Tung-Sol 6550 reissue bias in Cayin A-70T?

Probably a good idea to contact Cayin, though I thought KT88s and 6550s were interchangeable. For what it's worth, when I went to KT88s (including Shuguang Pentas)from 6550s on a JoLida 502B I stayed with the same recommended 50mV as for the 6550s. Seemn like the reverse would hold true. I've got years on the tubes running this way so it worked for me - but I'm no expert.

Thanks Ghost... I'm thinking the same thing - I'm a novice with this stuff too. I may try to call VAS (Cayin distributor) tomorrow. I tried today but didn't catch them.

Don't forget to turn the bias pot all the way down before you put in the new tubes. Once the tubes are inserted, bring the bias up slowly to the desired level.