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Is there a noticeably audible difference between two level matched solid state amps under controlled

  • Yes... I believe a notable difference can be heard.

    Votes: 136 48.6%
  • No... I do not believe there is any audibly significant difference.

    Votes: 144 51.4%

  • Total voters
    280
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Theresa, I would not be so quick to put the RCA and balanced in the same category. I've had terrible ground loop problems (with short cable runs, that is!!) and after trying EVERYTHING the only way to get rid of the hum and buzz was to switch to all balanced. Again, we're talking less than 10 feet!
Turning to balanced solves the Hum?, I presume completely or is there still some slight noise as I would think there is more likely a problem in the loop that would need addressing as runs of say 1M - 3M RCA is the preferred method.

Can you not run in a new spur for say the power amps to isolate them from the more sensitive parts of your set up?
 

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Turning to balanced solves the Hum?, I presume completely or is there still some slight noise as I would think there is more likely a problem in the loop that would need addressing as runs of say 1M - 3M RCA is the preferred method.

Can you not run in a new spur for say the power amps to isolate them from the more sensitive parts of your set up?
The noise is gone completely.

I have a complicated setup, a 2 channel main rig where my preamp acts as an HT bypass. The receiver's LR preouts go to my preamp. Lots of components connected together by short cables.

After 2 months of troubleshooting, I finally isolated the 2 problems where the amp (Pass Labs X350.5) and the sub (Velodyne CT-150) did not get along, also the HDMI was introducing some noise. I have dedicated 20 amp circuits, tried with and without power conditioners, you name it... The only thing that took care of it was switching from rca to all balanced and introducing an all balanced active crossover (dbx 223xl) to take over from the sub and to act as a buffer between the amp and the sub. Again, my cables are well under 3M.

It sounds really clean now with no noise whatsoever, and I'm pretty picky about my 2 ch. I used to feel the same as you about short rca - that's why I had it connected that way at first. Luckily someone suggested switching to all balanced on a forum...
 

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This problem is pretty common. AVRs have no ground connections, they use two-wire plugs. Subwoofers often use three-wire plugs, and that can cause a hum problem, because the neutral connection is never at the same potential as the safety ground. Adding a BFD or other pro gear that uses 3-wire power will also cause this. There are several solutions, but balanced output is one good one. rejecting common-mode ground noise is the reason for balanced connections in the first place.
 

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This problem is pretty common. AVRs have no ground connections, they use two-wire plugs. Sub woofers often use three-wire plugs, and that can cause a hum problem, because the neutral connection is never at the same potential as the safety ground. Adding a BFD or other pro gear that uses 3-wire power will also cause this. There are several solutions, but balanced output is one good one. rejecting common-mode ground noise is the reason for balanced connections in the first place.
I suppose that is good to know but most manufacturers say that RCA for short runs is the better connection and most AVR's do not have balanced connections but only single RCA outputs, so that can be quite a big issue to some?
 

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This problem is pretty common. AVRs have no ground connections, they use two-wire plugs. Subwoofers often use three-wire plugs, and that can cause a hum problem, because the neutral connection is never at the same potential as the safety ground. Adding a BFD or other pro gear that uses 3-wire power will also cause this. There are several solutions, but balanced output is one good one. rejecting common-mode ground noise is the reason for balanced connections in the first place.
Well said!

Yes, most affordable AVR's do not come with balanced connections, so plain and simple there is nothing we can do about that... Unfortunately..

Here is a great article I found a while back and I learned that a lot of the custom (but not necessarily expensive) cable makers adhere by it. For those interested, it will provide a wealth of information:

http://www.rane.com/note110.html
 

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I suppose that is good to know but most manufacturers say that RCA for short runs is the better connection and most AVR's do not have balanced connections but only single RCA outputs, so that can be quite a big issue to some?
I don't know what would be better about an RCA, single-ended connection. You only need to have the balanced connection on one end of the cable for it to break a ground loop. If you are planning to add an outboard amp you should look for one with a balanced input, so its available if you ever need it. The BFD comes with a balanced input. Long cable runs work best when both ends are balanced because the cable itself becomes a "component" and generates noise signals by inductive and capacitive coupling to noise sources along its route.
 

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I don't know what would be better about an RCA, single-ended connection. You only need to have the balanced connection on one end of the cable for it to break a ground loop. If you are planning to add an outboard amp you should look for one with a balanced input, so its available if you ever need it. The BFD comes with a balanced input. Long cable runs work best when both ends are balanced because the cable itself becomes a "component" and generates noise signals by inductive and capacitive coupling to noise sources along its route.
Agreed, Long cable runs are more suited to balanced connections as they are less likely to pick up interference than say single ended RCA plugs, but for 3M or less RCA should be fine, I used a BFD for a good few years and always used RCA with microphone adapter plugs for the RCA connection at the BFD end and I once never had any type of humming noise from speakers or sub.
 

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any good amps can recommend? looking for resonable prices..
Hello,
If you could be a bit more specific about your budget, it would greatly help. Also, whether or not you are open to used amplifiers is an important consideration.
Cheers,
J
 

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Can we really hear a difference between two amps?

More specifically... between two amps that have been level matched in a controlled listening test. We are not talking about amps that have been modified or are driven beyond their reasonable limits.
In a purely hypothetical sense, on paper, no. Two level matched amplifiers driven within their reasonable limits should amplify the signal the same.

In the real world you have to take into account slew and damping factors, the speakers (load) being used, even the difference between a MOSFET, bipolar and a SET output stage can produce auditory differences. Further, not even two amps of the same identical make and model are necessarily the same. Capacitors are certainly made within a tolerance, not exact, and that goes for all the rest of the components in any relatively complex electronic device. Combine all of the above with the frequencies it's being asked to amplify (no one listens to just 1kHz test tones!) and yes, I believe that differences that can be identified through an ABX are possible. An amplifier's job is simple... amplify an input signal and pass it on to the speakers while changing the signal as little as possible, adding as little coloration/distortion as possible. A perfect amplifier is certainly possible on paper but to the best of my knowledge no one, at any price, has ever made a 100% perfect amplifier. Most come close enough for the human ear to be happy with, but even 99% accuracy is not 100%.

Just my $0.02.
 

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Hey, What happened? How did we end up here..., one more time? Oktyabr does a nice job of rationalizing the numbers to say, "similar but not the same". Amplification is the same and without modification one will or can be adjusted to sound similar to almost any other amp.

But one question that has not been asked, "Will the music sound the same from begining to end"? The same nuance, same sustain, same recording Q's, like recorded indoors or outside in an amphitheater. Will I enjoy one more than the other. I mean will I simply want to listen to one more than the other?
 

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In a perfect world all amps would sound the same but we are far from that. As was just mentioned no one has made the perfect amplifier, just some do less harm than others so there can be a difference in what we hear between amps.

I know I have heard differences in amps and but the largest difference is in how loud and dynamic they can play without any audible distortion. This was with amps with similar specs as well.
 

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I just switched from an minimalist passive pre integrated amp to an AVR. No EQ possible on the integrated nor employed on the AVR. While both sound good, big difference in sound between the two of them.

The AVR is brand new and most likely needs some break in time. Also the AVR signal path is infinitely more complicated than the minimalist amp.
 

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Discussion Starter #178
Are you up for the $10,000 challenge, double blind listening test?

Of course you could have better ears than Steve Zipser, Tom Nousaine and the others that were listening in those original tests.
 

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I'm just going to make a simple observation, I will not respond to anybody looking to argue to win any point. I hope nobody is insulted. I am not attempting to make anybody wrong. I am saying I have a few thoughts not that I know anything in particular. I am willing to take a good honest look at any point made, including, watch and listen to two amps competing to sound equal or different. I hope two people someday do put together this experiment or something similar.

The $10,000 double blind test. Isn't that where a few especially talented techheads get together and take two amps of anybody's choosing and restrict amp setup with inferior wiring or optimize the amps to sound identical.

First requisite being neither amp is allowed to enhance overcome manufacturing short falls, audio obstacles, or bottlenecks in other words each amp must use inferior wiring and
connections. In other words you cannot use better cables that optimize or free the amp to play sound at its best. Because if you have a superior amp you can restrict its ability to play open and natural music by using an inferior cable.

I say that if I replace wiring to my Denon and continue with moderately priced Kimber Kable cables out to the speakers I can make a Denon AVR sound pretty good. If you use all of the same cabling for any cheap amp the sound will improve but will not equal the Denon improvements.

Or I will use the MIT cables I recently put in storage. I did have these in the AVR loop until I tried Kimber' 8VS. Right out of the box these sounded nice and they keep getting better. These are a nice match for Denon.

At this point I will add one more thought. I don't think the experiment says very much if two amps are taken out of the box and connected with wires that are not broken-in with the amp planned for this experiment. Also, all of the cables should be from a list of recommended cables for the specific amps used.

I do not have $10,000 for the bet. But this is the type of experiment that interests me. That is "How good can a cheap amp sound?"

I know I've steeped on some toes here, but I'm no fool. I do not buy electronics equipment because it looks Kool and not because its the most expensive (obviously) and when I do buy my ego is not so invested that I will not admit a mistake nor continue to use a piece of gear that does not contribute to better sound quality.

When I buy it is because I read something that made sense and several manufacturers are continuing the dialog in a competition to improve the product or ... . Some new technology I am watching now is "QOL" Audio completion. The more I read about it the more interesting it sounds. The cost on this technology is way to high for my budget. But I digress... .

I am interested in sound quality, I cannot afford to buy without good reason. Later when/if I find a flaw which is inevitable I will adjust to minimize the problem. but I have to remember that I still have room Tx problems that is I need room Tx. What I am trying to say is that if I buy and sound quality is neg impacted I am quick to admit it. The only expectation I have is that the product is exactly as the manufacturer has described and not what I want to believe I heard other people say. I am looking for pure copper wire and connectors. Low resistance and capacitance, inductance is managed and EMI, RFI are minimized..., I'm not sure about anything else except reputation.

"Bottom Line" I'm 61 years old this year and I love music. I listen to recorded music 2,4 sometimes 6 or more hours a day. I want the best sound I can manage to put together. I am always looking for improvements that fit my budget. I would like to buy a single Furutech speaker cable @ $133 per meter and I need 2 meter per speaker but I'm letting the Kimber warm up a little. These cables sound like they are building am inner charge..., then the sound begins to weaken and there is a tin-can/string effect in the upper mids and then it rolls into a couple of minutes of heaven. So I'll wait to see if they open up or become consistent at something. If that happens I might just live with these for awhile and instead buy two boxes of wall Tx. But I'm working/finishing a Telecaster build and I need Nitrocellulose Lacquer before I do anything else.

Enough rambling. Against my better judgement I am putting this out there..., hope you're all having a great spring.
 

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Discussion Starter #180
The $10,000 double blind test. Isn't that where a few especially talented techheads get together and take two amps of anybody's choosing and restrict amp setup with inferior wiring or optimize the amps to sound identical.
I think it is a bit different than this... but check out the first post story for how they setup that test. It had nothing to do with "trying" to get the amps to sound identical, instead they were trying to hear a difference... and they could not. All they did was level match them, simply because two amps not level matched could indeed have a drastically perceived difference.
 
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