Tube life in preamp. Please help


Hello-

Using an Audio Research SP9 and I've shut it down each time between listening sessions.

I find however it sounds better if I leave it in the standby position.

How much does this lessen the life of the two tubes it contains? They were Amperex and not cheap.

Please advise. Thanks!
jlj1
I used Telefunken in mine. I found the 6DJ8/ECC88 to sound better in the SP9 MKII , and the 6922/E88CC to sound better in the MKIII. They both lasted more than five years in standby.
Pre-amp tubes typically have a very long operating life (there are exceptions). In stand-by mode, there should be no appreciable effect on lifespan. There is even an argument to be made that doing so will lengthen tube life by eliminating current in-rush effect. I would leave it on stand-by unless I was leaving for vacation or other reason the pre were unattended for long periods, just as a safety thing.
I used Telefunken in mine. I found the 6DJ8/ECC88 to sound better in the SP9 MKII , and the 6922/E88CC to sound better in the MKIII. They both lasted more than five years in standby.
I have also found telefunkens to be the tube to beat. My amprex's had a hot top end that sounded a bit unnatural.
don't leave tubes on stand-by if you want to save your equipment and your dwelling. it's dangerous no matter how well tube electronics are designed. if you're not watching your equipment or go to bed you must turn that off.
A note about tube's being damaged by "current in-rush"...I've owned tube guitar (old low wattage stuff, high wattage English and US amps, etc.) amps that kept their preamp tubes for DECADES and were turned on and off thousands of times with and without "stand by" circuits with...here it comes...ZERO preamp tube issues. I doubt hifi amps get the abuse guitar amps suffer in their natural state (do you overdrive your preamp tubes to distortion for several hours while their in the same box as your speakers?...no you do not).
Well, Wolf, i once re-wired point to point VTL tube amp that started burning in front of my eyes, but I'm glad you're always holding premium cards that you don't have to fold.
Czarivey-You are a bit paranoid, aren't you? Not too many amps will "burn in front of your eyes" unless you mess with them...

Standby was created for a reason and generally speaking it works quite well at extending both tube and equipment life. An amp that burns up usually does that as soon as you turn it on, not after being on standby for 4 days or 400 days.

Yes, I do turn off gear when I'm not going to be around for a couple of days but never for shorter periods.
Preamp tubes should last longer in standby by avoiding the current rush. Many NOS 6922's can last 5000 to 10,000 hours.
The ARC SP9 series of preamps do NOT have your typical "standby" mode that some preamps have. Most "standby" modes reduce the voltage to the tube(s) and only keep the heater warm.

The SP9 preamp has only an on & off and a mute & operate toggle switch. The mute switch just mutes the output, but keeps full current to the tubes.

I agree with everyone above, if the SP9 had a real standby circuit, but it doesn't. I turn my SP9MKII on 30-45 minutes before I'm really ready to use it, then it takes an additional 30 minutes or so to warm up to full potential.

If even you keep it on full time, the tubes should last 5000-10,000 hours so you would need to replace them once a year or so.
02-25-15: Elevick
Czarivey-You are a bit paranoid, aren't you? Not too many amps will "burn in front of your eyes" unless you mess with them...
Paranoid is just definition and definition maybe just another form of bs. burning amp wasn't bs it was a fact.
Don't know if anyone messed with that, but it all started around just ONE failed power tube.
The one thing that no one has mentioned is the cost of keeping tube gear on all the time. I had an ARC SP9 at one time and it wasn't drawing that much power, but it together with a pair of ARC M100 monos and we're talking $20 to $30 a month in power usage. I also had one of the M100s catch fire in front of my eyes, but in all fairness the piece had been modified. As the years have gone by I have returned to solid state equipment for the reasons that first there is really no appreciable difference in the two technologies at the high end, and that I am more focused on the music than the equipment as I grow older.
Too right Brauser, all that happened to me as well !
I have a theory, most tube freaks never heard ,say, a quad of Sylvania 6550's from the 1950's in full cry, the junk output tubes available today make tubes a non-starter for me today.
My current "junk output tubes" are KT150s that sound astonishingly excellent, and if you leave tube gear on all the time...well...you get what you deserve.
The best tubes for the various SP-9's are rare NOS that go now for $75 and up, each. They are getting rare!

I have used all of the SP-9 models for years.

These tubes can last 5000 to 10000 Hours.

ARC can still repair, and refurbish, to original state, all the SP-9's.

I liked the original MKI and the MKIII best. I did not like the MKII.

Buy a lifetime supply of NOS tubes, and do not leave the preamp on for days, when not listening.

You will be set for a lifetime of good sound!
I am running Audiovalve Challenger 180 monoblocks and Allnic L3000 pre amp and never leave them powered up 24/7.
When I know I am going to be listening to music the system gets turned on a couple of hours before use even knowing both units have standby capability. I really don't have a good reason other than I don't want to chance a hardware failure that could result in serious system damage or maybe cause a fire.
As far as tube life my pre amp tubes always seem to last for several years and if I am questioning a tube I test it on my B&K 747 tube tester.
"I liked the original MKI and the MKIII best. I did not like the MKII."

I was an ARC dealer for many years and have personally owned about a dozen different SP9 preamps. I keep going back to this unit because it really is a great preamp. I know others disagree, but I've had a massive amount of experience with these units and still find them wonderful.

I've had (2) MKI, (7) MKII and (3) MKIII.

IMHO, the MKII is the best. Just personal taste, but it seems to provide the best mix.
Can you describe the sp9 sand why you liked it best mofi?