Budget Douk Audio A5 Class D Amp Mod- Nice amp addition for all audio enthusiast

NXSTUDIO-DRUMMER · « **Reply #20 on:** 19 Jul 2025, 10:12 pm »

I had fun using using the Douk Audio Amp, very impressive even in stock form.

One thing I'll point out, if your using a 48volt 10amp power supply, and your pushing it with higher SPL's, remove or flip open the top plastic lid. Also suggest placing some type of standoffs, below the unit, to elevate more, than the stock rubber feet. This enables the cooler air to travel up beneath the A5, and exit out the top, of the unit, enabling it to running cooler. The good thing Douk incorporated in the design, putting breathing holes on the sides of the chassis as well. Since circuit boards despise heat, hopefully, taking some of these easy measures, will improve the lifespan of the A5.

The blue LED's displayed in photo, are much brighter, than it really is in person.

nlitworld · « **Reply #21 on:** 20 Jul 2025, 01:01 am »

For me, it's either tube connector or KLE banana plug on the speaker cables. Currently have tube connectors on there but they stick out like ½". Not a surprise there though. I did pull those plastic nuts for now.

As for adhesives to secure everything, I sell auto paint and body shop materials for my day gig. I have stuff at home that could glue two pieces of sheet metal together where you'd rip the metal apart before the adhesive lets go. The way I figure, if it's good enough to glue a car back together, it's strong enough for audio. Lol.

As for power supply, I bought the 48v5a one that Amazon had packaged with the amp. Fine enough for now I guess.

NIGHTFALL1970 · « **Reply #22 on:** 20 Jul 2025, 01:42 am »

Nliworld,
I purchased the 10 amp power supply and it made a huge difference.

nlitworld · « **Reply #23 on:** 20 Jul 2025, 03:05 am »

@Nightfall, that's good to know. Did you just grab the Nobsound or similar one on Amazon, or did you snag something specific?

NIGHTFALL1970 · « **Reply #24 on:** 20 Jul 2025, 01:40 pm »

Nlitworld,
I paid $100 for the Douk Audio one off eBay. The one that NX studio drummer mentions is probably the exact same thing for less money so, you should grab that one. Everything sounds a lot better with the 10 amp supply. The crash of symbols were lackluster before. With more amps they become more lifelike. Definitely worth the upgrade. I would even bet that it makes a bigger difference than op-amp rolling.

I just picked on the link. It is the exact same one for a lot less.👍

nlitworld · « **Reply #25 on:** 20 Jul 2025, 06:42 pm »

So I got bored this morning and busted out a soldering iron. First off, if you go to mod, do yourself a favor and remove ALL the hot glue from the binding posts before attempting removal. I literally had to bust out a cutoff wheel to get the last one. PITA. Secondly, the underside does have some thermal paste going from the pcb to the case. If you go to tear it apart, make sure you have some laying around. Any computer geek probably has 2 or 3 tubes laying around...

Underside of board to show thermal paste heat transfer spot.

Next up, when you disassemble, the ground speaker terminal is just a solder filled cutout, and the GR Research solid core wire does fit in for the positive, but barely.

Next up for disassembly was the rca plugs. Seriously, F those things in the A. Holy balls. The crappy lead free solder they use needs a SUPER hot iron to flow (I had to double up like red hot tweezers). So make sure your iron is super powerful. Once those finally removed, I installed the KLE connectors with some VH Audio airlock cable.

Once those were soldered on, the backplate pops right on. IF given the opportunity, ream out those RCA holes a little to the outsides as it'll allow a little more space for your cables to not pinch.

Next was installing the tube connectors in an ancillary box as proof of concept. I'll go back and make things flushed up and pretty later. I oversized my drill holes a little and bobbed on a dollop of hot glue for temporary security.

Aaaaand done for now. I'll bust into it more next weekend when caps and opamps arrive. If you notice the little 10uf50v caps standing up right next to the opamps, those suckers are what's getting replaced.

Also thanks for the link to power supply. I'll pick one up soon.

-Lloyd

But how does it sound?....... You don't wanna know.

NIGHTFALL1970 · « **Reply #26 on:** 20 Jul 2025, 06:55 pm »

Awesome job Lloyd! Thanks for the pictures. Looks like more work and expertise than I could handle. Maybe I’ll just pay you to do the job for me. And pay for your therapy!🤣

NXSTUDIO-DRUMMER · « **Reply #27 on:** 20 Jul 2025, 08:36 pm »

Lloyd,
You'll no longer have issues with connectivity on the back side! Regarding your RCA jack upgrade, looks like the interconnects are butted tight, rubbing against one another, near the chassis. If you elongate the chassis holes with a Dremel tool or file, this will provide more spacing between the interconnects, not putting stress on your new RCA's jacks.

nlitworld · « **Reply #28 on:** 20 Jul 2025, 09:20 pm »

Funny you should say no connectivity issues as KLE rca jacks are notorious for needing a little wiggle to connect. But they sound so good. Also I did take a drill bit and ream the holes on the side a little to give an extra mm or two space between jacks. Nothing much, but just enough.

nc42acc · « **Reply #29 on:** 20 Jul 2025, 09:37 pm »

What about mounting the A5 in a new chassis and build a linear power supply???

Danny Richie · « **Reply #30 on:** 21 Jul 2025, 12:24 am »

I got one of these little amps too.

I am going to add some Sparkos op amps and explore putting it in a new chassis. It is going to get a beefy linear power supply for sure, and tube connectors.

NXSTUDIO-DRUMMER · « **Reply #31 on:** 21 Jul 2025, 12:31 am »

Topic result was a dead end, therefore removed.

mkrawcz · « **Reply #32 on:** 21 Jul 2025, 12:37 am »

I’ve been using a pair of these with Sparkos opamps to power Superminis with an active crossover and these hold their own against my Purifi and Hypex amps. They sound great. Probably the ultimate amplifier bargain I’ve seen.

NXSTUDIO-DRUMMER · « **Reply #33 on:** 21 Jul 2025, 06:04 pm »

Quote from: Danny Richie on 21 Jul 2025, 12:24 am

I got one of these little amps too.

I am going to add some Sparkos op amps and explore putting it in a new chassis. It is going to get a beefy linear power supply for sure, and tube connectors.

Danny, If you find the performance improvement, outweighs the extra expense, please keep us advised on your results.

Jon L · « **Reply #34 on:** 21 Jul 2025, 08:15 pm »

Quote from: Danny Richie on 21 Jul 2025, 12:24 am

I got one of these little amps too.

I am going to add some Sparkos op amps and explore putting it in a new chassis. It is going to get a beefy linear power supply for sure, and tube connectors.

You should try batteries on the Douk A5 along with your Battery-powered Dodd preamp! Off the Grid

genjamon · « **Reply #35 on:** 23 Jul 2025, 01:59 pm »

Quote from: NIGHTFALL1970 on 20 Jul 2025, 01:40 pm

Nlitworld,
I paid $100 for the Douk Audio one off eBay. The one that NX studio drummer mentions is probably the exact same thing for less money so, you should grab that one. Everything sounds a lot better with the 10 amp supply. The crash of symbols were lackluster before. With more amps they become more lifelike. Definitely worth the upgrade. I would even bet that it makes a bigger difference than op-amp rolling.

I just picked on the link. It is the exact same one for a lot less.👍

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.

NIGHTFALL1970 · « **Reply #36 on:** 23 Jul 2025, 04:35 pm »

Genjamon,
I think you are right about that being a scam. My CC showed this for the charge:

NXSTUDIO-DRUMMER · « **Reply #37 on:** 23 Jul 2025, 07:45 pm »

On a positive note, I did finally received my SX52B Op-Amps. So I'll install them, and eventually post up my opinion on the SX52B's.

Note: Pic is a A5 example of how the SX52B's look inside the chassis. This isn't my actual circuit board.

Lloyed, keep us advised on how the new capacitors sound.

NIGHTFALL1970 · « **Reply #38 on:** 23 Jul 2025, 08:31 pm »

Can’t wait to hear your review of them.👍

nlitworld · « **Reply #39 on:** 23 Jul 2025, 11:08 pm »

New Sparkos arrived Monday so popping those in was a big upgrade in soundstage. Added 10' to every room dimension. I'll pull soldering iron back out this weekend to tinker. Should be easy to fit having them squish with a staggered approach. They are much bigger by comparison, but they'll fit easily enough. Not expecting big gains, but any improvement is also nice. Definitely will keep you guys posted. As it sits, more than satisfied with my small investment so far.

-Lloyd