Help Tannoy XT6F with Primaluna


Hello all.
Just got a pair of Tannoy Revolution XT6F speakers. They are supposed to replace KEF LS50s. I'm driving them with a Primaluna Prologue Premium power amp. The new Tannoys sound awful with the Primaluna. Very peaky upper midrange and not much bass. Pretty unlistenable. Tried them with my old Rotel RB990 solid state power amp and they sound much much better. Tried the 4 and 8 ohm taps. Tried the stock Primaluna tubes and some KT 150s. No good. The Primaluna sounds great with the KEFs. Any ideas? Thanks in advance.
Ben
honashagen

Question for Al - I think you have probably nailed the issue in your second-to -last paragraph.

The question I have is - would it be possible to match the amp to the speakers via some type of custom built "matching transformer"?

I did have an issue with an amp many many years ago and had a matching transformer custom built by a very knowledgeable guy that built transformers for a living

Just trying to think of a solution for the OP - other than replacing the amp :-)

Cheers

Hi Steve (Williewonka),

That’s a logical question, but I doubt that it would be a good solution in this case.  While raising the load impedance seen by the amp with, for example, a set of Zeros, would ameliorate the effect I referred to, it would mean that the output tap of the amp would not be working into the load impedance it was designed for.  Which I suspect would have adverse effects on both the distortion characteristics of the amp and on its output power capability. 

Also, the cost of the Zeros ($540 without enclosures or $1140 with enclosures) is perhaps a bit unreasonable in relation to the cost of the amplifier ($2199).  And, finally, I note that subsequent to my post the OP reported that he is not even getting acceptable results with a solid state amp.  So it seems clear that other issues are contributing to the problem, in addition to the effect I cited.

Best regards,
-- Al
 
More info: Tried a set of Kimber 8tc speaker cables with amazing results. Silky top end and the upper mid peak is greatly improved. Truly amazing. Going to try bi wire and shot gunning to see what happens. 
Ben