Tweaking preamp and amp combination

Have you squeezed the maximum performance out of the current system?  Upgraded power cables, interconnects, decent equipment stand, power conditioner?  

I understood the original question.  Having played this game for many decades, I find audiophiles are quick to switch out components without first optimizing what they already have by paying attention to the details.  Best of luck.

SMC is hard to beat. You have one, and upgraded, so you must have a pretty good idea what to expect. Hard for me having had a DNA to understand why anything else is even on your list, unless there's something you want to change. Surely you'll have more improvement for the $$ from SMC, and without the risk of changing the sound you have now. AR will definitely change the sound you have now. So is that what you want?

Why are you looking at changing the amp anyway? Seems to me its the best component on your list.

What aspects of the sound you’re currently experiencing are you looking to improve upon?

I'm using SignalCorp.com interconnects, power cord for amp, and speaker bi-wire cables. The phono stage tubes in
the SP9 MKII are Electro-Harmonix 6922 Gold. The WX-2 cross-over filter that I'm using is set at 75K.
Thus at minimum an M5-HP (If I could find one) may make an improvement.

When listening to certain vinyl recordings I hear distortion in high timbre vocals and cymbals where playback is too bright which from my understanding may be due to the recording's improper mix or lack of proper compression.

In digging deeper to my original inquiry, can changes in interconnects, tubes, crossovers, cartridge or amplification compensate for playback of recordings to make them more listenable if they may have been mixed improperly?

charkune your last paragraph is exactly where I would start.The right nos tubes can make a huge positive difference.EH tubes have a clear 'modern' sound.Experiment with different brands that are known for a touch of warmth in the upper mids.
When you find 'the ones' that get you most of way there,then move on to try something else,maybe interconnects next.Room treatments are something to consider too.

Hi,
i had an SP-9MKII and i do not remember it sounding bright, quite the opposite and it had a very nice phono section. Neither is McCormack a bright sounding amp.
What kind of distortion? clipping? Is your cartridge correctly aligned? loading? You get this distortion from vinyl playback so you should start there.

Your problem is not your amp, and I find it very curious that when you say you’re having issues with vinyl playback you don’t bother to mention what analog gear you’re using.  Why???  Sheesh. 

I've owned the 3A Sigs and the SP9 MKII (and MKIII).  Neither caused any distortion on my vinyl.   What did cause the distortion you describe was bad cartridge setup, especially zenith.  
The Electro Harmonix tubes were ho-hum IMO.  In the MKII I liked Telefunken ECC88 but in the more detailed MarkIII I liked the E88CC.  
The 3A Sigs were sensitive to cables for sure.  I had cheap Monster Powerline 2 and going to Acoustic Zen Satori reduced glare dramatically.  Also, reducing "midrange glare" is a function of the tweeter control, not the midrange control, so a heads up on that.  Good Luck!  

Thanks all for the recommendations.  I decided to take guidance to revisit my cartridge setup.  I found a more current document online and when thru the tonearm setup. I realigned the cartridge on my tonearm and reset tracking force. I then set VTA and azimuth.  These changes have corrected the issues I was facing with cymbals and high timbre vocals. 

I'm due for a tube replacement in early July on the pre-amp so next step will be to try a different brand of tubes.  Thanks again.   

Option One looks good, I did that years ago when I had the same amp.....it was not a subtle upgrade....everything that was good got better. Let us know what you decided.