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
audphile1's avatar
audphile1
5,292 posts
 

Don’t plug the amps into Puritan. It’s limiting current. Those amps need to be connected to wall outlet or passive power conditioner.
You can keep your source components in puritan if you like how they sound.

ghdprentice
7,148 posts
 

@audphile1 

 

+1

peter_s
1,348 posts
 

Really?  It’s limiting current even on idle? I don’t know the amp.  Maybe it runs hot. But I’m  surprised at that.  Yes, plug it back into the wall and report back. 

skids's avatar
skids OP
75 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.

audphile1's avatar
audphile1
5,292 posts
 

@peter_s about your question…if you look at the specs of the amplifier…it idles at 230 watts.

I owned PSM 156 and I in my opinion it’s extremely overrated and overhyped. It does seem to lower the noise floor slightly but at the expense of reducing dynamics not only with amps but also with source components.

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