Just got my first tube amp

[antispatula]

Off craigslist. 150 bucks! Peavey Deuce. Got good reviews on harmony:

One thing I don't like is there's no distortion. I guess I'll have to get a pedal. What's a good distortion pedal? I play garage-rocky stuff.

So what's up with the pre gain and post gain? Does that refer to preamp gain and then just gain? Help me out, I'm new to decent amps.

Two more things:

1. I get a buzz when I plug it into my guitar. I don't think it's the cable, I've tried multiple. Should I try and shielding my guitar? I know it's not the amp, I tried it out at the guys house with his guitar, there was no hum. And it also has hum when I plug it into my fender rhodes, but it isn't grounded since I'm repairing it right now.

2. Ok, When I play low notes, I hear not an electrical buzz, but as if something is loose in the amp that is shaking super fast. Anyone have expirience with this?

3. Ok, ok one more thing! The speakers are all oxidized and are the original stock speakers. What's a good brand for 120w speakers. Yeah, 120 watts!

4. Ok, I SWEAR this is it: What would be the advantages of replacing old tubes? Is it hard to replace tubes? Is it as easy as desoldering them out of pcb and then soldering new ones in? Help a new guy out. Thanks!

 

[Henry Mars]

I guess you didn't do bad for $150. I own one of these amps that I bought new around 27(?) years ago. The only good thing I can say about it is that you cant kill it. It sounds ok thats all. In general I hate Peavey amps even though I own around 5 of them (only because you can't kill them). your average rock and roll fan wouldn't know the difference if it walked up and bit him on the ass anyway.

I like Traynor's and Vox tube amps myself especially the Traynors. I own a Vox modeling amp which is nice too. For shits and giggles, I also own a few Valve series Epiphones which sound to me like the amps I used when I was a young kid in the '50s

I have had a love hate relationship with amplifiers for most of my life.

 

[Clive Hugh]

Off craigslist. 150 bucks! Peavey Deuce. Got good reviews on harmony:

One thing I don't like is there's no distortion. I guess I'll have to get a pedal. What's a good distortion pedal? I play garage-rocky stuff.

So what's up with the pre gain and post gain? Does that refer to preamp gain and then just gain? Help me out, I'm new to decent amps.

Two more things:

1. I get a buzz when I plug it into my guitar. I don't think it's the cable, I've tried multiple. Should I try and shielding my guitar? I know it's not the amp, I tried it out at the guys house with his guitar, there was no hum. And it also has hum when I plug it into my fender rhodes, but it isn't grounded since I'm repairing it right now.

2. Ok, When I play low notes, I hear not an electrical buzz, but as if something is loose in the amp that is shaking super fast. Anyone have expirience with this?

3. Ok, ok one more thing! The speakers are all oxidized and are the original stock speakers. What's a good brand for 120w speakers. Yeah, 120 watts!

4. Ok, I SWEAR this is it: What would be the advantages of replacing old tubes? Is it hard to replace tubes? Is it as easy as desoldering them out of pcb and then soldering new ones in? Help a new guy out. Thanks!

First are the speakers 120 watts each or is the amp 120watts? I suspect the latter. In which case you don't want 2x120watt speakers.
I have Eminence Red White and Blues in one of my Fender 100 watt "The Twin" and I prefer it to the other which is stock. In fact I'm serious about putting them in the other one too, I just have to convince my wife that WE NEED THEM.
Tubes are easy to replace, they simply pull out of their sockets. The choice of tube definately can affect your tone, I have just retubed one with Electro-Harmonix and I am very happy with them too. But they have to be biased and of course they must be the correct tube.
What is the history of your amp? I note that Henry had one about 20 years old, if yours is of similar age I advise you to get it checked out by a tech as the caps might have dried out which is not healthy for amps, it tends to kill them. And he can bias it at the same time. Which is not an expensive job.
One more thing, welcome to the "Tube" club, you can never have too many tube amps.

 

[ggunn]

Off craigslist. 150 bucks! Peavey Deuce. Got good reviews on harmony:


So what's up with the pre gain and post gain? Does that refer to preamp gain and then just gain? Help me out, I'm new to decent amps.

The pre and post gain is actually a pretty neat idea. It enables you to overdrive a preamp with the pre gain and then dial down its output to the power amp with the post, so that you can get clean and dirty at the same volume.

 

[Outlaws]

First are the speakers 120 watts each or is the amp 120watts? I suspect the latter. In which case you don't want 2x120watt speakers.

Its not that bad.

120 watt amp with 240 watt cab is not worse than a 100 watt Marshall with a 240 watt (or higher!) 412 cab. Remember Vintage 30's are 60 watts each, so 4 x 60 = 240. Hell, lots of marshalls have 75 watt speakers...thats a 300 watt rated cab.
....then people whook two of those up to one head for a Marshall Full Stack.

 

[antispatula]

hey thanks for all the help gentlemen

So yeah, I meant to say my AMP is 120w. Does that mean I should make my speakers 60w each? I'm guessing thats how it works.

So how do you bias tubes? As long as there isn't a big chance of me being killed on the spot, I'd rather learn to do it myself.


So can ANYONE suggest what the rattling is when I play bass notes? I think it's more physical than electrical, as if somethings loose......

 

[Outlaws]

hey thanks for all the help gentlemen

So yeah, I meant to say my AMP is 120w. Does that mean I should make my speakers 60w each? I'm guessing thats how it works.

So how do you bias tubes? As long as there isn't a big chance of me being killed on the spot, I'd rather learn to do it myself.


So can ANYONE suggest what the rattling is when I play bass notes? I think it's more physical than electrical, as if somethings loose......

You don't want 120 watts of total speakers for a 120 watt amp if you play full volume a lot. 2 60 watt speakers isn't enough for what the amp will output when fully cranked. It will probably sound fine, but you will shorten the life of the speakers greatly.

The rattling is probably the tubes. Might be time for some new ones. Pull one or two and shake them by your ear and listen for any salt shaker sounds.

 

[ggunn]

hey thanks for all the help gentlemen

So yeah, I meant to say my AMP is 120w. Does that mean I should make my speakers 60w each? I'm guessing thats how it works.

So how do you bias tubes? As long as there isn't a big chance of me being killed on the spot, I'd rather learn to do it myself.


So can ANYONE suggest what the rattling is when I play bass notes? I think it's more physical than electrical, as if somethings loose......

Biasing tubes is not a straightforward operation, and the amp itself may or may not have an adjustable bias. Here is a web page that will give you some info:

http://www.diyguitaramp.com/bias.html

A word of caution: Unless you have some experience in electronics, IMO tube biasing is best left to an amp tech. There are LETHAL voltages on some nodes of even a small tube guitar amp while it is in operation, and these voltages can linger for days after the amp is turned off and unplugged.

As to the rattling, the obvious thing to do is to go over the amp and tighten any screws, nuts, etc. Get someone else to play the notes that cause it while you press on different parts of the amp to see if you can isolate the noise. Oh, and make sure it is indeed the amp. I once chased a noise coming out of my amp for a while only to find that the culprit was a bottle cap in the bottom of a metal trash can behind the amp.

 

[antispatula]

You don't want 120 watts of speakers for a 120 watt amp if you play full volume a lot.

The rattling is probably the tubes. Might be time for some new ones. Pull one or two and shake them by your ear and listen for any salt shaker sounds.

that's exactly what I was thinking! Yes, one of the tubes do shake. I have 6l6gc tubes. What's a good brand to get?

Wait, so what rating should I use on the speakers then, 60?

By the way, the "distortion" on this thing sucks.........I need a pedal.

 

[antispatula]

Biasing tubes is not a straightforward operation, and the amp itself may or may not have an adjustable bias. Here is a web page that will give you some info:

http://www.diyguitaramp.com/bias.html

A word of caution: Unless you have some experience in electronics, IMO tube biasing is best left to an amp tech. There are LETHAL voltages on some nodes of even a small tube guitar amp while it is in operation, and these voltages can linger for days after the amp is turned off and unplugged.

QUOTE]

yes, thank you I've been warned about this before. As long as I'm just switching tubes, is there much danger? Where in the circuit is it the most dangerous, the capacitors?

 

[Outlaws]

that's exactly what I was thinking! Yes, one of the tubes do shake. I have 6l6gc tubes. What's a good brand to get?

Wait, so what rating should I use on the speakers then, 60?

By the way, the "distortion" on this thing sucks.........I need a pedal.

No, I was refer to 2 60 watt speakers giving a total of 120 for the total rating.

I would get 2 100 watt speakers.

 

[ggunn]

Biasing tubes is not a straightforward operation, and the amp itself may or may not have an adjustable bias. Here is a web page that will give you some info:

http://www.diyguitaramp.com/bias.html

A word of caution: Unless you have some experience in electronics, IMO tube biasing is best left to an amp tech. There are LETHAL voltages on some nodes of even a small tube guitar amp while it is in operation, and these voltages can linger for days after the amp is turned off and unplugged.

QUOTE]

yes, thank you I've been warned about this before. As long as I'm just switching tubes, is there much danger? Where in the circuit is it the most dangerous, the capacitors?

There's no danger in switching tubes, but if the amp has a variable bias (I don't know about this one), then it's a good idea to get the bias set/checked when you change power tubes. Most folks recommend that you always change push-pull pairs together and used matched tubes.

 

[antispatula]

well guess what, the amp isn't working! It screached for a few seconds, and died. That's most likely a tube, right? I know that the tubes haven't been like ever changed, and one of them you can hear rattle even when I don't play anything, as if fillament is loose or whatever. It turns on, so it isn't a blown fuse, and it isn't a cable, since I JUST made my own out of horizon cable and switchcraft 1/4"'s and it worked perfectly. So I guess I need to buy some tubes, and might as well replace all 6. The preamp is solid state, so all I need to replace is the.....what do you call them? Output tubes?

Any suggestions on how to replace/bias the tubes would be great. I'm thankful for peoples general concerns, but please don't tell me to bring it to someone more qualified, because I'd like to do it myself, and how am I ever going to be qualified if I never accomplish anything myself? Plus, I'm 17 and don't have a bunch of cash

I'm for some reason exited that it's not working, that means I have to figure out whats wrong with it, then fix it myself!!

Oh, and what's a good tube brand? And to remove the tube,do I just twist and pull or something?

 

[Outlaws]

well guess what, the amp isn't working! It screached for a few seconds, and died. That's most likely a tube, right? I know that the tubes haven't been like ever changed, and one of them you can hear rattle even when I don't play anything, as if fillament is loose or whatever. It turns on, so it isn't a blown fuse, and it isn't a cable, since I JUST made my own out of horizon cable and switchcraft 1/4"'s and it worked perfectly. So I guess I need to buy some tubes, and might as well replace all 6. The preamp is solid state, so all I need to replace is the.....what do you call them? Output tubes?

Any suggestions on how to replace/bias the tubes would be great. I'm thankful for peoples general concerns, but please don't tell me to bring it to someone more qualified, because I'd like to do it myself, and how am I ever going to be qualified if I never accomplish anything myself? Plus, I'm 17 and don't have a bunch of cash

I'm for some reason exited that it's not working, that means I have to figure out whats wrong with it, then fix it myself!!

Oh, and what's a good tube brand? And to remove the tube,do I just twist and pull or something?

Tubes pull out. Don't twist anything. I have never seen an amp where you need to twist.

YOu can just replace the power tubes and see how it works. Rebiasing ain't gonna happen just yet....well, I ain't gonna type it out at least. Sorry.

Do a search on google if you really want to do it. It has been explained here I believe, but there are websites for it.

 

[antispatula]

hey, thanks a lot!

So Is there any danger on biasing an amp? I understand that amps run high voltages that can very easily kill you, and want to make sure if I try doing this myslef I do it safe.

 

[ggunn]

well guess what, the amp isn't working! It screached for a few seconds, and died. That's most likely a tube, right? I know that the tubes haven't been like ever changed, and one of them you can hear rattle even when I don't play anything, as if fillament is loose or whatever. It turns on, so it isn't a blown fuse, and it isn't a cable, since I JUST made my own out of horizon cable and switchcraft 1/4"'s and it worked perfectly. So I guess I need to buy some tubes, and might as well replace all 6. The preamp is solid state, so all I need to replace is the.....what do you call them? Output tubes?

Any suggestions on how to replace/bias the tubes would be great. I'm thankful for peoples general concerns, but please don't tell me to bring it to someone more qualified, because I'd like to do it myself, and how am I ever going to be qualified if I never accomplish anything myself? Plus, I'm 17 and don't have a bunch of cash

I'm for some reason exited that it's not working, that means I have to figure out whats wrong with it, then fix it myself!!

Oh, and what's a good tube brand? And to remove the tube,do I just twist and pull or something?

I hate to tell you this, really I do, but there are a lot of things that it could be, most of which are going to be things that you probably don't have the experience or tools to fix, and as we've said, poking around inside a tube amp is just plain dangerous. Anyway, the probability of your fixing your amp by throwing new tubes at it is pretty low.

Now, you certainly could go get some books on tube theory and amplifier basics and teach yourself enough to diagnose and fix the problem; it's not a quick process, but it's really interesting.

 

[antispatula]

hey, thanks for the advice, I've decided not to do anything that could lead to injury, such as trying to break into the chassis or anything.

But I was messing with the tubes, and took one out, and put it back in just for the learning expirience, and then I turned the amp on, and tried it out. If I played the guitar loud enough at loud enough volumes, it would come out in really loud, distorted bursts......Yikes! And Now, I get this really high ringing sound that seemed to be coming from a certain tube, so I taped it gently with a flashlight and it went BOOOOOM! And blew out......I don't understand how big of a chance it could be that the problem is not in the tubes. I mean, just this morning the amp was working great, and haven't done anything to it out of the ordinary, you know? Anyways, how much would fixing this thing cost, or should I say, how much COULD it cost? I know it varies, but an educated guess would be nice.

 

[Clive Hugh]

hey, thanks a lot!

So Is there any danger on biasing an amp? I understand that amps run high voltages that can very easily kill you, and want to make sure if I try doing this myslef I do it safe.

You obviously ain't gonna listen, so do it yourself, fuck it up yourself. Then advertise it in ebay.

 

[Cool711]

The ringing sounds like microphonics in one (or more of the tubes).
As for cost, it depends on what exactly blew up.

I'd suggest stop messing with it until you go to a qualified tech who explains things a little better.

 

[ggunn]

hey, thanks for the advice, I've decided not to do anything that could lead to injury, such as trying to break into the chassis or anything.

But I was messing with the tubes, and took one out, and put it back in just for the learning expirience, and then I turned the amp on, and tried it out. If I played the guitar loud enough at loud enough volumes, it would come out in really loud, distorted bursts......Yikes! And Now, I get this really high ringing sound that seemed to be coming from a certain tube, so I taped it gently with a flashlight and it went BOOOOOM! And blew out......I don't understand how big of a chance it could be that the problem is not in the tubes. I mean, just this morning the amp was working great, and haven't done anything to it out of the ordinary, you know? Anyways, how much would fixing this thing cost, or should I say, how much COULD it cost? I know it varies, but an educated guess would be nice.

A shorting tube (if that's what it is) can easily have blown up something interior to the amp. The odds are against you fixing your own amp with no knowledge or experience with electronics. But go ahead if you must, replace the tube that you suspect and turn it on and see what happens; it probably won't hurt anything. But it may be that the tube you found with a problem could be a symptom but not the root cause; it's possible that a new tube will blow up immediately. Oh, and in response to an earlier question: DO NOT twist tubes when trying to remove them, and don't putz with them other than very light tapping when the amp is powered up.

How much could it cost to fix your amp? Well, as my dad used to say in response to questions like that, how long is a piece of string? It can range from almost nothing to more than the amp is worth, depending on what blew up. An educated guess is only possible with data, and I don't have any.