I do have a adapter that goes from 6DE7 to 6F8 directly then you can leave out the 6DE7 to 6SN7 adapter.
Glenn, by all means in no way/shape/form did I mean your 6DE7>6F8G adapters was the reason for me having an issue with the glass touching the SP…its just the shape of both rectifier/drive tubes, so please don't take my post the wrong way, your adapters are excellent, and I always recommend them to others. After re-reading my post, it can seem to come across the wrong way which was not intended…at all.