I can advise of both in a Quicksilver Pre-amp. I find the EH much smoother and more lush. As Newbee mentioned I too find them a bit muddy in the bass department.
Sovteks have better bass but can be a bit edgy with vocals and symbals with my pre-amp.
Sorry I do not mean to digress from your question on ARC.
Go to Upscale Audio's website and search for 6922/6DJ8 - you will see some reviews of the EH listed as type 2 I believe, there is a review from a user of the EH tube with respect to his LS-16.
Sovteks have better bass but can be a bit edgy with vocals and symbals with my pre-amp.
Sorry I do not mean to digress from your question on ARC.
Go to Upscale Audio's website and search for 6922/6DJ8 - you will see some reviews of the EH listed as type 2 I believe, there is a review from a user of the EH tube with respect to his LS-16.