Valve Watts

[Little Dragon]

Often read how power created by valves is somehow louder, has anyone ever done some way of gauging that or is it taken on faith? I can't understand how a signal of the same wattage can reach a speaker in such a way as to increase volume.

[Bolo]

The power rating for tube amps is based on a signal without (=with minimal) distortion. When you push the gain beyond the point of distortion you get a lot of sweet sweet volume.

 

There are more forces at work but I think this is the major part (ooh err)

Edited April 25, 2022 by Bolo

[Little Dragon]

Yes but that is the power rating, if two amps were rated at, for example, 250w, some people will claim more volume, at peak, for a tube fed amp.

[BassAdder60]

I’m interested in this 

 

Would a 100w tube amp be as loud as my ABM600 using the same cab ? 

[Bill Fitzmaurice]

A watt is a watt. What differs with valves is that they can naturally compress the signal peaks, subjectively making them seem louder. You can accomplish the same thing more or less with SS using a compressor, but since that occurs before the power output stage rather than in the power output stage the effect isn't quite the same.

[BassAdder60]

My Ampeg SVT CL 300w head was perceivably louder than my ABM600 head.

 

Ive always thought the V4B 100w head would be nice but I fear it hasn’t got the volume for a very loud rock band ( not using PA ) 

[Japhet]

Maybe it's just a matter of perception but I have all valve, hybrid and SS amps. The difference with the all valve head is that volume gain seems to be more linear as you wind it up and stays full and fat sounding with a bit of tube distortion, whereas the hybrid (class D) and SS stuff seems to get more 'shouty' and increasingly brittle sounding. 200 watts of valve power easily keeps up with 600 watts digital or SS. Could well be complete rubbish, but that's how it sounds to me.

[itu]

Ear is not so sensitive to the distortion in the low frequency area. This way the tube compression makes the unit seem (hearm?) louder, although the "more" is produced in the area of distorted output.

 

The same amount of distortion in a solid state amp sounds worse because of the harmonics that are different. They just sound bad. You can find lots of info about this with a little bit of searching.

 

Remember:

Watt is not the same as loudness (expressed in decibels, dB), although they are faintly connected.

Edited April 25, 2022 by itu

[Pentode]

It's all Witchcraft, that's all I can say.....

[Woodinblack]

57 minutes ago, Bill Fitzmaurice said:

You can accomplish the same thing more or less with SS using a compressor, but since that occurs before the power output stage rather than in the power output stage the effect isn't quite the same.

 

But if you did that, you would end up with pages and pages of people ranting about TC Electronics lying about their power output

Oh never mind, deja vu!

 

[Reggaebass]

1 hour ago, BassAdder27 said:

I’m interested in this 

 

Would a 100w tube amp be as loud as my ABM600 using the same cab ? 

I use the V4B with a bb2 and it’s plenty loud I’d say for most standard situations, I’ve also had a lot of Ashdown heads and I’d say the V4 probably isn’t as loud as the ABM 600

Edited April 25, 2022 by Reggaebass

[BassAdder60]

49 minutes ago, Reggaebass said:

I use the V4B with a bb2 and it’s plenty loud I’d say for most standard situations, I’ve also had a lot of Ashdown heads and I’d say the V4 probably isn’t as loud as the ABM 600

Thank you 👍

[warwickhunt]

1 hour ago, BassAdder27 said:

Ive always thought the V4B 100w head would be nice but I fear it hasn’t got the volume for a very loud rock band ( not using PA ) 

 

I play in a loud rock covers band which regularly (nearly always) gigs without me using our PA to support the bass.  I had in my possession at the same time: Handbox WB100 (120w) all valve, EBS HD350 (350w) solid state, TC Staccato (350w) class D, Thunderfunk 550 solid state and a Tech Soundsystems Blackcat (1000w) valve pre / class D power.  I would happily (genuinely happy) gig the Handbox as I would any of the other amps with regards to being heard in a loud band.  

 

As an aside I have an Ashdown 120w SS combo which runs out of steam even when playing with an amplified acoustic band BUT the speaker in the combo could equally be the limiting factor.  Saying that I'd have no faith in using a solid state amp of less than 250/350 with my rock covers band.  

[ikay]

1 hour ago, warwickhunt said:

I would happily (genuinely happy) gig the Handbox as I would any of the other amps with regards to being heard in a loud band.  

Out of interest, what speaker set up were you using with the Handbox?

[warwickhunt]

20 minutes ago, ikay said:

Out of interest, what speaker set up were you using with the Handbox?

 

I have either a pair of TC RS210 cabs (never gigged with a single as the band are loud) or a TKS 115 / TKS 112 (x2).  Sounded equally good with either the TC or TKS though I preferred it with TC cabs, it tended to self compress (is that an actual thing) and fatten up even more than any combination of the TKS cabs (obvs couldn't gig all 3 TKS cabs).  

[ikay]

Thanks warwickhunt for the cab info.

Edited April 25, 2022 by ikay

[ossyrocks]

Does anyone gig a Bassman 50, I’m genuinely interested?

[Downunderwonder]

Mathematically it is easily observable. Power is proportional with voltage².

The voltage average increases with distortion while the peaks are clipped.

Hence the lower average same peak voltage undistorted signal plotted over time has less power.

 

If solid state and valve amps have the same clean RMS rating there won't be any difference in loudness until the valve amp is cranked past its clean rating.

 

Cranked tubes usually sound nice with high levels of distortion while cranked transistors often struggle.

 

Some famous SS amps have done a good job of overdriven tones. Some even do it in the power stage. So it's not a perfect rule but safe to say a lot of extra clever electronics is between the bass preamp and the final output when an overdriven solid state amp doesn't sound like derrière, but you could get a useful tone out of your grandma's old tube gramophone amp.

[Bill Fitzmaurice]

3 hours ago, ossyrocks said:

Does anyone gig a Bassman 50, I’m genuinely interested?

I did, from 1965-1972. I could see using one today in the studio, or for small club gigs, but that's all. As far as vintage valve gear is concerned the Ampeg V4B is considerably better.

[BassmanPaul]

14 hours ago, Bill Fitzmaurice said:

I did, from 1965-1972. I could see using one today in the studio, or for small club gigs, but that's all. As far as vintage valve gear is concerned the Ampeg V4B is considerably better.

 

As did I. A lovely Blonde blackface Bassman and it's matching twin 12 in late 1968. It lasted a weekend before I could return it. I still get nightmares about it. The worst amplifier I ever had the misfortune to play through.

[AScheck9]

I play a fender bassman 100t. 100w all valve, played through a barefaced big twin 2. It easily keeps up with a rock band, without PA support, in a pub/small club.

 

I have also had a Genz Benz Strml900 and currently own a 600watt GSS baby sumo. The 600 watt sumo doesn't compare, even when pushed with a preamp, but the streamliner was probably on par with the bassman.  

 

I even gigged once with it in 25watt mode. It just about kept up with the band, but there was zero headroom.

[Stub Mandrel]

There are two things that are forgotten every time this debate comes up:

 

1    A tenfold increase in power only doubles perceived loudness. A 1000 watt amp is only twice as loud as a 100 watt amp, all other things being equal (and they rarely are). The difference between a 100 and 200 watt amp is real but modest.

 

2   Distorted sounds are perceived as louder. Think of how you set your pedal so clean and distorted sounds are the same loudness, then you use it with the band playing and the distorted sound disappears. That overdriven valve sound is perceived as louder than it really is. https://derby.openrepository.com/handle/10545/583125

 

Also, speaker efficiency makes a big difference. The Barefaced Big Twin mentioned above is 100dB, a boost over most setups (it's marginally more sensitive than an SVT 8x10 so it will sound noticeably louder than most 2x12 or 4x10 cabs.).

[itu]

@Stub Mandrel writes stuff that should be founded easily from some place here. Likewise we already have detailed IEM handbook by @EBS_freak

Do you all think there should be a place here with writings of the basic things we are asked on a monthly basis?

[Lozz196]

2 - Distorted sounds are perceived as louder.

 

Definitely, I usually have the valve drive on my ABM600 on but in our rehearsal rooms which have 810s I have to take it all the way off otherwise the bass is overpowering. It just fills out and swallows up the whole room. 

[BassAdder60]

7 minutes ago, Lozz196 said:

2 - Distorted sounds are perceived as louder.

 

Definitely, I usually have the valve drive on my ABM600 on but in our rehearsal rooms which have 810s I have to take it all the way off otherwise the bass is overpowering. It just fills out and swallows up the whole room. 

Just out of interest where do you set your valve drive level ?