[hitchcca]

Currently I have a separate mono setup (Denon DP-1700, Grado ME+, Van Alstine Vision Q phono) and I'm curious about the benefits--if any--of a phono preamp with a mono button.  Any experience out there?  Sometimes it seems the center image is slightly off center with my current setup. Would a mono button help lock it in place? And if I'm going to make the switch, I'd prefer to add some "tubiness" to the mono chain.  Thanks!

[vinyl_lady]

Depending on your budget, either the ModWright PH 150or ModWright PH 9 would meet your requirements. I have the PH 150 and I love it. The mono switch definitely helps when I play mono records.
https://www.modwright.com/

[S Clark]

Your Grado should be putting out the same signal for both left and right.  Therefore the phono pre should make no difference if a mono button is in or not.  Could the shift in center image be room related? What are you using for an amp?  Any tubes that could be getting weak?

[nlitworld]

I've also noticed on my turntable a shift in center image from adjusting anti-skate and azimuth. Both of these are very sensitive on some arms and definitely so for my schiit's unipivot arm. Not saying a mono button couldn't be useful, but it might not be the golden ticket you're looking for.

[rollo]

Your Grado should be putting out the same signal for both left and right.  Therefore the phono pre should make no difference if a mono button is in or not.  Could the shift in center image be room related? What are you using for an amp?  Any tubes that could be getting weak?

  That is correct. Check Rob Wyatt the mono Man.
charles

[hitchcca]

All of this is excellent!  It's absolutely possible that I have a room and/or turntable issue.  When the center image if off, it's only off by the smallest amount. But in my mind, with mono, it really makes me crazy when the sound doesn't line up just right. 
I do have tubes in my AVA Transcendence 10 preamp, but I'd be surprised if it was time to change them out. 
On the flip side, my stereo rig has a solid center image so it would make sense the mono table isn't perfect.  I'll need to investigate this weekend.   

[nlitworld]

Try starting with the antiskate. If the image is too heavy on the right, lessen the antiskate. Too heavy to the left, increase it. See if that helps. 

[S Clark]

All of this is excellent!  It's absolutely possible that I have a room and/or turntable issue.  When the center image if off, it's only off by the smallest amount. But in my mind, with mono, it really makes me crazy when the sound doesn't line up just right. 
I do have tubes in my AVA Transcendence 10 preamp, but I'd be surprised if it was time to change them out. 
On the flip side, my stereo rig has a solid center image so it would make sense the mono table isn't perfect.  I'll need to investigate this weekend.

Reverse the tubes from left to right channel. 
Also, not trying to be a dick (although many think I fail), if you're off by a handful of inches do what I do.  When my center isn't quite right, I shift 6 " in my seat.   

[nlitworld]

When my center isn't quite right, I shift 6 " in my seat.   

The most economical of fixes. Lol.

[hitchcca]

Ha! Love it. The seat shift is my current fix.