Tube combo amp

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Kingofpain678

Kingofpain678

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im thinking of picking up a peavey valveking royal 8 tube amp tomorrow. it has an 8 inch speaker and i think like 1 preamp tube and 1 power amp tube, but i have a few questions...

1). are there any disadvantages to miking up an 8" speaker vs. a 12" speaker?
2). with only one 12AX7 and one EL84 is that gonna give me enough gain for some hard rock and metal tones?


im not sure how tube amps work, i dont know if its the multiple tubes that gives it gain or if its something else.
 
Kingofpain678 said:
1). are there any disadvantages to miking up an 8" speaker vs. a 12" speaker?
2). with only one 12AX7 and one EL84 is that gonna give me enough gain for some hard rock and metal tones?
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1) Yes. In simple terms, less bass.

2) Probably not, but if you put some kind of a gain pedal in front of it (a clean boost, a compressor, a distortion pedal, an overdrive, a fuzzn - any of that stuff) and it will add something to the drive. That amp appears to be pretty similar to the old Fender Champs, at least in premise. Clapton and all used an old champ on Layla and Other Love Songs. While that amp will probably be a bit different, that will give you an idea about the distortion levels.




As for understanding, well...

If you look at the attached image, you will see one cycle of a sine wave. The actual signal we deal with is much more complex, but a sine wave is a lot easier to understand, and is good enough. There are two types of amplifier which is commonly used for guitars - type A and type AB. There are a LOT more types of amplification out there, but for guitars, those are the most common.

In a type A amplifier, the entire signal is amplified by a tube. In a type B amplifier the two parts of the signal (part A and B) are amplified by separate sections of the amplifier - i.e., separate tubes or transistors. A type AB is essentially a type B amplifier, but each section amplifies a portion of the other sections signal. Type AB amp are more efficient, and there is a difference in sound between type A and AB amps. Most high gain amps are AB, and traditionally only student amps are type A (because it is cheaper and requires fewer parts). However, there are a lot of very high end amps being made type A these days. (By the way, people have always thought of the Vox AC30 as a type A amp - it isn't, it is a type AB, but it's crossover point is much wider than most AB amps).

My recollection of the sound you're after, you are probably after an AB amp. Still, I'd rather have the one you are looking at than any modeling amp, personally.


Light

"Cowards can never be moral."
M.K. Gandhi
 

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i didnt see any attached image... and your right, it cant be any worse than my crappy solid state half stack. Musician's friend is having a sale on it now and its only 100$ so i figure if nothing else it will give me a nice little practice amp.

i do have a compressor and a few other things sitting around, im not sure if it would help at all but i have a noise gate and an eq. to my understanding the preamp is driven my how much the input is being driven so if i were to raise the volume before the amps input would that help me get a little more gain?

another thing im confused about is im seeing people jimmy rig the speaker cable output to a 1/4" cable and plugging it into 1x12 and 2x12 cabs but couldnt that blow the amp? and isnt that a bad idea since the 5 watt output couldnt drive the 12" speakers very hard?

also, thanks for helping understand things a little more.
 
Kingofpain678 said:
i didnt see any attached image...
Click to expand...

Whoops - fixed!

Kingofpain678 said:
i do have a compressor and a few other things sitting around, im not sure if it would help at all but i have a noise gate and an eq. to my understanding the preamp is driven my how much the input is being driven so if i were to raise the volume before the amps input would that help me get a little more gain?
Click to expand...

That's the idea.


Kingofpain678 said:
another thing im confused about is im seeing people jimmy rig the speaker cable output to a 1/4" cable and plugging it into 1x12 and 2x12 cabs but couldnt that blow the amp? and isnt that a bad idea since the 5 watt output couldnt drive the 12" speakers very hard?
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Nope. Size has nothing to do with the speakers impedance. All you need is to make sure the speaker's impedance is not too low for the amp, which WILL blow an output transformer. Well, or too high, but you have some fudge factor in that direction - you just get a bit less volume from the amp.


Light

"Cowards can never be moral."
M.K. Gandhi
 
ok so, i suppose i could run my eq before the amp and raise the volume on the eq to get some more gain... only problem is that its a 31 band eq and it would be REALLY annoying to dial in different tones lol.

and i guess ill mod it to make it more like a head and plug into my 2x12 cause less volume (for me) is better. something i cant seem to understand is on slipperman's guide to distorted guitars it says that its good to get speaker excursion but with only 5 watts it wouldnt be pushing the speakers very hard (less volume like you said). im not sure how speaker excursion applies to open vs. closed back cabs but im assuming that speakers in open back cabs move more freely because the cab isnt acting as much like a vacuum.

but other than the lowered volume will using the 2x12 affect the amps tone too terribly much?
 
Kingofpain678 said:
im thinking of picking up a peavey valveking royal 8 tube amp tomorrow.
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Don't waste your money on that horrible sounding P.O.S. Your crappy solid state amp produces godly tones compared to that Peavey.
 
why do you say it sounds crappy?

i thought peavey valvlekings were good :confused:
 
Get one - it'll mean you have solid & valve in your arsenal - at that price I'm really envious! Anything upfront that adds some extra grunt to the guitar signal will push the gain & give you more of what you're after.
By the way that term is actually "jury-rig" - it has always caused problems with pronunciation & spelling for me - I almost always misspell it & no one ever seems certain of its pronunciation.
Oh, & as they say in the movies..."follow the Light". He knows what's he's talking about.
 
ok cool, thanks. i dont know why ocnor says its bad? alot of people around here have recommended little 5 watt tube amps, and if i can run it through a 2x12 or smaller why not?

thanks ray.
 
Kingofpain678 said:
ok cool, thanks. i dont know why ocnor says its bad? alot of people around here have recommended little 5 watt tube amps, and if i can run it through a 2x12 or smaller why not?

thanks ray.
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A 212 will not automatically be quieter - it is a matter of the impedance of the cabinet. Depending on the speakers inside, and how its wired, a 212 may actually be the same impedance as a 112, or a 412, or a couple of 412s. And yes, I've seen guys plug a 5 watt amp into a 412. If the impedance is the same, doubling the number of speakers will probably give you a little more volume, and will certainly give you a more low end. You just have to wire the speakers in such a way that they don't change the overall impedance load on the amp. Of course, there is a practical limit to that - at some point, the physics of it just don't work any more.

The problem comes in when the impedance is out of whack. Impedance is kind of like resistance, and if the impedance is too low the amp will try to push too much current through the speakers, which will make the wires in the output transformer overheat, and then they will die. Too much impedance, on the other hand, is not going to kill your amp, but will make it a bit quieter - not much, and possibly not enough for you to notice without a dB SPL meter, but a bit quieter - up to a point, of course, because eventually you can have problems. You don't want to plug an 2 ohm output into a 16 ohm speaker, but an 8 ohm output into a 16 ohm speaker (or group of speakers) is fine. Just don't go the other way. As a rule of thumb, doubling the speakers impedance won't damage anything. Any more than that isn't worth bothering with.

By the way, I've not actually heard the amp in question, so I don't know what it sounds like. Tube amps are not automatically great, just as solid state are not automatically bad (well, for clean sounds - the Roland Jazz Chorus is amazing, and the Polytone Mini-Brute is fantastic, but only for clean sounds). I'd want to try the thing before I spent any money on it, even if it is cheap.


Light

"Cowards can never be moral."
M.K. Gandhi
 
Light said:
A 212 will not automatically be quieter - it is a matter of the impedance of the cabinet. Depending on the speakers inside, and how its wired, a 212 may actually be the same impedance as a 112, or a 412, or a couple of 412s. And yes, I've seen guys plug a 5 watt amp into a 412. If the impedance is the same, doubling the number of speakers will probably give you a little more volume, and will certainly give you a more low end. You just have to wire the speakers in such a way that they don't change the overall impedance load on the amp. Of course, there is a practical limit to that - at some point, the physics of it just don't work any more.

The problem comes in when the impedance is out of whack. Impedance is kind of like resistance, and if the impedance is too low the amp will try to push too much current through the speakers, which will make the wires in the output transformer overheat, and then they will die. Too much impedance, on the other hand, is not going to kill your amp, but will make it a bit quieter - not much, and possibly not enough for you to notice without a dB SPL meter, but a bit quieter - up to a point, of course, because eventually you can have problems. You don't want to plug an 2 ohm output into a 16 ohm speaker, but an 8 ohm output into a 16 ohm speaker (or group of speakers) is fine. Just don't go the other way. As a rule of thumb, doubling the speakers impedance won't damage anything. Any more than that isn't worth bothering with.

By the way, I've not actually heard the amp in question, so I don't know what it sounds like. Tube amps are not automatically great, just as solid state are not automatically bad (well, for clean sounds - the Roland Jazz Chorus is amazing, and the Polytone Mini-Brute is fantastic, but only for clean sounds). I'd want to try the thing before I spent any money on it, even if it is cheap.


Light

"Cowards can never be moral."
M.K. Gandhi
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ok, i get it now. i learned quite a bit about wiring speakers when i took the speakers out of my marshall to put them in an avatar 4x12 and forgot how to wire them back up, so i had to do some research and learn how to wire speakers and how different wiring affects the overall impedance. i usually keep my cab wired at 8 ohms with four 8 ohm speakers. the output impedance of my solid state head is 4 ohms and i never bothered to rewire my cab to see if it would sound better... maybe i should try that out. but either way the 8 ohms matches the amps output impedance. as for tone i assumed that since it was a tube peavey valveking it couldnt be that bad? i wonder if guitar center has one that i could play around with... i dont think it matters too much cause i cant ever tell a good amp tone until i put a mic in front of it.

i guess ill just have to see...
 
I don't know that amp.
My main question would be: is it really a tube amp or is it a solid state amp that they added a tube section to?
I've seen some amps like that and they aren't really what I'd call a tube amp in the classic sense. You open them and there's rows and rows of IC's and a couple of tubes.

As far as the small part: I wouldn't think that it would be a problem. Yes there's less bass but that can be a good thing as it puts the guitar in a zone above the bass guitar, and doesn't compete with it. I wouldn't expect to be able to play with a drummer with a small amp like that though.

There's no problem hooking amps up to external cabinets with 12's, that's commonplace.

Maybe it's a good amp. Trust your ears.

I know it's triple the price, but a friend of mine bought a Pignose G40V for about $300, and that's a great little amp, could use a 12" cab instead of the 10" though.

I'm not sure why, but I like the sound of old small magnet speakers with tube amps. Modern amps tend to have big magnet speakers.
 
ok so after TONS and TONS of searching i finally found a schematic for the royal 8. i dont know anything about schematics and i dont know if this will show you if it uses IC's or not but hopefull someone can tell me?

if not, i couldnt find any pics of the amps guts yet but ill keep looking.

Here's a link to the schematic if anyone wouldnt mind taking a look. its in pdf format.
 
resistors... capacitors... tubes... I don't see any IC's... looks like a real tube amp.

It's probably on a pc board but that's ok.

It's too bad you can't try one out or talk to someone who you really trust who's heard it.
 
yeah.... ocnor seems to be the only person who might have had an experience with this amp.

while searching for that schematic i came across quite a bit of people who seemed to like it and a select few who did some mods on theirs (so they must have known what they were doing) and they seemed to really like it.
i dont see why it would be a bad amp if i picked up a boss eq or something and ran it in front of the amp and maybe something similar to a tube screamer.
 
sounds good so far. i have another question though, is there anything wrong with using heavier overdrive or distortion pedals with tube amps?

im thinking some of the boss pedals, like the DS-1 or MT-2 or something similar
 
Kingofpain678 said:
sounds good so far. i have another question though, is there anything wrong with using heavier overdrive or distortion pedals with tube amps?
Click to expand...

Not a thing. I've got a Valve Jr. "stack" and one of my favorite sounds is that little el-84 pushed to the edge of meltdown, then kicked in the ass with my 70's MXR distortion+.
 
Kingofpain678 said:
sounds good so far. i have another question though, is there anything wrong with using heavier overdrive or distortion pedals with tube amps?

im thinking some of the boss pedals, like the DS-1 or MT-2 or something similar
Click to expand...

I think that using some pedals like that is the way to go. A lot of pro's still have their favorite stomp boxes.

Be careful with eq's... use them judiciously. It's good to try no eq and mess with the guitar, amp placement and everything else before using eq. The tracks I lay down that I like the best often have no eq on them - just get the sound right in the first place. Eq often makes the sound smaller because of phase issues and I see it as a last resort. Ideally you'd use none, but that's not the real world.
 
I just listened to https://www.youtube.com/watch?v=qqDMX--Fw5Y and I thought it sounded like a very usuable tube amp. Reminded me of a Supro...
the speaker is probably the rottenest component, there is something about a 12" for guitar that seems right... but that's easy to remedy if you'd even want to. It sounded quiet too.

Cool amp - I can't believe I like a Peavey amp! I've probably heard more horrible gear from Peavey than any other company but they always had some great products too like Black Widow speakers and Decca amps. I can't imagine their basses are too bad if Brian Bromberg uses one.
 
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