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?
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@jond
Why would you think they are single ended? I’ve owned Quicksilver mono amps that were push pull that looked similar to those!
Ah I just noticed they are monoblocks! You're right @yogiboy I was assuming it was a stereo amp!
Take a picture of the back of the amp and one of the bottom, with the bottom cover removed.


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