Tube 300w vs Solid-state 300w?

[agedhorse]

I've always heard a british amp like Marshall is rated differently than one from the USA.

The primary difference is the true British amps are rated for 230-240V/50Hz AC input where the US amps are rated for 115-120V/60Hz AC input. As far as the audio side they are the same.

 

[Wasnex]

Would it be equivalent loud? or somehow tube amps are 'louder' than the solid-state even when both are marketed as 300watss?

Part of the answer is going to depend on your perceptions and the type of tone you want.

Watts are watts...this is a fixed fact.

Some argue that a tube amp can be louder because it can be pushed further into distortion before it sounds awful. This depends somewhat on how the solid state amp is rated, and they are not all rated the same. A 300W solid state amp may actually be able to make more than 300W to cover transients, or it may clip harshly when the power level hits 300W.

In my experience many tube amps cannot actually play their rated power clean. They start getting more compressed as they transition over into distortion. But if you like distortion you may be able to push the amp to 450W or so. This varies by design as well. As an example, bench tests for the Orange AD200B often cite about 170W clean, and bench tests for SVTs often site about 270W clean.

Compression can be a bit confounding. Compression limits dynamic range and it is often used to make music louder (on average). This is done by reducing the dynamic range. The idea is the average SPL is increased, but the low SPL limit and high SPL limit are much closer together. Also, the peak SPL is limited. IMHO if you have solid amp with enough dynamic range to play the peaks cleanly, you may still perceive it as louder, even if the tube amp is louder on average.

I don't like playing with heavy compression, so in my experience whichever amp has the highest power rating is likely to sound loudest to me. I have tube amps rated from 12.5W to 427W. In all instances the volume goes up with their power rating. But there is also a pecking order for amps that share power ratings. For example my Hiwatt DR103 is my loudest 100W head by a fair margin. It's a great sounding amp, but IMHO it's not the best choice if you want heavy output drive. My Matamp GT120 is way better for heavy output drive, but it's not as loud. It's still one of my louder amps. My AD200B is noticeably louder than all of my 100W tube amps.

I also have solid state amps ranging in power from 260W to 2500W. The lowest powered solid state amps are my old GK RB series amps. The 2000RB is rated for 360W at 4 ohms and the 700RB is rated for 380W at 4 ohms. IMHO they seem slightly louder than my 300W tube amps and hang really well with my 400+W tube amps. Most of my larger solid state amps sound like they are still idling at low power when my 300W tube amps are hitting the wall and totally falling apart. I don't generally play at the volume my 400W tube amps are capable of, but my perception is all of my solid state amps with more than a 1000W rating are dramatically louder.

Another argument is that our ears are sensitive to distortion, and this will help make a pushed tube amp seem louder.

An additional factor to consider though. Speakers are voltage driven devices. As a tube amp is pushed into saturation the power supply voltage will generally sag under the loud. This sag reduces the peak to peak voltage swing the signal can achieve. So as the waveform begins to square off, the voltage decreases.

Despite the voltage going down, the power can still increase because the signal is staying at the peak value for a longer duration. To use a technical term, the duty cycle increases. However since speakers respond to voltage, the SPL decreases with the voltage despite to power continuing to increase. I have actually confirmed this with an experiment.

Explanation:

The sine wave and square wave in this image have the same peak to peak voltage swing. The square wave stays at the peak value for a longer duration, so the RMS power level is higher.

When a tube amp is pushed hard into saturation, any sag in the power supply will reduce the peak to peak voltage swing. Notice the relationship of the different values in this image

- The Peak, RMS, and Average values of the square wave are all the same.
- The Peak, RMS, and Average values of the sine wave are all different. Some valuse are higher than the square wave, and some are lower.

Note. Peak is simply 1/2 the peak to peak value.

My experience has been consistent over the many experiments I have run over the decades. A good solid state amp seems louder to me than a tube amp with a similar power rating. The first time this happened I was surprised, as I expected the tube amp to be louder.

My actual belief is this is a stupid thing to argue about. You should be able to find either a tube amp or solid state amp that is loud enough to exceed your volume needs. So go out and play a bunch of amps. Choose the one that you like best and don't worry about whether it's tube or solid state.

 

[ardgedee]

I once had a 400 Watt Walter Woods MI 400 8. In that particular amplifier the preamp and power amp were analog, only the power supply was class D.

Not to take anything away from your experience with the Walter Woods, but "Class D" does not mean "Digital".

 

[Jackcrow]

Except that tube clipping especially preamp and PI sections) are often not symmetrical and there’s MORE output impedance in a tube powered not less.



The Prodigy is voiced very differently, voicing has a big impact on the impression of volume. The WD-800 had greater low frequency extension which requires additional power to reproduce. Also, if using an 8 ohm cabinet, that rated power must be compared with the 8 ohm power rating of the Prodigy (which doesn’t change with impedance due to the action of the output transformer).


A big component of perceived volume is the combination of the speaker cabinet and the distortion that is generated which falls into the range where the ears are most sensitive.

I used a 4 ohm cab when comparing the 2. You can definitely tell that the voicing is different. The WD-800 is certainly not lacking in overall output, as I’m sure you would hardly ever need everything it can put out, but I was actually a little worried that the Prodigy might be not quite enough. That has not been my experience so far.

 

[mike buzzetti]

https://www.electronicdesign.com/po...Y8169O017IKjMpDkNSiBh8OyNW2-lFJ0aAjQjEALw_wcB

RMS vs PEAK power

 

[DJ Bebop]

Part of the answer is going to depend on your perceptions and the type of tone you want.

Watts are watts...this is a fixed fact.

Some argue that a tube amp can be louder because it can be pushed further into distortion before it sounds awful. This depends somewhat on how the solid state amp is rated, and they are not all rated the same. A 300W solid state amp may actually be able to make more than 300W to cover transients, or it may clip harshly when the power level hits 300W.

In my experience many tube amps cannot actually play their rated power clean. They start getting more compressed as they transition over into distortion. But if you like distortion you may be able to push the amp to 450W or so. This varies by design as well. As an example, bench tests for the Orange AD200B often cite about 170W clean, and bench tests for SVTs often site about 270W clean.

Compression can be a bit confounding. Compression limits dynamic range and it is often used to make music louder (on average). This is done by reducing the dynamic range. The idea is the average SPL is increased, but the low SPL limit and high SPL limit are much closer together. Also, the peak SPL is limited. IMHO if you have solid amp with enough dynamic range to play the peaks cleanly, you may still perceive it as louder, even if the tube amp is louder on average.

I don't like playing with heavy compression, so in my experience whichever amp has the highest power rating is likely to sound loudest to me. I have tube amps rated from 12.5W to 427W. In all instances the volume goes up with their power rating. But there is also a pecking order for amps that share power ratings. For example my Hiwatt DR103 is my loudest 100W head by a fair margin. It's a great sounding amp, but IMHO it's not the best choice if you want heavy output drive. My Matamp GT120 is way better for heavy output drive, but it's not as loud. It's still one of my louder amps. My AD200B is noticeably louder than all of my 100W tube amps.

I also have solid state amps ranging in power from 260W to 2500W. The lowest powered solid state amps are my old GK RB series amps. The 2000RB is rated for 360W at 4 ohms and the 700RB is rated for 380W at 4 ohms. IMHO they seem slightly louder than my 300W tube amps and hang really well with my 400+W tube amps. Most of my larger solid state amps sound like they are still idling at low power when my 300W tube amps are hitting the wall and totally falling apart. I don't generally play at the volume my 400W tube amps are capable of, but my perception is all of my solid state amps with more than a 1000W rating are dramatically louder.

Another argument is that our ears are sensitive to distortion, and this will help make a pushed tube amp seem louder.

An additional factor to consider though. Speakers are voltage driven devices. As a tube amp is pushed into saturation the power supply voltage will generally sag under the loud. This sag reduces the peak to peak voltage swing the signal can achieve. So as the waveform begins to square off, the voltage decreases.

Despite the voltage going down, the power can still increase because the signal is staying at the peak value for a longer duration. To use a technical term, the duty cycle increases. However since speakers respond to voltage, the SPL decreases with the voltage despite to power continuing to increase. I have actually confirmed this with an experiment.

Explanation:
View attachment 4599801 The sine wave and square wave in this image have the same peak to peak voltage swing. The square wave stays at the peak value for a longer duration, so the RMS power level is higher.

When a tube amp is pushed hard into saturation, any sag in the power supply will reduce the peak to peak voltage swing. Notice the relationship of the different values in this image

View attachment 4599811


- The Peak, RMS, and Average values of the square wave are all the same.
- The Peak, RMS, and Average values of the sine wave are all different. Some valuse are higher than the square wave, and some are lower.

Note. Peak is simply 1/2 the peak to peak value.

My experience has been consistent over the many experiments I have run over the decades. A good solid state amp seems louder to me than a tube amp with a similar power rating. The first time this happened I was surprised, as I expected the tube amp to be louder.

My actual belief is this is a stupid thing to argue about. You should be able to find either a tube amp or solid state amp that is loud enough to exceed your volume needs. So go out and play a bunch of amps. Choose the one that you like best and don't worry about whether it's tube or solid state.

 

[agedhorse]

I used a 4 ohm cab when comparing the 2. You can definitely tell that the voicing is different. The WD-800 is certainly not lacking in overall output, as I’m sure you would hardly ever need everything it can put out, but I was actually a little worried that the Prodigy might be not quite enough. That has not been my experience so far.

The voicing of the Prodigy is quite aggressive and it was designed to sound good overdriven. The impression of volume is in part based on these factors. Also, many speakers will simply not get louder with more power once the point of mechanical limits are reached. This power compression phenomenon is very real, and why the Subway cabinets are rated with the mechanical limits in mind for (in part) this reason. Other cabinets are rated using thermal limits and power compression can become a factor at 50% of their rated power.

One thing that's different between the WD and the Prodigy is the low frequency extension. With the HPF set around 60Hz, that will be a closer match. You will also want to operate the WD with the damping factor at either low or medium to get into the Prodigy range.

 

[drumvsbass]

If 300 Watt tube heads weighed 10 pounds we wouldn't be talking about this.

 

[agedhorse]

If 300 Watt tube heads weighed 10 pounds we wouldn't be talking about this.

There are players that prefer tube amps (voicing and all) and there are players that prefer solid state amps (voicing and all), regardless of the weight.

 

[Wasnex]

Anyone who thinks a 300w solid state amp is anywhere near as loud as a 300w tube amp can't possibly have used both. Generally I find that 300w solid state amps are comparable to 50-100w tube amps when it comes to perceived loudness (with slight variations between brands).

Back in the day, I considered buying a couple of 300W solid state amps, but you are correct I never did. I do however own 360W and 380W solid state (GK) amps currently and they seem louder than my 300W tube amps. By the time the GKs are starting to hit the wall, the 300W tube amps are pushed so far into saturation that I find the tone unusable.

IMHO, If your 300W solid state amp is comparable to a 50-100W tube amp, it's a crappy amp or you are not running it properly.

Something to keep in mind. Tube amps put out the same power regardless of impedance, providing they see the expected loud. This means an SVT will put the same power into 2 or 4 ohms.

In general, solid state amps try to hold the voltage constant. So when the impedance goes down, the power usually goes up. For example, my GK 700RB is rated for 225Ws at 8 ohms and 380W at 4 ohms.

In order to do a fair comparison, you need to use the same or identical cabs for both amps, and the impedance needs to be at the level where the amps produce the same power. The SVT is supposed to make 300W at 4 ohms or 2 ohms (3-5%) THD.

In order to compare an SVT to a GK 700RB, I would suggest using a 4 ohm cab like an 810E. Then you have an amp rated for 380W vs an amp rated for 300W. The decibel different between 380W and 300W is about 1dB, so you would not actually expect to hear a clear difference.

I have compared these two amps using a pair of EV TL405 cabs and the GK seemed noticeably louder. Both could play louder than I normally require, so ultimately it doesn't really matter.

 

[PhloopyYoopy]

So 300 tube watts is, from my experience, the power output at the disclosed distortion specification. You can push it past that, a lot, but distortion and compression gradually increases. An Ampeg 300w bass head I'd expect would be difficult for one person to carry, costs a mint, and could, "let the magic smoke out" if you don't know how to take care of it. Like your output tubes will only last for so many hours of use and would likely cost about $200 or more to replace a matched set of four 6550s for example.

Solid state amps will hit a distortion brick wall at their rated wattage. But it will also be lower maintenance, less expensive to buy and operate, and potentially much lighter especially if you go class-D.

 

[Wasnex]

If 300 Watt tube heads weighed 10 pounds we wouldn't be talking about this.

Sure we would...AFAIK, you would choose tube every time, and I am totally okay with it.

I would decide depending on my mood and the tone/feel I wanted.

Some others would choose solid state 100% of the time, even if tube amps were lighter and more reliable.

 

[SixtyCycleHum]

if you push a tube amp past its clean RMS, it can keep putting out power, sometimes up to 50% past its rated RMS. Thats part of why a 100 watt marshal head can blow speakers in a 100watt 412 Greenback cab. And a tube amp pushed to clipping will often (not always) sound good.

A solid state amp pushed past its peak will often sound like crap, harsh square wave output. CLEAN power? in theory, through the same speakers fed the same input signal, they should have equivalent sound pressure. In theory.

You summed up the post-clip difference really well, dude. Well done.

You're right, though. Not every tube amp sounds huge when you push them into oblivion. Most do, but not all.

 

[Wasnex]

So 300 tube watts is, from my experience, the power output at the disclosed distortion specification.

Solid state amps will hit a distortion brick wall at their rated wattage.

Both of these assumptions can be inaccurate IMHO. It depends on how the amps are rated and how much dynamic headroom they have. In regards to tube amps, it also depends on the quality and health of the tubes.

FYI the original specs for the SVT was 300W at 3% THD. The output circuit for modern SVTs is pretty much electrically equivalent, but I believe the spec for the most recent models has been changed to 300W at 5%. I have read several bench checks where SVT were tested at about 270W at 5%, and this seems about the norm. I have also read a few bench checks where SVTs made 350W at 5%, and these seem to be the exception.

I believe vintage Hiwatts frequently make more than their rated clean power, but IMHO their output sections don't necessarily transition very gracefully into saturation. So if I wanted the loudest tube amp I might choose a Hiwatt. But if I wanted great output drive, I would choose something else.

IMHO SVTs sound great pushed close to the edge, but not way over it. I would say for heavy output drive my Matamp GT120 is the best amp in my collection. It would be great for recording, but I usually want a bit more power for live work.

 

[agedhorse]

You summed up the post-clip difference really well, dude. Well done.

You're right, though. Not every tube amp sounds huge when you push them into oblivion. Most do, but not all.

Not all solid state amps sound like crap when pushed into over-driven territory either.

 

[Jeff Scott]

Tube 300w vs Solid-state 300w?

What I want to know is how do either/both compare to 300 atomic watts?

 

[sid sonic]

oh those even harmonics...mmmm tubes...oh oh those odd and even harmonics
combined aka ss class d to smack me down and gum up my ears when pushed... momma says run em both into a load bank, dial up and even out the output, keep the impedences correct and listen to the harmonic content back on the speakers, and remember the ocolloscope or spectrum analyzer never lies...just the wax in your ears HI!..ss

 

[mike buzzetti]

What you need is a hybrid amp Tubes output with xfrmr but a switching power supply ! light weight but a tube amp ( well kinda light ? )

 

[User474755]

 

[Wasnex]

What you need is a hybrid amp Tubes output with xfrmr but a switching power supply ! light weight but a tube amp ( well kinda light ? )

Example: Peavey VB3. AFAIK, the preamp and output section are all tube, and the graphic EQ is solid state. People usually call this all-tube.

SMPS power supply, 300W, 37lbs.

 

[GretschWretch]

Here's how it was explained to me:

View attachment 4599327

Let's not forget that stereo watts are better than mono watts. A drummer told me.