Nobsound Mini Bluetooth Power Amplifier Stereo Hi-Fi Digital Amp 2.0 Channel 50W×2 with AUX/USB/Bluetooth Input Wireless Audio Receiver PC Sound Card with Power Supply (Black)

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From my experience any decent vintage amp/receiver from 70s is much much better then any Chinese class D amplifier. Another major problem with filterless Class-D designs such as this Nobsound Bluetooth amplifier is EMI which stands for electromagnetic interference. I can understand them skimping on transformers which are costly devices, but the rest of the chassis is full of circuit boards, so why not just make a proper valve amp out of it to begin with?

The 103 third parties who use cookies on this service do so for their purposes of displaying and measuring personalized ads, generating audience insights, and developing and improving products. I have also enclosed a picture of the output waveform with a 4 Ohm load connected to one of the outputs when driving the amplifier with a sine signal. I can safely say, 100% goods sold are fake (not cheap) and they do it openly, and authority don't care. There is only one power transformer under the box, which delivers 17V to output transistors, 7V to microchips and 6.As such I would bet this amp does not meet the FCC Part rules section 15B which is a requirement by law and as such most likely is even illegal to distribute in the US. If the item comes direct from a manufacturer, it may be delivered in non-retail packaging, such as a plain or unprinted box or plastic bag. Update: I just read Veri's and others' earlier comments in this forum re the poor performance of this amp. Those of us at the coal-face (techs, engineers, etc) have a very healthy disrespect for Chinese made products.

The audio is detailed and transparent and quite revealing that my Mordaunt Short MS15 speakers, although lacking a bit of bas. The cheapest amplifier with just analogue inputs that I would be willing to risk my money with is probably the 2x100 watt Sony STR130. This is interesting as I used a signal generator with my standard HD650 XLR-4 cable and looked at the phase on my Rigol DS1054 oscilocope and pin for pin the input and output are in phase. Given the fact that the connectors aren't hand wired and are soldered onto the PCB correctly this leaves a few conclusions.By accepting all cookies, you agree to our use of cookies to deliver and maintain our services and site, improve the quality of Reddit, personalize Reddit content and advertising, and measure the effectiveness of advertising. A circuit diagram is very difficult to draw, because the circuit is on both sides of the board and the details are too small. There is general consensus in the audio world which of the pins are assigned to a signal as used by HIFIMAN for instance. After being lived in Shanghai for a year, my experiences just put me off that anything is made in china, especially Chinese brand. AUX mode has slightly better sound but I find myself connecting mostly with Bluetooth because it's so convenient.

Rubbish Chinese amps like this one are getting rarer - the majority of them now have excellent build quality and aspire to be a hi-end product.These kits have been put together after many hours of listening tests to confirm the valves performance in any given application. However, in this case it is safe to assume that the actual distortion that occurs inside the speaker will be magnitudes higher than the specs shown on the Nobsound data sheet since it is lacking the output filter. This results in a strange stereo image where bass is affected and voices and instruments cannot be placed properly, a fuzzier stereo image.