My First Tube Amp-Some Questions

[Le Basseur]

I bought a used Fender Hot Rod Deville and the guy said "I loaded it with groove tubes...its ready to rock" Its sounded pretty good but was bassy as hell...had to turn the bass almost all the way down and turn the treble almost all the way up to get a decent sound. I thought it was screwed up, but I decided to try a new set of power tubes before taking it to "the shop". Man, it was like a totally different amp...the highs were there, the boomy bass sound was gone.... and it had alot more power.

From now on, when I buy a used tube amp...THE FIRST thing im going to do is put in brand new power tubes (even if it sounds good and seems to be fine). Thats "square one" from now on with me.

Perfectly true.
The HotRod Deville you have is a "hot" amp (the output tubes are driven really hard) and you have the misfortune to get a worned-out or poor Groove Tubes (it's well known that Groove Tubes have LAAAARGE quality variations because they used to take and re-brand every Russian junk they could lay their hands on...that's why I deeply hate American importers like Groove Tubes,New Sensor and Ruby....they just re-brand everything without too much discernement!).I don't know what tubes you put on (you didn't mentioned) but I take you by word because of what I said about Groove and because it's obvious that different output tubes behave different in a given amp,especially if you go for output's stage distortion,not tonestack's.
Keep rockin',
PS
I might left the impression that I have something against Russian tubes.In fact,it's right the contrary...I love,praise and worship them very much but what I'm talking about is THE military-grade Russian tubes,not the re-labeled junk.
In every aspect (tone,reilability,versatility) THEY RULE!