BEHRINGER A500 AMPS / 2nd FOLLOW UP!

[pearsall001]

Hope everyone had a great Christmas!! This is my second follow up the A500 amps. After reading the initial thread about the amps I had to give them a try. I purchased 2 & run them in bridged mono mode powering my AAD 2001 monitors. All I can say is that I am extremely impressed with these amps to say the least. To me the sound in like "NOTHING" meaning that they are neutral in their sound. Just awesome raw power that makes my speakers sing like there's no tomorrow. You definetely owe it to yourself to give them a try. You just have to get over the price thing, we've been so conditioned in our minds that gear must be expensive to be any good!!! This is not the case here by any means. I'm no expert on electronics so correct me if I'm wrong but to me a power amp is pretty much a straight forward piece of gear. No bells & whistles, complicated switches or the like. It's job is simply to deliver power to the speakers. How much more expensive can the guts of one amp be from one manuf. to another? Where does the expense come into play when you see amps priced in the thousands of dollars? Are their componets that much better or is it that the companies know that people will pay their high prices because it's "THE BEST" or so they have you believe. How long have we been snookered?

 

[mtrycrafts]

Hope everyone had a great Christmas!! This is my second follow up the A500 amps. After reading the initial thread about the amps I had to give them a try. I purchased 2 & run them in bridged mono mode powering my AAD 2001 monitors. All I can say is that I am extremely impressed with these amps to say the least. To me the sound in like "NOTHING" meaning that they are neutral in their sound. Just awesome raw power that makes my speakers sing like there's no tomorrow. You definetely owe it to yourself to give them a try. You just have to get over the price thing, we've been so conditioned in our minds that gear must be expensive to be any good!!! This is not the case here by any means. I'm no expert on electronics so correct me if I'm wrong but to me a power amp is pretty much a straight forward piece of gear. No bells & whistles, complicated switches or the like. It's job is simply to deliver power to the speakers. How much more expensive can the guts of one amp be from one manuf. to another? Where does the expense come into play when you see amps priced in the thousands of dollars? Are their componets that much better or is it that the companies know that people will pay their high prices because it's "THE BEST" or so they have you believe. How long have we been snookered?

Great, thanks for this follow up

Who said there is a tomorrow out there??? LOL For one, it never gets here.

And, yes, we have to get over the cost issues, that more is better.

 

[buckyg4]

Power amp design is not completly straight forward. You have the design of the power supply where you want a nice clean signal. You have a class A, AB, D technology. You of course want to use quality parts that can hold up to all of the heat that is generated good heat sinks. I for one don't want to pay more than I have to and I wish I could try this amp out but the input impedance is to low for my passive preamp.

 

[gcmarshall]

if one's main speakers have recommended amp rating up to 250 watts, isn't one taking a risk by putting a bridged 500 watt amp (the A500) on said speakers? is there a risk of that being too much power and, thus, damaging the speaker?

 

[mtrycrafts]

if one's main speakers have recommended amp rating up to 250 watts, isn't one taking a risk by putting a bridged 500 watt amp (the A500) on said speakers? is there a risk of that being too much power and, thus, damaging the speaker?

Should not be a problem. You will not put 500 watts rms continuous power into that speaker but short dynamic peaks. The low drivers should handle that. Tweeters usually don't get much power at all.

 

[mtrycrafts]

Power amp design is not completly straight forward. You have the design of the power supply where you want a nice clean signal. You have a class A, AB, D technology. You of course want to use quality parts that can hold up to all of the heat that is generated good heat sinks. I for one don't want to pay more than I have to and I wish I could try this amp out but the input impedance is to low for my passive preamp.

Well, you do have a problem with a passive preamp, no matter what. Your interconnect better be a very low capacitance cable, or you will roll off the mids and highs rather fast. I would get rid of that passive gear in a hurry. More trouble than it is worth.

 

[buckyg4]

Well, you do have a problem with a passive preamp, no matter what. Your interconnect better be a very low capacitance cable, or you will roll off the mids and highs rather fast. I would get rid of that passive gear in a hurry. More trouble than it is worth.

I believe as long as you have the right power amp and stick bellow 100 pF / channel you should be good to go in terms of miminzing reactance and having the cutoff frequency of a low pass filter much much much higher than the audible range. You should be fine with a short run of almost any cable out there. The cables I use are rated around 8 pF / ft and I run 0.5 M. With all of the factors taken into consideration you can't beat the transparency of a passive pre.

 

[Ryan_Lilly]

Behringer makes very good products at lower prices than the competition. I have several of their pro-audio products, like mixers and headphone distribution amps, and I have always liked their quality.

 

[mtrycrafts]

I believe as long as you have the right power amp and stick bellow 100 pF / channel you should be good to go in terms of miminzing reactance and having the cutoff frequency of a low pass filter much much much higher than the audible range. You should be fine with a short run of almost any cable out there. The cables I use are rated around 8 pF / ft and I run 0.5 M. With all of the factors taken into consideration you can't beat the transparency of a passive pre.

Well, that passive most likely has a variable output impedance, and can audibly affect the frequency band with a capacitive cable. But, in your case, it may not matter?
What are the specs on it with this in mind?

 

[MacManNM]

What is the input Z of this unit? I can't seem to find it.

 

[PENG]

What is the input Z of this unit? I can't seem to find it.

10 kohms according to the manual.

 

[ExtraCheese]

Got a Buzz in my A500!

Hello. I purchased a A500 amp to go with my 3805 receiver.

When I put the receiver on an input that is silent (say a paused CD with digital connection) and I crank the gain on the amplifier all the way up, I get an audible buzz coming from the speakers (mainly from the tweeters). Audible as in I can barely hear it when I'm sitting 6 feet away in a room with alot of white noise (tivo, my laptop, etc). I have to set the A500 to about 50% to ensure that the buzz coming from the amplifier isn't effecting the sound.


Is this normal or might this be a sign that the 3805 and the A500 are not meant to be? Btw, if I disconnect the Amp from the receiver and crank the gain on the amp, I don't hear anything so it doens't have to do with something internal in the A500.

Do other people with the A500 have similar issues? Any feedback would be appreciated

 

[Reorx]

Thats normal with just about any amp/receiver. (I dont know about digitial amps)

That's why you dont leave the amp gain turned all the way up. Keep it at 1/2 or less.

Nice amp. I might buy 1.
Reorx

 

[WmAx]

When I put the receiver on an input that is silent (say a paused CD with digital connection) and I crank the gain on the amplifier all the way up, I get an audible buzz coming from the speakers (mainly from the tweeters)....
....
Btw, if I disconnect the Amp from the receiver and crank the gain on the amp, I don't hear anything so it doens't have to do with something internal in the A500....

....Do other people with the A500 have similar issues? Any feedback would be appreciated

You may have a ground loop, if it is a ground loop it can be eliminated by:

(1) Certain correction: Using an isolation transformer between the reciever and device that are looping.
(2) Possible correction: by connecting a wire from the chassis of the reciever to the chassis of the device that is looping.
(3) Possible correction: disconnecting the ground pin to the socket from the device causing the loop(if that device has a grounded power plug) by using a cheater plug. NOTE: This is not recommended due to possible safety issues.

If it's not a ground loop between the A500 and the reciever, it might be a ground loop with the reciever and something else connected to the reciever. Try disconnecting the other items(such as TV, VCR, Satellite, Cable, etc.). If the noise is gone, you can figure out which is the culprit by this method of deduction. If the noise is still present, and you don't have a ground loop between the reciever and A500, then your reciever has an inherantly noisey pre-amp output.

-Chris

 

[pearsall001]

ExtraCheese

I've got 2 - A500 amps running them mono-bridged. I ran into the same problem. However the same thing happened when I hooked up other SS amps & also a tube amp. It is not uncommon to get a ground loop when you add more 3 prong equipment in your system. From what I can gather it depends on how each manuf. runs the ground in their products. It's different grounding techniques that cause the problem, I think. Any body here more educated on this kind of stuff & wanna help out here. I found a fix for mine, I added a cheater plug to the amps power cords. This virtually eliminated the buzz from the speakers. Now I can turn the gain control knobs up to the 2:00 position & have near dead silence until you put your ear right up to the speaker. Some say that this is a dangerous practice & others say not to worry about it they do it all the time. I'll leave it this way until I find a definite cure. By the way how do you like the A500? I absolutely love mine in mono bridged mode. My AAD 2001 monitors really sprang to life. How about a quick review!!!

 

[mtrycrafts]

When I put the receiver on an input that is silent (say a paused CD with digital connection) and I crank the gain on the amplifier all the way up, I get an audible buzz coming from the speakers (mainly from the tweeters). Audible as in I can barely hear it when I'm sitting 6 feet away in a room with alot of white noise (tivo, my laptop, etc). I have to set the A500 to about 50% to ensure that the buzz coming from the amplifier isn't effecting the sound.

Are you saying that when you pause a CD, crank the volume way up, you hear a buzz that is barely audible??? If so, you are amplifying the internal amp noises. With music, this will be ancient history

 

[ExtraCheese]

Are you saying that when you pause a CD, crank the volume way up, you hear a buzz that is barely audible??? If so, you are amplifying the internal amp noises. With music, this will be ancient history

Just to clarify.

Here's the example setup:
CD player connected to 3805 via optical link. CD Player is not playing a CD.
Denon 3805 set to CD Input.
A500 connected to 3805 via RCA cables (A500 is not running in bridged mode). 3805 does not have balanced pre-outs.

Setting the gain to 50% on A500, I hear a slight hiss coming from the tweeter with my ear right up to the receiver.
Setting the gain to 100% on A500 I hear a significant static-y hiss, aubile from about 6 feet away in a room with significant ambient white noise.

Playing anything through the A500 with the gain on the A500 at 100% is unnacceptable (highs are muddy).

 

[ExtraCheese]

Greetings from NEWB-LAND.

Hey guys,

Thanks for all the excellent responses. It really helps to know that this is (fairly) normal behavior.

I'm very new to the world of audio equipment so it's hard for me to give a quality review of the hardware. I just purchased the 3805, the A500 and a pair of Dynaudio 72 SE's within a month. My previous setup was an OLD denon receiver with JBL S38 bookshelves. I can definetly say that the A500 provided an improvement to the dynamic qualities of the speakers compared to using the 3805 (which is not designed for 4 ohm loads).

I don't even have a proper equipment rack! I'm currently using Jenga pieces underneath the feet of the A500 to give it some breathing room from the 3805

When I get home tonight, I will try to determine if I have a ground loop in my system and report back.

 

[pearsall001]

Try the cheater plugs

 

[ExtraCheese]

BEHRINGER A500 Follow Up Review

Hey guys,

Thanks for all the excellent responses. It really helps to know that this is (fairly) normal behavior. yada yada yada...

When I get home tonight, I will try to determine if I have a ground loop in my system and report back.

Ok, so I'm back to report. First off, the cheater plug didn't do anything to reduce the hiss in the amp. I think the static hiss I heard is probably within normal operating parameters for this amp. I was probably just over reacting.

The big thing I wanted to mention is that I went back to the stereo shop and told them I can't get the sound I want out of my Dynaudio 72 SE's and I wanted to exchange for something else. The sales guy listened to my problems and gave me an open box Rotel 1075 amp to connect to my receiver.

I've been trying a bunch of different CD's, Norah Jones, DJ Honda, Massive Attack. I settled on Amon Tobin's Bricolage Track 1 as my test case. It's a significant difference.

The A500 I would compare as being VERY smooth in the highs, unfortunately this is true to a fault and you find yourself wishing the highs were more pronounced. The Rotel on the other hand gives you tons of detail but its almost sibilant and grainy in chacteristic. The nice thing about the rotel is that you get the feeling turning up the volume, that you have tons of head room, it just gets louder and louder, nothing really starts to get unbalanced or out of control. With the A500 you start to hear the mids get out of wack with everything else and the bass is out of control and undynamic.

In short I would say that the A500 was not a good match for my setup, it might be an improvement over the Denon 3805's internal amp but it just doesnt offer the steady current I need to drive these Dynaudios. Also, I think people were suggesting that it be used in a bridged config. Which wasn't possible for me with my 4ohm rated speakers.

I learned a big lesson in this whole experience and it's that there needs to be an overall balance in your system. Spending $2500 for a pair of speakers and then connecting it to a $200 amplifier or my Denon 3805 integrated is not cutting it. Even this $600.00 Rotel is not getting me EXACTLY where I want to be. I'm at the point where I might need to go to an even better rotel amp to get the clean highs that I want.