Ive got a 500b, (Ibba, mcshane kit, all good tubes, etc, etc). which has had most all the mods except the EFB, which will be next. I've had incremental gains with each mod but wondering where it peaks. Interestingly, it's also become a bit more clinical and perhaps accurate vs a very dark and musical sounding 6v6gt based voice of music push pull amp. Rolled off highs and tubby lows (the VoM), but gosh what fun. I'm quite happy with the sound, but just got a simic ii and nichicon (power supply) recapped luxman r-115 which has noticeably more detail and a super smooth and clear presence. Actually quite a difference, with much more authoritative and tight bass and great soundstage, really clean highs and ridiculously silky mids. I am re listening to all my music and songs where I wasn't 100 percent certain on the lyrics are crystal clear through this receiver. I realize these particular solid state receivers are a high bar as far as all in ones, but wondering if it's possible for the fisher series to get to this level of smoothness and clarity. I do most of my listening at the first watt level through fairly efficient horn loaded speakers, so I don't think the power overhead an issue. Until now, I never thought I was missing anything and the Fisher was at least equal to the naim system in my car, which is quite good. The differences between them are similar at all listening volumes, but I never turn them up so loud it hurts. Wondering if anyone has been able to push their fishers to these levels? Or does this push us into SET territory for tubes? I've never had an SET amp, but assuming these raise the bar for tube sound?