Fosi Audio TP-02 Subwoofer Amplifier Home Audio, Mini Bass Amp Mono Subwoofer Amp, with TDA7498E Chip 220W Volume and Frequency Control, for Powered Passive Subwoofers Bass ShakersClimatePartner certified

I use this with the Fosi MC331 integrated via a 3.5mm plugged cord. It's a simple set up that sounds great in my bedroom system. This little sub amp plays very cleanly with all the heft and detail that Class D amplification provides, especially in the low frequencies. I have the volume set at 1:00 and the crossover frequency set at about 100hz. The input sensitivity is fine for matching the MC331 integrated. There is no phase switch, but switching the speaker wire polarity is the easy work around if needed. I didn't.My small subwoofer now blends so well with the main speakers. It's noticeably quicker than the old $450 Class AB sub amp it replaced. It can play the sub louder to impressive levels, and exceeds my need for power playing even the heaviest music. For those seeking serious bass from larger drivers will be disappointed. "This ain't that."The form factor is good and the unit is attractive... but not as attractive as the MC331 case. I hope Fosi considers putting this same package into the new style case for more design continuity. Still, the combo looks great to me. I'm happily filling my life with more music and Fosi provides a cool, convenient way to have high quality audio reproduction for modest prices. I operate this amp for 8-10 hours per day and it doesn't produce any heat due to the high efficiency and has no perceivable impact on my power bill.This is a great, affordable answer to those needing a modest subwoofer amplifier in a small package. After a long life of having high end audio products, I really appreciate the niche that these products fill. It's an exciting time when quality and attractive audio products are now available to more people than ever. And, listening to music makes us a little less crazy. Rock on and hug your mom.

I have professional audio experience from home theater to running sound for bands. I hooked this up to a 100W Subwoofer in a furnished 20x16 room as part of my home theater system. It fills in the lows amazingly clearly for a compact amp. I'm very happy...

This thing packs a lot of punch for it's size! I have it powering a Skar Audio IX-8 D4 8" subwoofer in a slot ported enclosure as the low end for my computer sound system. This amp puts out way more power than the IX-8 needs, so I've only got the volume on this critter turned up about 25% and it sounds great. I like it so much that when a friend's powered home theater subwoofer's plate amp failed, I recommended this as an alternative to replacing the sub. He purchased it and is also very happy with it's performance and value. My desktop sound system consists of this amp for my sub, a Fosi Audio tube pre-amp, and a Fosi Audio 2x50 watt amp for the mains. The sound that comes out of this setup is nothing short of amazing! I highly recommend Fosi Audio products. They are excellent quality and last a long time. The tube pre-amp and two channel amp have been in service since 2016!

I bought this to replace a very old Carver amp that I was using to control the subwoofer portion of my bi-amped speakers. Unfortunately it gave up the ghost after over 30 years of service.Unlike the Carver these amps do not pick up the sound adjustments/volume of my AV receiver/amplifier.At first the bass not only overwhelmed the sound spectrum, it also was louder than the dialog and music on the rest of the sound track. I had to adjust the volume to barely above the on position to get a nicely balanced sound stage.However it is VERY easy to turn these knobs, e.g. in dusting the top of the amp which means hunting for the sweet spot all over again. There are no markings on the knobs so you have to guess where they were set before being accidently moved.It does take a week or so before the sound warms up nicely. If properly adjusted they provide a nice bass undertone to movies and tv shows and can shake the room when needed. (I don't listen to music much on my system.)I wish it was easier to keep the knobs from moving around or that there were markings available to make it easier to reset them if they do get accidently moved.Overall these little amps are worth the cost and effort to set them up.

I have a Definitive Technology PowerField 310 subwoofer that would not come out of standby. Replacement amps cost more than the subwoofer did when new, and it's not exactly a good subwoofer either. I wanted to get it working again and not break the bank. This little Fosi Audio amp did the trick!I removed all the DefTech electronics to turn my sub into a passive sub. Then I ran the wires from the subwoofer speaker to the Fosi amp through one of the holes I didn't seal up. The Fosi powers the DefTech without any problem. The sub was rated at 250W RMS, and this 220W Fosi has no problem powering it. I was able to run LFE from a Denon receiver to the Fosi's left input too (right input and subwoofer out on the Fosi not used). It did take the Fosi some time to begin playing audio the first time I went to use it.The only weird thing is the frequency dial. The sub gets very boomy when the frequency dial is set above the crossover. I had to do some tests with an online tone generator to dial things in. Also note that the Fosi does not seem to have a standby mode -- it's either on or off. Get yourself an energy-saving power strip as a workaround.Overall, happy purchase! Give your old broken sub a "backpack Fosi" if you want to get it working again like I did!