Behringer A500 Amplifier: Objective Test Results

[jeffsg4mac]

Guys, I think we have strayed way off topic from A-500's.

 

[jaxvon]

Guys, I think we have strayed way off topic from A-500's.

Aye.

One last point, RE: Stageaxe. I apologize if I came off as an a-hole. To me it seemed like you were another person swearing off science, saying that it has no place in audio. It seems that you were perhaps talking about your own definition of good sound. Of course, I agree with you here. Good music is good music, no matter what it's being played on. What sounds glorious to me might just be ho-hum for you. If your system sounds good to you, that's what matters. However, by making statements such as "The human ear defies science", you will often send the wrong signals, as you did to me. Science has everything to do with great audio. However, it cannot necessarily predict what will sound best to you.

 

[majorloser]

Aye.

One last point, RE: Stageaxe. I apologize if I came off as an a-hole. To me it seemed like you were another person swearing off science, saying that it has no place in audio. It seems that you were perhaps talking about your own definition of good sound. Of course, I agree with you here. Good music is good music, no matter what it's being played on. What sounds glorious to me might just be ho-hum for you. If your system sounds good to you, that's what matters. However, by making statements such as "The human ear defies science", you will often send the wrong signals, as you did to me. Science has everything to do with great audio. However, it cannot necessarily predict what will sound best to you.

Are you sure it didn't come about through "Intelligent Design"?

(I couldn't resist)

 

[jaxvon]

Are you sure it didn't come about through "Intelligent Design"?

(I couldn't resist)

I almost brought it up, but then thought that I didn't want a flame war with those who believe in it.

 

[Soundbroker]

Okay...I just got the new A-500 pricing. Not a huge increase...but the A500 is going up to $199 on Nov 1st. The EP-1500 is going up to $299 and the EP-2500 is going up to $349.

 

[mtrycrafts]

Okay...I just got the new A-500 pricing. Not a huge increase...but the A500 is going up to $199 on Nov 1st. The EP-1500 is going up to $299 and the EP-2500 is going up to $349.

That's 10% on the A500. Not that bad. Still seems to be a great bargain.

6 bridged channels at $1200?

 

[mantol]

I just remember reading that on audiogon. Most of the Krell amps double their power output in going from 8ohm to 4ohm loads. In fact, the Krell amps are about the only ones I've seen that can double their power output when the load is halved.

You are right! That all depends on the design limit. An amplifier rated at max output at the lowest load impedance rating would generally reduce its output power when the load impedance becomes doubled or quadrupled. For instance: given an amp rated at 2000 watts @ 2ohms speaker load. Per channel rating would be 1000 watts @ 2 Ohms load. Maximum power transfer can only be attained if the source impedance equals the load impedance. So if the speaker is only 4 Ohms, the max power transfer will only be halved, i.e. 500 watts. Making it 8 Ohms, only 250 watts can be derived. Never load the amps lower than its limit because you could virtually be shorting out the output. If it is protected, then the power will be tripped off.

 

[mantol]

Okay...I just got the new A-500 pricing. Not a huge increase...but the A500 is going up to $199 on Nov 1st. The EP-1500 is going up to $299 and the EP-2500 is going up to $349.

For all the avid fans of Behringer A500/ or EP model, why not try adding on your rig the UltramizerPro 1424P. Here you can set the limit of the loudness just prior to clipping of your power amp, thus protecting your valuable speakers. Prior to having this model, my 100 watts midrange horn got busted because of the slapping bass guitar, so I bought one. This is another inexpensive but very useful product of Behringer. For bi-amping or tri-amping there are lots of compressor -limiters to choose from to individually protect your speakers also at www.behringer.com. If you want a more sophisticated equipment try UltraDrive Pro DCX 2496.You can also download manuals in PDF.

 

[PENG]

You are right! That all depends on the design limit. An amplifier rated at max output at the lowest load impedance rating would generally reduce its output power when the load impedance becomes doubled or quadrupled. For instance: given an amp rated at 2000 watts @ 2ohms speaker load. Per channel rating would be 1000 watts @ 2 Ohms load. Maximum power transfer can only be attained if the source impedance equals the load impedance. So if the speaker is only 4 Ohms, the max power transfer will only be halved, i.e. 500 watts. Making it 8 Ohms, only 250 watts can be derived. Never load the amps lower than its limit because you could virtually be shorting out the output. If it is protected, then the power will be tripped off.

I would say that this has less to do with the "maximum power transfer" theory. IMHO, it has more to do with the fact that most manufacturers prefer to quote a higher output at 8 ohms because 8 ohm nominal speakers are more common. As a result, their output into 4 ohms cannot double.

Take for example: An amp may specify 100W into 8 ohms, and 150W into 4 ohms. This same manufacturer could choose to specify this same amp as 75W into 8 ohms and 150W into 4 ohms and would therefore appear to have double down capability. In doing so, they would have to under specify their 8 ohm output rating. Krell amps are generally so powerful that they can afford to be conservative with their numbers and their numbers will still be impressive.

 

[mantol]

.....well, I guess it's going to be a little audio heracy straight from Italy....Beppe, I didn't suggest you use the A500 strapped from here on and get another one and do the same with it, but that would be your call....I just wanted to see if you were more pleased with the A500 bridged....I fully expect the thing to heat up with it strapped on 4 ohm speakers which will vary to 2 ohms some.....

.....Krabs, it's about noon, I've been up since the crack of 10, and I'm starting on my fourth gallon of moonshine for the day....just thought you'd like to know....burp.......

Please do not do this injustice to any amplifier. When you are bridging a 2 channel amps, you are actually connecting the two outputs in series so the impedance load should be twice that of a single channel. Subsequently,the load should match the new output impedance which will become 8 ohms with twice the power output of one channel. Lower than this will impose undue strain on either the amplifier or speaker system. Impedance matching and power handling of the speakers is paramount in importance.

 

[mantol]

I would say that this has less to do with the "maximum power transfer" theory. IMHO, it has more to do with the fact that most manufacturers prefer to quote a higher output at 8 ohms because 8 ohm nominal speakers are more common. As a result, their output into 4 ohms cannot double.

Take for example: An amp may specify 100W into 8 ohms, and 150W into 4 ohms. This same manufacturer could choose to specify this same amp as 75W into 8 ohms and 150W into 4 ohms and would therefore appear to have double down capability. In doing so, they would have to under specify their 8 ohm output rating. Krell amps are generally so powerful that they can afford to be conservative with their numbers and their numbers will still be impressive.

You may have a point there but"maximum power transfer" is only basics in all designs whether it be radio-wave power transmission to the antenna, electrical power transmission over a long power lines, or audio power transmission of any amplifier designed specifically to drive a given load impedance. This basic knowledge of impedance matching between load and PA must serve as a guide to any one who is trying to harness the power to maximum efficiency, for it will determine the amount of power transfer you want to achieve or realize.

 

[don maico]

Excuse me jumping in but what is meant by doubling of power into 4 ohms and again into 2 ohms and what effect does that have , on say, an 8 ohms speaker as most seem to be.Does it mean lots more current, better coping with transients and better bass extraction? Most of our Britsish amps dont seem to give figures for 4 let alone 2 ohms and when they do there certainly doesnt appear to be much in the way of doubling. Even the hugely expensive Chord doesnt quite manage this:

http://www.chordelectronics.co.uk/products_detail.asp?id=20
So one has to ask how important is this doubling of power? An amp that is ablle to do this , is it more heavy and with a bigger transformer?

How do the Behringers rate in this regard?

 

[mantol]

Excuse me jumping in but what is meant by doubling of power into 4 ohms and again into 2 ohms and what effect does that have , on say, an 8 ohms speaker as most seem to be.Does it mean lots more current, better coping with transients and better bass extraction? Most of our Britsish amps dont seem to give figures for 4 let alone 2 ohms and when they do there certainly doesnt appear to be much in the way of doubling. Even the hugely expensive Chord doesnt quite manage this:

http://www.chordelectronics.co.uk/products_detail.asp?id=20
So one has to ask how important is this doubling of power? An amp that is ablle to do this , is it more heavy and with a bigger transformer?

How do the Behringers rate in this regard?

Actually, there is no such thing as doubling of power. It is just that the design limit of the amplifier rests upon or is determined by the source impedance of the output stage. The lower the impedance, the more 8 ohms load you can connect in parallel. Most professional PA has a source impedance of 1 or 2 Ohms per channel at the maximum rated power. This only means that if its two ohms for example, you will need to connect in parallel four (4) sets of 8 ohm speakers (8 ohms devided by 4 equals 2 Ohms) in order to attain the maximum rated power output. Of course, the total power handling of the sets should be equal to the rated maximum power output of the PA or greater. Just multiply by 4 the rating of each set of the speakers. The sum should always be equal to the maximum rated power of the amplifier or greater.
If you don't need these much power, you still have the option to use at least 1 set of 8 Ohms speaker for which you can obtain only a quarter of the maximum rated power. Doubling or quadrupling happens only as you add more speakers in parallel, that is so long as the source impedance of the PA would allow it. If the source impedance is high already, say 8 ohms you can never achieve this doubling or quadrupling of power as you add more speakers because of mismatch between the source and load impedance and ohmic saturation imposed by 8 ohms speaker load to the source or amp. Sorry, if I'm getting too technical about my explanation. Hoping you wouldn't mind at all.

 

[don maico]

Actually, there is no such thing as doubling of power. It is just that the design limit of the amplifier rests upon or is determined by the source impedance of the output stage. The lower the impedance, the more 8 ohms load you can connect in parallel. Most professional PA has a source impedance of 1 or 2 Ohms per channel at the maximum rated power. This only means that if its two ohms for example, you will need to connect in parallel four (4) sets of 8 ohm speakers (8 ohms devided by 4 equals 2 Ohms) in order to attain the maximum rated power output. Of course, the total power handling of the sets should be equal to the rated maximum power output of the PA or greater. Just multiply by 4 the rating of each set of the speakers. The sum should always be equal to the maximum rated power of the amplifier or greater.
If you don't need these much power, you still have the option to use at least 1 set of 8 Ohms speaker for which you can obtain only a quarter of the maximum rated power. Doubling or quadrupling happens only as you add more speakers in parallel, that is so long as the source impedance of the PA would allow it. If the source impedance is high already, say 8 ohms you can never achieve this doubling or quadrupling of power as you add more speakers because of mismatch between the source and load impedance and ohmic saturation imposed by 8 ohms speaker load to the source or amp. Sorry, if I'm getting too technical about my explanation. Hoping you wouldn't mind at all.

so for regular 8 ohm speakers in stereo 4 and 2 ohms are of no great necesity except some speakers "have difficult loads"which begs the question why bother designing them and yes you are getting technical but I dont mind really

 

[PENG]

Actually, there is no such thing as doubling of power. It is just that the design limit of the amplifier rests upon or is determined by the source impedance of the output stage. The lower the impedance, the more 8 ohms load you can connect in parallel. Most professional PA has a source impedance of 1 or 2 Ohms per channel at the maximum rated power. This only means that if its two ohms for example, you will need to connect in parallel four (4) sets of 8 ohm speakers (8 ohms devided by 4 equals 2 Ohms) in order to attain the maximum rated power output. Of course, the total power handling of the sets should be equal to the rated maximum power output of the PA or greater. Just multiply by 4 the rating of each set of the speakers. The sum should always be equal to the maximum rated power of the amplifier or greater.
If you don't need these much power, you still have the option to use at least 1 set of 8 Ohms speaker for which you can obtain only a quarter of the maximum rated power. Doubling or quadrupling happens only as you add more speakers in parallel, that is so long as the source impedance of the PA would allow it. If the source impedance is high already, say 8 ohms you can never achieve this doubling or quadrupling of power as you add more speakers because of mismatch between the source and load impedance and ohmic saturation imposed by 8 ohms speaker load to the source or amp. Sorry, if I'm getting too technical about my explanation. Hoping you wouldn't mind at all.

Again, I think you are talking about the famous "Maximum Power Transfer Theorem/or Theory". Sorry to disagree but I still say whether an amp can double down has less (in fact not that much) to do with this theorem. It has more to do with the voltage and current capability of the amplifier. That includes not just the power supply but also the output stages as well. In fact, under the maximum power transfer scenario, effciency may actually suffer as you can imagine 50% would be dissipated in the source impedance. That won't be good for an audio power amplifier.

Another point, I thought solid state audio power amplifiers typically have very low output impedance, i.e. less than 1 ohm. The numbers you quoted may be more typical for tube amplifiers. Anyway, may be I misunderstood your point, that can happen easily when things get technical.

 

[mantol]

Again, I think you are talking about the famous "Maximum Power Transfer Theorem/or Theory". Sorry to disagree but I still say whether an amp can double down has less (in fact not that much) to do with this theorem. It has more to do with the voltage and current capability of the amplifier. That includes not just the power supply but also the output stages as well. In fact, under the maximum power transfer scenario, effciency may actually suffer as you can imagine 50% would be dissipated in the source impedance. That won't be good for an audio power amplifier.

Another point, I thought solid state audio power amplifiers typically have very low output impedance, i.e. less than 1 ohm. The numbers you quoted may be more typical for tube amplifiers. Anyway, may be I misunderstood your point, that can happen easily when things get technical.

Yes you are right, thats why class AB amplifiers efficiency is rated only 50% because the other 50% is dissipated as heat. Unlike the new breed which is class D (switching amplifier) its efficiency is rated from 90-95% because the output stage is acting just like a rectifier using MOSFET and Pulse width modulator technology http://www.audiodesignline.com/howto/177102531;jsessionid=SPLWY2J13E33GQSNDLRCKH0CJUNN2JVN. Here, the output impedance is almost nil thus heat dissipation is very minimal. This new technology is where maximum power transfer theory will not apply and power depends much on the ability of the power supply to deliver high current demands( specially in successive peaks like when you are kicking the bass drum successively).

 

[don maico]

So its the high current that matters. Why would that be? Specs over here very rarely mention current out put and yet H.K always give them for their products whilstt at the same time giving conservative wattage figures

 

[mantol]

So its the high current that matters. Why would that be? Specs over here very rarely mention current out put and yet H.K always give them for their products whilstt at the same time giving conservative wattage figures

Yes, I came to know that when I was canvassing for an AVR 7.1 channel. During that period (two years ago) H.K. model didn't have Prologic IIx thats why I settled for Denon 3805 which incidentally was also being displayed in their show room. I have no Idea whether their amplifiers are class D already. But one thing is sure: electronic gurus say that transistors are current amplifiers while vacuum tubes are voltage amplifiers.
Well, that's true it's the high current that matters, that's why technically minded buyers/enthusiasts are very particular on the rating of capacitors being used in the power supply. Carvin is also claiming that their PAs can constantly supply peak current demands even on a heavy duty cycle situations such as successive bass drum kicks for example.

Most of the products available on the market today are class AB amplifiers (Home or professional model) because of its high fidelity. I have yet to find out a model that employs Class D amplifiers. And there is also Class H which I think (just guessing) could be a cross between Class AB and Class D ( H could stand for Hybrid).

 

[don maico]

Must confess I hadnt heard of Carvin but then again I hadnt heard of Behringer till last week but they both seem to be extraordinary good value . I am wondering whether the HiFi fraternity has been ripped off all these years by the likes of Krel ,Bryston or Levinson. Maybe they are smaller companies with lower turnovers therefore have to charge more but surely the bigger guys with their purchasing muscle and lower margins could produce something as good but much cheaper and I'm thinking that is where the PA amp guys can step in

Sadly nothing on the PA side for Carvin in the UK

so where does that capacitor rating figure on a spec sheet I personally wouldn t know where to start looking

 

[mantol]

Must confess I hadnt heard of Carvin but then again I hadnt heard of Behringer till last week but they both seem to be extraordinary good value . I am wondering whether the HiFi fraternity has been ripped off all these years by the likes of Krel ,Bryston or Levinson. Maybe they are smaller companies with lower turnovers therefore have to charge more but surely the bigger guys with their purchasing muscle and lower margins could produce something as good but much cheaper and I'm thinking that is where the PA amp guys can step in

Sadly nothing on the PA side for Carvin in the UK

so where does that capacitor rating figure on a spec sheet I personally wouldn t know where to start looking

Oh! I'm glad to hear that. I'm in the Philippines and here Behringer products is relatively cheaper than Carvin and Crown USA because it is assembled in China. For home user products, we have Pioneer, Kenwood, Denon, Harman Kardon, Sony and many more of Asian origin.

As regards capacitor ratings in the power supply side I may add that even the computer geeks on most reviews are very particular on the capacitor ratings in the motherboard which can be readily seen and examined when you want to buy one.For the amps it is not on the specs so there is no way to browse upon unless you want to peek inside the chassis.