Int. Amplifier with Focal 807W Speakers

Topten, my first post gives you your best type of intergrated amp to drive your speakers top to bottom without compromise, as I've pointed out in detail, for 2k to 2.5k.

Cheers George

EJR1953, On the Focal Sopra's, I just found graphs for you impedance and phase, the - phase angle is not too bad, but the real measured impedance is quite tough, from 80hz to 120hz it's 2-3ohms, so a good 4ohm solid state with good current ability is a good idea for these to get good controlled dynamic bass.

Last two graphs in this link.

http://www.soundstagenetwork.com/index.php?option=com_content&view=article&id=1445:nrc-measurements-focal-sopra-no2-loudspeakers&catid=77:loudspeaker-measurements&Itemid=153

Cheers George

"Sopra's driven by both tube and solid state electronics. In every case I found the tube equipment to sound "dull" and "restrained", to me not great qualities for these speakers."

This would effect the mid bass with amps that can't give good current at this frequency. (doesn't account for the dullness your heard with tube.)
I read in reviews that the Sopra's have a 3.1ohm impedance at 210hz this is not tube friendly. And that's not taking in to account what the - negative phase angle might be at that frequency added to the 3.1ohm, it could go even lower in EPDR impedance. (Equivalent Peak Dissipation Resistance)

Cheers George

Good pickup ZD, and good on NAD for doing a poweramp input, they (integrateds) should all have this feature, and yes a passive VC into the poweramp section will cure your too much gain problem.

Cheers George

Hi Topten,
Your Focal 807W are around tested 88db efficiency, about normal. The worst tested impedance is 4ohm between 100hz and 200hz, while this is not too nasty a load by itself for a good 4ohm say 50-100w tube amp. You have to add to that, it is tested also to have a negative phase angle of -45 degrees at 100hz also, that would give with 4ohm impedance load a combined EPDR (equivalent peak dissipation resistance) of around 2ohms.

While a tube amp will drive this and sound ok'ish, that bass region around 100hz will sound much more punchier and tighter driven by an amp with good current drive, 100w-8ohm solid state that can almost double to 200w-4ohm.

Cheers George