No, leave it on all the time. It will sound better. You don't need be be concerned about excessive wear.
15 responses Add your response
Techs will tell you to leave all equipment powered up 24/7 except for tube amps (output tubes tend to pass a lot of current and have to be turned off to prevent excessive tube wear) and Class-A biased transistor amps (which burn too much electricity to leave on 24/7 and which produce tons of heat). It is the thermal cycles (heating up and cooling down) that result from turning equipment on and off which tends to make equipment break. Cold equipment also sounds bad in high resolution systems. This is especially true with digital processors -- you have to leave them on 24/7 if you want them to perform as the manufacturer intended.
Of course, the above poster is correct about unplugging equipment to protect against damage from electrical storms. It is also not "green" to run equipment 24/7, but if you want to increase the chance that your equipment will break and if you want it to sound like crap, turn it on and off.
PS: The light on your DAC is almost certainly an LED -- it will last forever.
I usually agree with Nsgarch but tubes should be left on too. They live much longer since they are not expanding and compressing each time you turn the unit on and off.
Raquel, I am usually very envoronmental conscience but I never know when I'll get to listen and I found that I don't like waiting the various warm-up times. But I do agree that we should all be as "green" as possible.
p.s. It's nice to see a woman beside Elizabeth on the Gon. Welcome from all of us.
I have an Electrocompaniet DAC that I leave on most of the time.
Funny thing is, occasionally when I sit down to listen, it has this funny "out of phase" sound to it. Almost as though the entire system has been turned inside out. I would liken the sound to a kind of transistor radio feel. It really strange. It's not like the phase has bee switched 180, that would still be listenable. But it's like nothing else I've ever heard.
All I do is re-boot the DAC and all is fine. That's about the only time mine gets switched off.
Tubes last longer if turned off when not in use. The cathode has a limited lifetime where it is capable of full emission. There may be some turn-on stress, but that is outweighed by burning the life out of a tube.
On turn on, the filament is cold and conducts current with little resistance. The high in-rush current causes very rapid heating and thermal stress. Also, if the unit utilizes solid state rectification, the power applied to the plate come on almost immediately while the cathode may take some time warming up. This could lead to a condition called cathode stripping.
These issues are mostly non-existent if the unit uses tube rectification (the rugged rectifier takes all the abuse and slowly turns on the rest of the unit. In units with solid state rectification, the turn on can be rapid, but a lot of experts think that the "damage" is relatively minor.
It is possible to put a thermistor or other device in the power supply to slowly bring up the power in tube gear if that is a concern.
In response to your initial question I would agree with Jond, leave the DAC and the transport on.
However, since the topic has gone a bit further into the value of warm-up from cold start vs a constant on condition I've made an observation with a SS CDP left on 24/7.
When the rest of the system has been operating well past any reasonable warm up point (all tubes) when I use this CDP (Wadia) initially the upper frequencies are definitely overbearing in the highs. Dissapears within about 30 minutes or less (replayed the disc to verify). Thereafter, in that session there is no problem whatsoever.
Anyone else observed this in a different, or same, devices?
CDPs or DAC/Transport combinations draw very little power and usually don't put out much heat (high heat is what ages most components) so leaving them on is not a problem. With my CDP, if I turn it off, it can take several hours to get back on song. The manufacturer recommends leaving it on all the time. They claim that it takes quite a while for the capacitors to get back to optimum performance.
Larryi: It is precisely because most modern tube preamps use solid state rectification that powering them up and down kills tubes. I agree that a soft-start circuit (CAT preamps come to mind) or using a thermistor will do a lot to ameliorate the problem, but absent such a device, I stand by my statement that small-signal tubes last much longer if left powered up in most circuits. If a person is running a big Jadis or Aesthetix preamp with tube rectification, that's one thing, but most tube pre's (or anything else that uses small-signal tubes) do not, and 24/7 will yield better tube life (and to a point, better sonics -- as I have noted in other threads on this topic, they do degrade slowly over time).
The "TIPS & ADVICE" section of the owner's manual to my VAC Renaisance 140/140 Mk. III tube amps states:
"How long should tubes last? It has long been known in professional circles (and probably now forgotten) that a tube such as the 12AX7 will display BETTER performance characteristics after TWO YEARS of CONTINUAL operation than when it was new. In normal use it is not unusual for a low level tube to last 5 years or longer. Output tubes [i.e., power tubes used in tube power amps] are another story, as they are continuously providing significant amounts of current." (Emphasis original).
Good points, as far as general advice. All my tube gear has tube rectification so I don't worry as much about turn on issues.
I suppose the best thing to do is consult the manufacturer. Some linestages are quite hard on their tubes (old Counterpoints come to mind) and so turning them off might make sense, regardless of whether or not they use solid state rectification. Also, some gear run pretty hot (enclosed case, lots of tubes) so damage from heat could be an issue. Some caps and resistors don't stand up to constant exposure to heat.