Is Chinese SHANGHAI 6F2 tube interchangable with ECF82/6U8A?

[Meowsley]

So I've got a DYNACO st-70 clone...my first tube amp and I think I'm a tube elitist now. It's not perfect, but at its best...I've came to understand the appeal of tubes. It paired w/ my Forte ii's have really produced some magic! Anyway...it had a quad of unrecognizable el-34s, which I recently switched to Genalex Gold Lion KT-77. Again...more magic. So what I have left is a pair of the aforementioned 6F2s. I've bought in to tube rolling since so many consider that there is ample room for improvement. There is a pair of NOS German Telefunken ECF82s available on The Bay...so are they compatible w/ my power amp and does anyone have an opinion on if they will be an upgrade sonically? Thanks for any responses!!!

 

[BinaryMike]

Tube rolling results are usually clouded by the fact that few rollers check tube operating voltages to exclude tubes that don't bias up properly. Suggest you do so, especially if your clone is an accurate copy of the original circuit, because screen voltage at the 7199 was a critical issue.