Cornwall IV – tube (amp) choice

That little Luxman is a wonderful 10 wpc tube amp, punches above it’s weight class. I have it in my office. Lowest power amp I ever owned, and it did well playing my Wharfedale Diamond 225’s which are the least efficient speakers I ever had, 87db. Now driving my restored AR-2ax’s very nicely. In that 10 x 12 room, at the moderate level I listen to there.

I hooked it up downstairs to the big horns/15" woofer, at least 102db efficiency like the Cornwalls. Sounded great, but in that space, to get to live levels, and have some reserve for peaks, I felt I was pushing it too much, I’m not used to volume knob being nearly full on.

Tubes: Oh Yeah!

Power: enough, but not too much, with future considerations:

efficiency of 102db/1w/1m: ’not much’ power needed.

I drove my similar speakers (horns, 15" woofers) with 30 wpc tube amps for many years (they came with Fisher 80az mono blocks). Then 35 wpc, now 45 wpc, more than enough, never near full volume and I play fairly loudly, like live in a small club.

I only moved up in power for feature reasons, 30wpc is no compromise for those Cornwall IV's. I had and sold McIntosh SS 300wpc, the tube amps/15" woofers make lots of wonderful sounding bass, don’t worry about that.

That let’s you use a variety of tubes, so combine tube type research, optional tube uses (some have switches for this), easy Bias.

Personally, I have used EL37’s (originals, too pricey now), EL34’s, 6LC.... 5881, 7591, 6550, KT66, KT88, (never tried low power or higher power 120’s).

With my similar speakers, I preferred the KT66 in the Fisher 80az 30wpc tube mono blocks; and now prefer the KT88’s in my Cayin A88T 45wpc integrated tube amp

Consider weight/size/heat/placement options (as well as cost) when considering size of tube amps, line of sight for remote controls, ...

Your speakers can be either Bi-Wired or Bi-Amped. You might think about that now, more significant than tube rolling. That would be a very good reason to have a separate tube preamp with remote control features, and mono-blocks near the speakers.

Think Long, Go Deep.

pick tube type first, then find an amp.

that’s kinda what I was saying when I listed all the tube types I have heard, said research tube alternates, generalities of sound, keep easy bias in mind.

In addition to needing 16 ohm taps, KT88 is how I selected my Cayin which I knew could use either 6550’s or KT88’s. 6 moons review sold me!

I guessed the KT88 would be a slightly more powerful KT66. Some amps offer EL34 or it’s substitutes, or a switch for a different tube type.

Next we have your ears/preferences, for a first time tube experience, a trip or two to a showroom is wise, however, you would want to hear the same input/preamp/speakers, that’s not easy.

Live near me in NJ, come on by!

In any case, what brand KT88? what in front of it, 12ax/12au or 6sn7/6sl7. Cayin my first amp with 6sn7/6sl7, and I was quite surprised at the change in sound two different makers. 

Luckily I bought my tubes from Brent Jesse, he let me finish burning them in 60 hrs first, then exchange for full credit, tried a different brand at half the price, sounded twice as good!