By weight. Different manufacturers used different transformers, so you could weigh it.
(I'm joking).
Take pictures and share them.
(I'm joking).
Take pictures and share them.
How to identify tube amp
I just received a pair of mono blocks that don’t have any branding or identification. It didn’t come with tubes so I’m not sure what tubes to buy for it! How do I identify who manufactured the amp and/or figure out what tubes to get for it?