Just ordered a quad from The Tube Depot.I can say that those new TAD 6L6GCM-STR Redbase sound fanstastic in my VHX and Herbert Mk3. They offer a very even and clear frequency response.
I was going to go cheaper with a matched quad of JJ 6L6's ,but for another $50.00 I figured go for the TAD'sThey sound great, wish I'd tried it years ago. Go for it!