Class D "digital" amps. Opinions on performance

[seamonkey]

There are a lot of guys in the world of large PA systems who would disagree entirely with these statements. They will claim that amplifiers do not all sound the same and there are many blind tests to prove it. It's not so much about the class of the amps either. [Invalid or Expired Link Removed] example of a guy's review on amplifiers that describes how he thinks most of them have different sound qualities.

There are a lot of pro-sound engineers that know better. Double blind tests prove that there are not perceptible differences.

 

[Munjibunga]

There are a lot of pro-sound engineers that know better. Double blind tests prove that there are not perceptible differences.

It still gets down to the fact that even if there are measurable differences they will be imperceptible in practical applications (live gigs).

 

[nozkcb]

Tried several class D amps. Bought the Aguilar Tone Hammer 500. From low A up, it was pretty darn good, however, for whatever reason the articulation of lower notes got mushy to my ears. I tried a few different cabs and ruled out speakers then came to the conclusion that even the best class D amp I thought I liked got a little bit funny with low notes....that is however with the exception of my Markbass Combo Head II. While it's not as warm sounding as my Aguilar was, the integrity of the lower than A notes stay quite solid in fact it holds up well with my 5 string basses all the way down to B.

And while the Markbass is not as warm and full as my Aguilar DB 750 or my Thunderfunk 550, for the weight and stability, it's still the top of my list.

 

[Jeff Scott]

Tried several class D amps. Bought the Aguilar Tone Hammer 500. From low A up, it was pretty darn good, however, for whatever reason the articulation of lower notes got mushy to my ears. I tried a few different cabs and ruled out speakers then came to the conclusion that even the best class D amp I thought I liked got a little bit funny with low notes....that is however with the exception of my Markbass Combo Head II. While it's not as warm sounding as my Aguilar was, the integrity of the lower than A notes stay quite solid in fact it holds up well with my 5 string basses all the way down to B.

That does not match my experience with the amp. Sometimes I tune my low B down to A or even G, occasionally, and every note sounds well defined and clear, so long as I do not bash on the B string when tuned down like that (A is usually not a problem, just when tuned below that).

 

[Bob Lee (QSC)]

There are a lot of pro-sound engineers that know better. Double blind tests prove that there are not perceptible differences.

True. Also, Langston Holland knows how to compare amps and cannot truthfully be characterized as one of the guys who thinks "all amps sound different." His review of power amps, if you read it entirely, is a lot more nuanced than that; when he finds differences in performance he actually finds out why and under what circumstances it happens.

 

[KJung]

Tried several class D amps. Bought the Aguilar Tone Hammer 500. From low A up, it was pretty darn good, however, for whatever reason the articulation of lower notes got mushy to my ears. I tried a few different cabs and ruled out speakers then came to the conclusion that even the best class D amp I thought I liked got a little bit funny with low notes....that is however with the exception of my Markbass Combo Head II. While it's not as warm sounding as my Aguilar was, the integrity of the lower than A notes stay quite solid in fact it holds up well with my 5 string basses all the way down to B.

And while the Markbass is not as warm and full as my Aguilar DB 750 or my Thunderfunk 550, for the weight and stability, it's still the top of my list.

What you are hearing is the preamp, which is designed to be a bit chewy and fat. The Tonehammer pre will sound relatively similar through any power amp you want to drive with it. Has nothing do to with the power section topology, but it does sound quite different from the LMII.

If you want to hear a low end that will smoke most amps, regardless of topology, try the Class D Glockenklang Bliue Soul. It is all about voicing choices and the quality of the execution and design.

 

[Munjibunga]

If you want to hear a low end that will smoke most amps, regardless of topology, try the Class D Glockenklang Blue Soul. It is all about voicing choices and the quality of the execution and design.

Yeah, especially if you goose that 60 Hz bass control.

 

[chicago_mike]

After fixing so many bass amps over the years, power amps, consoles, you name it,,,everything about the amp makes up the sound. Even the output transistors.

A Sanken 2SC3264 will have a different tonal quality to an IRFP460. Is one better? That depends on what you want. I prefer the Sanken. But then Im using ears that do have a little permanent ringing..so...eff it.

Same with a ss preamp vs. tube..what do you want?

the driver / inverter stage even adds, or takes away freq response wich causes "tonal differences".

Two of my fav. sounding preamps are the old Quad Eight console strips and the preamps in a 1969 3M M79.

Oh heck, gear is gear. Don;t worry if you love an amp that someone else hates.

Just live and play.

 

[Jeff Scott]

..what do you want?

 

[chicago_mike]

If I was him I'd want a tan and a hair cut...

 

[Vince Klortho]

True. Also, Langston Holland knows how to compare amps and cannot truthfully be characterized as one of the guys who thinks "all amps sound different." His review of power amps, if you read it entirely, is a lot more nuanced than that; when he finds differences in performance he actually finds out why and under what circumstances it happens.

I disagree. I read all of his reviews of those power amps and other reviews and he often comments on the sound quality of amps. Here are excerpts from the thread linked to previously :

Alluded to earlier, this is simply the best sounding professional amplifier I've ever heard. It's a class H design and somehow manages to reveal the most subtle details in high-end recordings with earphone clarity over (excellent) loudspeakers. To date I've yet to hear a class D variant (including the following amps) that can present the width and depth of a recording anywhere near as well.

Sound is much better than average for class D - about equal with the PL380, though a more forward sounding midrange.

Most reviews I have read of power amps has a description of its sound quality. At this site they review many amplifiers and every one I looked at has a section on the sound quality of the amp. It is obvious to me that many people think amplifiers sound different. It is also obvious to me that not everyone can hear any differences but I don't think that means there aren't any.

 

[Bob Lee (QSC)]

If you get to know his amp evaluations better, you will probably understand what I mean.

 

[MAMMOTHvolume]

class d works great for bass as high end isn't critical. Theres a reason you don't see it a lot in hifi

 

[KJung]

class d works great for bass as high end isn't critical. Theres a reason you don't see it a lot in hifi

What God help us. Virtually every major front of house system and top of the line DJ system is powered by class D/SMPS amps these days.

 

[fdeck]

The audiophile verbiage in those reviews doesn't give one great cause for optimism.

 

[JimmyM]

What God help us. Virtually every major front of house system and top of the line DJ system is powered by class D/SMPS amps these days.

I've talked to a lot of soundmen about them, and the majority seem to agree that they do work well and make roadwork a lot easier, but I hear the same thing out of a lot of them that I hear out of many bass players...if you're used to a certain amount of wattage in a lead sled, you will want to overbuy class D wattage to have that level of headroom. I've also heard from a handful of holdouts that they don't like the sound of class D power amps. With all due respect to Bob and the other folks who build power amps, these guys hear differences enough to hold onto their lead sleds and put up with the schlep. Granted, they're not doing arenas usually, and that would likely change their minds, but I think there's enough testimony out there from soundmen to believe there's something to it. Not a single one complains about neos, though

 

[KJung]

I've talked to a lot of soundmen about them, and the majority seem to agree that they do work well and make roadwork a lot easier, but I hear the same thing out of a lot of them that I hear out of many bass players...if you're used to a certain amount of wattage in a lead sled, you will want to overbuy class D wattage to have that level of headroom. I've also heard from a handful of holdouts that they don't like the sound of class D power amps. With all due respect to Bob and the other folks who build power amps, these guys hear differences enough to hold onto their lead sleds and put up with the schlep. Granted, they're not doing arenas usually, and that would likely change their minds, but I think there's enough testimony out there from soundmen to believe there's something to it. Not a single one complains about neos, though

Have never heard one sound professional state that. None.

 

[JimmyM]

Yep, I'm a total liar. It couldn't have possibly happened if you never heard one say it.

 

[David Jayne]

Yep, I'm a total liar. It couldn't have possibly happened if you never heard one say it.

I'm sure you aren't lying.
Having said that, some sound guys hear with their arms.

 

[KJung]

I'm sure you aren't lying.
Having said that, some sound guys hear with their arms.

Bassists too