#1
I've had my Peavey 5150 combo for a few years now, and I bought it used. It's been at least 3-4 years since any of the tubes have been changed, so it'd probably be a good idea to do so. What tubes would I need, how much would they cost, and how would I go about changing them out? Would I need to change the preamp tubes, poweramp tubes, or both?
#2
Both preamp tubes and power amp tubes need to be replaced if it's been 4 years and you play regularly. As far as which tubes to go with, I recommend TAD 6L6 GCs for power tubes and for preamp tubes, I have always had good experiences with Tung Sol and JJ 12AX7s. Switching preamp tubes in each position can change tone/response as well; you're really getting into something fun (and expensive) to experiment with!
http://www.youtube.com/user/chuckmehh
Randall RM100/Basson Cab
DBX166XL/BBE Sonic Maximizer
Boss NS-2, sCream Cheese 2.0 OD, Zakk Wylde wah
Custom Epiphones
Monster Cables
Awe-in-One picks..and more
#3
Here is my take:

If the tone of your amp is fine, then you don't need to do anything. If you want to change the tubes for the sake of having new ones then go for it. 5150+ had a bias pot/test points I believe. You may or may not need to bias the amp with new power tubes. A new quad of power tubes can run you anywhere from $50 - $200 depending. New preamp tubes will cost you $10 - $20 each.

One idea would be to try some new preamp tubes and see if that does anything.

Chucks recommendations were pretty good. TAD 6L6s are good I hear as are JJs. For preamp tubes JJs will sound darker and Tung Sols will sound brighter. You can also get some different brands of preamp tubes and experiment with different positions. You might find a 12AT7 might be great in V1 or a JAN Phillips 5751 sounds great in V4 (for example).

I don't have direct experience with this amp, only a Valveking. I have some detail info on tubes in post #7 or something of the Valveking thread. I also have a biasing Blog. It may not be directly helpful to a 5150 but it will also give some safety tips etc. Also, here is a preamp tube test vid I did:
http://s545.photobucket.com/albums/hh384/buckethead_311/Amp%20stuff/?action=view&current=Microphonicpreamptube.flv

as far as where to buy my suggestions are these in this order:
dougstubes.com
tubedepot.com
thetubestore.com
eurotubes.com
hotroxuk.com (if you are actually in europe)

send doug an email with what you have and what you want tone wise and see what he says. Most of the shops I linked you too are well versed in what tubes are best for what amp, what are most available at any given time, how they test out, failure rates, etc. They also match power tubes pretty closely so there is a good chance any power tubes they send you will be well matched.

The 5150 (like Peavey's) are biased on the cold side.


wow, did I just type all of that
Last edited by 311ZOSOVHJH at Aug 26, 2010,
#4
I have enjoyed this post by Steve concerning Tube Life...

http://drzamplifiers.proboards.com/index.cgi?board=maz18&action=display&thread=30034

An informative post by benttop (Steve):
Think of your tubes in four different categories. Each has its own considerations.

1. Power tubes - they last about 300 hours or so (YMMV), and when they are worn out your amp sounds sterile and weak. A new set will breath new life into your amp.

2. Rectifier - this tube has the least contribution to tone of all of your tubes, but without it, the amp won't work. It's the core of the power supply that powers the rest of the tubes. Generally it either works or doesn't. If yours is working, the only reason you might decide to change it is for a reliability improvement. If you already have a NOS rectifier, do not replace it if it's working!

3. Preamp tubes - these generally last a very long time - decades are not unreasonable. My dad's old 1949 Gibson amp still has its original preamp tubes. Change these for tonality adjustments, and sometimes they do fail or go microphonic. So you address these differently from power tubes.

4. Phase Inverter - this tube looks like one of the preamp tubes, but is situated closest to the power tubes. I separate it out from the preamp because this tube gets a real workout. It drives the power tubes, so it does wear out faster than the other preamp tubes. I think Myles recommends replacing this with every other set of power tubes. Make sure you get one that is matched - this tube actually has two tube circuits inside. If they aren't matched, each side drives at a different level and you get distortion that you don't want.

So when it comes to "my amp sounds like poo lately" I start with a power tube replacement. That will bring everything back 99.9% of the time. If most comes back, but we're still a bit off, go for the PI next. Then make tweaks with preamp tubes if desired.
#5
Quote by BurstBucker Pro
I have enjoyed this post by Steve concerning Tube Life...

http://drzamplifiers.proboards.com/index.cgi?board=maz18&action=display&thread=30034

An informative post by benttop (Steve):
Think of your tubes in four different categories. Each has its own considerations.

1. Power tubes - they last about 300 hours or so (YMMV), and when they are worn out your amp sounds sterile and weak. A new set will breath new life into your amp.

2. Rectifier - this tube has the least contribution to tone of all of your tubes, but without it, the amp won't work. It's the core of the power supply that powers the rest of the tubes. Generally it either works or doesn't. If yours is working, the only reason you might decide to change it is for a reliability improvement. If you already have a NOS rectifier, do not replace it if it's working!

3. Preamp tubes - these generally last a very long time - decades are not unreasonable. My dad's old 1949 Gibson amp still has its original preamp tubes. Change these for tonality adjustments, and sometimes they do fail or go microphonic. So you address these differently from power tubes.

4. Phase Inverter - this tube looks like one of the preamp tubes, but is situated closest to the power tubes. I separate it out from the preamp because this tube gets a real workout. It drives the power tubes, so it does wear out faster than the other preamp tubes. I think Myles recommends replacing this with every other set of power tubes. Make sure you get one that is matched - this tube actually has two tube circuits inside. If they aren't matched, each side drives at a different level and you get distortion that you don't want.

So when it comes to "my amp sounds like poo lately" I start with a power tube replacement. That will bring everything back 99.9% of the time. If most comes back, but we're still a bit off, go for the PI next. Then make tweaks with preamp tubes if desired.

Don't worry about that part unless you have something with a tube rectifier (mesa recto series come to mind most often).
Current Gear:
LTD MH-400 with Gotoh GE1996T (EMG 85/60)
PRS SE Custom 24 (Suhr SSH+/SSV)
Ibanez RG3120 Prestige (Dimarzio Titans)
Squier Vintage Modified 70s Jazz V
Audient iD22 interface
Peavey Revalver 4, UAD Friedman BE100/DS40
Adam S3A monitors
Quote by Anonden
You CAN play anything with anything....but some guitars sound right for some things, and not for others. Single coils sound retarded for metal, though those who are apeshit about harpsichord probably beg to differ.
#6
Well obviously it's hard to tell if the tone has soured over time as I don't have anything to compare it to. The best quality of recordings I have are videos made with my webcam and just recorded with the mic on my laptop, here's one: http://www.youtube.com/watch?v=PDZ9Q6alNZo

I haven't been fully satisfied with the tone, but I'm not really sure if that's because of the tubes, the guitar, the pickups, or any number of other factors. I should mention that I very, very rarely crank the amp, usually keeping the volume between 0-2 (I live in an apartment, don't want angry neighbors haha). Does that mean that it's less likely that the power tubes need to be replaced, since I haven't been working them all that hard?
#7
OK. So here is my take again.

I can't tell you if you need power tubes or not. Power tubes usually work and then fade in volume and die. You'll know. Now, if a power tube is glowing too bright or inconsistent with the rest, then let us know. Otherwise, you might experiment with a new preamp tube or two. Like a JJ 12AX7 and then maybe a Shuguang or Tung Sol or Penta 12ax7. $10 - $15 bucks each is a bargain for improved tone.

Next, you could dig into the ins and outs of biasing your amp (power section) but you may have to take it in for that $40 - $120 ?? Free if you find someone who wants to help for free or a 6 pack or something

Next - what kind of guitar is that exactly and what pick ups are you using exactly? Any boosts or other pedals?

For a youtube/camera set up I thought it sounded pretty good. A bit thin and possibly an out of tune string/note selection ?? You are a better player than I so those were just my initial thoughts. I'd like to see you crank it up to about 4 or 5 and do some chugness or palm muting (only listened half way honestly so maybe I missed some of that if you did it).

Maybe get someone else to play your amp that has played a lot of these or take in for a Free Estimate.

I think I'd focus on some preamp tubes and pup swap depending on exactly what is there. Can you also tell us exactly what tubes you have and how they appear visually when amp is humming along? A full retube 'may' be needed as mentioned above but dive a bit further before chunking out $160 + labor. (guessing)

PS: I'm not an amp tech and I've never messed with a 5150.


Also: tubes can last a varying amount of time. I've seen them last 2 days, 2 weeks, 2 months, 2 years, 2 decades so
#8
A couple 'a JJs will bias right in the combo. They don't need to adjustable bias mod like the 120watt heads. I chopped the head part out of my combo, installed a Mercury Magnetics choke, and run it on a 4x12.