2. amps-preamps
  3. 1446647990

Transitioning from SS to tube amplification

Except during my early years in this hobby when monaural and vacuum tubes were the only choice, I've always used solid state amps and, mostly, electrostatic and ribbon panels. Recently, I bought a 20+ year old pair of good stand mount monitors (Reference 3A Serie MMC) that sounded very good with my solid state Peachtree pre and power amps so I thought it would be a good time to also try a vacuum tube amp in lieu of the many challenges associated with pairing tubes with my Martin Logan electrostatics speakers.

I started with a borrowed entry level but well reviewed Primary Luna Prologue One integrated amp paired with the Peachtree Audio Nova integrated as the preamp. I chose this combo because of the Peachtree's source input choices as well, of course, to use its remote control.

Because most of my listening is to various genres of solo guitar that's what I used to audition this combo. My first impression was mixed in that the sound seemed, at first, somewhat attenuated as if the strings had been muffled with a piece of cloth having been laid on the fret board. On the other hand, the sound was very pleasing with some of the jagged edges rounded off. Overall, and regardless of which might be argued as sounding most realistic, I'm very satisfied with what I'll call its more relaxed presentation. I like it and will very likely stay with the tubes.

Please don't read this as my support of one technology over another; first, I'm not qualified to make recommendations. Also, I'm 73 years old and have become more sensitive to certain sounds especially from percussive sources, so this becomes a factor in music choices as well as equipment.

Now that I've decided to stay with tubes, what I would like advice on is where to go next. I like this Prima Luna very much but have been advised by several whose advice I've learned to trust, that at 91dB these speakers may not be sensitive enough to get the best from the A3. I suppose what this means is that I need to look into another amp or more efficient speakers.
broadstone
broadstone's avatar
broadstone OP
310 posts
 
Tubegroover, thanks. I'm very early into this tube amplification quest and appreciate all advice especially when it comes to specific types and brands and what to expect from them. From what I've read and heard, I think you're right, The DeCapos and my speakers do have similar specs. I actually haven't found any shortcomings with these yet and haven't even experienced higher volume issues which was what I've been told to watch out for. My room is about 20X26X9 with my listening position about 16' from the speaker plane. I listen primarily to solo guitar, string quartet, light jazz and occasional orchestral music. I listen at fairly moderate volume.

My reference to attenuation of sound relative to what I'm used to, was not a complaint; I actually find it to be less fatiguing and more comfortable listening. To some extent it's also what I'm looking for in future purchases. Coincidentally, Davide, I actually used the plucked string example to explain the characteristic that described the difference between these two technologies to my wife. As an exaggerated example, I asked her to imagine the difference between plucking guitar strings with a plastic or felt pick.

Even though I'm sure I'll continue with tubes I'm not supporting one technology over another. In this case the decision is quite personal; age related hearing issues persuade me in this new direction as some sounds, especially those with percussive origins, cause me significant discomfort.
oregonpapa's avatar
oregonpapa
4,867 posts
 
Some of the most beautifully accurate and tonally right classical guitar reproduction I've ever had from my stereo system was when I had a pair of Atma-Sphere M-60s on loan in the system. Relaxed and gorgeous. They put the great guitarist John Williams in the room.

Atmos-Sphere makes a 30 watt stereo amp that looks great. Havent heard it, but if its close to what the M-60s did, it may be the ticket. Perhaps Ralph can fill us in on the retail price.

http://www.atma-sphere.com/Products/
broadstone's avatar
broadstone OP
310 posts
 
Thanks, Oregonpapa. Over the years I've received and applied much advice from him and would readily listen to whatever he says. However, because of several pricey purchases I've recently made, consideration for purchase will have to be postponed. In the meantime I'll keep researching and listening with what I currently have which, btw, is not an altogether bad thing.
atmasphere's avatar
atmasphere
12,061 posts
 
Looking at the specs, the speaker is rated at 92 db 2.83 volts/1 meter (being an 8 ohm load, the efficiency is the same). The minimum impedance is 6 ohms. This should be an easy speaker to drive and in most rooms 60 watts would be plenty of power.
broadstone's avatar
broadstone OP
310 posts
 
Atmasphere, I, too found the published specs as 92dB sensitivity but there seems to be a very wide range of reports regarding the efficiency of these things. I was directed to a graph ( don't remember the origin) and it looks, at best, like the sensitivity is in the 84-85dB range. I also spoke with a local dealer who used to sell them who confirms the same thing. One way or the other, this temporary combination of the Prologue One at +/- 30W and the Reference 3A's does seem to work OK at least at lower volumes.
More to discover