Ordinarily I would say you don't need an amp you need speakers. But unlike some I am not a fanboy and actually read the info and so since you are already fine with 60 watts then that's not a problem and you should be fine with the Carver Crimson 275.
Honestly though you should realize 60 vs 75 watts is insignificant. You are looking for the total tube experience (there I go again, actually reading the question) so you should know that is almost totally down to the first watt. You're pushing it trying to get away with speakers under 90 dB. My personal limit is 92. Won't even consider anything under 92. But you got em, like em, they're not going anywhere, and you're even happy running them with 60 solid state watts.
No idea why you would want pre-amp input. That will rule out a lot of really, really good integrated amps. Being on a budget, even a $4k budget, you should know at that level the interconnect alone will add another couple hundred bucks. Separates in general are a money pit. I think you'll be way better off in terms of "the total tube experience" to go with the Raven Blackhawk. https://www.ravenaudio.com/product/blackhawk-mk3/ For sure there is nothing at that price point that will give you more of "the total tube experience". If you really want the "total" experience step up to Osprey, run all kinds of tubes. Dave has a killer selection.
You get a few more watts, sure. But again, there is no significant difference. What you are really paying for is the flexibility of being able to run a wide range of NOS tubes.
The Blackhawk doesn't have pre-in, but it does have adjustable sub out. Just pointing it out. Seems to me for whatever reason, small room, low listening level, whatever the reason, you're okay with your current amp. This alone tells me you'll be okay, power wise, with the Blackhawk.
Not trying to "sell" you on it. Already said you'll be fine with the Crimson. Save you two grand you can put into something else, better speaker cables, interconnect, which you mentioned not having.
Nobody yet mentioned it, but since you are a newbie you should know the interconnect and speaker cable are every bit as important as the amp and speakers.
All the amps here, the Raven especially but frankly all of them, are leagues better than your 90's era solid state. You get the Raven, you are gonna be stunned. Whole new world. Unbelievable. But pretty much the same with any of the other tube amps as well.
Reason I mention this is people tend to look only at what's right in front of them right now. Odds are you get a great amp, it opens your eyes and ears to the potential. Right now you are probably thinking what you can afford to spend now and what you can get with it. I'm suggesting you think longer term.
The difference is one way you get the Crimson for $2k, put $2k into interconnect and speaker cable, maybe a power cord or two, and have one pretty darn nice system. Another way you get something like a Raven, its more of a lifetime anchor type component, and gradually add really good wire, source, etc.
You can see how much depends on things about yourself that are hard to explain on a "what amp should I get" level. Been there. Done that. Take your time. You'll figure it out.
Honestly though you should realize 60 vs 75 watts is insignificant. You are looking for the total tube experience (there I go again, actually reading the question) so you should know that is almost totally down to the first watt. You're pushing it trying to get away with speakers under 90 dB. My personal limit is 92. Won't even consider anything under 92. But you got em, like em, they're not going anywhere, and you're even happy running them with 60 solid state watts.
No idea why you would want pre-amp input. That will rule out a lot of really, really good integrated amps. Being on a budget, even a $4k budget, you should know at that level the interconnect alone will add another couple hundred bucks. Separates in general are a money pit. I think you'll be way better off in terms of "the total tube experience" to go with the Raven Blackhawk. https://www.ravenaudio.com/product/blackhawk-mk3/ For sure there is nothing at that price point that will give you more of "the total tube experience". If you really want the "total" experience step up to Osprey, run all kinds of tubes. Dave has a killer selection.
You get a few more watts, sure. But again, there is no significant difference. What you are really paying for is the flexibility of being able to run a wide range of NOS tubes.
The Blackhawk doesn't have pre-in, but it does have adjustable sub out. Just pointing it out. Seems to me for whatever reason, small room, low listening level, whatever the reason, you're okay with your current amp. This alone tells me you'll be okay, power wise, with the Blackhawk.
Not trying to "sell" you on it. Already said you'll be fine with the Crimson. Save you two grand you can put into something else, better speaker cables, interconnect, which you mentioned not having.
Nobody yet mentioned it, but since you are a newbie you should know the interconnect and speaker cable are every bit as important as the amp and speakers.
All the amps here, the Raven especially but frankly all of them, are leagues better than your 90's era solid state. You get the Raven, you are gonna be stunned. Whole new world. Unbelievable. But pretty much the same with any of the other tube amps as well.
Reason I mention this is people tend to look only at what's right in front of them right now. Odds are you get a great amp, it opens your eyes and ears to the potential. Right now you are probably thinking what you can afford to spend now and what you can get with it. I'm suggesting you think longer term.
The difference is one way you get the Crimson for $2k, put $2k into interconnect and speaker cable, maybe a power cord or two, and have one pretty darn nice system. Another way you get something like a Raven, its more of a lifetime anchor type component, and gradually add really good wire, source, etc.
You can see how much depends on things about yourself that are hard to explain on a "what amp should I get" level. Been there. Done that. Take your time. You'll figure it out.