Primaluna Dialogue Premium HP Driving PSB Imagine T2s

Have you asked Upscale Audio or Kevin Deal as he is the US importer of Primaluna and quite the expert? What is the efficiency of your PSB’s?

Great idea!  I will see if I can get in touch with Kevin right away. 

My PSBs are 90dB sensitive.   Crossover: 4th-order Linkwitz-Riley at 500Hz and 1.8kHz. Frequency response: 34Hz–23kHz, ±3dB (on axis); 36Hz–20kHz, ±1.5dB, (on axis); 36Hz–10kHz (30° off axis). LF cutoff, –10dB: 29Hz. Impedance: 6 ohms nominal, 4 ohms minimum. Sensitivity: anechoic chamber, 88dB; typical listening room, 90dB. Recommended amplification: 20–300W, program 300W
Read more at http://www.stereophile.com/content/psb-imagine-t2-tower-loudspeaker-specifications#RV6gmhVzpWYySfSV....

88 to 90 db efficiency for those speakers should allow you to drive 'em easily, and tubes simply seem snappier sounding anyway (whatever THAT means…more linear, instant tube juice, happier electrons...). I use a 60 something watt per side tube amp for 89 or so db main speakers and the thing about good, clean tube power seems to make you WANT to turn 'em up as it just gets sweeter the louder it goes.

As shown in Stereophile’s measurements the impedance of your speakers dips to around 2.4 ohms in the vicinity of 500 to 600 Hz, and rises to more than 8 ohms in the vicinity of 2 kHz. Also, Stereophile measured the effective output impedance of the Dialogue Premium (not the HP version) as being relatively high for some output taps and modes, and extremely high for others. The interaction of that kind of speaker impedance variation and those output impedance characteristics will tend to give greater emphasis, compared to your solid state Creek amplifier, to frequencies at which speaker impedance is high (i.e., especially around 2 kHz) and less emphasis to frequencies at which speaker impedance is low (i.e., especially around 500 to 600 Hz).

I would expect the degree of that difference to be somewhat less, however, with the Dialogue Premium HP, as it probably has lower effective output impedances than the non-HP version given the doubled quantity of power tubes.

Whether or not you would find that tonal difference to be preferable with the particular speakers in your particular room, and whether that difference would be overshadowed by differences in the intrinsic sonic characters of the Creek and PrimaLuna amps (which I would expect to be considerable), I of course can’t say. But in addition to the power and drive capability of an amp, and its intrinsic sonic character, the tonal effects of impedance interactions between amp and speaker are also a factor that should be taken into consideration IMO.

Good luck. Regards,
-- Al

I would ditch the Creek and go with the Dialogue Premium HP integrated amp.  Trust me, that amp will effortlessly drive your speakers.