What is the difference in amps

[stl1cjg]

1st off I've looked and cannot find this subject on 1 thread.

Whats the difference between solid state, tube, integrated, etc amps? Is there that much difference between a $1500 HT AVR and a 5 channel amp ($4000 mac)? What is the preference for mostly hometheater with 25% music.

I may sound stupid, but before I go and blow 10,000 on my HT, I'd like to know what the hell the difference is. So I don't get sucked into buying stuff I don't need.

 

[ParadigmDawg]

Here is a link on amp classifications. Not the best one I have seen but it will work.
http://www.moodym.com/audio/ampclass.html

In my opinion, amps are easy (if you even need one, most AVRs will run typical HT speakers) if you care about looks, get a mod priced consumer amp like outlaw, parasound, rotel, Emo. If you only care about power, get a pro amp like Behringer or Yamaha. If you have a lot of money, get a BAT or Classe.

 

[Adam]

Good info and advice, P-Dawg.

I'll add that a "regular" amplifier is a component that will take a signal and amplify it (and that's normally all it will do), and an integrated amp is an amp that also has a gain (i.e. volume) control and sometimes allows multiple inputs and has a way to select which input to play.

 

[DD66000]

There can be big difference between amps, with the same rated power, as far as their true power. Some companies really over state the power output, while other amps can be under rated.
And then there's the room its being used in and efficiency of the speakers used. Its true that most AVRs will run most speakers.
But the more power you provide, will give a much better presentation during dynamic passages of the recording, more like "being there" instead of listening to a recording.

 

[jliedeka]

Tube amps have two advantages, the distortion they produce tends to be lower even harmonics (which has a less objectionable sound) and they clip more gently. The other side of that is almost all amplifiers have distortion below audible levels and if used within their proper range, shouldn't clip.

IMHO, there's no useful advantage to a tube amp unless you have excess cash you need to divest yourself of.

As far a power goes, it's hard to know based on manufacturer specs how powerful an amp really is. My opinion is that if you think you will need the power, buy 50% more, that will compensate for any fudge factors.

Jim

 

[Mika75]

I may sound stupid, but before I go and blow 10,000 on my HT, I'd like to know what the hell the difference is. So I don't get sucked into buying stuff I don't need.

Speakers and the room u use are where u need to be thinking.... & how loud do u want it to be when the walls come caving in

Maybe start a thread about ur future system & the budget u want to work within

 

[WmAx]

1st off I've looked and cannot find this subject on 1 thread.

Whats the difference between solid state, tube, integrated, etc amps? Is there that much difference between a $1500 HT AVR and a 5 channel amp ($4000 mac)? What is the preference for mostly hometheater with 25% music.

I may sound stupid, but before I go and blow 10,000 on my HT, I'd like to know what the hell the difference is. So I don't get sucked into buying stuff I don't need.

Frankly, high end amps are nothing special. They just look fancy. Some actually have very poor performance. Tube amps are not what you want if you want transparent amplification. Tube amps typically modify the frequency response and some create audible levels of distortion, especially SET tube amps.

A very high grade performance option with very reasonble cost is to use professional audio amplifiers. The pro sector is very competitive. And the devices have to stand up to heavy/demanding use. The result is high power, very well made amplifiers that can drive just about anything. I personally recommend and use the Yamaha PxxxxS series, like the P2500S and P3500S. Superb, high SNR, no fan noise(many pro amps have fans that always run) and the rack mount tabs come off for home use(many pro amps don't have removable rack tabs). These amps only do one thing: transparently amplify the signal.

-Chris

 

[lsiberian]

If you have 10,000 to spend. I want to make sure you are using Front Projection system if possible. I see no reason to have 10,000 in home theater equipment on even a 50" display. IMO Picture size is very important. Far more than a person realizes in the store. It really shows up when you are watching a movie. If you have picture immersion. Then you can start looking at a home theater system.

I just want to make sure your display part is taken care of.

To be honest I think most people can be satisfied for far less. Especially with a DIY option.

 

[DD66000]

If you have 10,000 to spend. I want to make sure you are using Front Projection system if possible. I see no reason to have 10,000 in home theater equipment on even a 50" display. IMO Picture size is very important. Far more than a person realizes in the store. It really shows up when you are watching a movie. If you have picture immersion. Then you can start looking at a home theater system.

I just want to make sure your display part is taken care of.

To be honest I think most people can be satisfied for far less. Especially with a DIY option.

Picture size is important, but I've seen many HT where the screen was too large for the width of the room. As in then the only place for the main L/R speakers were in the corners, as there was only 12~15" between the sides of the screen and the side walls. The result was a narrow and pinched soundstage.
But that's just me, I'd always spend more on the audio than the video. But screen size I wouldn't do less than 65".

 

[mtrycrafts]

..., especially SET tube amps.

...-Chris

But that would remind the listener of listening to a vinyl

 

[LAURIE4]

whats 90 watts rms per channel in class a/b mean? 15 watts rms per channel in pure class a. isn't this contriditory

 

[DD66000]

whats 90 watts rms per channel in class a/b mean? 15 watts rms per channel in pure class a. isn't this contriditory

Class A amplifcation is always limited in its output, compared to A/B. People use class A when they want to really sit and listen to the music.

 

[no. 5]

But that would remind the listener of listening to a vinyl

Well, that would make the music more pure...

 

[highfigh]

whats 90 watts rms per channel in class a/b mean? 15 watts rms per channel in pure class a. isn't this contriditory

Read the tutorial on amplifier classes or go to the link:
http://en.wikipedia.org/wiki/Electronic_amplifier

Class A is the least efficient but it's also one of the cleanest designs. A Class A amp's output devices are on 100% of the time until the point of cutoff, where they clip badly. Class AB often runs in Class A until a certain voltage and in Class B afterward. The amplifier classes were determined before transistors and you can find this type in either form. A Class A amp is deceptively powerful. Pioneer had a 30W/ch Class A amp in the early '80s that kicked the crap out of many amps that were more powerful. As long as an amp is run in its linear zone and not into clipping, it will sound fine unless, as in the case of a transformer-coupled design, the load is of incorrect impedance.

Also, regarding tubes- many tube amps color the sound because of the output transformers not being suited for wide bandwidth. The tube circuit itself can do very high frequencies but once the output is coupled to the speakers through the transformer, the wheels can fall off if the amp designer opts for a less than stellar transformer based on price, not performance. As far as distortion, many good tube amps fall below 1% THD at rated output and this is inaudible. Anyone who listens to vinyl is hearing more than 2.5% at all volumes and as wonderful as some people think that format sounds, it's far from the cleanest we have.

 

[WmAx]

People use class A when they want to really sit and listen to the music.

So, a class A/B amplifier is not suited for these people?

-Chris

 

[WmAx]

A Class A amp is deceptively powerful. Pioneer had a 30W/ch Class A amp in the early '80s that kicked the crap out of many amps that were more powerful. .

30 watts is 30 watts. The only way an unexpected result would occur is if in fact the power was under-rated from actual in one case, or inversely, power was over-rated in another case, causing the skewed result.

-Chris

 

[jliedeka]

Actually, I think class A/B is like class B only with more overlap. Class B spends half time with the positive side and half time with the negative side so it's only biasing half the transistors at any given time. The switchover can lead to crossover distortion. Class A/B and variants (class G and H) leave some overlap to avoid the crossover distortion. They are slightly less efficient than class B but tend to sound better.

I hope I said that right, I'm not an expert on amplifier topologies.

Jim

 

[WmAx]

Actually, I think class A/B is like class B only with more overlap. Class B spends half time with the positive side and half time with the negative side so it's only biasing half the transistors at any given time. The switchover can lead to crossover distortion. Class A/B and variants (class G and H) leave some overlap to avoid the crossover distortion. They are slightly less efficient than class B but tend to sound better.

I hope I said that right, I'm not an expert on amplifier topologies.

Jim

Crossover distortion has not been an issue for decades, in properly designed/operating devices. Sure, you can probably find some random, very poor examples, but this would be limited to very rare cases where such problem existed anywhere near a threshold that is audible.

-Chris

 

[DD66000]

Crossover distortion has not been an issue for decades, in properly designed/operating devices. Sure, you can probably find some random, very poor examples, but this would be limited to very rare cases where such problem existed anywhere near a threshold that is audible.

-Chris

Actually, in a typical crossover when the signal crosses the dielectric zero point of the caps there is a slight phase shift, which is in fact distortion.

The way to get around that is to apply a bias voltage to the caps. The way JBL does it with their $15K, $30K speakers (K2, Everest II) is built charge-coupled crossovers. These have series capacitor pairs, to which a 9v battery is connected, through 6 megohm resistors, to all the common points of the cap pairs. That keeps the signal from crossing the zero point, thus eliminating the phase shift.

That is also the basic difference between a class A amp and a class B amp, the way I understand it.