I just finished a rebuild of a series II 400 and I ran into an unexpected change, in the bias measurement.
I was going from the original FPL909s to MJ21196 while using stock drivers. Prior to changing the outputs, I adjusted the bias to .350MV and bench tested the amp for an hour. No problems were encountered. Then I installed the MJ21196 outputs and when I went to check bias, both channels measured about .230mv. I had no problem adjusting it back to .350mv however, I was surprised to see such a significant change, in the measurements. The amp still performed flawlessly.
This is not the first time I've replaced stock outputs with MJ21196. However, it was the first time that I've seen, a significant change in bias.
Any thoughts?
Thanks.....Gary
I was going from the original FPL909s to MJ21196 while using stock drivers. Prior to changing the outputs, I adjusted the bias to .350MV and bench tested the amp for an hour. No problems were encountered. Then I installed the MJ21196 outputs and when I went to check bias, both channels measured about .230mv. I had no problem adjusting it back to .350mv however, I was surprised to see such a significant change, in the measurements. The amp still performed flawlessly.
This is not the first time I've replaced stock outputs with MJ21196. However, it was the first time that I've seen, a significant change in bias.
Any thoughts?
Thanks.....Gary