36.  Triple suspicious. 

I have filed a Paypal dispute over the $5.05 upcharge to create a record that this is potentially a fraudulent transaction, in case the product never comes.  I'm not holding my breath.  My biggest concern is that I'll start getting unauthorized additional charges and will have to replace my credit card or something.

I unfortunately used that link on Reeti and found out they charged on multiple other sites $0 as a test then tried to charge five figures $ on my card. 
So anyone who used that Reeti link should DEFINITELY close that credit card ASAP 

[Stercom]

I unfortunately used that link on Reeti and found out they charged on multiple other sites $0 as a test then tried to charge five figures $ on my card. 
So anyone who used that Reeti link should DEFINITELY close that credit card ASAP 

Damn that sucks.

[NXSTUDIO-DRUMMER]

That's very unfortunate, It's a shame we have so many dishonest scam artist, formulating false businesses. Thanks for reporting it . It appears were going to have to triple check these unheard of business for consideration, prior to handing out our credit cards.

[Solarflares]

I think that Reeti.org site is a scam. 
I have filed a Paypal dispute over the $5.05 upcharge to create a record that this is potentially a fraudulent transaction, in case the product never comes.  I'm not holding my breath.  My biggest concern is that I'll start getting unauthorized additional charges and will have to replace my credit card or something.

Cancel that card as lost and freeze it right now using your online banking. If not then phone the emergency helpline on the rear of your card. You’ll only wait a few days for a new card.
Cancel the whole transaction with your bank, and get them to block the seller’s account from yours.
Then start again.

[clm811]

Tried the SX52 op amps and found that OPA1656 sounded more clear in the mid-range with comparable bass response, at half the cost.
In my experience, the discrete op amps cost too much and don't contribute a proportional improvement in sound quality.
The Douk A5 is a remarkable small amplifier that performs well above its price class and is replacing a high bias class AB amp in my own system.
For under $130 total with upgraded op-amps & 36v power supply, it is hard to beat.

[NXSTUDIO-DRUMMER]

Another Dead end with LPS!

 

[Jon L]

Tried the SX52 op amps and found that OPA1656 sounded more clear in the mid-range with comparable bass response, at half the cost.
In my experience, the discrete op amps cost too much and don't contribute a proportional improvement in sound quality.
The Douk A5 is a remarkable small amplifier that performs well above its price class and is replacing a high bias class AB amp in my own system.
For under $130 total with upgraded op-amps & 36v power supply, it is hard to beat.

SX52 is probably the smoothest and least bright discrete opamp I've tried, so a modern opamp like OPA1656 can sound clearer and more immediate, all system-dependent of course.   

[NXSTUDIO-DRUMMER]

After receiving my A5's Power Supply, I determined the cabling attached to it could be improved upon. The existing cable has no shielding, and the gauge of wire is inadequate IMO. I decided it's time to upgrade the cabling. However, there is one caveat! You must disassemble the PS.
*Disclaimer:
This will void warranty on power supply. You will be responsible for your actions, in the event, you should inflict damage to your power supply.


Instructions for disassembly of a GaN power supply.
These basic principles should apply to a majority of manufacture PS. As long as their constructed in a similar way.

Step 1
Prepare a clean surface, for layout of PS. Obtain the following materials and tools. Clean cloth, rubbing alcohol, “Sharp” utility or exacto knife, hammer and a scraper or pry bar of some sort.

Step 2:
Fill a cap full of rubbing alcohol, then proceed to pour it around the entire perimeter of the seam on the PS. Wipe of excess, the focus is only at the seam  area. Let it sit for 5-10 approximately.

Step 3:
Now use the exacto or utility knife and run around the entire seam of the PS, multiple times. You may feel some area’s might of loosened up. Squeeze the PS a little, to assist in loosing up the two halves. No it won’t break loose, but the alcohol is loosening up the bond between the two halves.

Step 4:
Place the PS on a hard surface. This is where you’ll need the hammer. Proceed to tap around the entire PS. Be careful on the ends, and focus more on the long sides of PS. Use good judgment and don’t beat the hell out of the unit. After all this is a plastic casing.

Step 5:
Take the tool of choice, I used a scraper-pry bar personally. Now squeeze the long sides and see if you can manage to fit the prying tool of your choice inside the gap. Gently open up, a little at a time. Now go to another location and repeat, until you are able to move or open it up entirely. If your having difficulty with the process. Repeat Steps 2 thru 5 again. Exert patience, preventing damage to the PS.

Below, I’ve provided photo examples









Tool I used






_______________________________________ _______________________________________ _______________________________________

Viborg connectors provide a good balance of value & performance, for whoever decides to make their cables.
https://www.viborgaudio.com/

Another cheap alternative for elevating your speaker & power wires off the floor. Just cut pool noodles in pieces and slip over your cables. Polyethylene is an electrical insulator, not a conductor. Its tightly bonded molecular structure prevents the flow of electrons. Just cut to the width of your choice. As a budget experiment, you can be the judge, determining if it benefits audibly.

https://www.lowes.com/pd/Big-Joe-50-in-x-2-5-in-1-Seat-Pastel-Blue-or-Green-or-Pink-Pool-Noodle/5015570475?store=1122&cm_mmc=shp-_-c-_-prd-_-sol-_-ggl-_-CRP_SHP_LIA_SOL_Online_Mid_Priority(E+Band)-_-5015570475-_-local-_-0-_-0&gclsrc=aw.ds&gad_source=1&gad_campaignid=21087836046&gbraid=0AAAAAD2B2W8aHYBzoBZ3o8cXpVbRjOwdQ&gclid=Cj0KCQjw8KrFBhDUARIsAMvIApZBJYFKvG02qvXwwbMX0XW4mFPmDVY3yWPuHw5alWb9vMd9Pi74qzAaArX3EALw_wcB

[nlitworld]

Sounds like a fun project to upgrade the cheap thin power cord. You could also look at some VhAudio cord, or look at some stuff Sonic Craft has in stock. Interested to see what you come up with.

[NXSTUDIO-DRUMMER]

Finally found a Linear Power Supply for my A5.

Had some interaction with Douk Audio, they are very interested in hearing feedback on the differences in sound quality, using the linear power supply, versus their GaN power supplies. I told them I'll keep them posted.

I just obtained a ridiculous deal on a Acopian linear power supply for $35.00. Typically it sells for $750.00.
The local recording studio is doing some major renovations, I happened to be at the right place at the right time. It's a tank weighing in at 26lbs. I'm going to paint the chassis casing black, so it's more discrete in the backdrop of my bedroom.



For now, I'm in the process of doing a few tweeks with my new linear power supply. I want to install some good isolator feet beneath it, paint the chassis black. I'm either going to buy the terminal cover Acopian sells or, more than likely fabricate my own. Viborg connectors will be used for the wall outlet and DC 5.5mm 2.5 mm connector plugin to the A5. For the terminal block location on the Acopian linear power supply, I'm using copper terminal connectors.

Based on how I'm approaching this amp, doing budget upgrades, I'm also trying to balance out cost. If anyone from the community has some good suggestions, please advise me. The goal is locating some excellent performing cables on a budget. After all I only paid $35 for my LPS. Because one end of the cables are going to require only the copper terminal style connectors shown in pics below, I won't require connectors on both ends. But If I have to disconnect the connectors to have bare wire for termination of the copper connectors, that's ok too.

With 10,000 plus viewers, there must be some seasoned experienced cable guys, who could provide some advice. Much appreciated!








_______________________________________ _______________________________________ _______________________________________ _


Regarding the A5 Potentiometer,

This information only pertains if your using a preamplifier, alongside the A5. A tube preamplifier works really well with this class D amp.

The Douk Audio A5's has a budget potentiometer. Therefore, keeping the Douk's volume at maximum, means you are not adding a budget volume control / potentiometer, into the signal path, that can degrade the sound. Do what I do and max out the Douk's volume, you bypass this potential issue entirely.

A preamp output is designed to be the single point of control for overall system volume. Using two volume controls in series complicates "gain staging" and can result in either a weaker, noisier signal. I suppose one could replace the stock potentiometer and install a higher grade potentiometer, if your not using a preamplifier.

One thing I'm noticing about the A5, this chassis is too small, it really needs a large heat sink, attached to the bottom of the board, to dissipate the heat. Since I'm listening at levels around 70 to 87 max decibels, and it gets pretty warm for any amount of time used. I can't see this little amp lasting very long for anyone pushing it more than the levels I'm listening. Highly suggest keeping the plastic lid open, elevate the chassis with larger feet or what ever to enable more air flow through the bottom of the chassis. Especially if you have a 48volt 10amp power supply of any type.
The dual discrete op amps run the A5 a lot warmer, and proper ventilation will significantly help.

I'm going to place the A5 on top a heatsink, for better dissipation. Although, circuit board and components should be installed in a larger Hammond chassis. Enabling it to run cooler with a larger chassis & heat sinks. I'm not going their at this point, unless the LPS really takes this amp to another level, making it worthy.

This linear Power supply for this tiny amp is a beast. Actually overkill big time. It's capable providing enough current for an amp, to deliver up to 404 watts with headroom. I'm not comfortable with the 300 watt claims from Douk Audio. Therefore, the levels I'm listening, will not put demands anywhere near the 300 watt Douk Audio A5 specification, or near the linear supply's full current capability.

So why go to the trouble? Linear power supply's simply perform better across the board, either at low levels or attenuated at higher levels.
Most audiophile addicts know this already!