Tubes with Infinity IRS Betas

@georgehifi, You said it yourself "many moons ago"...let’s say customer A has a nice used pair of Beta’s, a fully refurbed Threshold S/500 Series II (of which you’re very familiar) and a 2nd hand ARC Reference 110 with new NOS tubes, where are you going to put the tube amp? Obviously on the mid/high panels. Today, refurbs and better NOS tubes offer performance gains which surely allow a fresh baked look at amplification options on old legends like the IRS Betas.

A tube amp with a low output impedance, like the Music Reference RM-200 Mk.2. But is 100w/ch enough power?

I often wonder if they are worth the hassle and what would I replace them with. I would like to pick up the Vtl 300’s and give them a try but I have concerns there as well. I know they are long in the tooth and worry about reliability issues. I spoke with bea at Vtl and although pleasent to talk to the vibe I got was they really don’t care about past Products they would rather promote the new which I get but with a daughter in college my budget won’t allow it at this point.I love my Infinity speakers of which I have the Betas of course and the Gammas, Ren 90’s, Kappa 9. I cannot seem to find much information or opinions on the Vtl's. 

You said it yourself "many moons ago"...let’s say customer A has a nice used pair of Beta’s, a fully refurbed Threshold S/500 Series II (of which you’re very familiar) and a 2nd hand ARC Reference 110 with new NOS tubes, where are you going to put the tube amp?

Wouldn’t change anything, if fact back then our hearing was far more acute, still remain the same, as that downward sliding impedance curve
3ohm@150hz
2.5ohm@700hz
1.5ohm @3khz
1ohm@20khz
This would still knock the HF out of the tube amps, on the Threshold s/500 things will remain flat out to 20khz.
And the Ref110 should cope still with the bass tower impedance, it doesn’t go below 5ohms on the Stereophile graph.

Cheers George

Yeah, cheers George...