Sonic qualities of SET output tubes?

Thanks Charles dad,
Didn't realize this had gone to 2 pages when I posted. Will check it out.
(BTW, thanks for the balanced power tip on a different thread.
I now have 4 EquiTechs. Balanced power seems to be one of the best kept secrets in audio.)

Leotis, 
You are welcome.  Balanced AC electrical power is a major asset for audio systems in my opinion.
Charles  

So I take it that higher impedance speakers make tubes sound better somehow.
So I used the 4 ohm taps on my PrimaLuna HP Int to my "8 ohm" speakers instead of the 8 ohm taps, giving the speakers relatively higher impedance vis-a-vis the amp.
And it does sounds better. More presence, more nuance, fuller sound, more real sounding.
But what is actually happening? Is it lower voltage and more current? Or vice versa?
Maybe it doesn't really matter, but is there a simple explanation for the difference between the 4 ohm and the 8 ohm outputs?
Thanks.

Inna > I mentioned LAMM and Wavac.

Blindjim > huge thanks Inna can’t say how much I appreciate all your feedback. yes, you sure did. I’ve been reading furiously on every suggestion, and all the technical data. I am getting confused with all the input I’m gathering, though I do have notes on nearly everything so far.

Saw at least one LAMM amp needs manual biasing. For me that’s a deal breaker. Its ticket is another I suspect, for now at least.


Grannyring > Did you buy that set of Thor TPA30s on Audio Mart?

Blindjim > sorry man, no. Not able yet to do anything worthwhile yet. Still waiting.
Yep. Bone stock, they were the best sounding little goobers I’ve heard to date, and on run of the mill Eff spkrs. That sound is why I bought the TPA 1000 Mk II line stage, and those VR4 JR spkrs. Although not in that order.

If or when possible, I’d buy them or the 60wpc versions in a heartbeat depending on a few buying selling issues.

saki70 > take a look at those with built in amps for the bass units

blindjim > Thanks man. Got it. I’ve seen a few but have decided to go only partly in on low power high eff as a secondary system now.
It could change, though the odds say it won’t, but all of the jury isn’t back yet. So we’ll see. Mostly it looks like a PP amp.


Leotis > So I used the 4 ohm taps on my PrimaLuna HP Int to my "8 ohm" speakers
is there a simple explanation for the difference between the 4 ohm and the 8 ohm outputs?

Blindjim > Leotis, been there and done that myself.
When an amp has optional output taps, the amp is designed to output the total voltage and or current it produces into that load. Ie., 60wpc amp via 4 ohm tap = 60wpc. Same thing for the other taps provided the load or IMP of the speaker is similarly matched, unlike SS amps that automatically see or ‘feel’ the changes and react differently.
.
Essentially, using a lower output tap or lower IMP on a higher IMP load or speaker will cut the power output by 50% or so. In any event it will be less power to the speakers if set up that way.

Speakers should be transparent enough to reveal upstream and room concerns, changes, and problems. For them to do their job as such, they need the right amount of power and the correct electrical operating environment, or as best is possible.

You can look at speakers like rocks. Look at an amp like a bulldozer or truck.

As strong as is a truck or bulldozer, it can only push a particular size of rock. Sure, it can easily push little rocks, or medium sized rocks, and even a larger 4 or 2 imnpedance sized rock but it has to match up to the rock as well with its gearing too, not merely its engine.

Using lower IMP taps sends less power to the speakers, IF the speaker IMP is much higher.

Highs will roll off, bass will be more bloomy, and usually the sound will be smoother and warmer because the speakers are being starved and can not fully demonstrate what they are capable of providing. Resolution will suffer, leading edges will get rounded off.

The sound will tend to be darker and more euphonic than normal as the speaker lacks the power to yield speed and fully demonstrate the entire bandwidth properly.

I did that mismatch with a couple different amps trying to get them matched up the best way possible. You don’t truly know what the imp curve is on many speakers, but amps do. They will tell you IF you pay attention and try the amps various taps..

Usually, the spkr maker gives you a really good indicator of what a nominal IMP for their spkrs run but that’s at one particular freq at one designated voltage. Like 1KHz at one watt, or 2.8 volts or so.

But what about power needs at other freqs? ImP will change then and music is made of many frequencies and volumes.

Its at times a best guess scenario so we use the amp to tell us what it likes, and we listen for the best match.

I liked the mismatched setting on a pair of speakrs I had as they were brand new and not fully run in. they sounded bright and thin on the right 8 ohm tap so I slid them onto the 4 ohm tap. Sounded much better then albeit a whole lot darker though.

after about three or four months I switched them onto the higher IMP tap and whoa! Night and day different! By then they were run in quite well. I begin getting loads of resolution, impact, better dynamics, more transparency, greater extension, every aspect of the reproduction improved. Thankfully they were 93db and an easy load of 6 – 8 ohms and I did not push them hard so the obvious lack of power did no harm to the tweeters. From clipping.

following the uptick to 8 ohm taps, and the greater resultant transparency ai was able to determine what did or did not work well in the system. Wha twas making things bright, rolled off, was buzzing, if there was a ground loop causing the trouble, more exactly how wires were contributing to the affair, etc., bedcause then I could hear things better.

Until then, I was like the system mostly in the dark. But for a while, it sounded OK to me. lol