Replacing Rotel power cords? Maybe not worthwhile!

[pbarata]

Hi all,

This is a good reading for many of us willing to replace original Rotel power cords:

Link deleted by admin

"To many in the engineering community, blind ABX is an accepted experimental design. Using the blind ABX protocol, we failed to hear any differences between an assortment of generic power cords and Nordost Valhalla. Therefore, we cannot conclude that different power cords produce a difference using the blind ABX protocol. However, we also cannot conclude that there are no differences. We simply failed to prove that differences can be detected to a statistically significant degree using a blind ABX protocol."

[spiffnme]

A very, very common result when people don't know what it is they are hearing. Aren't our brains a wonderful thing? They sure do like playing tricks on you.

[PiDD]

A very, very common result when people don't know what it is they are hearing.

This is so true! I do an upgrade of any kind and dance over the improved sound. Call my wife down and get a I cant hear the diff!?

And before you say its only in my brain .. she said that when I went from Onkyo receiver to the Rotel 1098!

I dont call her down for opinions anymore!

ah sweet ignorant bliss .. I envy her!

[Mitchell]

Hi all,

This is a good reading for many of us willing to replace original Rotel power cords:

link deleted by admin
"

That is fascinating and if you read through it it will lead you to a site that does other blind tests. It makes you think twice about all kinds of audio products.

[ht_addict]

Hi all,

This is a good reading for many of us willing to replace original Rotel power cords:

link deleted by admin

"To many in the engineering community, blind ABX is an accepted experimental design. Using the blind ABX protocol, we failed to hear any differences between an assortment of generic power cords and Nordost Valhalla. Therefore, we cannot conclude that different power cords produce a difference using the blind ABX protocol. However, we also cannot conclude that there are no differences. We simply failed to prove that differences can be detected to a statistically significant degree using a blind ABX protocol."

I read the article, then took a look at some of the reviews on AC cords he they have published onthe site. Seems to me some conflicting results. Personally I've replaced my AC cords on my NAD S250 and Pioneer 56TXi, but only because I have a local builder who puts together some nice 9AWG Cryo treated cords for $150CDN.

ht_addict

[shadow]

Blind testing is a very humbling experience for the golden ears as well as the rest of us. Over the years I have become convinced that most of the differences that are attributed to components other than speakers are largely the result of expectation, not reality. It is no coincidence that subjective magazines like Stereophile have avoided these controlled tests like the plague. If they cannot reliably tell the difference between two components in blind testing, why would anyone pay the outlandish prices for most of the equipment absent features or build quality justifying the expenditure?

[stantheman2]

Re classic double-blind testing, there is an interesting theory that the conditions of a double-blind test somehow negate the "real" psychoacoustic effects that we hear as differences in components. Certainly, if you believe every item in the sound reproduction chain inflences the end sound, then you certainly can believe that the switching devices used to A/B components affect the sound to a degree that masks the differences between the components being compared.

As for me, the jury is still out, but I tend to fall into the camp that there ARE audible differences in power amps, CD/DVD players, cables, etc. Just because we have not been able to design test equipment, conditions and protocols that demonstrate differences does NOT mean the differences do not exist. Two examples from the "olden days" of audio illustrate my point that, as we continue to increase our body of knowledge about music reproduction, we recognize more and more things that affect the quality of audio reproduction:

1. In the early 70s, it was generally believed that, if an amp could pass a 20 kHz sine wave, that was as "fast" as it needed to be. Now, everyone "knows" that a higher slew rate provides audible benefits in the reproduction of "real world" complex musical signals.

2. When CDs were originally introduced in the early 80s, there were many articles in audio and other magazines that stated definitively that music reproduction through CDs was "perfect". I can recall reading fairly technical treastises that "proved" mathematically that, as long as the sampling rate was at least twice the highest frequency to be reproduced, the signal reproduction would be perfect. A CD sampling rate of 44.1 kHz would thus reproduce all audio up to 20 kHZ perfectly. At that time, those who pointed out that CDs did not sound as good as a well-mastered records were told that they were wrong - mathematics had proved them wrong. Now, everyone knows (and can easily hear) that the higher sampling rates of SACD and DVD-Audio result in better sound than plain old CDs.

With an engineering background, I rely on science and the scientific method every day. But with music reproduction, I think "science" simply doesn't have it all figured out (yet).

[Jeff]

I wish to offer an alternative point of view based upon my experience. In the early days of my system I obtain one new power cord (as a gift) which I used on my power tower speakers. At that time I did not have my rotel 1080 amp or rcd-1072 cd player. I played cd's off a Toshiba 5700 dvd player($400). My two channal listening had a fat bottom end which needed to be tamed. Using Jazz bassist Brian Bromberg cd "Wood", the comparison was made.

My listening lengths were 45 seconds. I switch power cords 7 to 8 times to verify what I heard was real. There was a reduction in the low end boom. On a scale of 1-10 with 10 being the highest, it was about 1... maybe 1.75
The power cord was PS Audio Power Punch which is an entry level 12 guage cord.

Once I obtain the two Rotel products mentioned above, plus some first rate interconnects, the fat bottom end was all but gone. There continued to be low end standing waves in the front corners but that's to be expected.

I later performed the same test to consider an additional power cord. The difference was very very small. So small it's likely I would fail an A/B test. My point is many of the componants used in their test were state-of-the-art. I'm sure the sound was NEAR flawless. A notable improvement in sound would have been hard to find. However, placing those Nordost power cords on lower end components with very revealing speakers... IMO would have yielded a different outcome.

Jeff

[phillipk]

This topic is always good for controversy, but this thread seems pretty tame. I was thinking though, if our brains are so great at being fooled, why not just build you system entirely from illusions? Take the case from some REALLY high end brand and slip a plain old receiver in there... grab the grills from expensive speakers and put them in front of whatever speakers you have. I'm halfway serious about this.

Thanks,
Phillip

[shadow]

This topic is always good for controversy, but this thread seems pretty tame. I was thinking though, if our brains are so great at being fooled, why not just build you system entirely from illusions? Take the case from some REALLY high end brand and slip a plain old receiver in there... grab the grills from expensive speakers and put them in front of whatever speakers you have. I'm halfway serious about this.

Thanks,
Phillip

This happens now. Check the Secrets review where the reviewer had state of the art gear and the best cables and he guessed the right cable less than half the time. Your brain can be fooled only if you do not know of the substitution, hence blind or double blind testing! You can check various sources where listeners were unable to tell the difference between a cheap receiver and a MarkLevinson amp, for one example. The conclusion I draw from this is that the differences in gear other than speakers, if any, are very subtle. When people talk of huge differences in the sound of amps or cables, take such an opinion with a ton of salt.

[Cracking Oboe]

Results of ABX testing may lead you the wrong direction!

In the mid to late 80’s Stereo Review Magazine (now Sound and Vision) did ABX testing of stereo receivers and then later on CD players in a wide price range. Results: No difference, regardless of price. :E I took this to heart and decided that low price and features were the most important in choosing sound equipment.
It took me years to discover (by accident, and to my amazement) that there is a significant audible difference in equipment, (even cables!! Huh????). I had really enjoyed scoffing and ridiculing individuals who invested large sums of money into their sound systems, never mind how I felt about cables. Today I am angry that I allowed that magazines ‘studies’ to influence my purchasing. The result... I wasted good listening hours on crap for decades. :M
UHF magazine had a fine article on the fallacies of ABX testing and why it is not a valid methodology for assessing equipment. I wish I still had it to give you the date (about a year and a half ago) but I loaned my issue out and have not seen it since. A minute of listening to any source can be enjoyable, but after five minutes a listener may just want the darn noise off. I find with higher quality sound I can read a book while listening at any volume, but on a poorer sounding system I absentmindedly keep turning down the volume until it is essentially off. How do you design a test for this effect? Since investing more in my sound system, I find I often turn up the volume, and with my old system I spent a lot of time turning down the volume.
I had to replace the power cable on my RMB 1095 a few weeks ago ($100.00). Yes, there was an immediate improvement in sound, but the cable that was on the unit before was not the stock Rotel cable, but a long cable (un-insulated and unshielded) from an older receiver (I obviously did not believe that a power cable could make a difference as I used the cable for a couple of years until I had to replace it). Not a fair test to determine the need for an upgraded power cable. I'm still skeptical, but I am really glad I replaced the cable.




Cracking!

[phillipk]

That test didn't really test what I'm curious about--namely, letting the listener SEE the expensive equipment and then report a higher sound quality. That is, if I think it sounds better I don't really care if it's just some trick. What you need to do is a test where you have listeners who know the price of equipment... where you sometimes play the selections through the expensive equipment when you say you are and every other combination including placebos where you really do play it through the expensive equipment. Testing power cables, for example, you could have the listener plug in the cable himself. (By the way, that test only included 15 participants with just one female.)

For me, I generally accept that different physical objects used to produce sound WILL most definitely affect the sound. (I don't know how someone could even state that my walkman sounds as good as a decent CD player.) I don't necessarily believe the sonic difference is always "quality" and certainly don't always agree the sonic change justifies the price. I mean, even if I believe a $1000 power cord made my stereo sound notably better, I wouldn't buy one.

[DanR]

Here is my humble two cents on this topic. I do believe people often hear what they want to hear. I have an RB-1090 and before I bought it, I also listened to amps from Bryston, Krell, Levinson, Parasound, and B&K. I quickly came to the conclusion that all sounded great and the only real differentiator was price. I chose the Rotel because of price and great power. But I can honestly say that if I was in a room and all these were blind tested, I would never be able to tell the difference. And I really don't believe even Robert Harley himself could tell the difference. Human beings are such spurious creatures that any real definitive answer on this subject is impossible. But we can all recognize that we fall victim to perceived values. Is Krell really worth 3 times the money than Rotel- I don't think so. Someone may prefer the sound of the Krell over the Rotel or vice versa, but one really isn't better than the other. We all hear what we expect to hear, especially when we have to justify spending thousands of dollars on something truly not necessary.

[Kevin97225]

I agree with you DanR, I came to the same conclusions when researching and doing listening test and landed with the Rotel RB-1090 as well. I've been very pleased. I actually did like it better than all the ones you mentioned, the Rotel RB-1090 just does an all-around pleasing sound that I prefered, and an excellent value compared to the others. I've read alot of reviews that say the RB-1090 is as good as Amps 5x to 6x times its cost, and said to be scaringly close to some of the very best. I find that to be true. One always has to use his/her own judgement because as well all know, we don't always agree with each other. I'm just very happy I found the RB-1090! It's made me very happy with it's sound quality and build quality..... looks too!

[phillipk]

There's also a lot to be said for diminishing returns. I have a RB 1080 and know that it added a ton to my system when only using a receiver. You could calculate a factor by which one extra dollar had X amount of value. Assuming that an amp that costs $10,000 is in fact "better" sounding, it's a fair assumption that those extra 9,000 dollars didn't have the same value... say X/3 or something.

The part about this argument that's interesting is when people make the statement that because some overpriced items are mostly (or even all) hype, then necessarily no quality product is any better than the cheapest one ever made. Because we're talking about power cords, I'd say they are probably more on the fringe.

Here's my estimation of what matters the most... that is where you get the best bang for your buck:
--quality recordings
--speakers
--amplfier
--room acoustics
--pre amps/processors
--incidental materials (cables)
--drinking plenty of water

Sorry if the rest is way off topic, but here's a similar list for cycling:
--helmet
--gloves
--shorts
--shoes
--tires
--bicycle frame
--bicylcle components

The point is some things matter more than others.

[David Meek]

One thing that is almost never addressed in these discussions/tests is an individual's hearing acuity, whether talking about frequency range, sensitivity, ability to directionalize, etc. If you think there are lots of variables that come into play with regard to equipment, just start looking at the human hearing engine. I know for a fact that I have a couple of small frequency ranges that I don't hear well in. I also know for a fact that I can discern directional signals quite well compared to others. Having one person used as the "listening horse" in a blind or double-blind test (or at least evaluating what multiple persons hear as individual tests and then compiling averages) to me is a more statistically valid - hence relevant - method of testing.

I really have to agree with Stan in that

I rely on science and the scientific method every day. But with music reproduction, I think "science" simply doesn't have it all figured out (yet).

[will1066]

I tend not to believe in cables anymore. I recently went back to a stock cable and lo and behold, I thought it was actually better! Spend the money on real hardware.

[Blazar]

I would like to summarize the basic thread concept: reality vs. voodoo

Real differences: MOST important to LEAST important upgrades. In other words, where you should spend the bulk of your money. All of these have known diminishing returns in terms of cost : effect. In the high end, many components sound different but not necessarily better.

1. Speakers - greatest noticable effect. Of course even basic placement and room acoustic issues play a huge role in the sound.

2. Amplifier - very noticable, but most of the time not as much as speakers. Underpowered or electrically noisy amps (ie ground loops) are clearly audible.

3. Recording - if you can get a higher quality recording, this CLEARLY makes a difference. It's not enough to take old cd tracks and stick them on to a dvd-A. Newer microphones and recorders are superior in many ways to older techniques. Particularly for music that is modified in the mixing studio. It's often hard to upgrade since availability is often a problem. We won't get into the analog vs digital discussion. There are advantages of each. Even the difference between and Excellent cd quality recording is difficult to distinguish from DVD-A / SACD. Remember it is also in the studios best interest to make the new discs sound at least "different" so you feel like it's better. Again beware of upsampled old recordings.

4. Compression - CLEARLY low bit rate mp3's sound like crap on a nice system. The difference between high bitrate and non-lossy compression however is very VERY difficult to detect. If someone with "golden ears" can tell the difference 19 times out of 20 I would give them $100.

5.Source (D/A) - This makes a difference since no two D/A make exactly the same sound. Again with most high end D/A you will find some that you like "better" perhaps based on your preference in sound quality. I would bet my life that my RME Hammerfall DSP 9632 Soundcard with XLR outputs would be superior or no different than ANY source you ever heard at ANY price range. A crowd of 100 golden ears listening to 1000 songs would in a randomized study would find NO difference between the most expensive DACS in the world and the sound card. I would bet my life on it.

6. CD transport - what NONSENSE to spend $10,000 on a CD transport. I would bet all the money I have that you could not get a cd transport on this PLANET that would sound better than the exact same data coming from a computer hard drive. CDs have scratches and sampling errors that can be COMPLETELY avoided by doing a bit perfect CD copy to hard drive. A fool and his money are soon parted...

7. Power conditioning - part reality / part voodoo.

Voodoo:
Power cords
Rocks
Wire lifting "isolators"
"Isolating" tables, etc... lol.

Cables/Interconnects:
1. basic requisite shielding / grounding should be present.
2. 99% of all cable related nonsense discussions would be avoided if everyone just switched to XLR...
3. The studios mostly use plain-jane XLR cables. The musicians generally do to.... So WHAT MAJICS do you hope to extract with your $20,000 set of cables? This concept is moronic and plain naive.
4. Cables MAY make a sound "different" but again unlikely necessarily better.
5. The money is better spent on the parts of the equipment chain that ACTUALLY improve sound... see speakers.
6. The only reason you should spend money on speaker wire is for longevity and easy connections. Adequate guage for long runs is also reasonable.
7. I would bet 99.99999% of people that buy "fancy" cable didn't spend the money in the right place.

Power Conditioning (possible goals):
1. noise reduction? Worthwhile if noise is causing audible problems.
2. surge protection? Probably worthwhile
3. Prevent lapses in voltage? Probably not worthwhile if your voltage is not that bad to begin with.
4. Prevent lapses in current? Might be worthwhile if there is a current limiting problem to begin with. Large amps will benefit from dedicated 20 amp lines. Dual 20 amp lines if you have multiple HUGE amps.
5. Prevent ground loops? Worthwhile endeavour. Isolation transformers seem to be the best way to permanently solve this problem. XLR designs are also helpful.
6. DC noise leaks? This problem seems to be solved with "balanced 60v/60v" transormers.

Basically here is a multi-conditioner setup I would like to try: This seems like an acceptable combination of well reviewed conditioners
1. A device with basic surge / interference protection
2. Isolation transformers to get rid of noise from motors activating and lightswitches turning on / off (transients).
3. A "current sink" like the "Power Company" line of products.
4. A sine-wave AC producer that makes a perfect 120v AC sinewave. ie the PS audio or Exactpower line of products.
5. A device that prevents digital noise from one component from getting into another.

Here is what I propose:
1. An 1800 watt Hopsital Grade Isolation Transformer from "Tripp Lite". This takes care of surge / interference / transients.
2. A "Power Company" unit. Takes care of transient lapses in current. This only makes much sense if your Amp is running LOUD and sucking current like crazy...
3. An Exactpower or PS audio unit.
4. Finally plug in a device that produces balanced power. Like a Furman reference unit or a device from Balanced Power Technology.

I have not seen any head to head comparisons of these units. It would certainly make for a great double blind listening study.

[Lex]

locked. We are not a blind test type forum. We have the same rules as Adio Asylum in this regard.

Doug