Class D Amps

[Goldy13]

I'm not much of a "gear head"

Is Class D a "step down" from Class A or Linear amps? Can somebody explain the difference in layman's terms?

I currently have an SVT 4 and looking to possibly get a new rig. I was looking at the GK Fusion 1200 and want to make sure that the "Class D" isn't a step down, like less powerful or anything... I would think 1200 watts is 1200 watts. But like I said, not a real gear head.

Thanks for any advice / explanations!

 

[Old Garage-Bander]

Just for clarity sake. The D in class D does not mean digital. Not any more than A in class A means analog.
The amp classifications are just a naming convention agreed upon way before D ever became a thing.
The classifications generally represent how long during a full cycle, a device is conducting a signal.
Class D is a step away from this in the conventional sense, but has nothing to do with analog vs digital signals.
Class D is a solid state architecture. I suppose one could do class D with tubes. Maybe as a PhD thesis project, but otherwise not practical. Note that other classes A, B, AB can be easily implemented either with tubes or transistors, and can be found in instrument amps.
FYI, class C is normally seen in RF applications, used in transmitters from Ham Radio to broadcasting, radar and even some of those scanners at the hospital.

Is it a step up or down is subjective. For some, if it isn't tubes it's a step down. For others it can be up. It depends on your needs and desires. Many of the great, high power bass amps you see on the market use class D technology. Typically, with tubes it becomes impractical to get much more than 300 watts. This is where class D shines. Lot of the main stream manufacturers put a lot into making sure their amps measure up to the good old tube jobs. If people all perceived class D as a downgrade, the companies wouldn't be investing in that technology.

As always, if possible, try out the amp. There are many subtleties between manufacturers of class D amps.

 

[Goldy13]

Thank you for the explanation. That does help.

I've been wanting / trying to check it out. Sadly, Guitar Center isn't what it used to be... Keeping my eyes open though! Thanks again!

 

[agedhorse]

Virtually all power amps used in the pro audio touring world are class D. That industry sees it as a giant step forward. In fact I can’t think of a pro product released in the past 5 years that’s not class D (or TD which is a variant).

 

[Goldy13]

Awesome. Thank you very much!

 

[KohanMike]

I use a Class D Carvin MB15 amp and one of the benefits I find is that the inverter/battery I use with it lasts much longer than a Class A amp.

 

[InkCow]

Is Class D a "step down" from Class A or Linear amps? Can somebody explain the difference in layman's terms?

I just stumbled across this in a different thread a couple of days ago and I thought it did a good job explaining the difference between amplifier classes:

 

[mike buzzetti]

Virtually all power amps used in the pro audio touring world are class D. That industry sees it as a giant step forward. In fact I can’t think of a pro product released in the past 5 years that’s not class D (or TD which is a variant).

I was just reading up on Class TD amps interesting design ! , have you had a chance to A/B a D vs TD amp ?? from some claims they say it is purer ?? but I like the PS tracking the audio design., is anybody making class TD bass amps ?

 

[Killing Floor]

Class D amps are better than linear. D stands for dimensions. They have 3. That's why they don't sound flat.

 

[fdeck]

I just stumbled across this in a different thread a couple of days ago and I thought it did a good job explaining the difference between amplifier classes:

That video has made the rounds. It explains the basics of how the classes work. But the discussion of how amp class relates to audio quality probably doesn't hold up today. He does mention that Class-D amplifiers can now rival other classes, which is the present state of affairs for bass amps.

Today, everything is in the execution. There are good and bad designs of all classes.

 

[InkCow]

That video has made the rounds. It explains the basics of how the classes work. But the discussion of how amp class relates to audio quality probably doesn't hold up today. He does mention that Class-D amplifiers can now rival other classes, which is the present state of affairs for bass amps.

Today, everything is in the execution. There are good and bad designs of all classes.

Sure, it’s worth taking the opinions made in a 4 year old video with a grain of salt, but I felt he laid out the functional distinctions of the classes pretty well, and, more importantly, in a pretty straightforward way. But, yes, not new nor original, but perhaps “new to OP”.

 

[agedhorse]

I was just reading up on Class TD amps interesting design ! , have you had a chance to A/B a D vs TD amp ?? from some claims they say it is purer ?? but I like the PS tracking the audio design., is anybody making class TD bass amps ?

I haven’t been able to tell the difference between the two (with everything else the same).

Class TD was preceded by another continuously modulated rail design, BASH.

 

[mike buzzetti]

I haven’t been able to tell the difference between the two (with everything else the same).

Class TD was preceded by another continuously modulated rail design, BASH.

Ok , thanks , Now I'll have to lookup BASH ! lol

 

[akukulich]

Listen to the amps in as close to a real-world setting as possible. Trust your ears. Don't worry about amp topology. Go with what sounds best to you.

 

[InkCow]

Listen to the amps in as close to a real-world setting as possible. Trust your ears. Don't worry about amp topology. Go with what sounds best to you.

Your back may have a say in it, as well.

 

[mike buzzetti]

Listen to the amps in as close to a real-world setting as possible. Trust your ears. Don't worry about amp topology. Go with what sounds best to you.

Im interested in the new topologies' from a tech idiot standpoint !

 

[Oldbasslover]

1200 watts is 1200 watts, except when it isn’t. Lol
Aged Horse seems to be the guru at the top of the mountain concerning practical, common sense, and many years of actually designing and making these things so always kkep his comments in mind.

I didn’t have the opportunity to test out amps and basically looked at cost and the various subforums for those amps. Keep in mind the amps are going to sound different based on your instruments, your cabs, your pedals, etc, etc, etc so unless you have a standard go-to setup, you might be happy with some setups and not as happy with others. But, from all the hundreds of pages I read, pretty much everybody that is happy with their class D amps can make it sound great to their ears, and people who aren’t happy with the exact same setup can’t make it sound great. To me it seems like the arguments that people have about saying that certain high quality cable is better than other high quality cable.

The obvious great thing about class D amps is their weight. 4 -8 lbs for 700 - 1200 watts!!! Throw it in a gig bag because its small and lightweight.

Final caveat - I’m not a professional carting stuff on the road every day with famous bands. Like advice from aged horse, if you get those folks in the reply chain, probably good to give their opinion more weight. Good luck in your search!

 

[JeezyMcNuggles]

I'm not much of a "gear head"

Is Class D a "step down" from Class A or Linear amps? Can somebody explain the difference in layman's terms?

I currently have an SVT 4 and looking to possibly get a new rig. I was looking at the GK Fusion 1200 and want to make sure that the "Class D" isn't a step down, like less powerful or anything... I would think 1200 watts is 1200 watts. But like I said, not a real gear head.

Thanks for any advice / explanations!

It's just as powerful, but lacks the luster of mosfet. A watt is a watt.

They are notoriously clean. Til they get pushed too hard.

 

[ItsmeSantiago]

It’s subjective for sure. Anecdotally I’ve used good and bad class D amps, but I’ve used less bad class D amps than I have class A. Could be an age thing with the class A rigs I’ve used. Cabs play a role too.

 

[JeezyMcNuggles]

I'm not much of a "gear head"

Is Class D a "step down" from Class A or Linear amps? Can somebody explain the difference in layman's terms?

I currently have an SVT 4 and looking to possibly get a new rig. I was looking at the GK Fusion 1200 and want to make sure that the "Class D" isn't a step down, like less powerful or anything... I would think 1200 watts is 1200 watts. But like I said, not a real gear head.

Thanks for any advice / explanations!

I would call most anything, but a high power tube head, a step down from a 4 pro. I have a 4 pro, I've had a 3 pro, a 7 pro, I've had a v4b, a pf800, and I have a Micro vr.

In order of great to bland:

3 pro, V4b, micro vr, 4 pro, pf800, 7pro


The 3 pro is just about ampeg's best sounding amplifier. Never owned an SVT...yet.

Followed closely by the V4b. The B only comes in second because of the limited EQ. If they had more eq options, you couldn't beat that thing.

The micro vr actually sounds better than the 4 pro. Again though, very limited on features, and power.

4 pro. The do anything great, amplifier. Doesn't quite sound as sweet as the 3, but with 2 600w power sections, and the ability to run two 2 ohm loads, with crossovers, there is nothing it can't do. And it does it great.


Pf800. Clean and funky. Just a little sterile sounding.

7 pro. Just kinda meh. It's clean, it's powerful, it's solid, but the tone from it is just more on the meh side. The 800 just sounds better to me, but they are fairly even in different ways.



If that helps, great. If it doesn't make sense compared to your question, whatever dude.