On Sunday, February 12, 2017 at 12:54:08 PM UTC-5, Luigi Vogliobene wrote:
Hi to all, I am new in this forum, I own a MingDa MC368BSE audio amplifier and it is time to replace the final tubes, I was suggested to replace the original 4 Jinvina KT90 with a selected quartet of Electro Harmonix KT90EH; I wonder if the BIAS will be OK if not exactely the same (this amp has a fixed BIAS).
Thank you in advance for your kindly replies.
Luigi
The circuit uses fixed bias but as this is only adjustable using unlabeled internal controls the task is best left to a dealer; the two meters just show the output voltage at the 8ohm loudspeaker sockets.
Read more at
http://programming4.us/multimedia/16...MGZU4VOilTD.99
This is what I got from the net. I suggest you find someone specifically familiar with this amp and have them walk you through the bias process.
Peter Wieck
Melrose Park, PA