speaker match Primaluna Premium

Starting to think about a speaker upgrade. Any advice on what the difference would be in paring a Primaluna Dialogue Premium with Sonus Faber Olympica 1 versus Harbeth 7ES-3 ?
If you have the power amp as reviewed in Stereophile (http://www.stereophile.com/content/primaluna-dialogue-premium-power-amplifier-measurements#GapKvIofUDySIo8d.97 ), I would pay particular attention to its output impedance.

The output impedance varied widely, from an extraordinarily high 15 ohms with EL34s and 14 ohms with KT120s from the 16 ohm tap, both tubes in Ultralinear mode, to 2.4 ohms with EL34s and 2.15 ohms with KT120s, both tubes in Triode mode, from the 4 ohm tap. The output impedance from the 8 ohm tap was lowest with both tubes in Triode mode, at 4.6 ohms (EL34s) and 3.9 ohms (KT120s). Changing to Ultralinear mode raised these impedances to 7.9 and 7.4 ohms, respectively.

With these high output impedances, the DiaLogue Premium's frequency response will be altered to a significant extent by the Ohm's law interaction between these impedances and the manner in which the loudspeaker's impedance changes with frequency.

Thus, a speaker with a fairly flat impedance curve will yield a smoother frequency response. 

Eggelstonworks Andra III.

Bob_reynolds wrote:

"If you have the power amp as reviewed in Stereophile ... I would pay particular attention to its output impedance."

Excellent advice, and excellent subsequent explanation of that advice.

From time to time we come across someone dropping a high-output-impedance tube amp into their existing system, getting poor results, and predictably blaming the amp.  A closer look will show that there was a mismatch between amp and speakers, often along exactly the lines Bob pointed out, wherein the speaker's impedance curve is wrong for that type of amplifier.  This does of course reduce the speaker choices available for such an amplifier, but those who have taken care to match such amps with appropriate speakers are usually quite happy with the results. 


bob ;

"Thus, a speaker with a fairly flat impedance curve will yield a smoother frequency response . "

Can you elaborate on " a fairly flat impedance curve " please ?

Maybe some number ranges . 

Thanks .

To see some fairly flat impedance curves take a look at my web page which shows some of my designs impedance curves verses other name brand models. Google any loudspeaker and see if they have a Stereophile review and check out the curves of them. Unless they use series crossovers, standard crossover impedance curves usually look like a mountain range with large peaks and valleys. With a tube amp, this will result in an uneven frequency response with bumps and suck-outs due to the fact that tube amps will deliver more power to the frequencies with the higher impedance peaks.

Disclaimer- I'm Fritz, the builder of FritzSpeakers


Take a look at Vandersteen and Thiel reviews at the Stereophile web site for examples. I'm guessing that both do impedance compensation in the crossover. I don't know if the new Thiel designs follow Jim's. It seems that the majority of speaker designs today expect low output impedance amps, which generally puts the tube folks at a disadvantage.







Thanks bob . 

  Except for the Vandersteen 3a's , they look better than my Dicapo i's . Pitiful , because I thought that the Dicapo i's were pretty decent with tubes !

Happy Tunes . 


If this is your speaker:

It doesn't look bad to me (4 ohm variation) and depending on the tube amp you may not even notice it. Though with the wrong amp the upper midrange and lower treble will sound forward.

Thank you bob , that is good to know .

This is why I asked for some numbers to relate to . When I compared the Di Capo i graph to some of the others , it did not look nearly as flat . But I was not sure how much of a variance was acceptable .

Good luck .