• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

HIFI 250W Switch Power Supply DC300V@0.6A +12.6V@4A +6.3V4A

I wouldnt buy mains powered switchers from china, However that module looks well made. The designer knows his stuff. Lytics are likely to a price, but all in all not a bad product IMHO.



You can reduce the output noise with a 100uH 10uF external filter and a ferrite ring around the output wires.
 
Unless I can see the schematic I’d be sceptic.

I’d like my smps to have active pfc, be isolated and also be performant (efficiency, ripple and noise).

You can always add filters but switching speed and other aspects are more ingrained in the design.
 
Perhaps do some google searching for forum threads - that psu has come up before.

It has no safety compliance for mains AC connection, so even though it looks as well built as any other mains AC supplied psu you take all the risk.

Just for diy use, I'd buy it for initial assessment, but it is a few $, and it preferably needs some bench testing to see how it manages cold heaters and B+ load changes. It also helps if you know smps and can assess how well the pcb is laid out and the parts it uses and the cooling requirement for your specific application - otherwise you throw the dice when you use it in any practical amp and have to then work through any issue that may arise (from thermal shutdown to smps control mode changes to ground loop noise).
 
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It looks well built, nice walled off barrier strips, etc. I like the form factor of an aluminum tray sub-chassis, with all transistors facing outward then simply sinked to the tray. I can love that form factor for making any linear PCB based PS "module", filament module, Maida module, etc. I think I'll steal that form factor!
 

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I haven't tried it yet.

I have decided the SMPS are so cheap they are worth testing and have ordered the same power supply for testing. I intend using the SMPS in a SE amplifier and will report back to this thread re noise and performance when it is going.
The SMPS should make the amplifiers lighter and maybe look cleaner with one less transformer.
Ken Kranz