[Exsg]

Hi All,
Late last year, one speaker started emitting static noise audible from 1 m or even from my listening position. After swapping all cables, plugging the power cord into the power conditioner instead of to the wall directly and substituting another speaker, and the noise is still there. A qualified McIntosh tech checked the C2500 and confirmed there were no issues to it. The tubes were fine as well.
What could be the cause? I am tempted to swap the original tubes for Gold Lions to see if this would solve the problem. How do you bias the new tubes?

This has also set me thinking whether I should upgrade the set to C2700 or the Auralic Altair G2.1. I loved the Mac tube/SS combo and on the other hand, need to upgrade my Node 2i streamer so the Altair seems like a good preamp/streamer combination option, especially with the excellent reviews I have read so far. I will likely have a home audition soon for this which will help with making a decision.

Does the C2700 have the same capability as the G2.1? The THD seems way higher.

Any advice please?