Class D amps weaker than A/B?

#21
jwindham said:
In my experience with both AB & D versions of the Markbass LMII/III, I found the Class D LMIII version did not quite feel as taught/firm under my own fingers vs the older AB LMII/IIIs. My guess is its likely something to do with how the different power sections 'control' the speakers. I especially noticed that the class D LMIII ran out of steam rather quickly when turning up the volume powering an 8ohm cab. However, at 4ohms I found the LMIII to have plenty of power, though it still had a slightly "looser" feel to the sound vs the class AB models. In theory, the preamps of both AB/D LMII/IIIs are the same.

That said, I think the Class D LMIII may actually go a bit "louder" (but perhaps with less definition) than the AB LMII/III at 4 ohms. It seems that is where the Class D LMIII is at its strongest, with the most headroom. Just my observations...I still prefer the older AB LMII/III, as the sound comes across as a bit thicker/denser, less wide/clinical, to my ears. Also note, my observations are very specific to the LMII/III series, and the implementation of Class D in this particular model. Markbass also designs their own power modules unique to the industry standard ICE modules. Of course, any one amp, of any amplifier class, should be evaluated based on its own design merits & user experience. For example, the 800 watt module used in the current LMT800 seems to have quite a bit more clean headroom than the current LMIII at 8ohms.

Ive played many different lead sled and micro amps, and feel design/implementation can make a world of difference. Heavier does not always equal louder, smoother, or more defined bass either. Ive played a few "lead sleds" that didn't quite deliver upon expectation. However, the best of the AB amps Ive played certainly had plenty of headroom, presence, and definition that is very compelling. Overall, modern Class D modules- and more importantly, how they are implemented- continue to improve to the benefit of many bass players. But, I think its important to choose amps based on one's own ears and experience, rather than just looking at the specs.
Click to expand...
That's what he feels too. So he's not the only one though...
 
  • Like
Reactions: murphy and jwindham
#22
It is in what you are comparing it to.

There are A/B's that are better than other A/B's, are people blaming the class of power amp?

There just are some D's that are better than other D's, and some D's are better than some A/B's and some A/B's are better than some D's. Do not forget that some A/B's are Better than other A/B's

It is more than the class of power amp.
 
  • Like
Reactions: tshapiro, Bassdirty, Old Garage-Bander and 3 others
#23
S-Bigbottom said:
It is in what you are comparing it to.

There are A/B's that are better than other A/B's, are people blaming the class of power amp?

There just are some D's that are better than other D's, and some D's are better than some A/B's and some A/B's are better than some D's. Do not forget that some A/B's are Better than other A/B's

It is more than the class of power amp.
Click to expand...

Very true, and of course, it's still a very personal, subjective thing when comparing across different brands and amplifier class. Speaker choice, efficiency and tonal pairing also plays a huge role in how we hear and feel different amps. Often, a good way to determine what will work for a player is to actually use his/her amp/cab selection "out in the field" to see how it performs. In my experience, what may sound loud enough at a music shop, at home, or played solo may not always work as well in the mix at rehearsal or on the gig.
 
  • Like
Reactions: S-Bigbottom
#28
Old Garage-Bander said:
The class of the amplifier by itself is not the primary factor.
This all has to do with how we perceive different harmonics.

You can implement Class A/B as tube or solid state.
The first solid state Class A/B amps used N or P channel discrete transistors.
The class designations A through C are based on the conduction angles of the amplifying device, not what type of device is used to amplify the signal.

Class D can be implemented as discrete N or P channel transistors though it more commonly uses MOSFETS.
It could even be implemented with tubes, though it would be highly impractical.

To say that one class of amplifier is better, or weaker, or whatever you want to attribute to it, than another, based solely on the class of the amplifier, would be an incorrect statement.
If someone is comparing a tube amp to a Class D amp and assumes that tube always means A/B then they are comparing apples to oranges. The correct comparison would be tube vs solid state.

Tube amps treat harmonics differently than solid state amps. And it's the harmonics that give us the perception that one type of amp may be better sounding or louder. It depends on how you play. In a clean amp, there won't be much difference. But if you use a lot of overdrive (generate lots of harmonics) you may hear differences in how the different amps sound because of how each type generates harmonics, handles distortion.

As far as power is concerned, 500 watts, is 500 watts, is 500 watts. It doesn't matter if it's so called "tube watts" or not. By measurement a 500 watt tube amp is the same as a 500 watt SS amp. What does matter is how an amp sounds to you with the way you play. When you compare the rated power output of two amps, be sure that they are both running the same amount of distortion. Added distortion can make an amp sound louder.

A 500 watt amp operating at 10% distortion (heavy overdrive) will be louder than a 500 watt amp at 1% distortion (clean). Furthermore if the harmonic content of that distortion is more pleasing to you you, it will seem to you to be a better amp.

If you like the sound of tube amps better than solid state, by all means play tube amps. You like what you like and ther's no denying that. If a solid state amp is the right tool for you, then that's your go to amp. But let's try to get past this "A/B is louder, better, more powerful" because it is A/B.
Click to expand...

Can we sticky this post?
 
  • Like
Reactions: agedhorse, jwindham and BadExample
#29
birminghambass said:
I've owned/ gigged class D heads from 5 different manufacturers. None had the power or "heft" of my GK 700rb2 (despite being rated for more watts). Not saying it's a fault of class D amps, but it was enough experience for me to stick with my monsterously heavy 18lb amp.
Click to expand...

If it's heft you're going for, you should get an SVT. That'll be 5X the heft of that puny GK. :roflmao:
 
  • Like
Reactions: eff-clef, wncBass, zoonose and 3 others
#32
TB RECORD BREAKER! Well over a page of amp class discussion and no forum rage!

Kudos to all who have participated with well though out answers and civility. I hope WW3 doesn't break out before I hit reply :laugh::roflmao::laugh:

baxter_x said:
So it can be the preamp driving the power section or the power section itself? It's up to the maker?
Click to expand...

I'm a hack, but my 2 cents: Either, And, Or and Plus :D Of course you already know of ways to distort the signal before it ever reaches the preamp. Also a hot signal into the preamp can cause it to distort (can usually be controlled some by the gain knob if the preamp has one). The amp section can be designed to distort and to handle the distortion. Then the elephant in the room, the speaker cab. Hopefully the poor speaker is not distorting with the massive clipping many of us enjoy, but what goes in is not what comes out in an MI cab. If the cab did not distort the signal, they would all sound the same and one could stick any speaker in a box and be done. I think the cab distortion (of value) would be primarily be changes in amplitude vs. frequency and some wave shape changes, like a natural taming of fast spikes. Then the elephant in the room sits in the belly of a whale, which is the room itself. The room is usually out of our control, but we might have a choice of cab placement in the room. I'm a hack, so I yield to the more knowledgeable who call bull dookie on my thots :D
el murdoque said:
OP, you and your friend should rig up a setup that allows you to A/B a class-D vs. a class A/B amp.
Click to expand...
Ohhh that gives me a dyslexic headache!!! :D
 
  • Like
Reactions: BillMason
#33
lug said:
I recently compared an Orange bass amp to my Gorilla combo. My conclusion? Amps that are orange in color sound much better than amps that are black. Case closed.
Click to expand...
Brother lug, you are making me question my own hearing with these facts. I have two amps. One is dark red with white text and a black case. The other is kind of gun metal black (a couple of shades) and some blue, white text.

Which one sounds better?

How do I know for sure?

:D :D :D
 
  • Like
Reactions: mikewalker, LYNCHMAN and agedhorse
#34
BadExample said:
TB RECORD BREAKER! Well over a page of amp class discussion and no forum rage!

Kudos to all who have participated with well though out answers and civility. I hope WW3 doesn't break out before I hit reply :laugh::roflmao::laugh:



I'm a hack, but my 2 cents: Either, And, Or and Plus :D Of course you already know of ways to distort the signal before it ever reaches the preamp. Also a hot signal into the preamp can cause it to distort (can usually be controlled some by the gain knob if the preamp has one). The amp section can be designed to distort and to handle the distortion. Then the elephant in the room, the speaker cab. Hopefully the poor speaker is not distorting with the massive clipping many of us enjoy, but what goes in is not what comes out in an MI cab. If the cab did not distort the signal, they would all sound the same and one could stick any speaker in a box and be done. I think the cab distortion (of value) would be primarily be changes in amplitude vs. frequency and some wave shape changes, like a natural taming of fast spikes. Then the elephant in the room sits in the belly of a whale, which is the room itself. The room is usually out of our control, but we might have a choice of cab placement in the room. I'm a hack, so I yield to the more knowledgeable who call bull dookie on my thots :D

Ohhh that gives me a dyslexic headache!!! :D
Click to expand...
I lost a spelling bee once because I misspelled Lysdexic. :whistle:
 
  • Like
Reactions: agedhorse, BadExample and BillMason
#35
BadExample said:
Brother lug, you are making me question my own hearing with these facts. I have two amps. One is dark red with white text and a black case. The other is kind of gun metal black (a couple of shades) and some blue, white text.

Which one sounds better?

How do I know for sure?

:D :D :D
Click to expand...
When in doubt about rating amplifiers by their color, use the resistor color code.
Black is zero, so lowest rating.
Orange is a three, not bad, better than zero.

Red (2), White (9) Black (0)
Mix it all together and you have dark pink. ***! There's no Pink in the color code. That amp won't work.

Gun Metal Black? If it were GM Grey that would be an 8, Blue is a 6 and again White is 9 so even with the GMBlack this should Rock big time. But it all depends on how much if each color is involved.

The scale works backwards in on the other side of 50/50 World.
 
  • Like
Reactions: mikewalker, BadExample and lug
#37
90 percent of the time, I play an all class A rig - my pedalboard and the mixer that feeds my ears. I assume the house PA and subs are Class D, but I don't hear much of that (I do feel the subs, though). The other 10 percent of the time, the rig I play (it only has to keep up with an acoustic piano) doesn't come anywyhere near clipping (or the point at which an A/B amp would switch from Class A to B), so any amplification class would do, so long as it'll put out a few watts (maybe 10 at some points).

Since I don't get to the point where the class of amplification would make a difference, I use a class D amp (weight), but I bring 2. I had one class D head die, but thankfully it wasn't at the gig - it made it through the gig, but didn't power up the next day. So, rather than a 5 pound amp, I effectively have a 10 pounder - I can live with that.
 
#40
birminghambass said:
OP, tell you friend he is wrong and that his opinion is not welcome on TB. Real world experience is no match for the wisdom of those on internet forums.
Click to expand...
His friend might simply prefer the voicing of the amps that happen to have class AB power sections. Opinions don't have to be based in fact (or reality for that matter). When presented as opinions, no problem. When presented as fact, I think that's what many folks object to.

Like saying a P bass is better than a J bass... factually that's not true but it may be an opinion based on a particular player's own preferences (which is his opinion).
 
  • Like
Reactions: eff-clef, RoketRdr, Thorsoundcore and 9 others
You must log in or register to reply here.
Top Bottom
Back