Impedance Matching - Tube Amp/Speakers

I have Legacy Focus 20/20 and have only used tube amps with no damage. From Conrad-Johnson MV-52, to Conrad Johnson Premier 11a to now Wyetech Topaz monoblock. The question to answer is not is a tube amp a problem with four ohm speakers but how low does the impedance go. If it stays above say 3.5 ohms in general that could be fine. The Legacy's dip below that in a few spots but in areas where there is not a lot of need for energy from the amp in those spots. So while your friend is right, a solid state amp would give you more power and probably work better finding out the impedance chart for the VTL-ST-85 would provide you with the information you need.
Stereophile had a review back in February 1999. That might answer your questions.

Thanks alot. Stereophile review is saying "VTL-85 is optimized for a load of around 5 ohms (85Wpc)" so 6 ohms Dunlavy SM-1 speakers (with a 3-10 ohm range) should be no problem, is it right? But why my friend's multimeter measured 4 ohms on Dunlavys when they should be 6 ohms? Or this multimeter checking is not optimal and values are only approximate?

What you are reading with the multimeter is the speaker's impedance at a frequency of zero Hertz, or in other words its DC resistance. That will differ significantly from its impedance at audio frequencies, which is what matters.

According to this review "impedance is shown as 3 to 10 ohms, with 6 ohms nominal, which should be an easy load for most amplifiers to drive." I don't think there is any cause for concern, especially given that the amp is rated to drive 4 ohms continuously, and is specified for a recommended load of 3 to 8 ohms.

Regards,
-- Al

Just connect your speakers to the 4 ohm taps onyour amp. Will work fine. I use a VTL ST-85 to drive 4 ohm Maggie 3.6's with no problems