Rogue Magnum M-120 Loses Volume at Power Up

One of the two recently acquired Rogue Audio Magnum M-120 mono blocks loses its volume at power up. Music does not completely cut out but is very low in volume. After about 15-30 minutes of warm up, it regains the volume and is even again with the other amp.

Checked the tubes and found they are fine - both quad sets put out the same output. Also switched set of tubes, switched speakers, and determined that culprit is that same amp.

This problem has been consistent each time the amps are turned on from cold. The volume level returned to normal level after about 15-30 minutes from initial power on. In conclusion, the "Right Side" amp does not seem to be performing at its optimum in comparison with the "Left Side" amp.
I would call Rogue and speak with Mark. You may have a resistor going.
I do not want to violate any Audiogon rules but is it appropriate to ask on the this forum for recommendations on local repair service facilities? Rogue Audio is in PA which is going to be very costly to ship the amps.

If it is not appropriate to make it public, I would appreciate if you let me contact you by phone or email. We could take it from there.
A technician found the solder joints on a socket of an input tube was the culprit. He resoldered all the solder joints and the amp is working again.
Hello Morgandogge.
Finally found and fixed the problem...hah! Good for you.

Now you can enjoy the tube sound.

Btw,did you get your pre-amp ( tube) ?
Hello Pescolar,

Please see my thread on "Audible Illusions Modulus 3 and Rogue M-120 Okay?"