Douk Audio H7 Pro class D amplifier review (TPA3255) 

The amplifier might have 6dB more gain with the XLR inputs, however that does not change its max output power as the clipping point remains the same.

You will get more gain from the XLR input 6dB in fact, but this has nothing to do with the power supply. The larger power supply will offer more output power but at normal listening levels will make zero difference. The sound quality and overall gain will be the same.

I hope you are in good health and feeling better - I like your videos. Thanks for the comment to my reply.

Note that the spec is for THD ... not THD+Noise ... the chip can do .008% at about 50% power... but that is ignoring the noise floor.

Few class D amplifiers have low THD. If you want low THD you need to go class AB. You get what you pay for.

The power supply, makes or breaks ANY amplifier. It's like a car, low power engine, low performance car. Likewise, the power supply makes all the difference, but it is probably the most expensive item, so away to cut costs is use a simple or lower power PSU. Cheap always means compromise. With amplifiers that usually means, poor heatsinking and power supplies.

@@MichaelBeeny Indeed those PSUs need an upgrade. Good to see you posting, my friend. Hope all is well with you...

@@Douglas_Blake_579 Hi Douglas, I spend much more time watching other videos. I doubt I will upload anything in the near future.

@@MichaelBeeny I know you had a rough patch there and I'm happy to see you still contributing. Cheers mate!

I'm using a Douk DAC and have really liked it so far. I moved house and don't have a spot for my hifi junk yet so set up a smaller system to listen to music in the mean time. My normal DAC/disc player cost A LOT more than this little $50 Douk but I'm really happy with my temporary setup. I've been into hifi since the 80's and I never would have believed how nice of a system you could put together for so little money these days.

I am not sure about that… then you have to adjust two knobs just to turn down the volume …

With independent pots you can never find the real balance, you could be 3-6dB off depending on your ears.

@@MichaelBeeny I think you can find good enough balance just by ear - after all if it sounds right to you it is good enough. But you’ll have to balance whenever you adjust the volume, that would bother me big time and probably many casual listeners too. Don‘t know about the OP‘s skills in handling volume controls, maybe for some this comes natural.

The first version of this had dual volume controls ... no surprise, people couldn't figure that out... 🤔

With 48 volts, if driven hard can result in overheating and cutting out, especially into 4 ohms. Most of these cheap amplifiers have poor ventilation or even no ventilation at all. About 36 volts is a good safe voltage.

As Michael points out, because of poor thermal solutions and marginal power supplies these little guys do best at 36 volts. I run my TB10D from a 36v 10 amp supply and it sounds amazing. No cutouts or shutdowns... like you would get at 48 volts.

@@Douglas_Blake_579 I have an aiyima A07 with the same class D IC, I ran it for hours on 48V and as loud volumes as I could tolerate and I couldn't get the amp to shut down due to thermal protection and the metal case just became warm to the touch

@@electronicwaves I believe that. But you need to understand that a heat sink in a fully enclosed casing isn't a cooling device ... it's a heater. The inside of that amplifier would be considerably hotter than the outer casing... and given that the heatsink's purpose is largely defeated it is likely the chip is hotter still. The A07 or any of it's cousins will shut down if pushed hard enough. I didn't say it is wrong to use the 48 volt supply. I simply pointed out, as many others have affirmed, that 36 volts 10 amps is the best compromise between heat and performance.

@@electronicwaves You might get away with it at 8ohms but 4 ohms??

Only when troubleshooting 🤪

If wifey insists on having one speaker buried somewhere in the book shelf….

My left ear is about 4 db less sensitive than my right, the balance controls on my systems are always at about 11 o'clock.