One thing I want to add to the comments, Don't look at the power output specification, and to a slightly less degree, the THD spec. Those numbers don't mean a thing in sound quality.

I gave my stepson a pair of floor standing Kef Uni-Q and an old SAE ( Japan) amp I bought in 1979 ($470 at the time) that was less than 100W. After two years, the SAE burnt and I determined it's not worth fixing. Without telling me, my stepson bought an Onkyo AVR. I went there one day, I noticed the system sounded like a hand held transistor radio!!! I couldn't stand it, I gave him a Marantz 2 channel integrated amp that I paid $350 in the late 90s. It just sounded so much better. The Marantz is less than 100W also.

This is my opinion:
I would rather rely on picking up the amp and see how heavy it is than to read those specs on output power and distortion!!! The heatsink and transformer make up the weight AND you need both to be robust and heavy. In my very limited experience, two brands come to my mind if I am willing to buy used, Adcom and Acurus. I own and used an Acurus 3 channel 200W each for 15 years for my system until I bought the Nakamichi. I've seen quite a few on ebay. I paid close to $1000 for my Acurus in 1998, I have seen the same amp on ebay for less than $300. Depreciation is very steep. It's not a good amp for $1000, but it's a damn of an amp for $300 uesd. I don't think you can compare with the popular amps like Onkyo, Harmon Kadon( I owned), Marantz ( the one I owned). The Adcom GFA565 and another one I forgot the model were designed by Nelson Pass!!! The great Nelson Pass that designed my Nakamichi, Threshold and Pass Lab. They all have external heatsink ( in my opinion is a must).

It is also my opinion that if you cannot tell the difference between good and bad amps, you don't have good ears.........but take it as complement rather than insult. You save a lot of money if you don't have the ears. Then you just need a big sub to shake the house!!!! Sorry.

This is really not relevant to this thread directly, but indirectly, it makes my point of buying used amp.

Before I bought the Nakamichi, I was eyeing on ebay for a while ( I still do.). This is one amp that I labored over.

http://www.ebay.com/itm/KRELL-KSA-20...kAAOSwMVdYHQZH

I had a chance to bid for a fixer upper like this one. After I fix it, I challenge you to find a new amp 3 to 4 times the price of this one that can even touch the sound quality of this old amp. It's not the price that stop me, I really labor over one like this. It's the heat it generates......like a 1000W like bulb burning full time regardless of the volume. Just sitting there burning the electricity!!! On top, I would need to install an air conditioner in the living room and have it on whenever I turn on the amp. Can you imagine the operating cost using this amp? It would be hundreds of dollars a month if you are like me using it 5 hours a day!!!

I don't know how much it cost new at the time, but if you look on ebay, the same amp without problem runs between $3000 to $3500. It pained me to finally decided on the Nakamichi. The other reason is I am designing my own power amp and should be done in two months. I expect to beat the Nakamichi and the Nakamichi will be replaced. So it's no point of spending all the money on the Krell. But I just cannot help still drooling over this one.

Good deal like this don't come often. But good deals do come around if you look hard enough. You don't have to settle for less just because you pay less.

It's noticeable from your reply that you've never done a level matched DBT. I suggest you try it for yourself. It's an eye ear opening experience.

What about those who can tell the difference between amps during pre-DBT casual bias uncontrolled listening but cannot during DBT where expectation bias is controlled? Don't they have good ears?

I did not do DBT, but I design fixtures so I can A/B compare by just a flick of a switch. In fact I was just doing this today with a new preamp I designed. I was fine tuning the values of the components, I just have two preamp pcb in the fixture, I can flip the switch back and fore and listen to every details with different components. In fact I cut the test short as it took me one minute to conclude it make no difference. I spent a few hours setting the test up and lasted only one minute!!! But I got my answer.

Just last month, I did opamp comparisons for preamp. I had identical two pcb, each with different opamp and switch back and fore. You'll be surprised how much difference different opamps make on the sound, the warmness, clarity, sound stage and all.

You might not have good enough ears, you can't tell the difference. I myself have very sensitive ears. I had hearing test done before, my ears were so sensitive they kept turning the volume down and down. Finally they turned off the volume all together ( could hear the hiss turned off to indicate the amp was turned off) and I could still answer their question hearing their voices through the sound proving glass window of the studio.

I was a musician that was trained to hear the smallest little things for years. I could pick out notes and follow the radio and play along with the song even I never heard the song before. I sure can hear the minute little sound.

Everyone think they have good ears, it's the track record and result that prove that..................AND that is not exactly a blessing. Noise borders me, like the neighbor barking dog etc. My wife just tune it off but I can't. Every little screeching noise bugs me where people usually don't even hear it. I had to wear ear plugs to snooze during the day because every little noise disturb me. At night I had to have either the fan or air conditioning on, during winter, I have to have a white noise maker to drown out the noise from the environment. It's not a blessing.

What about fixtures for matching levels? Do you do that too when comparing audio components or no?

Of cause, that's step number one. Each have individual volume to match. You cannot compare with different volume. Sound open up when you have it turn higher. It's mighty important to match volume. I went back and fore many times to match the volume level before comparing.

BTW, it's all good to have DBT or claim to have good ears. But a real test is still live with it for a few days. Even DBT and ears at the moment forms a certain impression. But that might not even be accurate. You have to live with it for a while to really pick.

Case in point. I just bought a Rythmik F12SE to replacing my aging Velodyne VA1210 subwoofer. On the short comparing test, I really could not say the Rythmik is better. But I just simply use it. Then it surprised me like the footsteps sounds more attack, the house rumble more than I ever get from the Velodyne. These take time to appreciate. Only after 4 days that I can honestly say the Rythmik is better. The surprising thing is the better attack is not even the base, is things like footsteps, things drop that is not exactly in the base frequency. But it is. I never have that feeling from the Velodyne.

It is totally not what I expected, I expect to have better base.....which I don't think so. I never expect to have more attack but it does.

How closely did you match and what's the name of this matching device?

Someone told you that you aren't supposed to do that with DBT?

Matching by ears going back and fore.

I am not a tester, I just know how to listen. As I repeat, if you can't tell the difference between good and cheap amp, you shouldn't even talk about this. Some people have it, some people don't. I think just because you cannot tell and resort to all sort of analytical method.

I design guitar amp and effect pedal, I worked with people that has ears that can astound you, I even rely on them for input, that they can pick out the smallest little things. Not only you need gift, it's years of listening like playing music and performing. Not too many things skip my ears. Don't invalidating people unless you walk in their shoes.

One of the guy I rely on judging my pedal. He listened to it one time, next time he came over and play the pedal, he asked whether I change something. I sure did change the value of one component. Not only he could tell, he remember the sound from months ago. I cannot do that, not even close.

Alan, It's obvious that LFEer is a know-it-all, with poor ears. Maybe from years of LFEing? My ears are also very sensitive, but not quite to your extent. It's nice to read your experiences but I wouldn't waste any more time on this.

One of the primary purposes of DBT is to eliminate confirmation bias that causes humans to perceive two amps that measure audibly transparent with the range of human hearing as sounding different. Volume matching is necessary because even a slight difference in volume can cause people to perceive two amps that otherwise sound the same as sounding different. This is also true for DACs.

So you can claim your ear is as golden as you want, but this is not about how good one's hearing is. It's about how the brain processes what is heard.

There is your flaw, right there. Try voltmeter.

Let me repeat (via quote). What part of "the difference listeners noticed" don't you get? You want to hold that thought until you have actually tried level matched DBT because I used to think that way too. FYI, I don't anymore.

You want to hold that opinion until you have actually tried level matched DBT because I used to have such opinion too. FYI, I don't anymore.

For those of you who have lost sight of the OP's original question I have quoted it above. Here we are going on three pages and people are still arguing about blind testing ...

LFEer

I don't have golden ears, just good enough. I still rely on some others that have better ears.

Using a volt meter or DVM to match? You know electronics? I have a full lab at home. I have oscilloscope, spectrum analyzer, signal generator and all the equipment at home. Not just DVM. Attached is the picture of my room. I put the DVM right in the middle on top of the generators!!! I have most of the components and parts for building amplifiers, look at the part bins on the left side.

Human ears are so much more sensitive than ANY instrument. I use all the instruments to make sure the amp is operating as design. Then I turn everything off and rely on my ears. Using instrument to measure is only step one of the process!!!

How do you use DVM to match volume? Music is not a constant signal, what signal do you use for reference level? The explosion? The gun shot?!!!! What is the DVM good for in matching. Scope, spectrum analyzer are 100 times better, but still it's useless beyond functional check. You design the circuit, you know exactly how much gain you have down to 1% by design. This is more accurate than anything else.

There is no point of talking on this. I said everything in my posts. If you have it, you have it. If you don't, you don't. Just because you can't, don't say other people can't because you don't know.

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There is your flaw, right there.
If you believe you are right, then please tell me how come the instrument can tell the difference between 0.1% and 0.05% audio distortion but human ears cannot? Where did I say I can't under the same kind of condition as you and or other people were in?

There is ignore function on this forum, in case you didn't know.

Wrong, I just did comparison of opamps that all have distortion under 0.0003%, but when you listen, each sounds totally different.

Again, read all my post again. I don't think you know what those instruments can and cannot do. You want to talk tech, you really need to learn first. A volt meter to measure?!!! You are funny. I am done with this.

I think we gave all the info we can already. Until OP come back with response, the thread is done for now.

That's due to volume level difference. Check with one of your instruments if you don't believe me. You ears will never be able to tell the difference of change in 0.05% audio distortion. Yes, use of voltmeter to match volume levels. You haven't learned this?

Fixed it for you. vvv

Moderator

move on or leave the thread please

@OP, if you want HDMI inputs in your amp, then an AVR is the only option (unless there are HDMI input capable 2 channel amps). A moderately good AVR used just for 2 channel would give a good quality sound, if not exactly same as an equally priced 2 channel amp. Unless you are a critical listener I don't think you would notice much of a difference.

I use a combined system. I like music much more than video so always had a really good 2 channel setup. When I added the movie/multi-channel sound, I just bought an AVR with extra speakers and added it to the mix making the 2 channel setup as my fronts. It also helped me to expand channels since my AVR has an option to get more channels when combined with external amps. I have compared the 2 channel music between my dedicated 2 channel amp and different AVRs I had. I still like my 2 channel amp because of its sound signature, warmth and some characteristics (which I cannot put in words). I never felt the same with AVRs. But If I had been more into video and just want to listen music also, I would have never bought a 2 channel amp (or I would just a basic 2 ch amp to expand the AVR output).

I think you would be just fine with an AVR, provided you need HDMI. But if HDMI was not in the equation, I would still prefer a 2 channel amp, because you don't need an AVR to drive 2 channels.

Myself and others have already mentioned to the OP, he needs to try an amp and an AVR for himself to see if he can hear a difference, and if any difference is worth spending more money.

I hate having to use yet-another-app.

Although the whole app thing will become a mute point -- pardon the pun -- as I'll be placing the 2ch amp right in front where the volume control is within easy reach.

Hopefully the Cambridge Audio CXA80 will go on sale ... the waiting is killing me !

Yes -- use an SPL meter to make sure the volumes are the same, and then A/B the AVR and AMP.

_WHY_ there is even a difference in the first place though?

Let's turn to basic Math to tell us:

* A 5.1 $1000 AVR, let's be extremely generous and say, has roughly 75% of circuity for audio. That's $125 of parts/channel dedicated to audio.

* Now compare and contrast to a two channel $1000 amp which has 100% of circuity for audio. That's $500 of parts/channel. The fact that the circuit designer doesn't have to worry about "video noise leakage" means the (audio) quality _should_ be better. This isn't rocket science, just basic engineering.

So with the higher budget to play with, who do you think is going to chose the higher quality components? The AVR jack-of-all-trades that is going with the cheapest components to get the cost as low as possible, or the AMP master-of-one who doesn't have to pander to the race-to-the-bottom-of-the-barrrel extremely price conscientious consumer?

Obviously DSP room correction changes the equation, but dollars for dollars, a 2 ch amp should sound better then an AVR. Obviously, there are always exceptions.

Something else to keep in mind is that Music usually doesn't get down to 20 Hz the way Movies do. Sometimes you'll see amps sacrifice "extension", that is, fall off sharply at 40 Hz but what they give up they gain in quality -- they are much "flatter" across the board.

Audio quality is a constant battle between:

* THD
* volume
* responsiveness
* crossover balance
* DSP correction for sound nodes and sound nulls,
* etc.

This is why the one person can love one amp and another person can hate it.

This week I got to hear the Cambridge Audio CXA80 and the Yamaha A-S801. Immediately I noticed A-S801 was "brighter" -- the salesman was surprised I picked up on it so quickly -- but it was obvious to me. Some people prefer the "brighter" sounds, others want a more "neutral" or "laid back" feel.

It all depends on what you prefer.

Probably, but as I've said in other threads:

The _only_ way to KNOW is to listen in YOUR room -- because otherwise you're just listening to someone else's hyperbole.