[birdland]

Hi:

I was going to post this as a reply to the coupling caps topic but since the last post there was 2 years ago, I thought I'd post this as a new thread.

Does anyone know what failure due to the teflon coupling caps looks like?

I decided to check the bias on my power tubes in my REF150 and I found that the front tube of the right set power tubes on the left channel was reading 70mV! The last time I checked which was only a few listening sessions ago, they were are 64/65mV. The left side of the left channel were reading exactly what I set them to awhile ago.

The right channel had the same problem. The front tube of the right set of power tubes was reading 75mV!

I lowered the bias to 63mV and then checked the rear tube which was more than 64mV and then I went back to the front and it was already at 67mV.

At this point, I just turned off the power.

Could this increase in biasing voltage be due to the coupling caps starting to fail? My local tech mentioned that I should check my bias periodically because when the coupling caps fail, they do not take very long to completely fail.

Thanks,
Walter