Tube Amps

Then there's the issue of why tube amps are louder than solid state amps of the same wattage ... which is way beyond me to explain.

Because a 5W ss amp is just that, whereas a 5W tube amp is not just that. Tube amps are somewhat supposed to be able to operate beyond the specified wattage while that would result in sonical crap on SS amps. A 5W tube amp is quite likely closer to 12 then 5W.

Tube amps are somewhat supposed to be able to operate beyond the specified wattage while that would result in sonical crap on SS amps.

Yes, but why? Is it that tube amps compress while SS clips (I'm over-simplifying, I know, but "more or less"), or is it something to do with the output transformers used in tube amps? Or a combination? Or tube voodoo?

Yeah, that's gotta be it: tube voodoo! :lol:

Here is a very good website with lots of information about amps, pickups, guitars..... Really good and informative reading.

Here is the page about Power and Volume, but go to the Home page and read the various articles.

http://users.chariot.net.au/~gmarts/amppower.htm

With tube amps don't you want to be sure of grounding loops ect...? Isn't there a chance of shock?

art&lutherie

Tube amps are just as safe as solid-state amps unless a person chooses to open up a tube amp and sticks their hands in to change tubes or perform mods. There are capacitors that hold power even when the amp has been off, even for days. But otherwise, tube amps are grounded just like solid-states and are just as safe. If a person is not familiar with electronics it is best they hire a professional to change tubes or modifications to their amp.

Ground loops is a noise issue that can affect solid-state or tube amps. Ground loops often occur from connecting two pieces of gear (guitar amp, multi-efx board for example) into seperate outlets on the same circuit creating a loop antenna that picks up 60Hz AC hum especially. Here is an article that explains better than I could.

http://home.hetnet.nl/~elektronicaonline/ground%20loops.htm

There are safe ways to eliminate ground loops, probably the easiest is to plug all connected gear into the same outlet. There are also products like power conditioners you can buy.

The worst way to eliminate ground loop hum is to break off or lift your ground as some do. Then there is the real possibility of electrocution whether solid-state or tube.

thanks for the clarification.

As Wes mentioned, tubes amps have high voltages. The tubes use voltages ranging from 250V up to around 400V - not something you want sweaty fingers to touch! :shock:

I bought a tube amp when I last went to Germany. It's a Fame GTA-15. It's very loud, and when my good-player friends play on it, it sounds really great (I still suck at this, so nothing sounds really good when I play :-| but I know my time will come :-)).

Anyway, I have a question that I feel very ashamed of asking my friends (OK, they're not much of friends, they are more like guitar players that I hang with), because I feel it's a total newbie question. But this information has prevented me from buying more gears, since I cannot make a good decision.

My question is: will any (good) pedal sound good on my amp, or do I need some kind of special pedal for tube amps? Isn't connecting a digital equipment (the pedal) going to ruin the tube sound? Oh, my Fame amp doesn't have an effect loop, does that limit my pedal choices?

Thanks so much for any answer.

Strangedata

Do effects pedals sound better through a tube amp?

The answer is a simple Yes and No. :D

Most individual pedals sound great through a tube amp, in my opinion much better than through any solid state. But when you get to modeling effects units you can have some problems and usually need to tweak it. For instance, many modelers not only imitate a particular amp, but also a particular speaker cab. You might have a preset that imitates a Marshall head into a Marshall 4 X 12 speaker cab. Now, if you've ever heard a Marshall with a 4 X 12 cranked up you know they sound awesome. But this is usually too much for a tube amp and it will distort badly. I have found it is usually best to turn off cab simulations when using a tube amp. Solid state amps are very different, they can stay very clean to very high volumes. So a cab simulation will work very well. If you dial in distortion on the solid state while using cab simulations it will sound bad just like a tube amp. Lots of folks run modelers into their PA systems today, they don't even bring an amp on stage. PAs are solid state and produce very clean tones to very high volumes, so modelers work great like this.

But pedals like Overdrives or Distortions, Chorus, Phase, Delay..... all sound great through tube amps. And it is not a problem at all running straight into the regular guitar input on the amp. Many folks use effects loops, others don't. I don't use effects loops myself. Overdrives and distortions usually sound best straight into the amp, effects like Chorus or Phase usually sound better through the Effects Loop.

Hope that helped.

art&lutherie

Tube amps are just as safe as solid-state amps unless a person chooses to open up a tube amp and sticks their hands in to change tubes or perform mods. There are capacitors that hold power even when the amp has been off, even for days. But otherwise, tube amps are grounded just like solid-states and are just as safe. If a person is not familiar with electronics it is best they hire a professional to change tubes or modifications to their amp.

Correct me if I'm wrong, but isn't changing a tube as safe as changing a light bulb? Now sticking ones fingers inside is another story. That is why the access to tube changing is made relatively easy, while access to the dangerous parts requires taking the amp apart and there are stickers warning against such action unless one is a qualified service technician.

Hello everyone.

Thanks for the helpful answers. Maybe you could help me with something else: today I went to a guitar shop looking for a Hot Plate for reducing the output of my amp (or else, my neighbors will kick me out). The attendant told me that instead of using a Hot Plate I could simply use a lower voltage to plug my amp.

I have both 220V and 110V outlets in my house, and the amp is 220V. My question is, since the amp's circuit was planned so that it would be plugged into a 220V outlet, would it be damaging to plug it into a 110V outlet? What about the tubes, will they wear out quicker?

Thanks!

Yes, running the tube amp on 1/2 of its rated voltage will cause problems. The heater voltage on the tubes will be low enough to cause drastically reduced electron emission from the cathodes. That means they're functioning like worn out tubes. The voltage on the tubes' plates and screen grids will likewise be halved, and power drops exponentially.

Running tubes at below about 80% of rated heater voltage isn't recommended by the manufacturers. There's a concern about "cathode stripping" with the reduced emission reducing the normal cloud of electrons around the cathode so it gets bombarded with positive gas ions that sputter away the oxide coating. Hasn't actually been demonstrated in these small tubes, but it's a big concern in large, high power transmitting tubes.

Eddie Van Halen's reported to use a Variac to drop the voltage on his amps as part of his "Brown Sound." I'll bet he doesn't cut it in half, though.