The results of my level matched listening test between a 60 year old Dynaco ST-70 with Amir Measured SINAD of 63 and a new near SOTA Neurochorme Modulus-86 with SINAD of 109 are complete and I can not hear any difference between them either sighted or blind. The “switch” works seamlessly if pushed or released quickly and in that case the music just seems to play continuously and blind I cannot even tell the amps were switched. I am having trouble getting the 16-year-old test subject to participate and will update if he does before I disassemble things.
I can’t say I am surprised but looking at the measurement graphs between the two amps I thought I should hear some difference.
My biggest take away is how important level matching is. When I originally hooked things up before level matching I switched back and forth and was convinced I had made a wiring error as the lower gain amp did not just sound softer but sounded “broken”. I then level matched and miraculously the lower gain amp came to life and sounded exactly the same as the higher gain amp. You can read about it and intellectually accept it but experiencing it firsthand was still an eye opener for me.
Absolutely fascinating. Thanks for going to that effort and reporting back, levimax!
And the ST-70 is supposed to be a pretty "classically tubey-sounding" tube amp, as I remember.
I've had numerous eye-opening experiences with blind testing, some of which undermined sonic differences I "heard" sighted, others that offered confirmation. It definitely left powerful lasting impressions that influence how I receive the claims of other audiophiles.
Even in the realm of objective measurement discussions and engineering, one tends to be guided by one's personal experience. How does this test affect your audio views of amps, tube amps etc going forward?