how often do you replace your valve/tube in your amp?

tsunami

New member
Valve Amp?

Just curious, how often do you replace your valve/tube in your amp?

Or you will use till its dead then replace or replace say, yearly?

Normally, how much is a valve cost though?

Is it always advisable to have the expert to replace or it can be DIY??
 
Actually it depends on how u use ur amp. Generally, preamp tubes last longer than power tubes. If u are the kind that crank the master vol on the amp, then v often the power tubes wear out faster.

For me i change my preamp when it goes microphonic, like some hiss or irritating static like sounds. Power tubes, v ex so try to use as long as possible. Some say that when the output level seems to drop, thats when it time for power tube change.

Well, when i got my amp, there was a hum and hiss (Can test by switching on the amp, without any input). and the sound was alittle dull. When i put in new SED tubes, it came alive man. Better tone, brighter, better harmonics.

Well, at the end of the day, its a tube amp. Gd tubes means gd sound, and lousy tube means not so gd sound. Thats the hassle of maintaining a tube amp over a SS amp.

U can DIY tube change. However, if u change power tubes, it is advised to rebaise the amp with a matched pair/quad tube. After that, just get the same matching tubes for the supplier and there is no need to rebaise anymore. Thats the main guide, tho some choose to rebiase like 1-2 mths later again, cuz the tubes have broken in.

Like i said, u can DIY. BUT DO AT UR OWN RISK!!! There r voltage high enough to kill u in the amp, even tho its not switched on. Well, i not dead yet, but i dont wanna try. Preamp tube change shld not be much a difficulty, power tubes need the rebiase, n thats where the danger is. So send it to a Tech, n pray they charge reasonable.

Hope that helped
 
Whoa, sound like a solid state amp is much better.

Reason why i asked is because i am thinking of getting
a Kustom 12W amp. Sounds like its really troublesome
to replace a valve and it sounds expensive to maintain.

Thanks for the info, it helps a lot.
 
you have to understand there is no hard and fast rule as to how LONG it will last in defnitive terms.

if you push your amp at 10 ( which normally people dont ) it would maybe last a few months.

If you use your amp normally, at maybe 2 hours a day. Preamp tubes are SUPPOSED to last fr 2-3 years, and powertubes 1-2 years.

These are benchmarks and will vary GREATLY with your usage
 
Thats better! There were good estimates and variables in the last one which made the picture much clearer.
 
Humm,.. it really depends on how often u play with the tube amp and how often u push the amp. For me 3-4 times a week guitar practice with master volume of 1 should make the poweramp last for ard 1-2 years. But if u gig often with master set at quite high be prepared to change the tubes often...
 
Preamp tubes: 12AX7 the electro harmonix one should cost roughly 12 dollars other brands should cost roughly the same.
Power amp tubes: MANY typers, EL 34, EL 84, 6l6, 6V6 depending on amp.
Mine uses EL 34 around 30 dollars per tube. Am using the Svetlana Winged C brand.
Biasing well am no tech but roughly means tt its how u set the tubes in the amp. As each tubes differ slightly in the voltages or sumthing hence need to be set to the amp. Biasing will cost 40 sgd perhaps n yeah havta be done by tech if u are not experienced n dun wan to ruin ur amp.
But if ur getting hybrid amps say the kustom 12w/Marshall AVT series/Vox AD series no need biasing.
Full tubes need quite a bit of outlay ur looking at 60-100 sing every 1-2 years,..
 
BlackMoo said:
Questions remain.

How much are tubes?
Whats a rebiase?

Burlington Square (just next to Sim Lim Square) has 2 tube stores.

Of the two, Martin Electronics and Well Audio Labs, the latter has a website http://www.wellaudiolab.com/ which displays the tube pricing.

Poweramps tubes:
* Assuming you are using 6L6s or EL34s, you are looking at $15-$20 (avg) for each tube. Check the attached URL for more accurate prices on brands/tube types.
* Amps will need anywhere from 1-4 powertubes on average depending on the amp.
* tube life is shorter than preamp tube; highly dependant on how much you play, how high you crank the volume and for amps with variable voltage selector, which setting you play on most often (high voltage - punchy, low voltage - brown), and whether you bias cold/recommended/hotter (for those which allow manual biasing).
* my powertubes last me 6-12 months on amps which I run at 75% vol, high voltage and bias as per manufacturer recommendation. After which, I notice the amp start to react weirdly.

Preamp tubes:
* Assuming you are using 12AX7s, you are looking at $10 (avg) for each tube. Check the attached URL for more accurate prices on brands/tube types.
* Amps will need anywhere from 1-5 preamp tubes on average depending on the amp.
* tube life is longer than the poweramp tubes; highly dependant on how high you turn up preamp gain and number of gain stages in the preamp section.
* my preamp tubes last me 1-3 years.

Rebiasing:
* doing a web search on the word will give you a more clear definition than I ever could, hence I'll pass on the definition.
* For manual biasing amps, leave it to techs to do it for you if you;re not comfortable. Voltage shocks can kill. Beware.
* Many amps nowadays are fixed bias. Just plug and play tubes in 1-5 minutes.
* In addition, many later-model amps are being built with simplified (user-friendly) biasing controls which allow further tone shaping via use of front/back panel controls.

The info I've mentioned is very general. I would encourage you to read US forum posts, guitar/amplifier magazines to learn more about the in-outs of the subject.

Best regards. :P
 
If i am not mistaken, those valve 12AX7 produce by different country will differ in sound. Is that true??

Correct.

The tonal nuances are small though when seen as part of the bigger picture.
 
For full tube amps, my experience is that the user normally wait till the amp sound real bad or have many problems, or failed entirely. Before they would send it in.

If the amp still produces sound, even if it's already severely degraded, human habit is to just leave it as it is and play, and hope that tomorrow it will sound better......hahaha.... :lol:

I seldom comes across some guy who stick to a fixed regiment of replacing his tubes on a scheduled basis. Please don't confuse with those with itchy fingers to try to make their amps sound better by getting "better tubes", their original tubes are still likely quite new too.

Normally when a tube amp got problems, and sent to me. Then I guage the age of the amp and tubes installed, and make reccomendations accordingly. I got 8-10yr old amps coming in still on stock tubes, so I have to repair the amp and replace the tubes, which cost twice or thrice as much as just changing tubes.
 
Just a question. Say u buy a matched pair of power tubes at the tube store, the next step would just ask the amp tech to bias right? coz i heard tt (maybe just hearsay) the matching tubes bought at the tube stores sumtime are not very accurately matched and thus wun give the amp a good sound?
Comments?
 
Ok, if the amp is fixed bias, no need to worry too much, just pop replacement tubes in (for tech savvy guitarist). If not get the shops to do it for you.

Even variable bias amps, if you had the same type and brand tubes before (eg. fender matched pair), and you get a new set of same type and brand, not likely to need readjustment.

A matched pair or matched quad, simply means that before the tubes are put on the shelves, they are already matched to a tolerance set with each other. So something like a quality assurance step.

Does not mean a better sounding amp when you get a matched pair. But a severely mismatched set of output tubes could mean a poor sound.
 
The above question put in another way. Which amp sounds better, a marshall JTM45 or a Fender Twin Reverb??

Not a question of sounding better, as guitar amp is not a Hi-Fi amp. So the requirements are different.
 
I am confuse now. what do you mean?
Sorry, i think this might sound dump to you, i am really confuse, bro... :D
do you mean every valve amp use valve 12AX7 in their amp?
 
12AX7 is the most common pre-amp tube model around. But there are other models too. You don't need 12AX7 specifically.

Different models tube have different specs like gain...etc. It's up to the amp designer to dictate what to use.

Always check with or bring in to a speciality shop if you are not sure.
 
Oh i see. Thanks bro.

mikemann said:
12AX7 is the most common pre-amp tube model around. But there are other models too. You don't need 12AX7 specifically.

Different models tube have different specs like gain...etc. It's up to the amp designer to dictate what to use.

Always check with or bring in to a speciality shop if you are not sure.
 
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