I find the comments very useful.I will follow Lostbears recommendation and replace the 6550 in the power supply.
Thanks for all the replies.
Thanks for all the replies.
How do you know when to replace tubes
I recently purchased the Audio research Anniversary reference
The unit has 2600 hours on the tubes.The manual states replace the power supply tubes after 2000 hours.Do you indeed have to replace the tubes even if the sound is good.Another question is tube rolling enhance the sound .As an aside the Audio Research replaced the Einstein Tube pre amp noticeable improvement to the sound ,mainly the lower mid range and bass.
The unit has 2600 hours on the tubes.The manual states replace the power supply tubes after 2000 hours.Do you indeed have to replace the tubes even if the sound is good.Another question is tube rolling enhance the sound .As an aside the Audio Research replaced the Einstein Tube pre amp noticeable improvement to the sound ,mainly the lower mid range and bass.