Whats on your turntable tonight?

Sonny Stitt -- "Stitt Plays Bird"

Marcus Roberts -- "The Truth Is Spoken Here"

OK, for you tube guys, and to a tube ‘newby’. For the last few days, it has seemed to me that when spinning viny there was a lean towards my left channel. The soundstage seemed unbalanced. This has been driving me a bit crazy. It wasn’t extreme, but enough that I could hear it, especially with classical recordings and instrument placement within the stage. So last night tried some digital test tracks for R&L Channel, measured, and everything seemed fine, as did any digital music I played. So, figured it isn’t the amp, isn’t the preamp, so perhaps the vinyl front end. Last night took stylast cleaner to my stylus (which I rarely ever use), thinking there may be some ‘gunk’ on it. No real change. So tonight I focused on the Hagerman. Flipped the center two (of the four) 12ax7’s, mmmm…maybe a small difference? Then, just flipped the two 12au7’s, and presto!, everything filled in and a full balanced soundstage returned. And it isn’t like the right channel is now more prominent, it just sounds as it should.

Why in the heck would this happen? Very curious and confused. Maybe I’m just crazy 😜

Brian, all I can think of (also, a newbie in the world of tubes) is there is a mismatch.  Maybe they were well matched to begin with, but over time one of them lost its potential and the other was just fine.  Tubes are best when purchased in pairs or quads (depending on one's need) and after being tested and matched by the seller.  I know that Upscale Audio does that and most likely so do other quality tube sellers.  Anyway, that is my best guess.

Got back from Mammoth Mountain last night.  A fabulous week of skiing.

Atlanta Rhythm Section - A Rock And Roll Alternative  

Annie Lennox - Diva   Man, this is a wonderful album, both musically and sonically.

Albert King with Stevie Ray Vaughan  -  2 disc set, 45rpm Analogue Productions.  This is a piece of musical history.  And WOW, is it great!

@mammothguy54 

Yep Joel, what I was thinking too, but, the two NOS Brimar 12au7’s were matched from Upscale. So I have a good feeling they were sold as a good matched pair.

As I understand, a preamp typically isn’t as sensitive to matching or bias as an amp would be. Thus, unless there is a catastrophic failure, or an extreme mismatch, as far as I know, there should not be a significant difference.  

Curious.