In Reply to: another M60 bias question posted by ipaforme@gmail.com on May 13, 2012 at 19:13:42:
The bias on the amp is mostly determined by the voltage on the grid of the power tubes. This means that usually you can remove power tubes without having to readjust the bias. Since you are using 6336s though, the current that they draw from the power supply is significant, twice that of the 6AS7Gs, so the power supply voltage will increase when they are removed. So you should check your bias to make sure they are OK.
The other thing I would do is de-rate the fuse by the power cord- with half the power tubes in the circuit it should be half the current rating. Its not a bad idea to do the same for the middle (filament) fuse as well.
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Follow Ups
- RE: another M60 bias question - Ralph 09:52:28 05/14/12 (1)
- Excellent, thanks again, Ralph! (NT) - ipaforme@gmail.com 11:33:57 05/14/12 (0)