Maintenance

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Thomas234
Posts: 1
Joined: Tue Jan 15, 2013 6:58 am

Maintenance

Post by Thomas234 »

Hey guys!

I have a few questions regarding maintenance. I'm new to tube amps.

1. When im reading through turning it off they said to leave the stand by on and some say to leave the stand by on?

I have a peavey valveking 100w, not the best amp but it does the job :)

2. What would be the best valve replacement? (is it the preamp that defines the sound?) I love the sound of the marshall amps but I really dont know what valve I need. I love the JVm410 amps, i'm more into satriani stuff haha

3. How often do you have to change the output/power tube if you only use it at home? like 1-2 hours a day

4. how often do you have to change the pre amp valves? i heard they last for a long time

5. for maintenance, will the tubes last longer if I turn it on and off? i use it for home so I p[lay my guitar different times during the day so im not sure if its healthier for the tubes to stay on or off. I usually play for 1 hour sometimes 2 and sometimes 30mins and then i turn it off for 5 hours then i play again.

6. will my tubes last longer if i play in low volume (volume knob at 2oclock) considering there's not much wattage being used?

7. is it bad for the tubes if it hasn't been used for 2-3 months?

the condition of my tubes are good so far, everything lights up evenly and the glass is clear!

This will pretty much everything I need to know i hope!
Mark
Posts: 3271
Joined: Sat Jan 15, 2005 8:10 am
Location: Sydney Australia

Re: Maintenance

Post by Mark »

I wouldn't get too worried about the amount you are using your amp, bear in mind valves in HiFi amps are in there for ten to fifteen years.

I don't think you'll get night and day changes by tube rolling. A Mullard tube isn't everyones cup of tea, though the ones I heard didn't have a huge top end. It all depends on the amp and what you are after.

The standby switch leaves the heaters on so you can walk on stage flip the standby switch on and start playing immediately as apposed having to wait a minute or two. Most people do turn the power switch on and then turn the standby switch on so the bias voltage has time to stabilise. Once again I think if you switched the power on and then the standby on a second later would be fine. Mind you I haven't given any thought to the time constant of the bias supply.
Yours Sincerely

Mark Abbott
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Structo
Posts: 15446
Joined: Wed Oct 17, 2007 1:01 am
Location: Oregon

Re: Maintenance

Post by Structo »

Thomas234 wrote:Hey guys!

I have a few questions regarding maintenance. I'm new to tube amps.

1. When im reading through turning it off they said to leave the stand by on and some say to leave the stand by on?


I have a peavey valveking 100w, not the best amp but it does the job :)

2. What would be the best valve replacement? (is it the preamp that defines the sound?) I love the sound of the marshall amps but I really dont know what valve I need. I love the JVm410 amps, i'm more into satriani stuff haha

3. How often do you have to change the output/power tube if you only use it at home? like 1-2 hours a day

4. how often do you have to change the pre amp valves? i heard they last for a long time

5. for maintenance, will the tubes last longer if I turn it on and off? i use it for home so I p[lay my guitar different times during the day so im not sure if its healthier for the tubes to stay on or off. I usually play for 1 hour sometimes 2 and sometimes 30mins and then i turn it off for 5 hours then i play again.

6. will my tubes last longer if i play in low volume (volume knob at 2oclock) considering there's not much wattage being used?

7. is it bad for the tubes if it hasn't been used for 2-3 months?

the condition of my tubes are good so far, everything lights up evenly and the glass is clear!

This will pretty much everything I need to know i hope!
1) Also we should define what standby on is. When it is on, the switch is actually off.
It is in standby until you close the switch, which supplies the high voltage
to the tubes.
Switches don't generally like DC voltage which is what a standby switch is
switching. They tend to arc after a while.
So when turning off a tube amp with a standard standby switch it is fine to just turn the power off which is AC.

2) A tube amp is the sum of it's parts. Some guys can hear a mouse fart and can tell instantly the difference between preamp tubes.
As we age, we lose our high frequency hearing first.
As tubes age they lose their high end response first so it's kind of a double
edged sword if you are say, over 50 and have played loud music most of your life.
That being said, if you have a handful of tubes, roll them through the amp to see if you hear a difference.
Be aware if you are not playing the amp very loud, you may not hear a difference at all.
Preamp tubes can last a long time, (years) especially if they are good vintage tubes.

3) Power tubes generally have a shorter life than preamp tubes but a tube is a consumable device and they all have a finite lifespan.
Nobody can tell you that X Brand of tube will last 700 hours.
They may last well beyond that or they could short out and fail within hours of installation.
They will get weaker over time as well as lose their high frequency response.
This all happens pretty slowly over time in most cases and you may not notice it because we turn those tone knobs to compensate for all but drastic changes.

4) See above.

5) When a valve heater or light bulb is energized (turned on) it has a inrush of current because a cold element
has lower resistance than when t is heated, this allows a larger current to briefly flow when first powered up.
Not only that but there is a mechanical shock to the element due to EMF.
Ever notice that a light bulb will often burn out when you turn it on?
I think that if you are going to be playing through the amp an hour or two later it is fine to leave it in standby.
But I would not leave the house with a tube amp powered up.

6) Cranking an amp is probably harder on the power tubes but depending on the circuit and bias method the life time of the tubes can vary greatly.
The heater voltage and heating effects are often times what ages a tube even at bedroom levels.
Also after many hours of use, the coating on the cathodes is depleted, but that
takes a long time.
Sure diming an amp is going to be harder on all things considered.
But like I said, the hardest thing on a tube amp is turning it on. :D

7) No, but what does age more without use is the electrolytic filter capacitors.
They have a finite lifetime and actually not using the amp is harder on those filter caps than daily playing.
So at least turn on the amp once a month or more to keep the caps formed.
Google reforming caps.

Hope this helps and this is my own opinion which may be different from other members.

Welcome to the Amp Garage.
Tom

Don't let that smoke out!
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briane
Posts: 557
Joined: Wed Mar 28, 2007 8:41 pm
Location: seattle

Re: Maintenance

Post by briane »

what he said above!

Actually I think you worry too much for how little you play and how kind you are to your amp. Thats what I would consider 'grand mother usage' - about what my amp gets and my power tubes are still in great shape - pre's should last my whole life.

If you gig an amp hard - new power tubes every year or so - maybe more- preamp tubes should go at least between 2-5 years.

Leave in standby if youll be playing again in an hour or 2 - otherwise kill the power - electricity is expensive.

-b
it really is a journey, and you just cant farm out the battle wounds
boots
Posts: 573
Joined: Mon Jan 17, 2011 1:26 am
Location: SW Colorado

Re: Maintenance

Post by boots »

Life is too short to play through second-rate tubes! Unless you are gigging a lot, I think it is worth using fine tubes, because my enjoyment is well worth it. I am a big fan of used, old vintage tubes. You can find them for decent prices (they're USED, not NOS), and truthfully, I find very few tubes out of a big pile that are bad. If you collect a fair number of used (but good) tubes, after a while you stop caring so much about making them last as long as possible, because there is always another sweet one waiting in the wings!

That said, I agree that turning the amp on/off a lot is one of the worst things for tubes, and also leaving the amp on standby for long periods. For me, it is always a toss-up whether to shut the amp off when I think I will be playing again in a couple hours. But again, if I wear out tubes a little faster, to me, it is worth it because of the enjoyment I get from them.

I agree with Mark that it's fine to turn on the power first, then flip the standby to Play a few seconds later. I used to always wait a full minute, but I am convinced now that a few seconds is plenty of warm up time. When turning the amp off, I just flip the main power OFF - it doesn't matter what position the standby switch is in when shutting down.

That's just me. If you are gigging regularly, I suppose it makes sense to think about making your tubes last as long as possible. But I'm just some hack who really gets off on playing my amps with fine tubes.

As far as cranking your amp, I only really get to crank my amps when the wife is out of the house, so when I get the chance, I go for it! The amp (and tubes) are a completely different animal when cranked hard, so it's just part of the complete experience to me. I also really love the sound of a small amp played clean at bedroom levels, too. All part of the complete experience. If my playing habits wear out tubes faster, that's OK with me.

I realize this wasn't probably very helpful information, but more an insight into my philosophy about my own enjoyment of this guitar/amp hobby i'm addicted to.
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Structo
Posts: 15446
Joined: Wed Oct 17, 2007 1:01 am
Location: Oregon

Re: Maintenance

Post by Structo »

From the Valveking 100w owners manual:

STANDBY SWITCH
Placing this switch in the “Standby” position will effectively shut the amp off while leaving the tube
filaments on. Leave this switch in the “Standby” position for a minimum of one (1) minute after engaging
the POWER SWITCH (#19). This is also a useful feature, since much tube wear comes from the heating
and cooling of the tube itself. Leaving the unit in “Standby” when you take a break allows the tubes to
stay warm while you are not playing. To immediately resume normal amp operation with no warm-up
delay, place the switch in the “ON” position. NOTE: This switch does not replace the POWER SWITCH
(#19). When you are ready to stop playing for an extended period of time, it is better to turn the amp off
via the POWER SWITCH
Tom

Don't let that smoke out!
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