January 12, 2026
FURTHER UPDATED 01-16-2025
#533
Gentle reader,
There is no denying that China is the planet's factory for so many products. Yes, there are many things being sold which are made in China which are blatant copies of existing products. Sadly, Amazon regularly does that as well. Their "Amazon Basics" line is comprised of items being sold through them by legitimate manufacturers which Amazon has copied and sells of which they changed them just enough so as to not be sued by the original makers.
Douk Audio DU3 Pro Images courtesy of Douk Audio
I feel that the DU3 Pro is perfect for my needs. Using the remote to switch the different amps to other speakers, and vice versa has been quite revealing to my ears. I plan to spend a lot of time tomorrow playing with it and learning all that it can do.
Today, as promised, I reattached the Radio Shack APM-300 to the Douk Audio DJ587 tube power amplifier. (It can be seen beneath the tube amp.) I played the same CD I have been using to test this setup: David Sanborn's Upfront. A fun and rocking Smooth Jazz album. I was testing it using my half-century old Dynaco A25XL speakers.
Do I recommend that you buy one? Absolutely, it was on sale the day I bought it, the price was low enough for me to go ahead and give one a try. Now that I understand how everything works, and have set it up. I will not need to make any changes. I am completely tickled with this Asian beauty. What a great piece of equipment!
The listening room wall of sound. The large speakers are the last Cerwin-Vega! speakers made in the USA: Models LS-12. They are driven directly by the Marantz MM-7025 power amp. Also driven are the two Tannoy C-88 towers driven through the 1990's Dynaco QD-2 "FIVE CHANNEL HOME THEATER SYSTEM" pictured at the beginning of the photos of the various Realistic APM units. Both sets of speakers were thrift store finds at $99 a pair.
I have been intrigued by these meters since they first came out. The DU3 Pro is only the second component I have bought made by them, the first can be seen here: The Robb Collections: World Premiere Review of Douk Audio's Exciting new Class A DJ587 Tube Stereo Power Amplifier!Said 4 WPC tube power amp astride my 1990's B&K Components ST1400 power amplifier. You can see my (second) Radio Shack APM-300 watt meter nestled beneath it. I had to get some tall rubber feet to replace the factory tiny ones to make the LED watt meters fit and sill allow cooling air beneath the tube power amplifier.
Similar to many of the more expensive WBC (Worlds Best Cables) products I have purchased, it too comes in a nice black box, well protected.
ONE Little Bear is a new name to me. I have yet to see any products thus named.
Product protective packaging and product packaging itself seems to have been perfected by the Chinese.
They provide a nice remote which uses two AAA batteries and a 5 Vdc @ 2 amps power transformer cube and USB-C cable.
Quality, strong and well made three-way binding/banana terminals. Much better made than those on my Marantz MM7025 power amplifier:
After replacing every wire and cable in the listening room system with WBC units, I used the (above, black cables) removed Monster Cables Z Series 1R to replace the cheaper speaker cables in our modest home theater system. I had one short cable left over which was the one on the right. I bisected it and added some old banana terminals for testing purposes. The pink ones on the left are my test cables made from M.C. standard speaker wires. One never knows when they might find some awesome speakers somewhere.
I thought long and hard about the placement of the DU3 Pro unit and decided to place it where you see it above. I looked at all kinds of "jumper" speaker cables and even two to three foot long WBC units thinking that I could cut them in two...
For testing purposes, I placed the tube amplifier to the right of the big unit and snaked the pink wires around to the tube amp.
I had used a cloth measuring tape to see what the distance from the big power amp's speaker terminals to the inputs on the DU3 Pro unit and found that eight inch jumpers would work.
SO much effort is made by "high end" audio cable makers by using woven fabric outer coverings to cover their speaker wires/cables. I think it is just a clever ploy to separate us from our money. At least WBC's cable prices are a tiny fraction of the cost of so many other cable makers out there in audiophile land.
All of that thickness is just layers of woven fabrics. Yet, we think they look cool although there is no real purpose for all that thickening coverage.
As you can see, the eight inch WBC "Ultimate" jumper cables are exactly the right length. The pink Monster Cables copper wires which are 10 gauge, nominally, look tiny by comparison.
In the case of my system, (these two amplifiers are "extra" power amps) moving the tube amp to the left side worked perfectly. Where you position your DU3 unit in YOUR system is completely up to your needs and available space.
In case you haven't seen the listening room system before, here it is. The big power amp on the floor (which now has the DU3 Pro on it) used to sit where the Marantz MM7025 sits now. It is the matching power amp for the B&K Components PRO10 preamplifier. The ST1400 power amp had developed an electrical problem and I decided to buy something from THIS Century to replace it. Then, I fixed that amp's problem and decided to use it to drive my fifty-year-old Dynaco A25XL speakers.
I bought this set of Nakamichi banana plugs from Amazon. With fifty years in this hobby, I have tried all kinds of different ways to attach wires to speakers and amps. I have found that Nakamichi makes the best ones. The one danger is that the silver "barrels" are aluminum and thus conductive when music is flowing though them. Of course, we NEVER plug or unplug speaker wires when are amplifiers or receivers are switched ON. Right?
I replaced the ancient banana plugs on the Monster Cable Z Series 1R cables with those crisp new Nakamichi units.
A good look at what a well laid out set of speaker cables attached to a Douk Audio DU3 unit can look like. The Nakamichi barrels look like they are touching, that is an optical illusion.
The whole layout "in situ" as Latin speakers used to say. It may look like a bundle of snakes, but the cable are all laid out as neatly (and with power cables separated from signal cables) as the devices and thick cables allow.
The unit up and operating. Pay careful attention when wiring up yours, it is far too easy to plug a cable in the wrong terminal.
The unit is bigger and heavier than I expected it to be.
I will have to look and see if I have bought any "Ultimate" WBC speaker cables before.
I have so many of these little silk-like black bags now, with no future use for them...
A little closer look at the layout.
I thought of the sensual music Techmoan plays whenever he peals off the clear protective plastic film. Techmoan - YouTube
The directions are clearly laid out in understandable English, in the multipage manual, unlike countless other products from Asian manufacturers.
Image courtesy of Douk Audio.
Having a remote controller makes it so easy to switch from amplifier to amplifier and speakers to speakers. You can even drive both pairs with one power amplifier.
Radio Shack (I miss it, so) used to sell SO many wonderful things for all kinds of electronic hobbies. Some of which were Audio Power Meters. I've owned at least one of all four of the series. I have found the APM-300 (above) to be the best for critical observation of power being used. The one above is part of the main system. It is switchable for eight or four ohms (on the rear) and has two scales: 0 to 2 watts, or 0 to 200 watts. Also, it can be switched between RMS (constantly moving lights) to showing just the peak power. 
This is an APM-200. I was able to buy a lot of five of them. Unlike it's father, the APM-100, (below) it has LEDs and needle meters. Plus, it lights up in the dark.
And, the granddaddy of them all, the APM-100. No power needed. Simple as can be.
I also need to divine the sensitivity controller. I'm going to place the APM-300 back under the tube power amp, and use it as a basis for gauging where to set the DU3 Pro's sensitivity. With two completely different power amplifiers attached, this has become very interesting.
I thoroughly enjoyed setting up my unit, which I purchased from Amazon, no one EVER pays me to review equipment. I do no make any money from this, or my other two blogs. Pictures of Nancy. The Love of My Life. People Say I'm Special. But I Don't Know Why
This is an APM-500. It does not have as many features as the 300 does.
Images courtesy of Douk Audio.
These Douk Audio DU3 Pro units are heavy, robust, well made, well engineered and laid out. I absolutely love mine.
I haven't figured out, yet, what the microphone is needed for.
UPDATE RESULTS:
I used the DU3 Pro's remote to switch between the two amplifiers: tube amp (A) and solid state amp (B) and used the Gain (volume) control on the tube amp to adjust it's output, switching between the two amps using the remote control of the DU3 Pro until, to my ears, the output of BOTH amps were identically loud.
Prior to that, I used the Gain knob on the DU3 Pro to match it's meter's percentage readings with the LEDs on the APM-300. When the LEDs were just touching 1 watt (1/4 power output of the DJ587) on the APM-300, until the needles on the DU3 Pro were also showing 25%.
Lastly, I used the Sensitivity knob on the DU3 Pro to slow down the bouncing of the meter needles. It still shows the same peaks, just not too quickly.
FURTHER UPDATED:
The bottom loudspeakers are my fifty-year-old original Dynaco A25XL speakers. They are fantastic and were also $99 a pair via eBay. I couldn't believe no one else bid on them. They are driven by the 1990's B&K Components ST1400 power amplifier on which the DU3 Pro sits.
Atop the Dynaco's are two of the five Klipsch speakers my next door neighbor gave me. The Robb Collections: Having Friends Who Are Neighbors is a Wonderful Thing! Gifted Klipsch Speakers And More. They are driven by the Douk Audio DJ587 tube power amplifier.
However, now that the DU3 Pro is part of the system, either pair of speakers can be driven by either amp. OR, both pairs can be driven by one amp! Gotta love technology. 
One final thought, yesterday, when switching between the 96dB sensitivity of the Klipsch RB-35 speakers and the 92dB Dynaco A25XLs, the Dynaco speakers were audibly louder with the same amplifier output. That is counter to how we understand decibel increases. Every 3 decibels is twice as loud. Just my observations.
Like staring at a fire in a fireplace or a campground, it can be mesmerizing. The same with bouncing needles, especially when they are illuminated. Search YouTube for: Douk Audio DU3 Pro and see what I mean.
Thank you SO much for taking the time to read this rather long article. Writing this blog is one of my passions. I am so grateful to you and all the other folks who regularly read these pages.
Feel free to comment below, or via Facebook.
Scott Robb
January 12, 2026
#533
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