Douk Audio ST-01 PRO 200W Bluetooth Amplifier, 2 Channel Vacuum Tube Power Amp with USB DAC/Coaxial Optical Inputs/VU Meter/Treble Bass Control for Home Theater/Stereo Speakers (Upgrade Version)

This is a review of the Douk Audio ST-01 PRO 200W Bluetooth Amplifier. I am a low grade audiophile by my own description--I have spent quite a bit of time listening carefully to the same few tracks on a whole range of components over the last 25 years or so. Engineering background so I take a very pragmatic approach--if I can hear a difference myself then I will consider the costs for better gear across the board. I can't blow money on anything and I don't like to be wasteful so I do a fair bit of research before I buy. This little Douk tube amp has really impressed me! I had an old Denon AVR-5700 home theater receiver that had been demoted over the years to just providing sound for our computer--headphone jack outlet from the computer into the receiver, two passive NHT SB-3 speakers driven by the Denon receiver, and subwoofer line out to one passive NHT W2 subwoofer driven by a dedicated NHT amp. When the Denon died, I needed something to power the same speakers and sub but that's it, just 2.1 channels of sound and not audiophile quality to the Nth degree. There are a whole bunch of these tiny devices out there, I liked this one for its combination of price point, tubes for the two speakers, and subwoofer line out to go to my same NHT dedicated amp for the subwoofer. The size is quite amazing, others have shown the same sort of big ol' receiver that was replaced by this tiny cube--it's really just 4.5"W x 3"H x 6.5"D (from the wall to the front of the dials after I have all the connectors installed). The audio power is also impressive. The claims of 200 W/channel are debatable (another review has very solid points about the power supply and the output claims) and that also will depend on what speakers you are using, where their Ohm ratings will influence the power output. Our computer is in a modest home office sized room, about 10'x12' or so, my two SB-3 speakers are 8 ohms being driven directly by the Douk amplifier via the speaker terminals, and the subwoofer is using the 3.5mm line out to the sub amp, so this little device IS powering my speakers but NOT my subwoofer. When I set it up and started testing with my same old tracks, made some adjustments between the volume on the computer and the volume dial on the Douk, I found that this tiny box can rock this room just fine! I'm impressed with how much bass the Douk pushes to the speakers, which have a very good frequency range themselves, which is nice for most musical circumstances anyway where bass guitars, deeper drum beats, and lower ranges in classical performances get very nicely reproduced. The tone adjustment dials on the Douk are quite nice, recognizing that they are just the two simple dials for bass and treble, so I don't expect them to get any more complicated than that anyway. Between the digital equalizer window on my computer which has 12 bands to work with and the two dials on the Douk, there is quite a bit of refinement you can make to match your personal preference for the types of music you listen to and which parts of that music you prefer to dampen or boost. It's basic but it works well. Like another couple of reviewers, I too received tubes that are much smaller than those shown in the photos on the Amazon product page. However, with a little research it seems that the smaller tubes are most likely an improvement from those pictured. I don't know exactly what those larger tubes are--the product page does suffer from missing details like which tubes are included--but the ones I received are legit General Electric JAN 5725W tubes with "MADE IN USA" printed on the glass tubes themselves, which are mil spec quality (which means they are made to very high quality standards to be accepted for military purposes, back when the military was still using lots of tubes). These are usually offered as an upgrade set of tubes for this Douk so I don't know what happened there but I believe the smaller 5725's are top quality for this level of device. They sound terrific to my ear so I'm delighted with them. I have read way too many subjectively written reviews of the feel and warmth and crispness and all sorts of other floral terms describing how tube amps sound compared to modern transistor-based amps. I don't have two different devices side by side to switch back and forth against each other with every other part of the system being identical so I can legitimately compare point for point the tube am to a transistor amp. Suffice it to say that compared to all of my other experience with transistor amps over these years, this little tube dude sounds fantastic! I haven't had any tube amps before so I will have to see how it performs over time, with things like burn in and eventual failure being known factors, but I don't have the tube testing equipment to test exactly when those thresholds will be crossed, so I'm just gonna enjoy the sound until I hear something wrong. The little ol' analog levels dial with the meter jumping around is quite charming as well. It does give you some useful information, just a basic glimpse into how much or how little you are pushing the power. That feature is a nice little throwback to those old times of analog stereo gear back in the day. And while all you young whippersnappers giggle, you'll also notice how vinyl albums and record players are booming again. There truly is some meaningful, warm charm to having a little visual dial bouncing along to the music with you while you tap your foot and try to concentrate on whatever important task you were supposed to be working on while you jam out, right? Totally gnarly dude (yep, I was in high school in the early 80's, for better and for worse). I am just using the RCA inputs from the computer so I don't have any comments on the other input types that the unit offers. Based on what specs they have provided in terms of formats and frequency ranges, and on my listening experience now with this unit, I would guess that those other input source feeds should work just as well as the RCA input, but that is just a guess. For the money, I am delighted with this Douk, if the need arises I would happily buy another one. Hope that's a helpful review, and hope you get to enjoy your favorite music again like I am!

I cannot believe how good this sounds paired with Polk Audio T15 Home Theater and Stereo Bookshelf Speakers. This setup works great with a bunch of computers via a passive audio switch. Did I mention the awesome amazing sound? This is a very flexible and amazing amplifier. I wish I had bought one long before this! It sounds great, it looks great, and it is worth every penny. Thank You Douk Audio!

I simply cannot believe my ears. My previous three amplifiers were a Yamaha, a Marantz, and an NADC – 700. The last one stopped working, and I ordered a Cambridge AXR 100. I was not satisfied with the Cambridge because of the imaging and sound stage was poor so I thought I would try this one. I really did not expect anything, but just wanted to try it out. I am moving and I just needed something to hold me over. Boy was I shocked. The warmth, depth and sound stage on. This are absolutely amazing. The detail is crisp without being brittle, even at low volumes. The sound is simply amazing. I have listened to classical, jazz, Barbra Streisand‘s new album, and a little bit of rock and the one thing that is consistent is the faithful reproduction of the sound and the unbelievable separation and imaging you get with all genres of music. I cannot speak to reliability as I have just had it for one day. But it was very easy to set up. The only reason I gave it a four is the Bluetooth is a little quirky. Extremely easy to pair, but it flickers in and out, especially if you don’t hold your phone still. I’m only about 6 1/2 feet away from the amplifier. There is no passive subwoofer output, the holes in which to place your speaker wire are really difficult to thread because they are smaller than usual, and there is no plug for headphones. Basic sound reproduction you can spit a lot more money, but I don’t think you’re gonna get better sound quality than you get with this little amp. The warmth of the vocals on some of the Frank Sinatra, and Barbra Streisand albums will just knock you out, I have listened to a little bit of Ariana Grande, James Taylor, a touch of Taylor, Swift, and other music on the alternative charts. All I can say is just go ahead and get it. It is worth the $105. You’re going to pay for it. Highly recommended.

I use the unit solely as a preamp into KRK powered studio monitors. I bought it for my record player, but I also use the blue tooth function for playing video/music from the PC. I'm a guitarist and know quite a bit about tube amps, so let me dispel some things others have said in reviews. 1. The tubes are not for looks, they are used in the preamp circuit, one is for left side the other is for right. 2. If you want to use this as a preamp, simply use the aux out jack in the rear to input into your amp or powered speakers. You can also use the power amp functionality if your using passive speakers. 3. The VU meter works perfectly fine. 4. The EQ on the unit work great, HI/Low. very warm sounding unit. 5. The blue tooth function is great, I didn't test the range, but when I switch from RCA (record player) to blue tooth, it connects very fast which is nice. 6. I run the unit in an enclosed cabinet, I have no issues with heat. It's not like a guitar amp that has power tubes, your not gonna get that hot. However I am only using the preamp side, using the amp outputs may generate more heat, but I cant imagine its much. Bang for the buck, this thing is amazing and totally what I needed for the record player. Boosts the signal great and adds warmth, added benefit of blue tooth input. Also, if you want to upgrade the sound (a bit warmer and a bit better volume) update to this model of tubes. I compared side by side, very nice. (5654W) https://www.amazon.com/dp/B01BFJDTW0?ref=ppx_yo2ov_dt_b_fed_asin_title

Great little amp. Sounds great, lots of input options and has tone controls. Remote included is well made and works perfectly.

This little Tube Amplifier’s sound quality is amazing. I connect my HiFi system equalizer and CD player to this Amp, it’s handling the Quality of sound. Very impressed with this Tube Amplifier. Recommend it.

Great sound

It is amazing what a nice sound this little thing can provide. Especially I like warmth of the sound (kind of softness) produced by tubes. Pair it with Polk's speakers (like I did) and you would just "bath" in music all day long.

Buena potencia. Buen sonido, Buen precio.