? Tube Replacement Question ?

The gain is not as high, in the other stages(compared to phono related) of your preamp, but noisy/microphonic tubes will still be audible. Upscale's graded tubes are tested for triode balance, as well as noise/microphony, which will also improve channel balance/imaging, in the SP-16. Everything hinges on how much you value performance.

Kit,

With my sp16, I hear a tad more hiss/background noise only in the phono stage at higher volumes with nothing playing using the Groove Tube Gold 12AX7s compared to the original "low noise" tubes that came in the unit for ARC. Not an issue for me but for those who cannot handle any extra noise at all in their phono stage ever, it might be.

You might want to consider using tube dampers in the phono stage, at the very least. These tubes are more susceptible to micro-phonics due to the increased gain in the phono stage. When you are using the phono stage you are actually using the phono stage and the high level stage together to get the necessary gain. I use the dampers in both the high-level and the phono stages with excellent results. The ARC tube dampers work very well and are inexpensive.

Thank you, everyone, for your suggestions. This will allow me to weigh the pros & cons of my various options & to make an informed decision. Thanks again.

A note regarding tube dampers.

The tubes in my SP16 came with removable dampers.

I put these on teh new tubes when I replaced them.

The gal at ARC told me that the dampers were not removable and reusable with some older production units. ie they tended to adhere to the tubes over time.