Tube amp for "difficult" speakers,,,

Tvad I don't have the specific info at hand but my speakers are a good match to my VAC 70/70. Just for others,I found this article on the VAC website.

http://www.vac-amps.com/Technical_Monograph_90-9.htm

I know an older gentleman who used to own Consequence. He has gone thru many amps, from high power solid state like Bryston 7B-ST to a 70wpc tube amp. His favorite was the medium power tube amp that was made in Canada, but the company has gone belly up and I can't remember the name at this moment.

I used to own Confidence 5 which many believed are the modern iteration of Consequence. I have tried 10+ amps on those and I would not recommend tube with them. The best tube amp I had success with was Sonic Frontiers Power 3, but even then they could not fully bring out the bass.

If you are not dead set on Consequence, I suggest you look for a new speaker that has more resolving power, quicker, more transparent, and easier to drive. As much as I loved the Confidence 5, I have moved on and much happier now.

Tvad you must be right because I experience a lush midrange with plenty of balance,weight,and lucidity in both mid and low frequency.

Just a thought you might contact Kevin Hayes at VAC and get his thoughts. I have a Ren 70/70 and it has plenty of power for Dynaudio drivers although the crossovers are custom. I know the speakers efficency is in the high 90's. Kevin's amps have tremendous transformers and really deliver more then there stated output in my experience.

Roger

Ultimately your right, difficult impedance loads (not necessarily but jagged, irregualar dips and spikes) really do need SS.

If your speakers do present a difficult load, there is proabably no better all tube amp (hybrids would also work)to deal with dipping impedances the Music Reference RM9 Special Edition which is one of the few amps that actually increases power into 4 ohms (200 watts)compared with 8 ohms (160 watts) and that should be enough power to drive speakers with your sensitivity. However if I did have a difficult speaker load I would proabably look at the Pass XA.5 amps that Tvad recommends.

your krell should be maximizing those dynaudios. just get a nightlight to see a glow. even a big mac with tubes isn't going to do any better.

Since tube amps are more sensitive to overall load than most solid-state amps, it is better to know not only the speaker voltage sensitivity of 83 db/watt/meter, but the impedance load. A lot of speakers with low voltage sensitivity are relatively easy loads, so all you really need for a good tube amp match is a fair amount of output power. Conversely, you can have a 92 db sensitivity, but the load can have low impedance dips and can be reactive (high inductance and/or capacitance). In the latter case, it can significantly change the tonal balance of the speakers and/or cause the tube amp to run out of power, especially in the bass. You should be able to procure an impedance versus frequency curve for the speaker from the manufacturer, or you could ask them if they recommend tube amps. I seriously doubt any type of SET amp would work with these speakers, but perhaps some of the more powerful push-pull amps might.