Review on 🔊 Fosi Audio BL20C 320 Watts Bluetooth 5.0 Stereo Audio Receiver Amplifier 2.1 CH Mini Hi-Fi Class D TDA7498E Integrated Amp U-Disk Player for Home Passive Speakers Powered Subwoofer - Power Supply Included by Samuel Bowen

I used to have a good receiver for my Micca MB-42x and a subwoofer. But that died and I needed 2.1 amps since my subwoofer was a passive device. That's how I came across this interesting amp. I liked how you can fine-tune the sound parameters by simply turning the knobs. When I had a receiver, I had to push a lot of buttons to set it up. As soon as I plugged it in, I heard a faint buzzing noise. However, once I played the sound, it sounded great. But when it was quiet, that rumble continued. And the next day it gets worse. I work from home and hearing this buzz is driving me crazy. I have tried many troubleshooting methods here. I ran it with no inputs connected and there was no hum. I've tried plugging it into a different outlet and also tried running only one speaker to isolate the problem. Unfortunately I could not find anything that solves this problem. Also, if I touched any part of the metal on the amp with my hand, the sound would isolate even more. Then I approached Fozie about Revain. I literally waited all day and they finally responded the next day to contact Fozie directly. And what is strange to me is that one of the email addresses is a Hotmail account. I then sent an email to two addresses with all my detailed troubleshooting instructions and it took me a full day to get a response. Then they wanted a video from me showing the problem. I sent it and then never got a reply. It may take a few days. Interestingly when I looked at other Revain 2.1 amps like the Nobsound they looked very similar save for the brand name. The position, size and position of the adjustment knobs remained the same. I researched Fozie on Reddit /r/budgetaudiophile. It is generally accepted that Fosi as a brand should be avoided. I researched further and tried to find a 2.1 amp that didn't look like this Fosi amp. I found one through the Dayton Audio DTA-2.1BT. I ordered this one and there is no buzz at all. Calm. and much better results than Fosi. I also like that the grips were bigger and simpler than Fosi's. Now it's entirely possible that I just had a bad block. However, now that I have this problem, I have to consider customer service and warranty issues. What leaves me with a negative impression is that I had a very detailed email to Fosi describing all the issues. However, they then wanted a video and two days later they still didn't answer me. It's possible this is the norm of customer service, and who knows. Maybe they would ship next week. I also compared the warranty. Fosi gives 18 months warranty + 6 more months if you sign up. The Dayton amp gives me 5 years and I didn't pay too much money for it. Eventually you can get one of these amps and they work great. However, do your research to find the best choice for you.