As a follow up question. I know that tube amplifiers need to warm up before sounding their best, but is it necessary to warm them up to avoid damage? If so, what's a general guideline for doing so?
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30 min warm up time is usually about right for my tube monoblocks and preamp. For the first one hundred hours or so I would leave it on continously and play music when you can. It will break in the fastest this way, but by then the electronics should be well settled in. If you're lucky you will get to be present when a break in "bloom" plateau appears; I recently had this happen with a new preamp and fortunately I had audiobuds over for a listening session when it happened. Everyone went "whoa!"
Tubes are amazing.
Always make sure you have speakers hooked up to a tube amp, turn it on last, when starting up, turn it off first,when shutting down. Let it warm up for a few minutes then play music. You should run the amp at least 3 hours or not use it. When you shut it down, leave it off for about 3 hours before turning it back on, and never leave it unattended. You should be fine. Have fun, tubes are great.
Note that it's OK to leave it unattended when it's not on. Waiting 3 hours to turn it on after turning it off is silly. Tube amps, if designed and built properly, are tough little buggers and don't need nearly as much pampering as many think. My experience says you should simply enjoy the damn thing and it will "break in" from listening to it, and might last longer than you with less upkeep.
I was going to verify that I could leave it alone when turned off as I would rather have an iPod if I have to carry it with me.
I'm aware that heat cycling the unit has the potential to shorten it's life, but once it has reached a steady state operating or ambient temperature it seems that any additional time would be unjustified. I currently have my system (that includes home theather and stereo components) setup to leave everything turned on once it is turned on and then shuts everythign off a single time rather than cycling everything when switching sources.
I shouldn't have any issue abiding by the leave it off for 3 hours before turning it back on again "rule", but with two small kids I'll have a difficult time finding 3 hour windows for listening where I will be available continuously so I guess I'll just have to risk it.
Did Audio Research tell you where you should wait? Can you pace around or should you just sit there? Leaving a new tube amp on for one hundred hours continuously is fine if you're going to sit next to it...this should be easy if you have 2 kids as they can visit you from time to time to see if "the insane dad" is still breathing. The "bloom plateau" is often only a power surge, radiation leak, or stomach virus, group hallucination included, but your results can vary. There is no "3 hour wait" rule by the way, so feel free to ignore that one, and anything I or any of the other certified nut jobs around here say.
Considering I can't leave the tube amp on without speakers connected and I only have one pair of speakers that need to be connected to my home theater system the majority of the time it'll be hard to leave it on for more than a few hours at a time. Especially, considering I can't leave it unattended while it's on.
I'm starting to appreciate solid state more all the time :-)
Mcjelo- Wolf is right. People are making this much too complicated. Because of the potential to damage the output transformers, the general rule of thumb (not necessarily applies to every design but being conservative never hurts) to to always make sure that there is a load (read speakers) connected to a tube amp before you turn it on. Of course, that also means that you should turn the amp off before disconnecting the speakers. Not leaving it on while you are away is a fire safety issue, but similar to leaving the iron or stove on when you leave the house, it's most likely not gonna burn the house down.
Otherwise, the rest of it is, IMO, hokum, at least as far as being "bad" for the equipment. Tube gear warms up more quickly than most ss gear (Class A ss excluded). If you want to wait 1/2 before listening, that's your call but w your kids or my schedule, that most likely ain't gonna happen and it's nothing to sweat over. As far as switching it off and on frequently, unless you use expensive NOS tubes, there is no reason to be overly concerned about "thermal cycling" If your amp has a current or inrush limiter or soft start circuit, that concern is effectively eliminated. As far as other issues, some designs push the tubes harder than others, which IMO, is much more likely to have a real effect on tube life than how long you leave it on or off, or break-in. As Wolf said, just fire the sucker up and enjoy!!!
Wolf ..., ARC told me the same about waiting 5 minutes between a shut off and restart. But you asked a good question about where one should wait during the 5 minute cool off period.
I was told that I should wait in another room and that I must NOT look at the amp during the 5 minute cool down period. Otherwise, the amp may not start up again. So I wait upstairs and lock the basement door for 5 minutes. Doesn't everyone???
To answer your question about playing music...yes .
Don't just turn it on and walk away , PLAY MUSIC !
Tubed equipment , as I have been told , need the electrical changes to aid in the break-in process .
I have not noticed a big change in electrical components resulting from break-in like I have from speakers .
And I agree about it taking @ 30 minutes to warm up for tubed equipment .
So if you only have short periods of time to listen ,tubes are the way to go . My SS phono stage needs at least 7 hours of on time for warm up and my SS amp even more .
Most people leave SS on continuously and turn tubes off when finished to save tube life .
Just another 2 cents worth .
I had the large caps replaced on my former ARC CL-60. I walked into the store's back room where my amp was sitting on a table. It was turned on with no speakers attached.
The tech told me it is alright to have the amp powered up as long as you don't try to drive it (no input signal from a pre-amp).
A dealer told me that broken-in tube equipment takes about an hour warm-up to sound best whereas solid-state takes 24 hours.
Yogiboy - I'm strongly considering doing this, but the audiophile in my struggles with the idea of something unecessary in the signal path.
Wolf_garcia - Will the tape outputs bypass the preamp in the receiver? I did figure out the setting last night were my receiver will pass all audio signals to the TV so I can just set the speakers to "no" and use the TV for volume when the speakers are not connected. This is also a workable solution for everything but movies that don't happen often.
Yogiboy - The primary reason is that I only have a 1,200 sq-ft house and the WAF alone would prevent me from having multiple sets of speakers in the same room. Plus, giving up my good speakers for blu-ray would be a very poor choice because both my wife and I really enjoy the HD audio quality. My wife has only commented on a single CD being a bad recording, but definately notices when a movie's soundtrack isn't HD, it makes a significant improvement.
Wolf-garcia - One of my EE audio friends suggested that the pre-outs with the recievers volume set to 0 db might be a better way to go. His comment was "tape out would work but I think the impedance and signal voltage may be slightly different than an actual pre-amp output." I guess I'll have to try both and see what works best. I'm guess that both will work and I might not really be able to tell the difference.
Tube amps are generally more natural sounding than ss though certainly the design, parts quality and overall synergy with your speakers and the rest of your system remain the most important variables for best sound. I'm not familiar with your brand (I'm assuming it's built in the far east)but many general guidelines have been shared here already. Try to remember simply to have your amp be "ON' the shortest time period versus the rest of your system...this will mean, as previously mentioned: "Last ON, First OFF", and that will go a long way to avoiding unforeseen accidents.
As for actual break-in, yes, playing music through them is ideal because the caps and transformers and all throughout are actually processing a signal which is much better than simply idling on.If I were you and I knew I would be home for a couple of hrs at least, I would turn it on and play some music through it (CD player on 'repeat' or better yet, just a tuner). In a few weeks you'll be close enough that you have a couple hundred playing hrs and I'm sure you'll be satisfied by then.
Tubes typically like about a half hr to warm up and sound their best but again, it depends on the particular model. I have found that some are faster to sounding their best, than others.
For example, my VTL monos were pretty good after 30 minutes but were better by 60... I could still hear improvement even later and by 2+ hours they were simply engrossing with all their attributes at full bloom (rich tone, amazing staging and focus...). Note that by then they were certainly running at a [literally] "hot" temperature as well.
My CJ monos were a decidedly different animal in so much as they really wanted at least 45 -50 minutes or so before they started sounding decent and over an hr before they were truly listenable critically. On the other hand they never became especially more than warm to the touch unless I was doing some sort of 5-10 hr listening marathon at generally loud levels as this could lead to "slightly" hot.
The last example I'll mention is my Cary amp (which I still have) and the Cary has even more 'personality' than either of the others. It has the greatest difference in sound quality between cold and 'fully cookin', and unlike the VTL and CJ it simply wants well over an hour (and really a good 2 hrs) before sounding really listenable but by then it is simply amazing: pure seductive tone, rich mids, surprising punch and extension as well as great width and depth of stage with excellent imaging. But it does run Hot. Yes, it's designed to do so and its been perfectly reliable but it is the only one of the crowd where you want to be conscious of it a bit more.
By coincidence I happen to be breaking in my "End of game" amps right now, my TRL GT 200's which use heavy, solid core copper wiring, massive transformers and Duelund cast caps...all of which will need in excess of 750 - 1000+ hrs before sounding their consistent best. I have over 400 hrs on them so far and they are already magnificent...they are remarkably cool and stable and running them 24/7 (over the weekends at least) is not an issue.
I hope this gives you a little better idea how tube amps will vary but that in general, they are great music makers and IMHO (and many others) well worth their bit of extra care. Happy Lissn'n
I notice with my gear that after 30 minutes the sound starts to have better imaging and soundstage;after about 1 hour of listening the system sounds right to my ears.
I think you will know when it had broken in for you; it may translate into feet moving and other physical reaction as well;(air guitar,drumming,singing or even conducting the symphony;some type of envolvement).
Tubes are fantastic and a very fun part of this hobby just enjoy it.
I don't monitor the warmup of my tube amp because it's generally on providing background music from the moment I start my day until I can get around to doing some "active listening." I can comment of guitar tube amps though, because when I plug in to practice or record or simply try to entertain my neighbors, It really settles in after 20 minutes to a half hour or so...this with any one of a number of tube amps I currently use, and especially with a Class A amp I just bought. So there.
My tube amplifier is in a cabinet that I either leave the door open on or just remove when the amp is running. I have noticed that if I turn the amp on and leave the door shut for a few minutes it really warms up much faster.
Is this a good way to speed up the warm up process? Obviously, I don't plan to leave the door closed for a long period of time, but it seems that 5 or 10 minutes could really speed up the process of getting the amplifier closer to fully warm operating condition.
Is heating up faster significantly harder on the tubes themselves?