[MozartMan1201]

Hello,
I just got my first tube amp (Pathos Aurium, technically a hybrid) and have the following questions --
 
(1) Would you recommend leaving the amp on all the time (it gets really hot) or only when in use?  
 
(2) Is it bad to turn it on only for short periods (under 1 hour) then turn off?  
 
(3) Conversely, is it bad to turn it on too quickly after turning off?   How long should I wait before turning it back on?
 
It pairs really nice with my AKG 812 and Sennheiser 600, thinking about getting Audeze LCD-X for the holidays.
 
Thanks for your input!
 
 
 

 

[flatmap]

(1) Would you recommend leaving the amp on all the time (it gets really hot) or only when in use?  

I would not, as it just shortens the life of the tubes.  Turn it on when ready and you'll maybe have 10-15 minutes before it warms up.  I always turn mine on and start listening right away, knowing it'll get a bit better in a few minutes.  There is a school of thought that some SS gear benefits from being left on all the time and I can't say anything one way or another about that.
 
 
(2) Is it bad to turn it on only for short periods (under 1 hour) then turn off?  
 
Well I do this all the time with my tube amps because a lot of my opportunities for listening are of that length.  If you're worried about shortening the life of the tubes, I don't think this will be a particular problem.  Especially in modern equipment there are standard ways to stabliize the startup current so you get a nice soft start.  What tubes are they using in this unit? 
 
 
(3) Conversely, is it bad to turn it on too quickly after turning off?   How long should I wait before turning it back on?
 
Well, don't just flip on/flip off.  I may not be so crucial with these small tube preamp tubes, but with tube power amps you can get some crazy transients in the first few seconds.  I don't know about any absolute time, but wait  maybe 10 seconds before turning it back on.  Again since this has tubes only in the preamp section, it may not make a difference.
 
It pairs really nice with my AKG 812 and Sennheiser 600, thinking about getting Audeze LCD-X for the holidays.
 
Holy smokes!  What a nice set up!  Are you enjoying the 812's?   Having owned and loved the K-702s for many years, these  are on my wish list.  And the Pathos stuff is said to be just lovely; you are so lucky. 

 

[MozartMan1201]

Thanks, the tubes that come with the Aurium are Electro-Harmonix 6922.   One school of thought is to leave the tube amps on all the time to lengthen the life of the tubes.  Personally I think my electric bills would cost more than the tubes, so I may just use it as a space heater in the winter.  

 
I still have my old AKG 702 but cannot bear to listen to it after acquiring the 812... the new cans are just that good (read my Amazon reviews of each under 'GoBears').  I haven't heard the Senn 650, but my 600 sounds pretty darn good next to the 812, only slightly lacking in the soundstage width and clarity department.  In some music (lieder, chamber music, string orchestra), I  actually prefer the Senn for its greater warmth and feeling of intimacy.  But as far as 702 vs 812...it's like night and day, 2D vs 3D, VHS vs 4K...it is THAT dramatic.   Previously I had auditioned Senn 800 but it sounded awful in chamber music and songs, amazing in large-scale orchestra and choral music.  The 812 is the best overall headphone IMHO.  The 702 is now put on ebay pending best offer
 
BTW- I was able to audition all these headphones before finally deciding on the 812 thanks to Amazon's generous 30-Day Policy.  
 
Cheers,  

 

 

[flatmap]

Wonderful to hear that the K812 is such a great headphone and that you've got a sound and setup you like.  So, even when powered by the Pathos, the K-702 just is no match at all for the K-812.  That's how it is, I guess.  Sigh. 
 
Right, the replacement cost of the 2 EH 6922 tubes is about $28, so not a disaster to replace them over time.  Compare to the cost of a  300B which is about $130/tube for standard current production. So really you've gotten off easy!
 
For tubes, as with light bulbs, I think the information about keeping them on to extend life comes from wanting to avoid the inrush current at switch on.  But with current limiting, or similar, I just don't feel this is a problem with modern equipment.  Regardless of what you decide, I bet those tubes last a good long time.

 

[tomb]

A couple of things:

• People who recommend leaving tube amps on all the time fail to recognize that all amps have electrolytic capacitors.  Tube amps have more of them than most.  Electrolytic capacitors have a finite life.  At elevated temperatures, the life is much shorter.  Many capacitors are spec'd with lifetimes at 85 deg.C or 105 deg.C.  Regardless of which you have in the amp, the fact is that the life is finite.  I guarantee they're a lot harder to replace than the tubes. 
  
• Depending on the amp's configuration (I don't know specifically about the Arium.), a relay-delay may be present at the headphone connection to protect against DC.  This can happen if coupling capacitors are used to block the DC from the tubes, but they take time to charge up after first flipping the power switch.  For this reason, many tube amps will have a headphone delay-relay that keeps the headphone jack switched out of the circuit until enough time has passed that the coupling capacitors have charged.  As mentioned above, quickly cycling the power switch can result in the relay actuating too soon - before the coupling caps have had time to re-charge.  This would expose your headphones to DC if they are plugged in.  If you wait a while before cycling the power switch again, this will give all the caps time to bleed down and the relay should engage after the proper delay.

 
Again, I have no idea if this is the way the Arium is set up (for delay circuit), but many tube and tube hybrids operate this way.  It doesn't hurt to be safe.

 

[David Chew]

I can confirm that the Aurium does have a 10 second startup headphone relay delay.