Jadis OR bias value for Mullard RL34 and KT88 help


I just swapped my Gold Lion (reissue) KT88 tubes for Mullard EL34's and was vwery surprised that the volume was so much lower. I checked the bias and found it to be less than 10mv while the KT88's had been biased at 110mv.
I rebiased the EL34's up to 90mv and the volume increased to what seemed to be "normal".
I am looking for the correct voltage to bias the new EL34 to in a Jadis Orchestra Reference.
Any help is appreciated.
128x128mattzack2
Mattzack2, your experience perfectly mirrors my experience when it comes to bias. As I said, as you increase the current flow in the output tube, outside of tube life, EVERYTHING gets better.

At this point, I don't want to encourage you to stray far from the recommended values. But I will say that if one calculates the JOR's plate current in the traditional manner, 120 mV divided by the 5.62 Ohm bias resistor would yield 21.35 mA, an incredibly (low) cold figure.

In comparison, my Dynaco ST70, which uses the same circuit, aims for a bias of 50 mA. The rule of thumb in the guitar industry shoots for 70% of maximum (25 watts for an EL34) plate dissipation, which obviously comes out to 17.5 watts. Though so many maintain the Dynaco's biased way too hot (415V B+ X 50 mA = 20.75 watts), I argue that after all these years you find so many with their original Mullard EL34, the assertion proves false. Figuring on the JOR's approximate 450V B+, at 21.35 mA, we're only at 9.6 watts, not even 50%.

I did send an e-mail to Patrick on Friday, but as of yet, have not received his reply. He's usually very prompt in these matters. We'll hope to hear from him soon. Again, I want to get his answer on the matter before saying to aim higher, as Jadis does employ a novel twist on connection to the output transformer, and the usual way of calculating these things might be very, very wrong. But, there's no need to back off from 120mV.
Thanks....
It it really sounding pretty good right now. It might be interesting to see if it can be safely increased to 140mv or so. I am not concerned with tube life, but I want to avoid burning something else.

I will increase it as soon as I hear from you. It sounds very clear and airy right now.
Mattzack2, thankfully, I've received two replies from Jadis. Both, from principals of the company.

The JOR conforms to the traditional means of calculating bias current. So, the calculations above ARE correct.

Patrick used 150 mV and stated, "the sound will be better but the tubes are not so secure." 150 mV / 5.62 would mean 27 mA of output tube current, still very easy on the tubes.

As I have maintained of late, I don't want to say much here in public regarding my personal experience, as it's prudent to have folks stay within the manufacturer's recommendation.
No, I think that is Joe Abrams of Equus Audio. I remember his banner ads here on Audiogon.

Please let us know how the amp sounds at 150 mV, and whether you feel the Mullard EL34 should stay.