ARC VSi75SE v. MF Nu-Vista 800

Get the MF NuVista!  Why?  Because it's fits into your setup best.  Will it sound just like the ARC?  No, but so what.  It will sound great anyway.  If these are really you're only choices, then don't overthink this.

Now to overthink it, I would worry about having that much power being fed to the Harbeths, especially with other family members using them in the HT setup.

@cundare2 

Wow, that does not sound right.. but I can’t refute it with any knowledge. I’ll do a little research. I’d like to know. But it sure does not sound right.

This is from the manual.  But one has to wonder if they are afraid a person new to audio and tubes will shock themselves or if the unit is just unfriendly for anyone, even with experience, to bias.

MAINTENANCE

Vacuum Tubes It is recommended that you replace the vacuum tubes of your I/50 in sets. All of the tubes in your amplifier have been matched to have similar operating characteristics, to provide the best sound quality and reliability. 6550WE tubes should be replaced at approximately 2000 hours. 6922 tubes should be replaced before 4000 hours. Upon replacing a power tube or tube set, the I/50 must be biased by a trained technician to ensure proper operating values.

I contacted ARC directly and, as usual, it shot back an immediate response: The company does not recommend users biasing their own tubes but does so for general safety reasons.  The rep emailed me a 16-page illustration of the procedure.   It looks way more complicated than it needs to be -- even the Dynaco ST-70 was mroe user-friendly in this regard -- but it's nothng I can't handle.

The advice I've gotten here is, as usual, excellent.  But TBH, I really am losing my mind.  “Overthinking”?  Well, yeah, maybe.

Priority #1 is giving my Harbeths whatever they need to shine, spending up to $10-12,000.  There are constraints, but are dealbreakers if the sonics are there.  The perfect choice would be an amp that:

i) my 70-year-old back can lift

ii) has an HT bypass

iii) will also work halfway decently powering the front speakers of a home theater (e.g., minimal warm-up time)

iv) has either a line- or speaker-level output for a sub

v) can be programmed to work automatically with a Logitech Harmony

I’ve considered several ARC & MF Nu-Vista models, as well as integrateds by Hegel, Levinson, HiFi Rose, and Ayre.  Bottom line is that the best-fit ARC model is its entry-level I/50, which lacks most of the functionality I want, but at least is light & has a HT bypass.  The Nu-Vista 800.2, which has just begun to ship, has an equally impressive reputation, but at 300/500 wpc and 90 pounds, it’s not perfect.  A better fit would be the lower-powered, lighter 600.2, reportedly due Q1 2024, but so far that’s just a rumor.

So maybe I need to rethink this from Square One.  I just started looking at a Pass Labs solution: the 20lb XP-12 preamp and 48lb XA25.  Just not sure if a 25wpc class A has enough oomph for the Harbeths, but I think Stereophile gave the Pass a rave review based on listening through a larger Harbeth model than mine.

Still, the I/50 is tempting.  It’s just hard to say whether I’d prefer the ARC or Pass “house sound”.  It’s not even personal preference, since there’s no way for me to audition either one first-hand.

I guess this is all part of the fun of this hobby!  Was it J. Gordon who defined “audiophile” as a person thinks more about stereo equipment than he does listening to it?