[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.






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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
 





Plugged into 48 Volt Power Supply


Photo showing actual size of cables, Stock versus new cable



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

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.


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[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]

Communicating with this company regarding their LPS. Waiting to hear back if they might offer it in a 48 volt 5 amp, or 32 volt 10 amp configuration.     

https://www.teradak.com/index.html

I see it's available in a 32 Volt 5 amp configuration.

[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.