Thanks, I may actually just keep them both, although one person so far has expressed interest in buying the amp.
I've always thought about trying different tubes, but the uncertainty seems so great, and once I go too far with tubes, then the Bravo's budget price no longer seems worth it :\
I'll look into it some more though. If it turns out no one wants to buy my Bravo, I might just grab another tube for it and give it another try.
You really have nothing to lose at this point. I've become something of a 12AU7 collector (and some of its variants), and I can assure you that you can change the character of the sound quite readily just by swapping tubes. It is kind of amazing if you've never tried it before. I honestly didn't believe it until I tried it for myself, and I'm now a believer.
You know, I like to think of myself as a frugal person. And then I went and started buying tubes.
I realized that I needed to slow down when I had accumulated about 20 tubes lol.
I had some rather tragic stuff going on with my family this last summer, and I really needed a distraction from the grief. So this kind of became my distraction for the negative crap going on. Fortunately, it really isn't too expensive, if you research a bit.
I have purchased old American NOS tubes for as little as $2.50 on eBay. Heck, the shipping sometimes costs more than the tubes I buy lol. Just search for 12AU7 (or it's variants) and put in a bid on any old American tube. Some fellow was selling 5963 (a 12AU7 variant that is a drop-in substitute) tubes for $2.50 each in bulk a couple months back, so I grabbed a half dozen of them. That purchase was under $20 including shipping. You don't need to buy Mullards or Telefunkens to get better sound.
I will say though that there are a lot of sellers on eBay who are driving up the prices of Mullards and Telefunkens to the point where it has become ridiculous. I also think some people react poorly to the whole concept of auctions, and get sucked into the drama of bidding wars. These folks wait until the last 30 seconds of an auction, and bid up the price to 3 times what something is worth. Others put up tubes with fixed prices that are way above what they are worth, and some folks buy them anyway (probably because they see "Mullard" and go nuts). The old adage about a fool and his money comes to mind.
Bravo V2's can be had on eBay for about $50-55 bucks including shipping, or on Amazon for $69 bucks. So their resale value isn't going to be real high.
I'm also saying this because I do have a Magni (and a Modi), and have spent some time doing direct comparisons of the sound of both amps. Depending on the cans you are using, you might regret getting rid of that Bravo amp prematurely. The Magni is a nice amp, but it's solid state, and the Bravo is a tube hybrid. Even a hybrid tube amp produces some of the warm sound that tube amps are famous for. Some folks prefer tube sound over solid state, and some like it the other way around. I don't know your taste preferences, but I think you'd be better off doing your own little comparison once the Magni arrives, to see which sounds better on your setup.