#1
Picked it up on craigslist for $350. Not a bad deal, eh?

I play mainly bass, but goof around on guitar and jam a bit, so this is my first tube amp. Anything I should know about tube amps before I dive into this thing trying to find a good tone? Some simple things I picked up: Tubes take time to warm up, tubes sound better when cranked.

Any maintenance involved with these amps?

I may plan to remove the head from the combo and create a custom case for it, and just leave the speakers as a cab. We'll see.
...it was bright as the sun, but with ten times the heat
#2
Those are the two most basic things, another thing to remember is always have your impendence correct and always have a speaker load on the amp.

And about 50% of the time when the tubes blow it'll take a fuse with it, at least its been my luck, I would think it should always blow the fuse. Fuses are cheap, keep some handy.
#3
Cool, thanks for the info. It being a combo, as long as I keep the head in it, I shouldn't have a problem with the things you listed, but good to know nonetheless.

What causes a tube to blow? Or do they just do that when they get old?
...it was bright as the sun, but with ten times the heat
#4
Well, I've done exactly what you want to do with my Valveking 112, I took the power amp out of the combo, made it into a head, and turned the combo into the speaker cab, worked out beautifully. I need to build a new matching cab though.


Yeah, when tubes get old, especially the new makes of tubes, they usually blow with 3 to 5 years of heavy use if your lucky, old NOS tubes from the 60's and 70's have been known to last 10-15 years of heavy use.

I always consider it a best practice to retube the entire amp when you buy it just so you know where you stand on your tube life.
#5
That's one sweet looking cab. You can't beat good looking wood grain.

Is retubing something I can do myself. Just buy the tubes and slip 'em in?

Did you make a thread about your valveking project?
...it was bright as the sun, but with ten times the heat
Last edited by c3powil at Feb 10, 2014,
#6
Quote by c3powil
That's one sweet looking cab. You can't beat good looking wood grain.

Is retubing something I can do myself. Just buy the tubes and slip 'em in?

Did you make a thread about your valveking project?


You should be fine just popping some new tubes in there, I'm pretty sure it's a fixed bias amp like mine but it's just biased real cold so you wont run the risk of redplating the tubes. Just make sure you don't bend any pins on the preamp tubes, it's kinda easy to do if you're not seating them correctly. I'm sure there's a sticky thread somewhere on how to retube an amp.

I think I did make a thread, but it was a few years ago and hell if I know if it's still around
#7
I just snagged a MXR 10 band EQ and its a huge difference with the 5150. Tube screamers are also a common add for them. I have a Joyo I'm still playing with.

When you change tubes be sure to use some Deoxit D5 contact cleaner on the pins of the new tubes. I got mine used and had to insert/remove the new tubes about 3 times to get the plugs nice and smooth. Look at Eurotubes for the tubes - all come pre-tested and matched.
Guitars:
Jackson Kelly KE3 - MIJ (Distortion/Jazz)
Jackson DKMGT Dinky (EMG 81/85)
ESP E-II Eclipse Custom (JB/'59)
ESP LTD EC-1001FR (EMG 81/60)
Fender MIM Strat

Amps:
Mesa/Boogie Dual Rectifier Roadster 212
Laney IronHeart IRT-Studio
Peavey Vypyr 30
Peavey ReValver Amp Sims
TOOOO many T.C. Electronic Pedals. . .
#8
The whole, "needs to be cranked to sound good" is a hangover from the days before master volumes were invented and it has persisted today in a strange way. Those old amps had to be cranked up to get any distortion out of them without pedals; that isn't the case with the 5150.
Sure they sound better when you turn them up a bit (ie. they're a bit lack luster at speaking volume) but they don't have to be cranked because you can get preamp distortion out of them by simply turning up the gain. For the sort of music that they normally get used for, you don't actually want power amp distortion anyway.

Nice score.
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
#9
Cool, thanks for thine info. The amp has plenty of gain for me, but what type of tube would you suggest for a better cleans sound? I'm sure sacrificing a bit of gain is no problem with this amp...

Also, I finally got to crank up the amp a bit last night. At higher volumes, it started to squeal and buzz (not feedback). Like a background noise, and worse when I wasnt playing or had my guitar volume down. Is this a sign that I need new tubes?
...it was bright as the sun, but with ten times the heat
#10
You can run pretty much any 12A__ tube in the preamp on those, even 12AU7's which are very low gain. Buy a few different ones and just experiment with them in different positions. 12AU7, 12AY7, 12AT7, 5751, 12AX7. Thats in increasing gain factor. ie. lowest to highest.


It sounds like a tube has gone microphonic. Tap each tube gently with a pencil while it's turned on and up a bit. If the tapping comes through the speakers that tube is gone. You may hear a little on all of them but one will be particularly loud. That's the faulty one.
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
Last edited by Cathbard at Feb 11, 2014,
#11
Quote by Cathbard
You can run pretty much any 12A__ tube in the preamp on those, even 12AU7's which are very low gain. Buy a few different ones and just experiment with them in different positions. 12AU7, 12AY7, 12AT7, 5751, 12AX7. Thats in increasing gain factor. ie. lowest to highest.


It sounds like a tube has gone microphonic. Tap each tube gently with a pencil while it's turned on and up a bit. If the tapping comes through the speakers that tube is gone. You may hear a little on all of them but one will be particularly loud. That's the faulty one.


Thanks man. So If I buy a bunch of different tubes its okay to use them all together?

I have 5 spots in the poweramp section so I could buy one of each of those that you mentioned and swap places to explore sounds?

What about the two preamp tubes?
...it was bright as the sun, but with ten times the heat
#12
Yeah, man, you can stick any of those tubes in any position. Just have fun with it.

You mean the two power tubes, yeah? JJ 6L6GC are the best value for money. It's got two? So it's a 60W'er?
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
#13
Yes, I meant power tubes. It's the combo so 60 watts I believe, and the head version is 120 and has four tubes so that makes sense.

Power tubes don't affect the tone?
...it was bright as the sun, but with ten times the heat
#14
They do to a degree but nowhere near as much as preamp tubes. If you are running it into power amp distortion (ie ****ing loud) the power tubes have more effect on tone, but otherwise it's a pretty marginal difference really. The JJ's are good and they're cheap.
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
#15
Cool, thanks for the info. I'm about to order a pair of 6L6GCs from eurotubes and mix and match some preamp tubes.
...it was bright as the sun, but with ten times the heat
#16
Okay, I wen't to Eurotubes and got:

ECC83S Balanced for the inverter in V5
5751 Gold Pin for use in V1
ECC82 Standard
ECC81 Standard
ECC83S Standard
6L6GC Matched Pair

I couldn't find a 12ay7, so I just went with another 12ax7 since I'm probably using the 5751 in V1.
...it was bright as the sun, but with ten times the heat
#17
If you are trying to reduce gain, the ECC81 and ECC82 should be in V1 and/or V2. But don't be scared to experiment.
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
#18
That would make the most sense. I just heard a clip of someone who put a 5751 in V1 and it sounded really great, so i want to try that. Is it bad to hang onto old tubes and use them as backups?

Also, I tried tapping on each tube while the amp was on with a metal screwdriver. I couldnt really tell if one was louder than the others.
...it was bright as the sun, but with ten times the heat
#19
It all depends on how far you want to drop the gain.

When you get the new tubes take the ECC83S and try it in each position and see if the problem disappears. That's the easiest way to identify which tube is dodgey.
It could also be microphonic pickups, esp if the problem is related to where you are standing.
If however, it doesn't feedback when you are muting the strings then it is actually operating as intended.
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
#20
Nah, pickups are good, but I'll try replacing each tube like you said and I'm sure that will get it. Can't wait to get 'em in!
...it was bright as the sun, but with ten times the heat