Nobsound G2 PRO TPA3255 Hi-Fi 300W Subwoofer Power Amplifier Mono Channel Class D SUB Audio Amp

I only have only logged a few hours of listening so far but that may be ample for leaving my preliminary thoughts. Also, unlike most who seem to be buying this as a mono amp for subwoofer amplification, my intent was to buy two of these for use as mono amps for stereo left and right channels. I’ve always been curious about the benefits of mono amps for stereo and these amps provide an inexpensive way to experience that.These amps add to my ongoing collection of high value, surprising performance Chinese high fidelity products. I have come to expect performance beyond price and these mono amps follow through. The general build, the switches, and the connectors are all quality. Setup was easy and was up and running in less than 10 minutes. I simply connected my Bluetooth DAC, an FX Audio X6 and another high value component, to my vintage tube preamp, then the left output on the preamp going to the left input on one mono amp and the right output going to the right input on the other. After connecting my speakers, I set the mode on both amps to PBTL and I was ready to go. The preamp was likely not necessary but I thought it might be nice to add some tube warmth to the experience. At some point I may eliminate the preamp from the chain to evaluate the mono amps on their own.My first impression was that the sound was very midrange forward with good high end. Bass seemed to be very subdued which, given the bass capability of my Tekton Lore speakers, was noticeable. However, after about half an hour, the bass started to bloom. Perhaps needing time to warm up or charge capacitors, these amps were now sounding truly full range. Clarity, separation, and dynamics were all there. With just about 1/3 of the volume turned up, volume was room filling. Considering those speakers only need a watt or two to get going, these amps have way more power than needed, which brings me to my next point.I don’t know how Nobsound can call this a 300 watt amp and I believe they sacrifice credibility by promoting this spec. The power supply can only provide 160 watts and thats into a 4 ohm load. I’m not sure how that translates to 8 ohms but power is not a limitation for my purpose. Being class D topology, these amps can stay on for hours while feeling only slightly warm. I suspect I may only be getting closer to 100 watts out of these amps, which is still more than ample for my highly efficient speakers, especially since one amp is dedicated to the left channel and the other is dedicated to the right.These amps merit comparison with my class AB Aragon 200 watt amp from the 80s, despite how some may deride class D operation. I suspect the Aragon amp will seem somewhat more refined, perhaps warmer and fuller where the Nobsounds may be thinner, but that amp was many times more expensive and is very heavy. I am skeptical that it is that many more times higher in fidelity.At this early juncture, I am very pleased with these mono amps. Time will tell how well they hold up but other Chinese components I have have been problem free for the longer term. How these amps compare against vintage class AB gear will have to wait. I’m enjoying these mono amps too much on their own merits to spend time on such comparisons right now.Update 12/26/20: I have since bought a Nobsound 6p1 tube amp, also with positive results. While more expensive than a pair of G2 Pros, the 6p1 represents a great value in a true class A tube amp. Nevertheless, I decided to give the 6p1 a rest and hook the G2 Pros back up. Even compared to a hand wired class A tube amp, the G2 Pros still cane across as impressive and equally enjoyable. If anything, they seem more broken in than before and compelling through the full audio range. I continue to be impressed with Nobsound/Douk Audio products, both tube and solid state. I still have not A/B compared them with vintage or higher cost gear, but I think I would have to listen very critically to discern the differences.

I just revived an old and mediocre subwoofer (6-ohm, 120w RMS) that had its original built-in amp fried due to sudden high volume surge. Bought this small unit, G2 Pro, to turn a below average active sub (only with a single LFE input + volume control) into a fabulous passive sub with this G2 Pro functions as its external amp with precise cross-over control & volume to match the pairs of full-range desktop monitors. The sound is so easily balanced and tuned to the room size (12x12x10) which makes the whole thing sounds as if produced by much more expensive setup. Knowing the G2 Pro's real capacity is the key for its successful use.First of, its max power produced is restricted by the provided power supply at 32V5A = 160watts max. As the provided power supply implies, the max current is 5A for the internal circuit and components to operate safely. So, feeding it with a more powerful power supply will only make it run super hot then quickly dies.. may be taking along your other valuables in a house fire (not exaggerated).Use the provided power supply and stay within the following limits, you will enjoy it fully. Driving a 4-ohm sub, S2 Pro puts out 100 watts max (restricted by 5A max) For an 8-ohm sub, it sends out 160 watts max (restricted by 160w power supply) NEVER use any sub lower than 4 ohm since the spec says it does not support and can be dangerous.What I did was the following: 1- replace the original driver, 6-ohm/120 watts RMS, with a modern DVC 8x8 driver (80 watts RMS) wired for 4-ohm impedance 2- Connect the new driver directly to the S2 Pro speaker out L/R 3- drive the new driver with the volume dial at 12 o'clock on the S2 Pro (likely at 50 watts output) 4- Adjust the crossover to match the full range speakers to produce a balanced overall sounds for the room.I have had plenty of low end thumping on my chest and shakes everything in the room even with the volume dial at 12 o'clock. The bass is now much more defined with details, deep, and a lot tighter than the original. Notice that I only need about 50 watts out of its 100 watts max produced by the S2 Pro and also stay way below the driver power handling at 80 watts RMS. I have plenty of headroom to safely go even louder (can't think of why I want it louder unless I move this setup out to a bigger room). The unit is never felt warmer than my hand during its hours of operation.If you need something more powerful or believing that this is a 300-watt amp as advertised then better look else where but don't push the S2 Pro beyond its limits. It can be dangerous and you won't hear its fantastic low end I described above due to distortion.I am not associated with the seller or manufacturer. I bought this on my own and like it a lot. I think the potential users should know this product's real limits from real user in order to make sense out of the purchase. I think the company should put out more useful information. Despite of the above limitations, it is still a bargain for an excellent product to serve my purpose.

Bought this monoblock amp to power an Alphasonik 10” dual voice coil sub for my bedroom media setup. I was running it in a vented car box I had modified with a 250 watt Dayton Audio plate amp that suddenly died after several years. Since the old vented car box couldn’t be reused, I bought a sealed box which is actually better for my application of listening to music, watching TV/movies and playing the Sega Genesis Mini. Very tight and accurate bass response. I have a Douk Audio M3 2.1 amplifier’s low level sub output feeding the Nobsound G2 Pro.The DVC sub is wired up for 8 ohms and it’s providing adequate power but I feel as though there should be a tad more volume to spare. There’s probably a way to wire this rig so the speaker is at 4 ohms but I haven’t investigated the possibility. That would increase the output significantly and the Nobsound G2 Pro is supposedly rated to handle 4 ohm loads.Overall it sounds really good after flipping the dip switches on the bottom for a little db boost and adjusting the sub frequency properly to match the other speakers. The volume gain on the amp is set nearly to the max. It’s certainly moving the sub easily with enough volume and the amp doesn’t feel unusually warm. Just slightly warm as one would expect.If it holds up for several years or more I’ll be happy with the purchase.