Optimizing tube/valve life

OldPicker

Silver Supporting Member
Messages
64
Newby questions here. I recently got my first tube amp - I've used solid state amps because they were always more affordable. But my favorite local shop had a used Blackstar HT-5R for $200, so I jumped on it. I like the tone from the clean channel - it's much warmer than my Katana 50. And since I'm not into the high-gain music, I can dial the overdrive channel to where it just starts to break up. So it's really good for practicing at home where I can't really crank it up much. And I've been experimenting with sending my dry signal to the Katana and the wet signal to the Blackstar (I have a Radial Bigshot ABY to do the split and handle isolation and phase flipping.)

I've read conflicting information about tube life: Some say that tubes last from 2000 to 10000 hours - that's a lot of variation. Some say that the tubes need to be used periodically or else they slowly degrade from disuse. I've also read that a tube amp should be allowed to warm up for 10 minutes before playing thru it.

So I'm wondering what's true or false or arguable, or if there are the real facts, or if the answers are really quite fuzzy.

First question: Is there some place where all of my newby questions have already been answered?

How often does a tube amp need to be run to optimize tube life?
Is once a week enough? Or once a month?
How long should the amp be played at each use?
Does the amp need to cranked up occasionally to optimize tube life?
When we get back to playing live, is there a problem with playing for 20 minutes, then leaving it in Standby for 45 minutes, and then playing for another 20 minutes?

What are the rest of the newby questions that I need to know the answers to?

Cheers!
 

rockon1

Platinum Supporting Member
Messages
12,980
Tubes dont care how often or not they are used. Standby for 45 minutes isnt an issue either. Capacitors supposedly like to be charged/used occasionally though- but that would apply to any amp.
 

marsos52

Member
Messages
2,128
turning the amp on and off puts a lot of hits on the tubes

just use the standby to warm the tubes and lesson the power hit
do this on power up and powering down

many have said to change tubes yearly...i do follow that myself

with that said ,I know guys that have gone years with out changing them
 

rockon1

Platinum Supporting Member
Messages
12,980
turning the amp on and off puts a lot of hits on the tubes

just use the standby to warm the tubes and lesson the power hit
do this on power up and powering down

many have said to change tubes yearly...i do follow that myself

with that said ,I know guys that have gone years with out changing them

Yeah some caveats... If you run the amp hard power tube life will shorten. If I ran my amps really hard I might think about a yearly change. As it is even gigging they dont get above 3-4 on the MV. Havent changed power tubes in over 5 years now. Pre amp tubes will last a lot longer even being cycled on and off. From experience if a tube survives the first week or so they last a long time. Havent had an outright failure in many years.
 

drbob1

Gold Supporting Member
Messages
27,581
Change tubes when the amp starts to sound thin or noisy. Power tubes wear out much quicker than preamp tubes (although a lot of techs will replace the PI, the last tube before the power tubes when they change them).

Short of cranking the amp to put a strain on the power tubes, nothing you do but play is going to put wear on the tubes. And mechanical damage-if you gig, carrying the amp to the gig is harder on it than playing it.

Stand-by switches are a love hate thing. I don't think they've very useful. My suggestion would be to get a shorting cable (the kind that cuts off the sound when you unplug your guitar or pedalboard) and just unplug when you're not playing. The Stand-by is certainly NOT going to coddle your tubes and prevent them wearing in any meaningful way.
 

Anomaly

Member
Messages
72
Yeah some caveats... If you run the amp hard power tube life will shorten. If I ran my amps really hard I might think about a yearly change. As it is even gigging they dont get above 3-4 on the MV. Havent changed power tubes in over 5 years now. Pre amp tubes will last a lot longer even being cycled on and off. From experience if a tube survives the first week or so they last a long time. Havent had an outright failure in many years.
3 - 4 on the MV is quite high on a lot of amps. You are getting 100% of the rated wattage before distortion, so at 4 or 5 on the MV on a typical tube amp you are getting approximately 100 watts on a 100 watt RMS rated amplifier. Some amps hit that breakup wall earlier, like 3 or 4 ish. It's the point where the amp no longer gets any louder but just distorts and compresses more. So tubes are usually (not always) running quite hard at that point.
 

rockon1

Platinum Supporting Member
Messages
12,980
3 - 4 on the MV is quite high on a lot of amps. You are getting 100% of the rated wattage before distortion, so at 4 or 5 on the MV on a typical tube amp you are getting approximately 100 watts on a 100 watt RMS rated amplifier. Some amps hit that breakup wall earlier, like 3 or 4 ish. It's the point where the amp no longer gets any louder but just distorts and compresses more. So tubes are usually (not always) running quite hard at that point.

3-4 on my MV amps is no where near full output- plenty of headroom left to get much louder. Should have qualified that statement. Suffice to say if your not running them hard the power tubes last a long time.
 

56Tweed

Ge Fuzz-o-holic
Gold Supporting Member
Messages
2,479
If I recall correctly, part of the JAN spec (Joint Army Navy - military grade spec) was for expected tube life to be 10k hours. Granted in those days people would just leave the electronics on all day. I've heard stories of studios leaving gear on for months at a time. I find that mind blowing given the electricity draw and how much heat these things put off, but we live in a different world now.

I have a bunch of amps, and while some get more play than others, I don't have many tube failures. I have a few amps that I've gotten 10-15 years out of the current tubes. One of which is currently being serviced and then will have a completely fresh set of (NOS) tubes put in.
 

HotBluePlates

Member
Messages
10,266
If I recall correctly, part of the JAN spec (Joint Army Navy - military grade spec) was for expected tube life to be 10k hours. ...
I haven't seen a "JAN data sheet" that I can recall. However, data sheets from other sources sometimes have "operating time" stated.

Russian 6P3S-E (like the Sovtek 5881WXT):​
Bottom of 1st section says "минимальная наработка" (minimum operating time) - 5,000 hours.​
"90-процентный ресурс" ("90% Resource" or 10% drop in all specs) - 10,000 hours.​
Russian 6P6S (Sovtek 6V6): Service Life Guarantee 1,000 hours.​
Russian 6P14P (Sovtek EL84): Service Life Guranatee 3,000 hours.​
Telefunken ECC803S: 10,000 hours, but also 1.5% failure per 1,000 hours (to account for tubes that fail earlier).​
 

HotBluePlates

Member
Messages
10,266
... How often does a tube amp need to be run to optimize tube life? ...
It's worth you knowing that whatever will make a material impact to tube life has already been set in stone when the designer came up with their amp-design.

Apart from losing bias & causing the tube to melt-down, there's really not much left for the end-user to impact to cause the tube to last-longer/fail-earlier (except possibly physical damage or cracks).
 

teemuk

Member
Messages
3,150
HT-5, as far as I remember, doesn't have a stand-by switch. The feature is, on the other hand, implemented properly (unlike 99% of usual stand-by switches) and fully automatic.

Edit: There is stand-by switch in mk I HT-5 but not in mk II. In both the stand-by feature does not disrupt HT plate voltage (which can be detrimental to tubes and usually stresses power supply components significantly) but instead biases the power tubes cold and mutes input signal to power amp. This way the amp can also disable power amp stage when input coord is not plugged in or when the headphones are used.
 
Last edited:

OldPicker

Silver Supporting Member
Messages
64
HT-5, as far as I remember, doesn't have a stand-by switch. The feature is, on the other hand, implemented properly (unlike 99% of usual stand-by switches) and fully automatic.
The HT-5R that I have does have a Standby switch. I know there have been a few different models over the years so you could be right, too.
 
Messages
938
It's worth you knowing that whatever will make a material impact to tube life has already been set in stone when the designer came up with their amp-design.

Apart from losing bias & causing the tube to melt-down, there's really not much left for the end-user to impact to cause the tube to last-longer/fail-earlier (except possibly physical damage or cracks).
I'm not an expert here, but from everything I've read and heard (I was a digital/solid-state guy for a long time, too), this is just about right. There are plenty of older amps for sale, even from the ’70s and ’60s, with the original tubes in place, and there are also some bad designs that chew through ’em. Other than having backup tubes on hand and making sure your amp is biased right, assuming it's not fixed-bias, the only two things I know to do are

1) Standby/Pre-Heat: point of much contention, whether this really does anything or not. Mesa/Boogie tells me to let my amps idle on standby for 30 seconds before I turn them fully on, so I do that, and I let them cool down on standby for a moment before I turn them off. I have no idea whether it's really necessary. Dave Friedman says it doesn't matter at all, Randall Smith says it does, and maybe there's a difference in adjustable vs. fixed bias amps.

But here's the inarguable one:

2) Don't drag or roll your amp. More than one amp builder has told me that, bar none, the absolute most common and most severe source of user-end tube damage is dragging amps over rough surfaces like concrete/cement/asphalt, or putting casters on them and rolling them everywhere. I know casters seem like an obviously good idea, but they rattle the hell out of your tubes and make it much more likely that there'll be a mechanical failure either inside the tube itself or at the tube socket. You really just want to pick up and carry the damn thing.
 

gldtp99

Member
Messages
3,790
Many amps I've built and sold to local players have gone 10+ years without a tube failure or a failure of any kind.

1) a 50 watt Hiwatt DR504 clone I built was bought by a working band who played locally and throughout the SW USA, Mexico, and also toured in South America

This DR504 clone was brought back to me after 12+ years of use for a "Tune Up" (it was still working 100%)

I inspected the amp, cleaned it up, and tested the tubes----- some of them tested a little weak but all were still operating

I put in all new tubes--- biased the two EL34's---- and the owner tested it out

He said it sounded good, but it always sounded good to him

He said he'd see me again in @10 years as he was leaving

2) a Hiwatt DR103 clone I built was used by a series of several owners over a period of 10+ years

It usually saw daily use

I bought it back from the last (4th) owner for $200 because it had stopped working

I inspected it, cleaned it up, and found one failed preamp tube

I put in a new set of tubes and used it as a Bass head of the Bass Stack in my shop

It's still being used as my bass head---- except for a few months when it was being used by a local Grindcore band------ they brought it back and it's sitting on top of my Bass Stack

These are just two examples of amps whose history is known to me

Sometimes an amp I've built will come across my work bench---- It will usually have the exact same tubes I installed when I built it

IME most tube amp owners don't worry about the tubes in their amps----- they just play and play them until the amp doesn't work any more

This type of amp owner is much more common than the type of owner who is diligent about tube replacement after a certain length of time

Most players just play the amp until it dies---- and only then will they seek the most inexpensive way to return the amp to service

Here on TGP we have players who actually care about tube life, tube brand, proper biasing of output tubes, and other such things

We are in the vast minority of tube amp users in my real world experience
 

Jabby92

Member
Messages
3,673
Newby questions here. I recently got my first tube amp - I've used solid state amps because they were always more affordable. But my favorite local shop had a used Blackstar HT-5R for $200, so I jumped on it. I like the tone from the clean channel - it's much warmer than my Katana 50. And since I'm not into the high-gain music, I can dial the overdrive channel to where it just starts to break up. So it's really good for practicing at home where I can't really crank it up much. And I've been experimenting with sending my dry signal to the Katana and the wet signal to the Blackstar (I have a Radial Bigshot ABY to do the split and handle isolation and phase flipping.)

I've read conflicting information about tube life: Some say that tubes last from 2000 to 10000 hours - that's a lot of variation. Some say that the tubes need to be used periodically or else they slowly degrade from disuse. I've also read that a tube amp should be allowed to warm up for 10 minutes before playing thru it.

So I'm wondering what's true or false or arguable, or if there are the real facts, or if the answers are really quite fuzzy.

First question: Is there some place where all of my newby questions have already been answered?

How often does a tube amp need to be run to optimize tube life?
Is once a week enough? Or once a month?
How long should the amp be played at each use?
Does the amp need to cranked up occasionally to optimize tube life?
When we get back to playing live, is there a problem with playing for 20 minutes, then leaving it in Standby for 45 minutes, and then playing for another 20 minutes?

What are the rest of the newby questions that I need to know the answers to?

Cheers!
1) Tube Amplifier Care – 12 Habits that Extend the life of Your Amplifier - Carvin Audio
2) Its good to run it at least once a month or so IMO, I run mine at least once a week or more.
3) I always try to play it at least 1-2 hrs or more.
4) No. In most cases you don't need to crank the amp to get a good sound and it doesn't help extend tube life.
5) No not at all. This keeps the tubes warmed up and ready to go. This is ideal than shutting the amp off and cooling/warming them up again.

In general you want tube amps warmed up and ready to go. Personally what I do is turn the amp on and let it warm up 1-2 mins.. and then just play for 1-2 hrs and use standby if I need to take a break. I get lots of tube life this way and never had an issue. Also its ideal to keep the amp biased for the tubes in use.
 




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