Cheap tube mic preamp power supply

[mrtnasty]

Is there any reason why using one of these cheap power supplies to power a tube mic preamp like an RCA Ba1a is a bad idea? It says it produces 280V DC and 6.3V for the filament:

https://www.aliexpress.us/item/3256...srl2EXR8glhoCeVIQAvD_BwE&gatewayAdapt=glo2usa

Thanks! David

 

[mjrippe]

With 5A @ 6.3V and 200mA @ 280V you could power several BA1A. Extra filtering on the 280V rail could also drop it a few volts if needed. I have not used one of these switches for a tube project yet, but for the price I might try one.

 

[pucho812]

The only reason to avoid it is that it is a switch mode. Will probably need filtering after the psu to eliminate switch noise