Soundstage drastically worsened when I replaced a solid state AV amp with tubes.


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Hello. I am streaming music with Qobuz and Apple Music through a McIntosh MX123 A/V processor, into a McIntosh MC8207 7-channel solid state amplifier (200 watts x 7 channels), into Klipsch La Scala speakers (105 dB sensitivity). (I also have an SVS 2000 sub-woofer.) (The components are behind the wall in the photo.) With that setup, I had a 180 degree soundstage, extending laterally well beyond my speakers and from ceiling to floor in height. I wanted to see if tubes would improve the system for music listening, so I added a McIntosh MC275 amp to power the front L and R LaScalas. Now the MC8207 is used only to power the surround speakers. The MC275 improved the warmth of the music and greatly increased the bass. However, the lateral soundstage is gone. I now have a deeper soundstage focused perfectly between the speakers, but the lateral and height extensions are gone. It is as though I am back in the 1950s listening to a single mono speaker directly in front of my listening position. The music is beautiful, but I miss the soundstage. Other than replacing the amp for the LaScalas, everything else is the same. I did have to temporarily add an extension chord to the McIntosh power cord until I can get one of the proper length, so that could be the culprit. Otherwise, does anyone have any ideas regarding why the soundstage so drastically changed? I expected the soundstage to improve with the tubes, but it worsened. Thanks for your thoughts!

therandyman

If you haven't already do turn off all audio processing on the MX123 including Dolby: Dolby Atmos, Dolby Surround Upmixer DTS: DTS-X, Neural:X Surround Upmixer, DTS Virtual:X Auro: 3D, Auro-Matic, 9.1, 10.1 IMAX Enhanced.  Also turn off Audyssey or any other EQ.  

You guys think my ideas were too obvious but ... I have gone through exactly these issues at two different dealers. The excessively wide Soundstage was due to a speaker polarity flip.

@erik_squires , this got me thinking about an amp I auditioned around 25 years ago. Do you remember the Stereophile that featured The Mesa Baron on the cover? Two monoblocks in a single chassis with all sorts of neat looking things--rack handles, meters, switches, 12 output tubes. . . . Anyway, I had it for a weekend and it was to be an upgrade from a Cary entry level stereo amp. What I first noticed, and what first appealed to me, was when switched to 1/3 triode 2/3 pentode, the soundstage was up front/in your face/ and maybe all over the place. Vocals had a musky quality that I was not used to, & initially appealing to me. But, after I had just about made up my mind to trade in my Cary, I did an A/B and the cleanliness (even though it was small) of the Cary’s soundstage made me feel this would not be a total upgrade.

Anyway, I wonder if there was some polarity trickery going on with the electronic design of the Mesa Baron?

 

The great designers of our time know how to engineer an amp to get specific but desirable results. I'm still shocked how one amp could do one thing and then just going to a different model of the same manufacturer can produce different results, but it does happen. I vote to put things back the way they were.

Something is amiss. That amp should be able to drive a truck! I’d want to drive it with a preamp. 

Soundstage is overrated. I attend many live music performances. Solo acoustic and electric, medi and large ensembles, a variety of acoustic spaces mostly I hear the sound a a giant quilt devoid of any pin point location. Soundstaging in sound reproduction is an interesting presentation controlled by the production team. I enjoy it but it is a peculiar concept in the realm of live music IMHO