difference in class a, b and d amps

[southpoleman69 10+ year member]

real quick explanation, dont need a lot of detail, jw whats the difference, if any?

Click to read more...

 

[adam71 5,000+ posts]

This is a pretty simple approach to explain the differences.

http://www.norh.com/docs/amps/

 

[dB-r 10+ year member]

Some very expensive high-end equipment features balanced inputs. Most of these are gimmicks. The reason is that in order to compare the two signals, you literally have to have two amplifiers for every one. What most high-end equipment manufacturers do is they provide balanced connectors (called XLR connectors) and then convert this to a standard signal. The benifity is that it allows you to use XLR connectors instead of RCA connectors. It doesn't offfer the ability to drive longer cables and eliminate noise.

quoted above is from the link.

I love this part.... Gimmics.... if you guys only knew how much BS (captial letters BS for sure) is pushed onto you guys you would shit a brick.

 

[stereo_luver 10+ year member]

Thats some funny shite right threre

 

[adam71 5,000+ posts]

Yep. Another good gimmick is "24 bit". When absolute state of the art sound is 20 bit. The last 4 bits are called "marketing bits".

 

[southpoleman69 10+ year member]

so class d amps really are better than the other classes.

 

[adam71 5,000+ posts]

so class d amps really are better than the other classes.

NOPE!!! They're just more efficient. Class A amps are some of the best sounding amps on the planet. Not to say in the least that full range class d amps can't sound good.

 

[dB-r 10+ year member]

Just my opinion, in SQ the order goes like this from best sounding to worst:

Class A

Class B (or Class AB)

Class G, H, or T (T= Tripath)

Class D

I don't care much for regular class D full range.... Tripath is okay, but only the T, G, or H would sound good with Full range.

A is not practical, and many of the so-called Class A amplifiers out there (Soundstream 10.0 comes to mind) are not true class A all the way. They are Class A operation for the first 8 or 9 watts, after that they are AB. The so-called Class A's are just Class B's that are biased really high so the transistors stay on, but they are not fully on all the time, just on. It really doesn't matter though, I doubt there are many ears that can really tell the difference from AB to A.

 

[gunz4me2 10+ year member]

I am probably going to get blasted for typing this, but, I have noticed that some Class D amplifiers tend to clip hard and fast when compared to most Class AB amplifiers. Granted, the only budget D I tested was late last year and it was a Hifonics 1606d. Basically, that nice, pretty, ocean like sine wave would square off into a saw tooth at the first sign of clipping. My Crossfire BMF1000d exhibited the same clipping characteristic while connected to an oscilloscope. On the other hand, most class ab amplifiers tend to square off gently at the top of the pretty, ocean like sine wave, and slowly turn into a saw tooth from there.

As a result, if anyone asks me for advice regarding a Class D amp, regardless of budget, I always recommend that they go one size higher in power output than they would have normally gone. For example, if someone wants 1000 watts RMS at 1 ohm and asks me which budget amplifier to get, I tell them to get the Hifonics BXi1610d and they are as happy as can be when they get their system dialed in!

 

[dB-r 10+ year member]

Yep, that is a good rule of thumb because of the clipping (hard clipping).

The 1606 is really bad about "sawtoothing".... It will get loud, but it doesn't do alot of unclipped power. I was kinda suprized the first time I put one on the scope, just like you were that it clipped so hard.... I had it running into a 2 ohm load (after rise) so it would probably be better at 1 ohm after rise... But anyway, those amps are history and the new stuff is supposed to be a lot better.... Will be glad when I get to test one... Most recent HiFonics stuff I have played with was 08 models.