Tube info

What is your budget?

The Amperex 7316 is my personal favorite, but pricey.

I also like the RFT 12AU7.

On the domestic side the black-plate 5814s are an excellent value.

Have you decided on power tubes?

My experience is that they can make a bigger difference than the smaller tubes.  You can fine-tune your sound quality by mixing different qualities in the power tubes and the driver tubes.

FULL DISCLOSURE:  I occasionally sell tubes from my personal collection.  I can post a listing here if I have something that interests you.

I have several power tube options available, again depending upon your budget.

The premium European 12AU7s will likely be above your $30-$40 each budget.  The US options should be well below that.

The Gold Lions are nice.

I have quads of GE, RCA, and Ken-Rad domestic and 2 different styles of RFT Germany 12AU7s that are under your budget.

I have some Sylvania and Raytheon pairs and trios, but no matched quads that would also be well below your budget.

My Amperex/Valvo/Mullard/Siemens/Tungsram varieties aren't going anywhere anytime soon.  ;~)

Enjoy.

@mechans, my personal collection could easily be called obsession or even addiction.  From 2008 to 2010, I acquired over 1,500 tubes.  

Fortunately, I regained control and am down to somewhere in the 275 range.  Still, entirely too many.

The adrenaline rush of buying or winning an auction is far out-weighed by the real work of prepping, testing, taking pictures, posting listings, answering silly questions, ignoring low-ballers, packing, and shipping involved in selling. 

Buying is fun; selling is work.