I'm still laughing at the claim that some listeners reckon they can hear a difference between different valves. We have over 30 years' experience with using and listening to high end audio amplifiers and over 25 years in improving the valves. 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. I can safely say, 100% goods sold are fake (not cheap) and they do it openly, and authority don't care. Update: I just read Veri's and others' earlier comments in this forum re the poor performance of this amp. A circuit diagram is very difficult to draw, because the circuit is on both sides of the board and the details are too small. Reddit and its partners use cookies and similar technologies to provide you with a better experience.Class-D amplifiers work by switching the output between ground and the supply voltage at a high frequency.

There was reported that Russian tubes sound much better, and the tubes with golden grids make the best sound. Looks like they keep putting out newer/revised models and actually do a great job of fixing/adding features each year. 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. 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. On topic, I've also heard some excellent sounding Chinese gear like Ming-Da and Line Magnetic (have an LM dac myself) and have built gear using affordable (not cheap) Chinese line transformers, plate chokes etc.After being lived in Shanghai for a year, my experiences just put me off that anything is made in china, especially Chinese brand. These kits have been put together after many hours of listening tests to confirm the valves performance in any given application.