Will an AB Power amp work well with a Pre for DTS Master Audio

[rkumarblr]

Hi,

Will the older class AB amps work well to support the dynamic of Master Audio and Dolby True HD ?

I would like to know if a class AB multi channel power amp (example Sherbourn, Anthem or Parasound) will work well with a pre-processor that supports Master Audio and Dolby True HD (example Rotel RSP 1580 or RSP 1582)

Most of the power amps these days are Class D for reasons of efficiency.
Is the class D got anything to do with audio dynamic that comes the above audio formats.

The primary question is of ability to truly reproduce Master Audio and Dolby True HD with class AB
The secondary question of the matching between the above pre and power amps.

Thanks

 

[markw]

Maybe this will help you understand what's going on here.

http://www.audioholics.com/audio-amplifier/amplifier-classes

Read it through and look at the chart.

 

[fmw]

Oddly, the amplifier has no way of knowing what it is reproducing. It has no understanding of dynamics either until it reaches clipping. The design of the amplifier has nothing to do with these things except that it has to be able to provide sufficient current to handle the application.

The class D amp is more efficient. What that means is that it does its job with less current lost to heat. The class D amp will run cooler than an AB amp of the same power rating. It won't produce better results.

 

[j_garcia]

Your question has more to do with what speakers you are using and the acoustics of the room rather than just what you're listening to. The answer to the question you asked isn't going to have as much of an impact on your sound as you seem to think.

 

[highfigh]

Hi,

Will the older class AB amps work well to support the dynamic of Master Audio and Dolby True HD ?

I would like to know if a class AB multi channel power amp (example Sherbourn, Anthem or Parasound) will work well with a pre-processor that supports Master Audio and Dolby True HD (example Rotel RSP 1580 or RSP 1582)

Most of the power amps these days are Class D for reasons of efficiency.
Is the class D got anything to do with audio dynamic that comes the above audio formats.

The primary question is of ability to truly reproduce Master Audio and Dolby True HD with class AB
The secondary question of the matching between the above pre and power amps.

Thanks

Class A, AB, D or any other amplifier class has nothing to do with being matched to a preamp- one has to do with the amp's input and the other has to do with its topology.

Listen to some amplifiers. Buy the one you like. If you're trying to save money over the life of the amp, find something that's extremely reliable and efficient. If you just want to enjoy the music, buy the one that sounds best and is reliable.

This used to be so much easier. The buying decision was based on (the order wasn't an absolute, but this shows what I heard as the common needs):

Sound quality
Power output
Cosmetics
Price

You need to define:
-Listening level- if you'll be listening at high SPL, a low power amp will only be adequate if the speakers are extremely sensitive and the dynamic range is low. OTOH, amplifiers that are capable of high power output may not be pushed hard, but they'll usually have no problem delivering what's needed under most conditions.
-Speaker sensitivity
-Dynamic range of the program material
-Your ability to hear the difference between amplifiers- if you don't hear the difference, don't buy something just because the sales person treats you like a leper and yes, it does happen. Also, don't feel compelled to buy something that's more expensive than you want to spend because of reviews and flowery reviews. If these glowing comments are accompanied by others that tear it apart, look closer or put the model(s) aside for further consideration.

If you can hear the difference, make sure it's not because someone told you what you'd be hearing. That's a common tactic in sales and it's not likely to make you happy with your choice, in the long run. Let them switch between make/model, but let them know you want to hear it for yourself.

 

[fmw]

If you can hear the difference, make sure it's not because someone told you what you'd be hearing. That's a common tactic in sales and it's not likely to make you happy with your choice, in the long run. Let them switch between make/model, but let them know you want to hear it for yourself.

Won't really help. There is no way to understand the existence or lack of audible differences in amplifiers with a sighted comparison that is not level matched. Waste of time. Just buy what makes you happy. They will all amplify.

 

[highfigh]

Won't really help. There is no way to understand the existence or lack of audible differences in amplifiers with a sighted comparison that is not level matched. Waste of time. Just buy what makes you happy. They will all amplify.

Yeah, yeah, heard it before. I have been in the business for 40 years and can recognize differences when I hear and feel them and yes, I feel notes with the Parasound that I don't with the Denon AVR. No EQ or controls being used with either and the speaker positions haven't changed. Different electronics, and there are lots of differences between the two front ends, make for different sounds.

I agree that blind testing is best, but I hear differences. On a certain level, I don't care if I hear a difference, or not- there's nothing that forces me to keep anything I don't like and yes, I like to think I'm making a good buying decision (like anyone else), but when I'm doing critical listening, make, model, price and cosmetics don't mean anything- I'm going for sound, nothing else.

 

[rkumarblr]

Thanks all for the replies. I have a class A (valve amplifier) for my 2 channel audio listening and I can hear a big difference. Its sounds more real and appealing to me.
HT I felt needs to deal with the peaks and lows of the movies (true for some of the music genre as well, but not the ones I listen to often)

I agree the best option is to listen and decide but unfortunately getting gear home to listen is not an option in all places.

From the replies, I am inferring that a quality class AB will go well with a pre for the HD audio formats and that speed and timing will not be an issue.
I do understand that the signal would have been decoded by the time it reaches the power amp.

My speakers are Focal 726 , 49Hz to 28kHz , 91.5db sensitivity and suggested power of Amp between 40 to 250 W.
Room acoustics unfortunately has scope for improvement and is always the challenge at home unless its built for it. Which in most cases isn't.

If any of you have access to information that helps an end user match pre to power from the specs, that would be helpful. I do agree that specs are not always reliable.

Not looking for physic and engineering response but more on the lines of voltage, current that is produced by pre that needs to match the power and if manufactures do provide it in their specs.

Thanks again.

 

[slipperybidness]

Thanks all for the replies. I have a class A (valve amplifier) for my 2 channel audio listening and I can hear a big difference. Its sounds more real and appealing to me.
HT I felt needs to deal with the peaks and lows of the movies (true for some of the music genre as well, but not the ones I listen to often)

I agree the best option is to listen and decide but unfortunately getting gear home to listen is not an option in all places.

From the replies, I am inferring that a quality class AB will go well with a pre for the HD audio formats and that speed and timing will not be an issue.
I do understand that the signal would have been decoded by the time it reaches the power amp.

My speakers are Focal 726 , 49Hz to 28kHz , 91.5db sensitivity and suggested power of Amp between 40 to 250 W.
Room acoustics unfortunately has scope for improvement and is always the challenge at home unless its built for it. Which in most cases isn't.

If any of you have access to information that helps an end user match pre to power from the specs, that would be helpful. I do agree that specs are not always reliable.

Not looking for physic and engineering response but more on the lines of voltage, current that is produced by pre that needs to match the power and if manufactures do provide it in their specs.

Thanks again.

A power amp should have a very high input impedance. The result of high input impedance is that it takes very little current to drive the input stage. In other words, your statement "current that is produced by pre that needs to match the power and if manufactures do provide it in their specs" is mis-guided.

In general, buy a pre-amp, buy a power amp, hook them up, and listen to music! You MAY run into problems if you are trying to mix and match gear intended for home audio and pro audio.

In general, the specs that you need to look at for matching the pre to the amp would be:
*The maximum output voltage of the pre
*The sensitivity of the amp inputs (ie how much input voltage will drive the amp to full output)
*Is the pre-amp Vout capable of reaching the amp Vin for max output?

To put it in technical language, it is the overall system Voltage Gain Stucture (Av) that is important to answer your questions.

 

[rkumarblr]

In general, the specs that you need to look at for matching the pre to the amp would be:
*The maximum output voltage of the pre
*The sensitivity of the amp inputs (ie how much input voltage will drive the amp to full output)
*Is the pre-amp Vout capable of reaching the amp Vin for max output?

To put it in technical language, it is the overall system Voltage Gain Stucture (Av) that is important to answer your questions.

Thanks, My bad its more about voltage and gain.
The issue is, I do not understand enough to to know if the following are well matched as a pre and power from the specs.

If you or anyone on the forum does, the help is very much appreciated

The Sherbourn 7-150 (power amp) gives the following specs
150 watts per channel (x7) at 8 Ohms (with no more than 0.05% THD from 20 Hz to 20 kHz, all channels driven) , 220 watts per channel (x7) at 4 Ohms (with no more than 0.05% THD from 20 Hz -- 20 kHz, all channels driven) , Power bandwidth: 5 Hz to 150 kHz , Signal to noise ratio: 110 dB A weighted , Gain 30 dB , Input impedance 40 kOhms , Sensitivity 1.1 volts , Dynamic headroom 1.3 dB

The Rotel 1069 (Pre-process) has the following specs
S/N (IHF A-weighted) 95db (analog bypass), 92db(Dolby, dts) 0dbFs
Input Sensitivity/Impedance Lim Level 200 mV/100K Ohms
Peramp Output Level/Output Impedance 1.0V/1K Ohms

Are they a good match as a pre and power ?
How to tell form the spec ?
Knowing this will help match my existing Pre (the Rotel) with a AB processor like a Sherbourn.

I am aware that the Rotel RSP 1069 can not process HD Audio.
I am researching if a source player that does can process and have the pre pass through that to the power.
But is a different topic. So will post that independently.