2. amps-preamps
  3. 190750-149162

ARC Ref75se bias

So I have a ARC Ref75se, with tubes under 300 hrs, and a new Puritan 156, with maybe 30 hrs. I checked my tube bias not long before getting the Puritan. For some reason I decided to check it after the Puritan was installed, with my amp plugged into the Puritan. I found it odd the bias on all four tubes was on the low end. Not in but close to the "bias zone" on the meters. I know I could plug the amp back in to the wall and see what the bias does. It always remained very stable on all four tubes. Any ideas? 

128x128skids

Showing 2 responses by skids

skids's avatar
skids OP
77 posts
 

I will plug it back into the wall and see. I do let the amp sit for a half hour with no signal running through it, before checking bias,as per ARC's recommendation.

skids's avatar
skids OP
77 posts
 

Just an update, it does appear keeping the amp out of the Puritan does keep the bias happy. I will continue to check it for a little while yet, and continue to get some burnin time on the Puritan.

@audphile1 Can I assume your Puritan had enough time on it to fully burn in? So the 156 was  not a good choice for your system. I imagine it can be a system synergy thing like a lot of things.

 

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