Building the Audio Note Kit 1 SET amp...

02-13-15: Mikirob
Sebrof, thanks for chiming in. Do you still enjoy the Katz? Were you trying to sell them a while back?

I had an either or ad up, IIRC: Either the Lores or the Katz. I liked them both but didn't need them both so I think I opened either 2 ads or 1 ad that said take your pick. The Lores sold first. I listen to the Katz every day while I work from home.

02-13-15: Rebbi
The other thing I noticed, in retrospect, was that the Kit 1 did not play as loudly on his much more sensitive speakers as I thought it would. (This later led me to wonder whether the amp is even putting out its rated wattage at all.)

3 watts, 8 watts, what's the difference? Seriously there isn't much, and I thought the Kit 1 played about how I expected it to. I mentioned that I usually have my 2A3 amp's volume at 11:00 or 12:00 when I listen at my normal levels (low 80 dbs) and I'll go to 3:00 on rare occasions. That's all about the gain of the amp. Power is when it starts to clip, which you won't know until you get the issue sorted out. I thought it sounded very nice until it almost blew up my speakers (joking and exaggerating), and it looks beautiful. Despite your issue I'm seriously considering looking into one of their PP kits to bi-amp my bass drivers.

Sababa!

I agree with Sebrof's experiences as there not being much difference between 3watts and 8 watts.
I have Wavelength 45 amps and 300B amps. (driving Beauhorn Virtuoso speakers @ 106 db with single Lowther DX4)
There is not much difference in max volume levels.

To be precise, 8 watts is 10log(8/3) = 4.26 db greater than 3 watts, everything else being equal. To put that in perspective, the classic rule of thumb is that a difference of 10 db (10 times as much power) will be subjectively perceived as "twice as loud."

Regarding "everything else being equal," though: Assuming that those power ratings are based on an 8 ohm load, to the extent that the speaker impedance varies from 8 ohms at various frequencies, and to the extent that the output impedances of the two amplifiers are not the same, that 4.26 db difference may change significantly in either direction. Other design-related differences between the amps, such as in their power supplies, of course can also affect that value significantly, depending on the impedance characteristics of the speaker, the dynamics of the music, and other variables.

Sebrof, great job helping out! Rebbi, continued good luck.

Best regards,
-- Al

Almarg, as an aside, do you have any thoughts about the ability of the Coincident 300Bs driving any of the Daedalus speakers?

Hi Rob,

Although I haven't personally used any SET's, low powered or otherwise, in my own system, I'm sure that would be a wonderful pairing for most listeners with the great majority of recordings, and for many listeners with all of their recordings. However, I also feel certain that at least a few recordings that would be listened to by some listeners would cause the amp to clip, or at best to experience a substantial rise in distortion.

My collection includes many classical symphonic recordings on labels such as Telarc, Sheffield, Reference Recordings, Chesky, etc., which have brief dynamic peaks that reach SPL's of 100 to 105 db at my 11 foot listening distance. I can't conceive of an 8 watt amplifier, no matter how robustly designed, being able to comfortably handle those peaks, even with the 94-98 db efficiencies of the Daedalus speakers.

That is why I chose a VAC amp which uses four 300B's per channel, in a push-pull parallel configuration capable of 65 watts. I wanted to draw a compromise between the magic that a 300B can offer in a SET configuration, and having power capability that would not be marginal (or worse) under any circumstances that could conceivably occur with my particular listening habits. And I made that choice while realizing that the cost of upgrading eight 300B's from the VAC-supplied Chinese tubes would be prohibitive.

Another point to keep in mind is that although the impedance curves of the Daedalus speakers are exceptionally flat, and they are extremely benign loads in terms of phase angles, their impedances are in the 6 to 8 ohm area (6 ohms in the case of my Ulysses), as contrasted for example with the 14 ohm nominal impedance of Charles' Coincidents. So I suspect that his Franks are capable of providing a bit more power when used with his speakers than they would be capable of with mine.

But as I say, I suspect that for many and perhaps most people the Franks would do just fine with the Daedalus speakers.

Best regards,
-- Al