Bluetooth Amplifier Board

I’ve been using this Drok Bluetooth audio module for a few days now, and it’s been working great. It connects easily to my phone and the sound quality is solid for what it is. I installed it in a 10-year-old Makita jobsite stereo that originally had no Bluetooth. I wired the audio output directly to the radio’s internal AUX input by tapping into the 3.5mm jack PCB—worked perfectly and kept the install clean.For power, I tapped into the battery connection PCB and added a bulkhead rocker switch on the side of the radio to turn the module on and off independently. The stereo runs on a 20V Makita battery, and even though the module’s cut sheet says 12V (with the website claiming 27V max), it handles the 20V just fine. No issues with overheating or instability.I mounted the board inside the radio using hot glue. It’s been sitting out in the sun during use, and while the top of the radio gets warm, it doesn’t get hot. You can tell the module is inside doing its job, but it’s not stressed.The board itself feels like a higher-quality unit than many of the cheap Bluetooth modules out there. The PCB is clean, the build is solid, and it even comes with documentation—which is rare. It seems like buying a single unit results in better quality control. Honestly, if I had bought a two-pack, I’d half expect one to fail and just use the backup. But this one has been reliable from the start.Overall, I’d recommend this module if you’re upgrading an older stereo or building a basic portable Bluetooth system. There are much higher-end DACs out there for home audio, but for portable or jobsite use, this is a great solution that works well and sounds good.

I am a purchasing consumer reviewing a product I purchased. I am not receiving anything for posting this.5-stars easy. No complaints, I bought twoSome of the reviews below state this board is a 24-35V device. It uses a GH27G / AZ1117E power input chip, that's only designed for 13V max. I STRONGLY DOUBT this device can withstand over-voltage by a factor of 2x-3x. The Amazon product description seems correct at 12V. Disclaimer: I only power mine with a standard 5V micro USB cable. I haven't actually tried it at higher voltages.[5/8/25] 2 Month review.I stand by everything posted below. After 2 months this BT board has been absolutely bomb-proof reliable. I use it every night, all night to listen to relaxing music and fall asleep. The BT radio has never dropped out or dis-connected from my old iPad. The analog side of the circuit has been just as reliable. Outstanding.[3/21/25]After several more days/nights of critical listening I stand by all my initial impressions below. I don't know if its component burn-in or what but something slightly "bloomed". The sound image is more layered now compared to a Y-RCA cable straight out of the ipad headphone jack. The harmonic content surrounding notes, room acoustics and ambience in recordings seems slightly more distinct now. The sonic differences between L/R Multi-tracked instrumentation are a little bit clearer and easier to hear. There also seems to be more energy at the extremes of the sonic spectrum. Below ~45Hz is bloomier and more resonant. Above ~6K seems more delicate, articulate and refined. The difference is very slight mind you, maybe an ~8% perceptional difference (if that). It's (honestly) probably just my hearing perception adjusting and picking it up for the first time.This is my finding with all my headphones, none of which are commonly known to be high-detail revealing. I am going to dust off my old AKG K701 and Koss A250 today and give a listen with those. Those are my most analytical / accurate headphones. FWIW I am not a 100% believer in electronic component "burn-in". I know for me personally my hearing perception sensitivity can vary greatly. I am a STRONG believer in blind A/B listening tests, and that's really the only way to validate my impressions. The eyes can strongly influence what the brain / ears hear. I attached a pic of my electrical tape mod to help dim the blue flashing LED.The instructions have an illustration with headphones plugged directly into the TRS output jack. I tried that and it was awful. Probably a gross impedance miss-match with lower Z cans and IEMs, and a severe power deficiency with my 300 ohm HD650. I would only use this as a line-level device.[3/13/25]I power with a micro-USB plug. Plug into my Larocco PPA headphone amp with a cheap RCA "Y" cable. I use an ipad as BT source for ALAC and 320k mp3 files. Absolutely no issues what so ever after 3 nights of critical listening. The circuit is "black background" silent. No hiss, no hum, no clicks/pops or digital artifact noises of any kind regardless of ipad volume setting. No radio frequency noise / interference either. Sound quality seems to be well balanced no offending boost or cuts to the sonic spectrum. It is a very "dry / uncolored" sounding circuit when used as a line level device. I A/B compared it with a plain "Y" cable out of my ipad... and I really could not hear any significant sonic differences. These impressions were made using sennheiser HD650, Koss KSC75, Grado HF-1, Truthear Zero Red, JBL T110. Frankly I am pleasantly surprised. BT connectivity / reliability has been solid... as reliable as the cheap RCA-Y cable it replaces.I bought two of these so I could use my headphone amps with BT. This will help reduce some of the wires and clutter on my desk and nightstand. I will probably mount one in a small project box and just use a micro-USB plug for power. The second one I think I can squeeze in the second amps enclosure, and tap into the 12V DC part of the circuit.The blue LED is CRAZY bright at night. I cover it with a small piece of black electrical tape and it helps. I wish it were the opposite, solid ON when connected to BT and flashing when waiting to be paired. But that's not nearly major enough to take away a star.Reliability of course remains to be seen.I will post dated updates to this review as my opinions change.

Decent Bluetooth receiver module. I like how robust it is built. Also really like that there are numerous input/ output power and signal interfaces. Very convenient for building boomboxes and such. No annoying voice prompts when pairing and connects to my iOS devices immediately.My only gripe with this receiver is that there is still mild ground loop background noise coming through the speakers even though I used a high quality dc-dc isolating converter to clean up the power. It’s not horribly loud, but I feel there should be no audible ground loop feedback at all if the power supplied has been properly isolated.

Short and simple:Small, runs on almost any common DC voltage (5V-35V), great sound quality, little power draw, connects quickly and seamlessly. Great for almost any DIY bluetooth project, this is the one to buy.The long story:Used this in a project I just finished, a late 1980s Panasonic RX-FM16 boombox. Instead of D cells the boombox is now powered by an Anker USB battery pack through a USB to 9V adapter. I connected the module also off the 9V line and put it on a switch so it could be turned off when the radio is being used on FM/AM bands. Through some research I was able to figure out which IC on the radio's mainboard was the tape-preamp and remove it, then wire the output from this module (through a 3.5mm male cable) to the pre-amp output pins. Simply push the play button on the tape deck (which now has the motor disconnected and removed) and the amplifier turns on, then switch on the bluetooth module on and you have your music in crystal clear sound. As you can also see everything tucks neatly away in the original battery compartment, as if it was meant to be. Don't mind the hot glue. I've had zero issues with connectivity and the sound quality is excellent, no issues running on 9V but your mileage may vary. Unit connects immediately.