Classic tube gear in theory should give you better resale value, but usually comes with issues. For instance, unless it has been played regularly, your classic MC30 or MC240 will probably require new power supply capacitors. And then you get into a thorny issue about whether to stay "pure" and replace only with original parts (to retain its value) or to use superior modern alternatives. No guarantee either that the expensive NOS caps you buy to replace the originals will even be still good after all these years, so you might have to do it all over again.
And then there are the notorious "bumblebee" coupling capacitors. Notorious because they tend to leak DC, which screws up your output tube bias. If you keep NOS tubes, there's nothing like looking up to see the output plates glowing cherry red b/c a coupling cap is leaking. BTDT.
Now Mac gear is damn reliable, and will continue to sound OK for a long time, even when everything isn't working as well as it could. But materials science has come a long way, and things like RCA jacks, and speaker terminations are far better on today's amps than they were back in the day.
I spend a lot of my free time fussing around with classic tube gear, but I am not a purist, and I don't make an effort to maintain resale value. If resale is important to you, I think you may find modern gear easier to live with. I happen to think Quicksilver gear is fantastic (had a set of V4's I still regret selling). Unless you're a wiz with a soldering iron, I'd recommend you stick with today's gear.
If you are willing to mod classic gear, you can end up with nice sounding stuff. Putting motor run oil caps in the power supply, adding modern coupling caps, and tube rolling to get a great sound... lots of fun. But it screws your resale value. There are always exceptions. For instance, the HK Citation-II amps have fantastic iron in them, and Jim McShane sells well-regarded mod kits that actually enhance resale value. But Mac and Marantz buyers, especially those in the far east who have kept the prices up, really value authenticity. So you're better off not fussing with them.
Just my $.02
And then there are the notorious "bumblebee" coupling capacitors. Notorious because they tend to leak DC, which screws up your output tube bias. If you keep NOS tubes, there's nothing like looking up to see the output plates glowing cherry red b/c a coupling cap is leaking. BTDT.
Now Mac gear is damn reliable, and will continue to sound OK for a long time, even when everything isn't working as well as it could. But materials science has come a long way, and things like RCA jacks, and speaker terminations are far better on today's amps than they were back in the day.
I spend a lot of my free time fussing around with classic tube gear, but I am not a purist, and I don't make an effort to maintain resale value. If resale is important to you, I think you may find modern gear easier to live with. I happen to think Quicksilver gear is fantastic (had a set of V4's I still regret selling). Unless you're a wiz with a soldering iron, I'd recommend you stick with today's gear.
If you are willing to mod classic gear, you can end up with nice sounding stuff. Putting motor run oil caps in the power supply, adding modern coupling caps, and tube rolling to get a great sound... lots of fun. But it screws your resale value. There are always exceptions. For instance, the HK Citation-II amps have fantastic iron in them, and Jim McShane sells well-regarded mod kits that actually enhance resale value. But Mac and Marantz buyers, especially those in the far east who have kept the prices up, really value authenticity. So you're better off not fussing with them.
Just my $.02