#1
so today i plugged my guitar to my amplifier i was playing then out of a sudden i heard this loud Screech come out of the amp and then when i turn it on it sounds like the amp hizz,static kind of like radio station.

i think my tubes die i have never changed them since i bought the amplifier.

i tried reading around the threads and the stickies.

and i know that i need to change the tubes and Bias them.

i have Peavey valveking 112

I opened the back and saw that the Big tubes i think they are the power amp tubes are 6l6GCM-STR i think the brand is Ruby some other info on tube PC:36 TC3100

so i now i have a bunch of questions.
1.does the brand matter when i buy the tubes?
2.does the tubes have to be 6l6GC?
3.do i need to change the small tubes the 12AX7(i think they are the preamp tubes)?
4.if i buy the same Model will i need to Bias them? are the tubes different from brand to brand?
5 how do i Bias them?
6.if they are the same tube do i need to bias them at all since they be on the same setting?
7.where can i buy the tubes online? there's no guitar center or samash here.
8.what do you guys recommend me to buy?

this is the page im looking at to buy the tubes from
http://thetubestore.com/peavey-valveking-112.html

are these in a good price range? is there a webpage you guys recommend?
1 (Matched pair) - Tung-Sol 6L6GC-STR$43.95
3 - Tung-Sol 12AX7$14.95

any help is appreciated
my guitar stuff:
ESP JH-600
ValveKing 112
DigiTech Whammy Pedal
Taylor 314CE
Dunlop SW-95 Slash Wah Pedal
Cordoba C7 Nylon String Acoustic Guitar
Metal muff
Fender American Deluxe Stratocaster Ash
#2
1. The brand matters, yes. JJ or Tung-sol are good 6l6s.
2. Yes.
3. You don't have to change them at the same time, but this is probably a preamp tube problem, not a power amp tube. You can replace preamps one by one, power tubes need to be replaced all at once.
4. You don't need to bias with a Valveking.
5. Don't. If you really want a bias circuit added, you'll need to pay a tech to do it.
6. They are not the same tube. Biasing corrects for manufacturing tolerances, so with a few exceptions, amps that need to be biased should be biased whenever the tubes are changed.
7. Tubedepot.com, dougstubes.com, thetubestore.com
8. That kit is fine. Otherwise, one Tung-sol 12AX7 for the preamp tube farthest from the power tube; the rest of the 12AX7s, Sino gen9. Tung-sol 6l6s.
#3
ok just double checking my tube Says 6l6GCMSTR

but there are two types of 6l6
there is the

Tung-Sol 6L6G
Tung-Sol 6L6GC-STR

http://www.dougstubes.com/power-tubes/6l6-5881-kt66.html?brand=11


does it have to match dead on? or will i be fine with any 6l6 and is it worth the $2 extra dollars?

you don't have to change them at the same time, but this is probably a preamp tube problem, not a power amp tube. You can replace preamps one by one, power tubes need to be replaced all at once.


will it be a bad idea to change all the tubes at same time? will it cause me more headaches or will it be fine after?

if i change all of them at same time will it improve my tone?
or should just buy the preamp since the extra spending wont do really much for me anyways?
my guitar stuff:
ESP JH-600
ValveKing 112
DigiTech Whammy Pedal
Taylor 314CE
Dunlop SW-95 Slash Wah Pedal
Cordoba C7 Nylon String Acoustic Guitar
Metal muff
Fender American Deluxe Stratocaster Ash
#4
Changing them all at the same time is fine. It will probably improve your tone, but there's no guarantee. It's good to have a set of backup tubes, so my suggestion is to get a full retube set, then change out the preamp tubes one by one, playing the amp in between changes. When the problem goes away, throw out the tube you changed most recently. If the problem is still there, change out all the power tubes. If the problem is still there, you need a tech. If the amp works after the power tube change, throw out the entire set of power tubes. You can keep the power tubes as backups if the problem was a preamp tube.

6l6s are classified into four categories: KT88, 5881 (6l6), 6l6GB, and 6l6GC. These are all distinctly different tubes and it is not a good idea to use them interchangeably unless you know what you're doing. You need a 6l6GC. Sometimes tube makers will add extra letters to the end like WXT or STR to designate origin or just look cool, but if you get anything with 6l6-GC in the name, you're good.

Also, you need to buy a matched pair. You'll see that option after clicking on the tubes. (I assume you have the 50 watt valveking; if you have the 100 you'll need a matched quad.)
#5
Did you try the amp with just the guitar plugged straight into it. I had the same thing happen to me yesterday. Turns out is was a bad power supply to my pedal board.
#6
Listen to Roc8995. If you have the extra cash buy a pair of SED Winged C 6L6GCs. Wonderful tubes, I love JJ's, but I was blown away by the SEDs.
#7
I've always thought matched power tubes were kinda a sales gimmick . I like the slightly mismatched sound an unbalanced set gives, it's more natural or organic sounding to my ears.

TS, listen to Roc above anything I say though. He knows his stuff
Endorsed by Dean Guitars 07-10
2003 Gibson Flying V w/ Moon Inlay
2006 Fender All-American Partscaster
SVK ELP-C500 Custom

1964 Fender Vibro Champ
1989 Peavey VTM60

[thread="1166208"]Gibsons Historic Designs[/thread]
#8
You're right in that slightly mismatched power tubes are not a bad thing. They often sound great! The problem is, tube manufacturing these days doesn't generally result in "slightly" mismatched tubes, hence the need for matching, IMO. Some new amp designs let you set the bias for each tube individually so you can decide how closely they match each other, which is very cool. You can also use mismatched tubes in the first place, too, since you can "match" them with the bias.
#9
reviving this old thread because i finally got the tubes and the university is not kicking my ass at the moment.

I bought the kit that has the power tubes and pre-amps.

I took out the power-amp and pre-amps, but after reading this thread it seems like I can test the pre-amps one by one.

Is it bad that I touch the tubes with my hands? I don't remember what piece of electronic equipment is affected by skin oil. Are tubes the same way?


If I take out a pre-amp and I put the new one in to see if it's defective, the new pre-amp doesn't have to match the old ones right?

If after I put the new one in and it doesn't work, can I immediately unplugged i it from the wall and remove it or should I wait before removing so I don't shock myself

(I don't know if amps are like televisions that hold the charge for awhile)
my guitar stuff:
ESP JH-600
ValveKing 112
DigiTech Whammy Pedal
Taylor 314CE
Dunlop SW-95 Slash Wah Pedal
Cordoba C7 Nylon String Acoustic Guitar
Metal muff
Fender American Deluxe Stratocaster Ash
#10
Nah you can touch them with your bare hands, just be careful because they get hot after you jam for a bit.

You can swap out any 12ax7 for any other one no problem. They're plug and play . Try them in different positions too, having "A" in V1 and "B" in V2 can sound different from "B" in V1 and vice versa. Even two identical tubes can sound different by swapping their order to some degree. Power tubes are the ones you can't swap around as you please without adjusting the bias.

You don't have to unplug the amp from the wall, but after you kill the power (and standby) you can immediately pull them and put something else in. Just remember the one you're pulling can be hot, nothing sucks worse than dropping/shattering a tube and having mild burns on your fingers .

Amps do hold charge well after you unplug them (indefinitely actually) but the tubes aren't going to shock you. No need to worry about the amp storing power as long as you're not probing around on the circuit/turret/eyelet board.
Endorsed by Dean Guitars 07-10
2003 Gibson Flying V w/ Moon Inlay
2006 Fender All-American Partscaster
SVK ELP-C500 Custom

1964 Fender Vibro Champ
1989 Peavey VTM60

[thread="1166208"]Gibsons Historic Designs[/thread]
#11
^ what he said is correct, and Colin. Not all amp will hold a charge indefinitely though. The rest looks correct.

I don't recommend it but you can technically swap preamp tubes while the amp is turned on.

I found Tung Sols too bright for the Valveking but let us know what you think.

All of your questions can be answered in the Valveking and associated Wiki pages. There are extensive tube recs and answers in there.
#12
Agreed with all above. When changing preamp tubes, it's perfectly safe to swap out one at a time while the amp is in standby (power on, standby switch set to mute). It can be a little nerve-wracking at first, but you'll find that it saves a lot of time when experimenting. If you're curious, you can even pull a preamp tube out completely and turn the amp on to see which channel it amplifies. It won't hurt anything to not have a preamp tube plugged in.

Be bold! Experiment. The thing you'll want to be careful about is the heat. I use an oven mitt to change the tubes out while they're hot.
#13
^I've always wondered if you could swap them in out standby haha, the only current going through them is for the elements and it made sense that you could just pull it out without harming anything. Just didn't want to waste $10-15 if I was wrong . Why have I never thought of an oven mitt?! It's such an obvious way to go about it . I've always used a rag and made sure I had a good hold on them, up until I read Roc's post that is..

I always assume the amp holds the charge indefinitely, no reason to sidestep a 2 second process and have the amp knock you on your ass (or worse) if it didn't drain itself properly.
Endorsed by Dean Guitars 07-10
2003 Gibson Flying V w/ Moon Inlay
2006 Fender All-American Partscaster
SVK ELP-C500 Custom

1964 Fender Vibro Champ
1989 Peavey VTM60

[thread="1166208"]Gibsons Historic Designs[/thread]
#14
I tried to change one pre-amp to see what it would do and it changes the tone drastically in my opinion.

I also have another problem.

if i turn the volume all the way down when im on the Lead Channel I can still hear the guitar playing at a very low volume with distortion on it? is that normal?

I don't remember my amp doing that before

I saw some guy tap the pre-amps in a video with a pencil to find the Pre-amp that is bad? is that a reliable method?

I tried doing that i tapped the 3 pre-amps with a pencil and only one i could hear the tap through the amplifier.I changed that pre-amp and did tap test again but i still could hear it through the amp.

what does that mean? is the test a crappy way of testing?
my guitar stuff:
ESP JH-600
ValveKing 112
DigiTech Whammy Pedal
Taylor 314CE
Dunlop SW-95 Slash Wah Pedal
Cordoba C7 Nylon String Acoustic Guitar
Metal muff
Fender American Deluxe Stratocaster Ash
#15
My valveking head does the same thing with the volume of on lead channel :p i think its normal
AMP:
Rocktron chameleon 2000
Roland GP16
Audio Technica wireless
Peavey valveking
Clydesdale custom case
GUITAR:
Indie super T black (modded with active and passive pickups)
Daisy Rock Rock Candy Special
#16
Most tubes will have some microphonics. It's when the tapping comes through really loud that you know it's faulty. It is also possible for another tube to transmit the tapping noise from vibrations through the chassis. That can be quite misleading at times, the accumulative effect of multiple tubes picking up vibrations can be a real head****.
What I do is test the tubes in a Fender Champ which only has one preamp tube. Then once I know it's a good one I use that one as my test valve. If your tubes are old there's a good chance that more than one is faulty. It's best to have a few spares on hand.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#17
Quote by stefan1988
I tried to change one pre-amp to see what it would do and it changes the tone drastically in my opinion.

I also have another problem.

if i turn the volume all the way down when im on the Lead Channel I can still hear the guitar playing at a very low volume with distortion on it? is that normal?

I don't remember my amp doing that before

I saw some guy tap the pre-amps in a video with a pencil to find the Pre-amp that is bad? is that a reliable method?

I tried doing that i tapped the 3 pre-amps with a pencil and only one i could hear the tap through the amplifier.I changed that pre-amp and did tap test again but i still could hear it through the amp.

what does that mean? is the test a crappy way of testing?

I wonder if that was mine?
http://s545.photobucket.com/albums/hh384/buckethead_311/Amp%20stuff/?action=view&current=Microphonicpreamptube.mp4

But I consider it a pretty good way to test. Like Cath said, all preamp tubes are microphonic by nature. When they become overly microphonic is when it becomes a problem. I'd buy some new preamp tubes to totally sure. Make sure they are seated all the way in too. Take those aluminum shields off and leave them off. I personally like to be able to see my tubes to make sure one is not overly bright. If it is shut the amp off and try again. Being able to hear the yourself with the volume off is not completely abnormal, especially if the preamp gain is turned up. That said, that never happened with my Valveking but I have experienced it with other amps.