Tube amps and speaker ohms


In your opinion , do push pull amps work better with 8 ohms or 4 ohms. .I am under the impression the lower the ohms, the more power is demanded from the amp....Another question, are there low powered SET amps ,and high power SET amps?
I'm looking at a 40 watt 845 tube amp for my 8 ohm, 89 db speaker.. just cked the Thor has a 86 db W18 midwoofers(2 per cabinet) and a 88 db tweeter. Will an 845 amp rated 40 watts be able to drive the 86/88 db speaker? With authority, bass, mids, highs, in dynamic sound stage? Synergy? Or poor match?
bartokfan
+++ but since I do not care for ss amps +++

That is sad. The failure you mention your experienced with your tube equipment would not occur had you been using solid state.

I own (and have owned) solid-state amplifiers that are extremely musical and will work on most speakers.

++ I look for certain tube amps that can carry a relatively heavy load +++

These tube amps are not the best sounding tube amps and more often than not, cannot compete musically with good transistor amplifiers.

+++ though even 8 ohm speakers can dip to 4 ohms on huge orchestral challenges+++

Musical genre does not influence speaker impedance. If speakers dip to 4 ohm on Orchestra, they will dip to 4 ohm on every genre of music known to man.

Speakers rated at 8 ohm that dip as low as 4ohm are not suited to for tube amplification if quality reproduction is a requirement.

+++ TRhe point of the topic was to ask the GENERALIZED question that tube amps prefer 8 ohm speakers +++

No it wasn’t. You asked a myriad of questions but not what you state here.

+++ Which is fine. I'm staying with 8 ohms, and thats that.+++

I don’t believe anybody told you not to purchase an 8ohm speaker. Most posters indicated that there are other factors you need to consider also.

Fact is, most of the posters here have system that can do orchestra. By your own admission, your system cannot – and you do have 8ohm speakers already.

Regards
Paul
Raul, I am not going to argue with you, mainly because I do not quite understand your comment. I think this is mostly due to the fact that neither you nor I have English as our mother tongue.

Transistor amplifier have lower output impedances and are therefore much more suitable for the majority (99%) of modern speakers. They can easily maintain a constant voltage against a speaker load where a tube amp will struggle. In the perfect world, vacuum tube amplifier should have speakers rated at 64ohm/128ohm and higher to do so. Hopefully one day I can get somebody to build me speakers like that to fully optimize my tube amplifiers.

I also believe almost all vacuum tube amplifiers are used against speakers where they do not perform well – Bartokfan is a good example of this.

However, you are incorrect if you say vacuum tube amplifiers cannot maintain a constant voltage against a loudspeaker. It is simply a more difficult to achieve.

You are welcome to disagree and I know and respect your view on transistor vs. vacuum tube.

Regards
Paul
Ok, here is a question that may show my ignorance of this subject but, I will ask anyway. I have a TAD-60 AMP (60 WPC ultralinear).. It has 8 and 4 ohm terminals. I am running Vandersteen 2CE signatures which are rated at 7 ohms nominal and 4 ohms minimum. I am currently using the 8 ohm terminals in my set up. Would I be better off using the 4 ohm terminals? If so, then why. If not then why not.
Thanks,
Eagleman
Eagleman,

A simplified response -

If bass control seems to be a problem for you when you use the 8 ohm taps use the 4 ohm taps. If you use the 4ohm taps and the highs are not smooth use the 8 ohm taps.

Simply said, use the taps which sound best to you. My guess is that if you are listening at moderate levels the 8 ohm taps might sound best.
Eagleman, feel free to ask w/o feeling you will get criticized. I get snides and insults due to lack of tech knowledge, snotty attitude, "mister-know-it-all", negativity, closed minded-ness. So as long as you don't follow me, you'll do all right here. btw I liked your question and Newbee's appropriate answer. I was not aware of how the 4 ohm and 8 ohm taps respond on different fq's. I still don't grasp ohm idea. Only that 4 ohm draws more volts/current from the tube amp. So it was a good question.