What Speakers SOUND GREAT with Moderate-Powered Tube Amps (27 -85 WPC)? SET or Push -Pull is fine! What are those Speaker Designers doing differently?

[loki1957]

Viking Acoustics Tube Master. They are 98db but not horns.

 

[Atmasphere]

Viking Acoustics Tube Master. They are 98db but not horns.

They certainly look interesting!

 

[microstrip]

No. If you monostrap a 36 watt tube amp to be 72 watts, if you have it matched properly to the speaker it will be 72 watts. Tube amps do not double power as the load impedance is halved; if they are behaving as a voltage source then they might halve power as the impedance is doubled. Not quite the same.

Yes, it is why tube amplifiers usually have impedance taps in the output transformer - we get maximum power at the best matching impedance.

However sometimes people prefer an non matched set up because of damping - for example many people prefer the 8 ohm setting in Audio Research amplifiers when driving Wilson Audio 4 ohm speakers.

 

[microstrip]

I used to own CJ MV60 (60 watts/channel), and at the time CJ was very supportive of creating a monoblock configuration out of them by getting a 2nd MV60. I wonder if one could do the same with their current reference level ART 27a amp which is an SET Triode at 36 watts/channel into 4ohms and apparently sensational. That takes it to 72 watts per channel, but as I understand because the amp sees half the impedance load (or something like that?), it actually becomes 144 watts/channel?

As far as I have seen the ART27a is a triode push pull amplifier- it uses the KT88's in strapped mode.

 

[Atmasphere]

Yes, it is why tube amplifiers usually have impedance taps in the output transformer - we get maximum power at the best matching impedance.

However sometimes people prefer an non matched set up because of damping - for example many people prefer the 8 ohm setting in Audio Research amplifiers when driving Wilson Audio 4 ohm speakers.

If ARC did their homework right this will cause the power tubes to run hotter, since more of the output power is dissipated in them rather than the load. This would have the effect of reducing the output power (that heat has to come from somewhere after all) and increasing distortion. And it would reduce the damping factor. IMO a poor way to go about it

 

[microstrip]

If ARC did their homework right this will cause the power tubes to run hotter, since more of the output power is dissipated in them rather than the load. This would have the effect of reducing the output power (that heat has to come from somewhere after all) and increasing distortion. And it would reduce the damping factor. IMO a poor way to go about it

I can admit that ARC did their work right, as shown by the measurements and excellent sound quality results of systems using their amplifiers. Since long I know that in the high-end some times what matters most is the result, not our technical criticism.

I found a similar situation shows with other brands - a Lamm user also told me that he prefers to use the 8 ohm setting on the ML3 with the XLF. Most people with experience with tube amplifiers with output transformers having taps will advise users to try and pick the best setting by hearing.

BTW, I have found that people have extremely different opinions on the best value of damping factor.

 

[LL21]

No. If you monostrap a 36 watt tube amp to be 72 watts, if you have it matched properly to the speaker it will be 72 watts. Tube amps do not double power as the load impedance is halved; if they are behaving as a voltage source then they might halve power as the impedance is doubled. Not quite the same.

Thank you! Very clear. Well, 72 watts does provide a bit more power if one wanted to go there, and my recollection is that the CJ designs have historically allowed people to do that.

 

[Atmasphere]

Well, 72 watts does provide a bit more power if one wanted to go there, and my recollection is that the CJ designs have historically allowed people to do that.

Most tube amps can be monostrapped- that is their outputs and inputs paralleled, thus doubling their output power (in most cases; with one of our smaller amps the output power is actually tripled) and allowing them to drive an impedance half of what they could before. So the 16 ohm taps become 8 ohms, 8 ohms 4 and so on.

 

[Addicted to hifi]

Klipschorns would sound great with a set amplifier.

 

[steve59]

The gent I bought my Kef Blades was using a 27 wpc tube integrated and it sounded great within its limits.