My parents have a gen 5 or 6 Mac MC275 (new ~ 2018). Preamp = Mac C2600. Speakers = Klipschorns. Music - mostly lossless streaming with very eclectic listening ( Yes/Pink Floyd to Musicals, Johnny Mathis, Stevie Ray Vaughn, etc..)
They replaced the pre-amplification tubes in the Mc275 a couple years back with Gold Lions. I'm looking for recommendation on a matched quad of KT88, as the ones they are running probably have > 2000 hours and to me are starting to sound less defined and articulate when I visit.
Budget ~ 400 bucks would be nice to stay at. I am sure a lot of you have an MC275, and would love to hear your thoughts about replacement KT88 power tubes.