Best Integrated All-tube Amp?

I am not aware of an integrated amp that meets your requirements (single-ended, triode, 300B-based, class-A, no negative feedback, low distorsion, point-to-point wiring, good bass, and a well-known brand), especially one that is "affordable", whatever you mean by that.

The VAC Avatar is about the only thing that comes close, and I believe it is $3k-$4k used. The VAC Renaissance 70/70 Mk. III amp (not integrated) meets all of those requirements other than being single-ended (it is push-pull), but costs $5k-$6k used and you would need a preamp. The VAC amps do come close to the single-ended sound and avoid the significant disadvantages. Singer in Union Square carries VAC -- ask for Dave Lalin.

I agree with the others - you have way too many requirements. You are making yourself overlook many good options (like the Mc2275). I second the Jolida 302b which is cheap and comes surprisingly close to fantastic sound quality. I have one in my audio room now and it was a shock to me. At its price, you could try it at least.

Don't get hung up on circuit design details (I am an electrical engineer). There is more magic involved that you think and basing your decision on your criteria is doing you a disfavor. Trust your ears instead. If you love the Mc, go with it. Good luck! Arthur

I've owned the Rogue Tempest and loved it. One of those components I wish I still had.

You could be better off--if you are willing--to expand your horizons into monoblocks. You will have more to choose from (Wright, Wellborne, etc.), and you could always use a Placette RVC (remote volume control), and spend considerably less than the MAC you referred to above. Your other option is to get a CD player that can be run directly into your amps, and again, you would have remote.

In any event, I'm sure you know that SET does not sound the same as push/pull. I've heard the Jolida 302B, and owned the 502B, and despite being quite satisfying, they are distinctly, sonically, not SET. We currently own $6K 50W push/pull triode monoblocks, and while they sound absolutely incredible, they do not give you the peeled-open SET midrange like our 4W 2A3 SET amps do. Or the 300B that we previously owned.

If you think that 17W is not enough (why not?), and that the MA2275 is too expensive (what DO you want to spend?), you are unlikely to find the product that meets your requirements unless you spend WAY more money, and are willing to buy from a boutique manufacturer. An integrated, high-watt (for SET), class A 300B for an entry-level price? I just don't see that happening.

One of the most musical sounding amps I've heard is the Audio Mirror 40W 6C33C tube SET monoblocks. They will drive just about any speaker, and the 6C33C tube is both much cheaper and more robust (not bloomy) sounding than the 300B. They are about $2300 brand new. And no, I don't have any affiliation with them.

Good luck!

One more thing, Josep. As you alluded to in your initial post, you might upgrade your Antal's at some point. I'm sure you are aware that any amp, no matter how punchy in the bass department, is going to be challenged to deliver the goods to you with a speaker that cuts off at 50Hz, as do the Antal's. You might want to consider a sub, or doing that speaker upgrade first, or at least simultaneously.

Just a thought.