Tube Amps

Vic,
I don't know a lot about this, but tube amps do pack more power with the same wattage. And there's lots of discussion about tone. Lots of players believe that the tone of a tube amp is distinctive. I think, however, that nowadays there are a number of solid state amps that do a good job of emulating tube sound.
I have a solid state amp myself -- A Crate 120 watt amp with two 12 inch speakers. In terms of tone, it sounds like the tube amps the other guys in the band use, but I need the 120 watts and the two speakers to hit the same volume (basically to move the same amount of air) that the tube amps do with 60-75 watts.
Tim

The following is very untechnical:
Tube amps er in English- valves.
Tubes naturally produce that classic rock sound. Some solid state amps (or preamps) can now 'model' this sound to varying degrees.
Other than the tone and volume issues MF mentioned, I've seen Joe talk about the feel of tube amps, they respond to his picking/ angle of attack in a different way, though I believe even in feel efforts have been made to bring the higher end solid states closer to tubes.

Here's one quick primer
http://users.wpi.edu/~elwood/ph1121.html

Don't get me wrong in this reply, I'm not slamming digital modeling, tube/solid state hybrid amplifiers or saying don't exclude todays advancements in the technology, I'm explaining what the Question asked about "All tube amps". I use both tube and solid-state amp, combined with new effects and old to achieve my tone. The more I experimented and tested, the more I found a completely different sound, the more I wanted to push things beyond the norm.

"Thus began my quest."

Speaking for myself I grew up on tube amps. At that time a didn't really think about it I just played. After figuring out how to control the sound and feel I could achieve from them I never looked back. The choice of amps was pretty thin then. The only ones I remember Ampeg, Fender, Gibson, Marshall. (also a few smaller companies). Around that time a few companies did come out with a few solid-state amps, I thought they sounded terrible, plus you just couldn't get the same sound and feel out of them, even using a few of the limited number of stomp pedals available at the time.

The tone a tube amps some call it "break up" or "breaking up", meaning the distortion comes in gradually with increased gain where in many solid state amps, the distortion curve is very steep.Once you've played a cranked up classic tube amp from the '40's on to this day, knows that the sound, feel, articulation, and control just can't be beat. They also amplify your character, not just your volume. Dynamic sound like this is a product of the natural characteristics of tubes, speakers, and archaic circuits being pushed to their limits.

Regardless of how much Amp modeling technology, EQ, excess gain, digital pooh-ha, or preamp trickery you employ, the fundamental tone of any amp is really determined by the dynamic response of the amp's power supply and output stage. That is why old-style amps with their tube rectifiers, loose unregulated power supplies, inefficient biasing schemes, and uncluttered preamp circuits sound so real life and complex. They have a non-linear response that varies according to your playing style from with-in you.

Please keep in mind that my school of thought is based on years of experimenting, building, tweaking, hot-rodding existing models, and anything else I could plug my guitar into. Which I hope you may find to be useful in structuring and filtering your search for the best tones that bring out the best in you and your playing.

Rule of Thumb, "TONE FIRST", "Power second", "Effects third".

Joe

What is a tube amp? In general people mean amps that use tubes in both the pre-amp and power-amp section, whereas 'normal' amps use transistors instead. Do note that 'normal' transistor amps came after tube amps so tube amps basically are the standard.

Why do people use tubes? Initially they had no choice. tubes were in all audio products since transistors weren't being used on the scale you see today. In the 50s electric guitars and amps were mostly amplified backing instruments, and 'overdriven' was practically unknown. In the following years young bands started to push the amps to their limits and found out that tubes being pushed too far actually sounded pretty darn cool. The beginning of an era where many tube amp producers researched the effects of different components and the effects they had on the overdriven sound.

Later the transistor became hot. It was modern, new, cheap, light-weight and sounded like total crap. You sometimes even run into amps that are full-tube but can be switched to transistor. At the time people seriously expected tubes to be obsolete within a few years. However, it became quite obvious that despite all the advantages of transistors there was a big problem: transistors being pushed too far sound horrible. So the rockbands of the 70s and 80s mostly continued to use 'old' tube amps because there was very little alternative.

In the early nineties companies started to research 'modeling' amps. Transistor amps that mimick the way tube amps work. While fun from a technical point of view, they left a lot to be desired and by the mid nineties every self-respecting guitarist only mentioned 'modeling' when telling jokes. New companies like Line6 kept on advancing their technologies resulting in ever improving quality. And objectively modeling has a few promising advantages:

-Much cheaper
-Far more versatile
-Light weight
-Transistors don't wear out from use
-Full control over the sound at all volume
-Much easier to record directly
-Far more options to create 'your sound'

Then why isn't anyone using digital amps? Well, there are a number of reasons. The main one is that many digital amps still have problems with responding to picking techniques and seem somewhat 'plastic'. Try putting a tubescreamer in front of a Line6 SpiderII and you'll notice that digital amps often respond in another way to pedals then tube amps do. Which doesn;t apply to all amps; I myself much prefer a digital Vox AD30 over a Fender Pro Junior or Epiphone Galaxy. A second reason is people (and guitarists espescially) are conservative. If your idol plays tube amps, and his idols played tubes amps, then you'll want a tube amp as well. Note the ammount of 'reissues' are constantly released and the ammount of truly innovative tube amps. 'Vinage' is where the real money can be made, and companies know that well. Also note that even modern digital companies fail to use the technology to their maximum. Modeling amps should do far more interesting things then pretend to be a '58 bassman. A final point is that tube amps are far easier to use. No submenus, paramers, effectslayering or ampcombining. Just a few knobs and a on/off switch.

Few final remarks:
-A 100W tube amps in't louder then a 100W transistor amp. It is *perceived* as being louder, which is something very different.

-The most dynamic amp possible would be a transistor amp. Tubes tend to add natural compression of their own. Overdriven tube amps are drenched in it.

-Taste matters more then anything. Noone could deny the construction quality of a Bogner, but that doesn't mean they sound best.

-Tube amps have a few advantages I haven't yet mentioned, like being way cheaper to repair and often being constructed with more care then a 'factory' transistor amp.

In the early nineties companies started to research 'modeling' amps. Transistor amps that mimick the way tube amps work. While fun from a technical point of view, they left a lot to be desired and by the mid nineties every self-respecting guitarist only mentioned 'modeling' when telling jokes. New companies like Line6 kept on advancing their technologies resulting in ever improving quality. And objectively modeling has a few promising advantages:

<snip>

Few final remarks:
-A 100W tube amps in't louder then a 100W transistor amp. It is *perceived* as being louder, which is something very different.

-The most dynamic amp possible would be a transistor amp. Tubes tend to add natural compression of their own. Overdriven tube amps are drenched in it.

-Taste matters more then anything. Noone could deny the construction quality of a Bogner, but that doesn't mean they sound best.

-Tube amps have a few advantages I haven't yet mentioned, like being way cheaper to repair and often being constructed with more care then a 'factory' transistor amp.

Some interesting points, Arjen. However, a few of your techie points need some tweaking:

Modeling amps are not transistors sounding like tubes (or whatever other amp is desirable), they are digital signal processors running mathematical models of tube amps. The technology is in the math and implementation of that math on a specialized computing device which is surrounded by at least one analog-to-digital converter plus at least on digital-to-analog converter. It might seem as if I'm splitting hairs, but there is a big difference. Transistor amplification often is used with modeling because, the requirement is for low distortion, sonically transparent amplification to boost the modeler's signal -- transistor amps do this better for less $$$. The modeler is one thing, the transistor amp another.

Tube amps can and are played louder for the same wattage rating. How many watts are actually translated to sound depends on how the amps are played. Amps are rated for max power output based on a total harmonic distortion level. (Making this number up) 1% distortion max power level for solid state is the same as spec'ing 1% distortion max power level for a tube amp. If everyone plays only to 1% distortion (and all other factors being the same), the loudness is the same and perceived to be the same. But .... many people don't play tube amps at 1% distortion levels, but play into saturation -- a form of compression. When this happens the peak power may (or may not) increase by much -- certainly not linearly, as it is in compression. But the average power does continue to go up -- that is more power and louder -- really. We don't normally play into compression on the SS amp, because that generally sucks. But on a tube amp playing to 5 or 10 % distortion levels sounds "cool" (well to some -- or most). BTW this is why many FM radio stations use heavy compression on music -- the peak power stays roughly the same, but the increasing sonic density raises the average power and, viola, a compressed station sounds louder than one that is not. Anyway, tubes amps are not "tricking" the ear into believing the same wattage is louder -- they are louder because more watts are being pumped out.

Tube amps operating in saturation are indeed compressing as you point out. When players refer to tube amp as being sensitive to touch, it's not plain and simple loudness response that is being described, but a combination of volume compression and tonal change that reacts to finger/pick attack in a fashion generally pleasing to the player. Most people actually like compression, as it smooths out their playing -- but don't confuse this with the aspect of touch response tube players rave about -- it's the tonal response, not loudness response they are trying to tell you about.

Some tube amps are less reliable and more difficult to repair than solid state amps. The printed circuit (wire) boards than have been great for solid state design and manufacturing are often not so great for the mechanics and thermal issues from which tubes suffer. This is the reason point-to-point (and hand) wiring is favored for tubes. Unfortunately, most PC boards are much cheaper to make, so some poorly designed versions have found their way into many lower cost tube amps.

-Greg

i wouldn't say tube amps cost less to repair i would say that they are possible to repair if a solid state breaks there's a very small chance that you can figure out what went wrong with it because their so digital.

Modeling amps are not transistors sounding like tubes (or whatever other amp is desirable), they are digital signal processors running mathematical models of tube amps. The technology is in the math and implementation of that math on a specialized computing device which is surrounded by at least one analog-to-digital converter plus at least on digital-to-analog converter. It might seem as if I'm splitting hairs, but there is a big difference.

Right. They are basically, if not literally in many cases, computers running audio processing programs. That tripped me out when I found that out and I was like, "Man would I love to see the source code for that!"

In response to the very first post. I don't know everything there is to know like some of these people. I will say i did have a soild state. A crate gx-15 and made a huge leap to a Fender Hot Rod Deluxe. WOW! That sucker is loud. I will just tell u that i honestly don't know all the technical differences, however as a player the sound quality is great!!! It has a nice warm feel. The clean channel is excellent. For the music I play such as Jimi Hendrix, Led Zeppelin,Rolling Stones,all the classic rock, people were like when u get a new amp u need a tube amp,(which as i metnioned i later did get the hot rod) recently i have also gone into playing phish and grateful dead once again, this amp is great for that. I really think u need to look at your favorite guitarist and or who u would like to sound like. Hows this go to a guitar store play a nice soild state and then go play the exact same thing into a hot rod amp and you will probably hear the difference i am speaking of.

Hotrod: You are comparing a $90 amp with a $600 amp...

So anyone got any recommendations for a cheapish tube amp....15 to 30 watts'll do for now, not like I'm going to be filling the Albert Hall anytime soon.....say $150-250.....

Vic

For combo amps Epiphone Galaxie 25, Fender Blue jr, you might want to check these boutque amps out.

Sombrabella.com. These are hand built. I have one the first ones he built and they sound great.

Joe

A used Blues Junior might be $250 -- new it's close to four bills. A Pro Junior is just under $300 new.

Tube amps always have a small amount of distotion present (called "even-order" distortion) that serves to "warm up" the sound and make it stand out a bit. Solid state amps try to imitate that tube presence, but very few are able to nail it perfectly.

Plus, tube amps distort differently--they compress the sound, whereas solid state amps 'clip' it. Draw a waveform on a piece of paper. Now draw two parallel horizontal lines that touch the waveform at its peaks and valleys. Imagine "squishing" those two lines together--the waveform will get kind of squashed, right? That's how a tube amp responds to distortion. It's a nice singing tone, almost smooth.

Now, draw the same waveform and the same parallel lines. Squish the lines together but DON'T squash the waveform--let the lines cross the waveform at the peaks and valleys so that those areas are cut off. That's called clipping, and it's how solid state amps respond to distortion in the signal. It's ugly and choppy, which is why solid state amps model tube amps in their response to distortion.

Make sense?

I actually also went from a GX 15 to a hot rod deluxe.

But like Arjen said, we'd be comaring a 90 buck amp to a 600 buck amp.
I actually never thought my GX 15 sounded bad. I went to guitar center, and asked to play the hot rod, and I noticed no difference. And then, I asked them for a GX 15, and I thought "wow,I was playing on that?!?!???" (Note the exccesive use of question marks and exclamation points, I was really surpised)

What does that tell you? Nothing much at all really, I thought it was a story that had a relation to what we are talking about.

Vic- Try out all the amps you can in your price range, tube and not, go with what YOU like best. I went with a tube amp, I love it, you might not.

However, you may want to wait until you got some more dough saved up. Buy 'em big, and you don't need to get 'em bigger, comprende?

Love,
Taso