Amp and speaker matching.

Some ss McIntosh amps don't quite behave like many typical ss amps.

That is understandable. Dynaudio loudspeakers are designed for transistors. Its hard to make them sound right with tubes.

I wanted to Thank everyone that responded...Most particularly
Atmasphere for the very informative link and Yes I agree it would have to be a 200watt or better tube design.Maybe a Audio Research. It this point i'm really thinking of improving the preamp with something more on the level of the McIntosh Amp. I am liking the tube/solid state combo for these dynaudios.

I have used this mix for many years. So, Thiel CS 3.6 (2.5 to 4ohms, 86db) with CJ Premier 11a and 6550 based Sam's Audio Labs Integrated. So, both 6550 based amps.

The results have been both excellent and problematic. I have had success in a smallish 13.5 X 16' room, but Sam Kim had to employ unique technics to give me the gain I desired, like a 3-ohm tap for the Thiels.

I have recently decided to purchase more sensitive speakers for my amp. This decision became clear when trying hi-rez digital files in my setup. When playing 96/24 files, I could not approach the sound levels of my analog front end without raising the noise floor where the music became harsh sounding. I also got this result when playing Redbook CDs, but level drop became quite apparent when playing Chesky CDs that are lower-level.

I would not recommend the combination for digital playback and it's marginal, at best, with analog.

Note I use a Prima Luna Tube PreAmp...Prologue 3. McIntosh MC352 power amp Dynaudio Contour 3.0's and A Rega P3/24 with groovetracer upgrades and Nagaoka mp200 Cartridge. Cables from: Signal,Morrow Audio,Nordost. Thanks agian for the great INFO.

Well I currently use a McIntosh MC352 and it is a very good match with the Dynaudio Contour 3.0's. So Im going to stay with the Tube Pre and Solid state Combo,I love my speakers and dont want to change them. I listen to stuff pretty loud I like slam! so Ill keep my MAC. Thanks everyone :-)

86 db means that you will generate a SPL of 86 db at 1 meter with 1 watt of power.

It is easy to get confused about this! In this case the spec is Sensitivity, not Efficiency. Sensitivity is 2.83 Volts at one meter, meaning that with a 4 ohm load the power is 2 watts. So the *efficiency* of this speaker is more like 83 db (since 2 watts is 3 db more than 1 watt) while the Sensitivity is 86.

There is also the issue of whether tubes will sound OK on the Dynaudios regardless of the power; IMO they will sound OK but the speaker will be the sort of load that has a tube amp at a disadvantage. For more about this see

http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php

If you really want to get the most out of your tube investment dollar, I would get a different set of speakers! OTOH if you want to optimize these particular speakers you are probably looking for a transistor amplifier or a very large tube amp (+200 watts).

It'll work and might sound decent but not an optimal match. Getting optimal amp/speaker match is essential to get the best objective results.

HI Grannyring,
It`s hard to know sometimes,I suspect it depends on the particular tube amplifier. Two amps with the same power rating can in reality be night and day different(transformer,power supply robustness etc.). Jerroot and Ard`s experiences suggest they got great results rather than merely adequate compromise.

Rrog is spot on. The 70 watt tube amp will work and produce nice sound, but the power reserves and headroom will not be there for complex and demanding material at higher volumes. The speakers will not sound as good as they could as they will be dynamically limited in respect to your current amp.

When someone asks if a cetain type of amplifier will drive their speaker I am assuming they want to know if the amplifier will drive their speaker properly. I have tried many combinations like driving Maggies with 15 watt Quad tube monos and driving the giant Duntech Sovereigns with a 14 watt single ended amp. Although I was able to play music through these speaker with these tiny amplifiers the speakers did not sound their best. Simple music is ok, but on complex large scale music at high volume, forget it.
Stereophiles favorable review of the Dynaudio Contour 3.0 was with amplifiers like Bryston 4B-ST, Bryston 7B-ST monoblocks and Levinson 331.

The answer is definitely maybe. Yes, your Danes lower sensitivity is an issue. If 3.4 ohms is their low point, that's not too much of a concern since most tube amps have 4 ohm taps as well as 8 ohm taps. Bigger questions are about the size of the room and how loud you like to listen. Remember, 86 db means that you will generate a SPL of 86 db at 1 meter with 1 watt of power. That means 10 watts will generate 96 db. 10 db = twice as loud, so 96 db is twice as loud as 86 db. However, the farther you are (from 1 meter) from the speakers, and or the bigger the room, that 86 db rating will drop. How lively (reflective) the room is will also factor into the equation.

So the only real answer is to try for yourself. See if you can borrow a tube amp for demo. Do you have any local audiophile friends or dealers who may be able to assist you here?

My gut feel is that you should be fine, unless you are in a very large room and/or listen at very high levels. Most of us don't use nearly as much power as we think we do. You are probably using less than 10 watts of your 350 watt amp now.

I have driven my Maggie 3.6's (86db 4ohms)with my VTL ST-85 in triode mode which is 40 watts with no problem. It is hard to answer your question unless you try the combination or someone here has tried it
Alan

I run a pair of Totem Mani-2's (4ohm/85db) and had previously auditioned them with several tube amps. The closest to what you're thinking would have been a Jolida 502B (60W rated/85W max) There were a couple of others, a Prima Luna Dialogue 2 and a Synthesis (Italian but sorry, can't remember the model) both of which were of lower power. Although each of these amps did drive the Totems nicely in some areas, my overall opinions kept me looking for another tube amp without the deficiencies I was hearing. The sound was always, well, too thin if that makes sense. In the interim I pushed them quite satisfactorily with a W4S STI500. Then I found my Cary CAD-120S MkII (120W Ultra/60 W Triode) with which I have been thrilled. My search has ended for now. Having inefficient, power hungry speakers made for a long, sometimes frustrating search, auditioning amps that many (especially sellers) told me would pair well with the Mani-2's. I ended up where I always suspected I needed to be...with a tube amp of higher output. FYI- I listen to broad range of musical styles, 85% vinyl/15% CD. YMMV. Good luck.

My experience with Dynaudio drivers tells me they like high quality solid state amplification and the Contour 3.0 is no exception with the impedance dropping to 3.4 ohms. This is of greater concern than the 86db sensitivity rating.