The trouble with boards and similar is that neither of the output leads are at ground potential¡ if one accidently hits ground with either output, the board is toast.? Reminds me of the old 1920¡¯s radio where they ran the HV through the headphones!? Best to work from a design where the output is AC/capacitor coupled so that no DC shorts can occur.? Transformer output is, of course, OK too.? There are plenty of low wattage boards like this.? The jaclAl unfortunately suffers from this affliction too.