Jadis Orchestra Signature Bias Adjustment

Thank you guys. My Jadis Orchestra Signature came with 4 x KT90 tubes and 2 x 12AX7...I suppose I can replace those four KT90 with KT88, EL34 or 6550 just like the other model Orchestra Reference? It's too bad that they don't show Orchestra Signature on their website.

I've not encountered an Orchestra Signature yet, but based on it coming with the KT90, you have the transformers that allow you to use any of the tubes on your list. You cannot use the 6L6 (according to Jadis) as there is too much plate voltage (my statement, not Jadis') for that tube to handle.

My personal experience/tastes are that the EL34/6CA7/KT77 are the best sounding tubes for the JOR. And, I like the magical midrange of the JJ EL34/E34L better than their more bottom heavy KT77. I'm not much of a fan of the Ei KT90 Jadis uses or more or less any 6550. I've not tried the EHKT90, though they certainly have their legion of fan ala some of the more recent Rogue designs, which I do greatly respect. Of course, this is all a matter of personal taste.

Finally, one thing I neglected to mention above is to NEVER operate a tube amplifier with output transformers without a load, as you can blow the one part that is proprietary (in addition to likely the most expensive) to just about every individual product.

During JOR bias adjustment, the speakers should be connected to JOR or no?