AudioAficionado.org  

Go Back   AudioAficionado.org > Manufacturers Forums > Audio Research

Audio Research State of the Art Audio Reproduction

Reply
 
Thread Tools Display Modes
  #1  
Old 07-24-2018, 09:54 AM
sonicmatter sonicmatter is offline
Guest
 
Join Date: Jan 2018
Posts: 72
Default ARC ref75se bias adjust

Hi Guys,
When first got this brand new I adjust the bias as per instruction. My question is how often do I have to adjust the bias or you only do it the first time when the tube is new?
Reply With Quote
  #2  
Old 07-24-2018, 12:11 PM
2fastdriving 2fastdriving is offline
Guest
 
Join Date: Jan 2013
Location: Seattle, WA
Posts: 5,772
Default

Quote:
Originally Posted by sonicmatter View Post
Hi Guys,
When first got this brand new I adjust the bias as per instruction. My question is how often do I have to adjust the bias or you only do it the first time when the tube is new?
There's no hard and fast rule. Do it as often as you like

The Ref75 makes it soooo easy that when I had one, I did it every few weeks. I don't plan to do it very often on my Ref150, which takes a lot more effort!
Reply With Quote
  #3  
Old 07-24-2018, 02:21 PM
audio bill's Avatar
audio bill audio bill is offline
Senior Member
 
Join Date: May 2013
Location: Chicago suburbs
Posts: 1,641
Default

It depends upon how much running time the amp gets, but in general I'd suggest checking the bias again in a couple of weeks and then again in a couple of months as there can be some drift from when new. By that point the tubes and related circuitry should be burned in, so then you can just check them a couple of times a year to verify its bias stability.
Reply With Quote
  #4  
Old 07-25-2018, 03:53 AM
sonicmatter sonicmatter is offline
Guest
 
Join Date: Jan 2018
Posts: 72
Default

Tks for the fast reply guys.
Can I adjust the bias after listening to it after long hours? After switching it on how long should the amp warm up before adjusting the bias?
Reply With Quote
  #5  
Old 07-25-2018, 07:44 AM
audio bill's Avatar
audio bill audio bill is offline
Senior Member
 
Join Date: May 2013
Location: Chicago suburbs
Posts: 1,641
Default

Bias should stabilize after being on for about 30 minutes with no significant difference after being on for a longer period. Make sure that there is no input signal to the amp when biasing (no active source.)
Reply With Quote
  #6  
Old 07-25-2018, 10:27 PM
JPrest's Avatar
JPrest JPrest is offline
Member

 
Join Date: May 2009
Location: Minneapolis
Posts: 310
Default

I know how conservative we get about our equipment to protect it, but ARC equipment is tested to the max here in Minneapolis, I've been to the floor. IMO you could easily be 10 percent off and not here the difference or suffer much shorter tube life. So enjoy it and relax.
__________________

ARC REF6, ARC Ref PH 2SE, ARC Ref 150SE, Esot N-05, SF Oylimpia III, Garrard 301 Reed2p, WW Silver Eclipse 8, Kimber Kable Select IC XLR

C22, MC275, MR78, PS Audio Dac, Tannoy Daltons 12" Red's Tannoy ST200 Tweeters, Kimber IC's, Mac Mini, Transparent ULTRA Speaker.

Marantz 7C, Marantz, 9, & 10B Tuner, Tannoy 15" Red's in York Corner Cabinets

ARC Ref1, ARC VT 100II, MR74, Tannoy Red 12 LSU/12/8, Spider Transcription TT, Nordost Spk Cable

Fisher 400C, MR78, Fisher SA 1000, BenchMark Dac, Auditorium 23 Speaker Cables, Tannoy Supper Red 10" LSU/III/Z Monitors

ARC SP3, MC 30's, MR67, Devore Supper 8's, Wadia i171, MicroMega Dac, Transparent Supper Spk

C20, MC75's, MR71, MS300, Tannoy 12" Golds, Auditorium 23,

C11, (2)Harmon Kardon CitationII, Shindo Montille, MC2505, McIntosh 117, Audio Research ST70, Knight KB85, Pilot Sa 232, Marantz 8B

Scott 130 Preamp, Scott 272 Int, HH Scott 250's MR71 tuner, Tube Guru F2a Mono's,
Reply With Quote
  #7  
Old 07-26-2018, 05:30 AM
sonicmatter sonicmatter is offline
Guest
 
Join Date: Jan 2018
Posts: 72
Default

Quote:
Originally Posted by audio bill View Post
Bias should stabilize after being on for about 30 minutes with no significant difference after being on for a longer period. Make sure that there is no input signal to the amp when biasing (no active source.)
Tks , noted.
Reply With Quote
  #8  
Old 07-26-2018, 05:31 AM
sonicmatter sonicmatter is offline
Guest
 
Join Date: Jan 2018
Posts: 72
Default

Quote:
Originally Posted by JPrest View Post
I know how conservative we get about our equipment to protect it, but ARC equipment is tested to the max here in Minneapolis, I've been to the floor. IMO you could easily be 10 percent off and not here the difference or suffer much shorter tube life. So enjoy it and relax.
Will do
Reply With Quote
  #9  
Old 07-26-2018, 10:48 AM
The Lost Bears's Avatar
The Lost Bears The Lost Bears is offline
Senior Member
 
Join Date: Apr 2012
Posts: 383
Default

You should check and if needed, adjust the bias often when the tubes are new. The bias on new tubes can drift until they settle in. That is why it is important to purchase well matched tubes from someone like ARC. ARC burns their tubes in a bit before the hand match them. Some tube dealers also do this but most don't If the tubes are only (tube) factory match, they will tend to drift a bit more in the beginning. If you are running matched pairs than they can drift in opposite directions and one tube will run hotter than the other. Running tubes too hot can affect tube life.

I bias my tubes at .63ma. I usually check the bias after listening. I mute the preamp and let the amp settle for at least 5 minutes. The first few days with new tube I check the bias often. After that I check the bias about once a month. I also dust the top of the tubes so the have better heat dispersion.

Last edited by The Lost Bears; 07-26-2018 at 10:55 AM.
Reply With Quote
  #10  
Old 07-26-2018, 01:15 PM
2fastdriving 2fastdriving is offline
Guest
 
Join Date: Jan 2013
Location: Seattle, WA
Posts: 5,772
Default

Quote:
Originally Posted by The Lost Bears View Post
You should check and if needed, adjust the bias often when the tubes are new. The bias on new tubes can drift until they settle in. That is why it is important to purchase well matched tubes from someone like ARC. ARC burns their tubes in a bit before the hand match them. Some tube dealers also do this but most don't If the tubes are only (tube) factory match, they will tend to drift a bit more in the beginning. If you are running matched pairs than they can drift in opposite directions and one tube will run hotter than the other. Running tubes too hot can affect tube life.

I bias my tubes at .63ma. I usually check the bias after listening. I mute the preamp and let the amp settle for at least 5 minutes. The first few days with new tube I check the bias often. After that I check the bias about once a month. I also dust the top of the tubes so the have better heat dispersion.
^^ this seems like really good advice and information to me.

I just want to point out (for those that don't have one) that setting bias on a Ref75 is FAR easier than most products. Doing it monthly, or even weekly is very reasonable. It takes like 2 minutes and you don't have to move the amp at all, regardless of how you have your gear arranged. Still probably doesn't need to be done more than once a month at most.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Audioaficionado.org tested by Norton Internet Security

All times are GMT -4. The time now is 05:50 PM.



Powered by vBulletin® Version 3.8.10
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
©Copyright 2009-2023 AudioAficionado.org.Privately owned, All Rights Reserved.
Audio Aficionado Sponsors
AudioAficionado Subscriber
AudioAficionado Subscriber
Inspire By Dennis Had
Inspire By Dennis Had
Harmonic Resolution Systems
Harmonic Resolution Systems
Wyred4Sound
Wyred4Sound
Dragonfire Acoustics
Dragonfire Acoustics
GIK Acoustics
GIK Acoustics
Esoteric
Esoteric
AC Infinity
AC Infinity
JL Audio
JL Audio
Add Powr
Add Powr
Accuphase - Soulution
Accuphase - Soulution
Audio by E
Audio by E
Canton
Canton
Bryston
Bryston
WireWorld Cables
WireWorld Cables
Stillpoints
Stillpoints
Bricasti Design
Bricasti Design
Furutech
Furutech
Shunyata Research
Shunyata Research
Legend Audio & Video
Legend Audio & Video