Since my dual 2N3055 driven flyback power supply was accidentally thrown
away, I was pondering building another until coming across subject
mentioned assemblies. They're on eBay and elsewhere. Looks like various
drivers with flybacks. Example: https://tinyurl.com/y4lzxt85 Questions
would be:

1) Do these have built in diodes? I DO want to be able to drive a HV
multiplier.

2) Performance/ versatility/ durability comments? Any specific
recommendations of one over the other, etc? Most seem to fall within the
$15-$20 US range. The 3055's with flyback and tripler could output 30-40
KVDC with mA's available. Could one of the prebuilt Chinese units do the
same?

Might be cheaper to buy than to build another from scratch so your
thoughts/ experiences appreciated.

Thank you,
Jon