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Tube watts vs Solid State watts

#143
I apologize if someone brought this up in the past many pages - but here's the facts to answer the OP's question - Why guitars seem louder with smaller amps -

It has NOTHING to do with tubes or SS, It has nothing to do with watts.

1. Our ears are LESS SENSITIVE at low and high frequencies and most sensitive in the midrange where guitars are - so they seem louder to our ears even if the actual SPL is the same. Our bass amps have to create 10-20 times the SPL to SEEM the same. and - It takes TEN TIMES the amp power to seem twice as loud to our ears. It also takes lots of cone area and movement to generate that SPL.

2. Bass is non-directional so a lot of the sound created is wasted going around the sides, back, top and bottom of our amps. This is why you will be louder with the amp on the floor, against a wall, or (best of all) in a corner to direct more of the energy out towards the audience. The mids and highs of a guitar are more directional, so more of the sound produced hits your ears - again louder with less effort.

The end result is that we need 3-400 watts and lots of cone area to generate the same perceived volume as a guitar player with 30 watts and a single 12.
 
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#144
agedhorse said:
This isn't a good example because propane has less BTU available per unit volume and with a comparable stoichometric mixture will produce less mechanical power with which to drive the generator, thus less power (watts electrical). IIRC (I took this class 40 years ago), the correction factor is between 5 and 10% less.
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That's true, but the carburetor has been re-jetted to compensate for this. The propane unit consumes more fuel per watt produced, but produces the same output wattage when demanded. So it's actually pretty similar, since tube amps (generally) consume much more input power, per watt of output than solid state amps.
 
#145
A watt is a watt, doesn't matter if it was produced by tubes, transistors, mosfets, alternators, etc.
There are those that purport tube amps deliver far more power than the rated output, but if the playing field is leveled by the amplifier operating in the linear region, this argument is quelled. Once you start introducing distortion, you're comparing apples to oranges.
 
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#147
The Watt was named after James Watt, the inventor of the steam engine. This has nothing to do with electronics. There are mechanical watts and electrical watts, both relate to horsepower. There’s both electrical and mechanical horsepower.

Like a motor, a speaker consumes elelctrical watts and produces mechanical watts. It does this very inefficiently. Good thing that speakers are not rated in mechanical watts or horsepower, as this tube vs sand state discussion would be even more confusing.

Tube amps are very inefficient relative to many solid state amps. Is a horse more efficient running through sand than it is on hard packed soil? Horsepower is diminished due to inefficiency. It has to do with the underlying process. Even more confusion.

Tube glass envelopes are made with sand. On outward appearance, they have something in common with solid state amps.
 
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#148
byacey said:
No problem; I meant it as a tongue-in-cheek, humorous way. Unfortunately this doesn't translate well in typed text. I hope this thread and the one I posted the link to, answer some of your questions.
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Yeah stuff doesn't always translate well online when you can't hear the tone of one's voice or see their face as they speak.

There's been questions answered, and even more questions arise out of the subject, which is good. I like it when discussions lead to me using my brain to think or go online to do even more research. I'm geeky like that.
 
#151
Clark W said:
Is there a difference in how loud a tube watt is vs a solid state watt?

Or....

Why is it a guitar player can bring a 30 watt single 12 combo up on stage, barely turn up the volume and be loud as heck vs a bass rig?

I guess what I'm asking is what is going on between not only tube vs solid state, but even more so between guitar vs bass heads as far as loudness?

Why does a bass player need a 300 watt head when a guitar player can get by with only a 100 watt head? Does the frequency spectrum the instruments cover have a hand in this?
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There has been a lot of digital ink about this.
Yes there is a difference between tube watts and SS watts. And yes, guitar players can get away with a lot less in terms of wattage.
Part of both has to do with what you are using them for. To a lot of people's ears a slightly cranked tube sounds better than a slightly cranks SS amp. The "headroom" of a tube amp is a little higher because it breaks up in a more gentle way. The exact science is beyond me, but the ratio of tube watts to ss watts seems to be roughly 1:2 or 1:3. A 700-900 watt class D performs about the same as a SVT-CL.

As to why guitar players can get away with less wattage has to do with their frequencies and what they are doing. Highs and mids are cheap to produce wattage wise. Deep, 200hz and lower frequencies require a lot of speaker movement, which means more watts. Also, a fair majority of guitar players are running the tubes at some level of breakup. Anywhere from "grit" to all out chainsaw distortion. They could make a 300 watt guitar head, but it would be super hard to distort a beast like that because it would have so much clean headroom. If you want nothing but distortion a fairly moderate volumes, 50w is great. You want the preamp and power amp to be clipping. Bass, generally, doesn't want that level of distortion. We want some, but not full guitar levels, so we need more watts for clean headroom.
 
#152
Ok, fine. I'll concede. There is an actual, quantifiable difference between tube and solid state watts:

Code: 
Amp           Watts     Price          Price/Watt
SVT-CL        300       $1,799.99      $6.00
SVT-7 PRO     1000      $799.99        $0.80

A bonafide difference of $5.20 per watt.

Edit: I just thought of something else too. Tube amps are heavier per watt. Maybe that's where the idea that tube amp watts have more "heft" comes from?

Source: Sweetwater.com
 
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#153
Bassamatic said:
I apologize if someone brought this up in the past ...

1. Our ears are LESS SENSITIVE at low and high frequencies and most sensitive in the midrange where guitars are - so...
Click to expand...

In other words, Invalid Link Removed. One might notice, at lower SPL, our hearing is less sensitive to lower frequencies. That is why a loudness switch was added to stereo receivers/preamps in the 1970s.

I'll add, there is the physics of sound, and there is the psychology of hearing. Where the two intersect in intriguing stuff. Consider the difference between frequency versus pitch, or amplitude versus loudness.
 
#154
The difference between tube watts and solid state watts is one is produce via solid state and the other by tubes. Here's a formula that will help you calculate it:

1 tube watt = 2 x .5 solid state watts

As you can see it takes twice as many .5 watts of solid state to equal 1 tube watt, that's why tube watts are louder.

I'm sorry if this offends the mathematically challenged.
 
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#156
Low Class said:
The difference between tube watts and solid state watts is one is produce via solid state and the other by tubes. Here's a formula that will help you calculate it:

1 tube watt = 2 x .5 solid state watts

As you can see it takes twice as many .5 watts of solid state to equal 1 tube watt, that's why tube watts are louder.

I'm sorry if this offends the mathematically challenged.
Click to expand...

I didn't know there'd be math...

:bag:
 
#157
I am engineer and suppose to be logical sensible etc. But I just like tube amps. My home and computer audio go through tube power amps. Even my bluetooth receiver is tube, the preamp portion of it anyways. I like how they sound not that they are louder. If I can I try to bring a tube bass amp. I practice with a tube amp 90% of the time
 
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#159
socialleper said:
The "headroom" of a tube amp is a little higher because it breaks up in a more gentle way. The exact science is beyond me, but the ratio of tube watts to ss watts seems to be roughly 1:2 or 1:3. A 700-900 watt class D performs about the same as a SVT-CL.
Click to expand...

It really depends on how the amp is rated. Many solid state amps can play clean musical transients that are significantly above the amp's continuous power rating. Most of the tube amps I have played become compressed and distorted before they reach their rated power. So tube amps don't necessarily have more headroom.

As I said earlier in the thread, my 380W GK RB700 plays a little louder clean than my 300W SVTs pushed into distortion; so IMHO the ratio has no scientific basis. As evidence that the GK is not a red herring, my class D Epifani UL902C rated at 900W per channel is even louder.

IMHO, if you have a 900W amp that is about as loud as an SVT, either something is wrong with it or the manufacturer is using BS power ratings instead of RMS.
 
#160
I find that it takes about 10 times as much power from a SS amp to put out as much clean sound as a tube amp did. I run a 3800 solid state watt amp nowadays. It takes that much to be significantly louder than my 200 watt tube amp did. There are many widely varied technical reasons for it, physics, electronic, impedance coupling, power crest factors, tube soft clipping etc .
 

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