Jadis Orchestra Reference bias adjustment?

Apparently, there are somehow inconsistent views about how often the bias on the JOR needs to be adjusted.

While most owners here at Audiogon feel adjustments are necessary every few months, one dealer in Europe says, adjustments are only needed once every 4 -5 years due to the fact, that Jadis only uses selected and well burned in power tubes.

Jadis in France says, the JOR needs no bias adjustments at all, unless power tubes are changed.

How often do you owners adjust your JORs if you don’t change output tubes?

Joe,

Thanks again for your posting at Audiogon.

Like you say, a picture is worth a thousand words, and I wonder, if perhaps you could email me a few JPGs indicating the two points, where I have to put the black and red probes of my multimeter.

I think, I will manage to unscrew the bottom part, and sides of my JOR and put it back together.
The location of the bias potentiometers are obvious
I guess, and if I know what the values are (110mv), adjusting the bias should be no big problem.

Basically what I don't know is, where I have to put the black and red probes of my multimeter.

I also don't know, if the value of 110mV stays the same for KT90, KT88, KT77 and EL34 tubes, or if the value changes accordingly, and if it does, what the values for each kind of tubes are.

Perhaps changing the driver tubes, lets say from 12ax7 to
5751 or within different 12AX7s affects the bias settings
as well. I don't know.

Unfortunately I am not living in Canada or the US, otherwise I could ask Pierre Gabriel

The dealer here in Thailand has told me, the JOR has auto-bias, but obviously, it has a fixed bias setting. So, the local dealer seems not to be of great help in this case.

Thanks again for your help.

Best regards,

Robert

Thanks a lot. I really appreciate all the help. With the pictures and descriptions, it should be easy now.

It’s great to get all the support here at Audiogon

Pierre Gabriel, the US /Canada Jadis Distributor must be highly recommended.
Even I live in Asia, he still took the time to speak to me for about an hour on the phone, giving me all kind of information about the JOR and other Jadis amplifiers.
He has great technical inside, and is real fun to talk to. It was a very positive experience, I like to say.

This is a great forum! Thanks to everyone who helped me with my questions and concerns. I have learned a lot, met some nice people on the way, and got all the information I have asked for.
Now I know how to adjust the bias on my JOR. It is actually no big problem, and could be done by anyone in a short time. On my JOR, the bias on all four tubes was still within the specified range, but after adjustments, they are now perfectly biased again.

Hi Mcfarland,

thanks for your post. It would be great, if perhaps
you could email me those bias instructions.

My email is: [email protected] and my fax is
66-76-202670

Thanks a lot.