Jadis Orchestra Reference ---- tube biasing

There's some preposterous stuff on here -- first of all, the amp (Orchestra Reference) IS NOT autobias. And, autobias IS NOT a step up -- it sounds worse than fixed bias almost all of the time (because you are listening to an extra capacitor).

The easy way to bias these amps, if you can work with 550v without killing yourself (and if you cannot, do not) is to:
1. measure the output tube plate voltage to ground.
2. measure the output tube cathode voltage to ground (should be about zero).
3. look up the negative bias voltage for the output tubes you use, at the plate voltage measured, on the tube curves available at duncanamps.com or elsewhere.
4. find the grids of the output tubes and measure the voltage there.
5. adjust the bias pot that corresponds to the grid you are measuring, until you set the voltage you need as found in step 3.
6. Check twice.
7. Wait 30 minutes with the amp on, input shorted, output loaded with 8 ohms or speakers.
8. Check and adjust again. If there are any bias changes more than a volt, wait another 30 minutes and check again.
9. If after three such checks you are still getting voltage changes, you need different output tubes.

If any of this sounds strange and unfamiliar to you, STOP and find someone to whom this does not sound strange and unfamiliar, to do this work.

I have owned this tube amp for over 4 years now, with the tubes still going strong despite putting about 15 hours/week on them.

Still, I don't doubt this is perhaps the most difficult tube amp to bias out there. And, while most people consider my AtmaSpheres hard, I find them a walk in the park. Autobias wouldn't be a bad thing...

Below are the instructions, minus the big warning about high voltages - you shouldn't try this at home, and an illustration that I obviously can't show in my post. Enjoy!
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1) See accompanying diagram representing only one channel.
2) Using a digital voltmeter measure the voltage closest to the resistor(5U62, found on the route between the tube and the output transformers, you're going to measure the voltage across the resistor - TRELJA) until the meter reads between 95mV and 120mV(preferably 110mV) as you adjust the 22KOhm pot(outside the 2 tubes - TRELJA).
3) Using another Digital, connect the leads to pin 3(yellow wire) on the output tubes of the same channel. Adjust the second 22KOhm pot(between the 2 tubes - TRELJA) until the reading is close to 0.0mV. This adjustment may change the first reading, so adjust both pots until the readings are correct.
4) Do the same for each channel.
5) Very important. Please note that changing the tubes on any Orchestra unit requires very fine adjustment in order to prevent any damage to the amplifier and to insure continued excellent musical reproduction.
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I own a jadis orchestra reference, I replaced my tubes 6ca7 to KT90's. I asked jadis to what tube to use for my amplifier. As far as they said as long as you made your biases for tubes (it's manual and you have to take off the bottom cover and measure the voltage on potentiometer) it's a hard job and you have to do that every time you change tubes if not you could blown your transformers. So biasing manually is must, be carefull on changing the tube types.
Regards

As far as I know, Jadis Orchestra Ref has auto bias and requires no bias during the life of tubes. And because of that fact, match quad is not necessary but still recommended.