Hello

My preamp/processor ia an Outlaw 990. It offers about 12 different modes for phono. These include basic stereo (I think all other spkrs are turned off, limits bass to Khorns), bypass, 5ch, some Dolby PL IIs, Neo 6? etc. Not all of these include output to my subs.

Most of my new "old" records are from the 50s-80s, Jazz-Rock. Some were recorded in mono. I think some of the records are awesome. I can't explain it, but I think they sound better than some CDs. Most of the sound modes offered on the 990 sound quite nice, but they are very different. In order to achieve the closest approximation to being in the studio when the tracks were laid down (which I think is our goal), is simple good old fashioned stereo the best mode? I will assume the answer will also be true for my cassette tapes, mostly from the 80s-if not, let me know.

Also, what is the best playback sound mode for mono records?

Thanx for any advice.

Khorns c. 1975 - MC240 Tube amp c. 1964
Academy center c.1993, LaScalas c. 1975 or Heresys c. 1975 rear - Outlaw 750 SS 5 ch amp c. 1991
Madison Amps M1-218s 2007, paired subs - Dayton 1000w sub amplifiers (2) 2007
Oppo 981 DVD 2007
Outlaw 990 Pre/pro
Tascam Tape Decks (2) c. 2000
Technics Sl 1200 M3D turntable c. 2000, Stanton 505 and Ortofon OM NIGHT CLUB S cartridges
Homemade Audioquest interconnects (1/1, MAC-3 and MAC-6 wire, ITC 24 plugs)

26" Sony TV c. 1986, even Hurricane Katrina couldn't kill it; so forget about 50" LCDs, besides it would cover over the 10' painting of my home, the French Quarter

Listening to Jazz vinyl from the 50s-70s in stereo tube amp Khorn mode in the French Quarter former home of 1970s trumpeter Al Hirt - priceless

For the most "pure" sound to the original recording's intent, straight stereo is best - after all, that's how the records were recorded. Mono recordings also sound best in the stereo mode, as the identical signal will come from both speakers.

In the old days, preamps had a "mono" mode which routed identical signals to both the left and right speakers by summing the left and right phono inputs. What this did was cancel out any vertical stylus signal from the cartridge - this signal was mostly rumble from the turntable. I've not seen a mono mode on home theater components.

I would concur with Altec - in fact, you ought to give bypass a try (let the analog source remain in analog all the way through) and see how that sounds compared to stereo.

I agree with Gonk - try Bypass first, in fact I don't see why any analog signal needs anything else. But why on earth are your Klipschorns in a bass-limited mode, and them good down below 35Hz? I'd run them full range; there's vanishingly little on vinyl they'd have trouble with.
I hope your turntable has a shockproof mount, preferably a wall shelf unless your floor is on a concrete slab. On the third floor of a condo building I sure need a shelf - and haven't yet got one.
I also wonder how often your all-Klipsch system uses even 5% of your amps' output capability.