The Placebo Effect - isn't it weird?

[twelvebears]

I've just thinking how much our brains can sometimes fool us because of something that happened to me last night.

So yesterday another G1000HD digital lead arrived from Mark and I set about hooking things up.

Basically I now need to use all three digital inputs on my Benchmark DAC1. Optical for my iMac, Coax (BNC) from the SCD777ES, which left my SB3 needing to use the remaining XLR input.

Now as the SB3 has a 75ohm RCA output, and the Benchmark has a 110ohm XLR input, Benchmark had advised that I could/shouldn't use a direct RCA to XLR lead and that I should use an impedance transformer to match things up. I duly ordered my self a suitable widget from Neutrik (very nicely made it is too) which I was waiting for the cable to arrive from Mark.

As if my way, in the few days while this took place, my brain got to over analysing the fact, that in addition to connecting RCA to XLR, I was also introducing extra connections AND another component (i.e. the transformer) in the digital path. Surely this is *a bad thing* and bound to have an impact right?

So, anyway, last night I've hooked it up and quickly stuck on a track I know and love - A Matter Of Minutes by Shawn Colvin. I was immediately CONVINCED that it sounded *different*. I wasn't sure how exactly.... Did the bass seem to have a bit more weight?... Surely the focus of Shawn's vocals seemed better didn't they?...

Now the odd thing here is that although I had been worrying (yeah I know, I need to get out more, there are worse things) about the RCA/XLR/Impedance Transformer thing, when I thought I heard differences, I actually thing it sounder BETTER not worse than before.

As it happened, the same album was in the SCD777ES at the time so I flicked the input selector on the Benchmark, hit play and flung myself onto the sofa to be baffled but the now OBVIOUS differences between the CD/CDP/RCA version and the one coming via Lossless/SB3/XLR (with widget).....

And?......

Bugger all. With only very subtle difference that you might expect considering the different digital sources via the same DAC, they both sounded equally good and essentially identical.

So the moral of the story for me is that even in your own home, with your own system, using a track you really, really know, anything other that direct A/B testing is VERY unreliable.

[Dave Cawley]

Expectation bias...............

Dave

[twelvebears]

Expectation bias...............

Dave

Indeed! Although as I'd been worrying about the use of the impedance transformer, I was surprised I thought it sounded better.

Perhaps I'm just an optimist. :)

Any news on your Super Platter btw?

[Steve Toy]

It exists but expectations are frequently confounded...

[DSJR]

Expectation bias is what often rules the whole Top End audio scene.... sad, but, I suspect, true in a hell of a lot of cases...

[Spectral Morn]

My only concern in this is....the cable and impedance matcher are new therefore not run in. For these sort of comparisons to have real meaning the items in question need to be run in fully. Now in saying that, there are differences in sound between the three types of digital connections and the cable types/plugs etc that are used....so in the context of your system one of those may show up as being better even before cable burn in(imagine the improvement after that has happened)

Frankly I detest the term placebo effect had enough of that to last an eternity..rammed down my throat and other peoples elsewhere ;) to justify their closed mind attitudes (not saying that about you Steve-Twelvebears) I know my mind, my listening abilities, and I do not ever feel I have been aware of a placebo effect. I expect nothing every time I listen to something new, but when I hear it, I hear it.

As to the question...I don't know you Steve except through what you write hear, but on that basis I believe you have heard what you have heard. I for one feel you can hear and have pretty good ears.


Regards D S D L

[twelvebears]

With hindsight, placebo was the wrong word. 'Expectations Bias' is probably a better one.

At the end of the day it was more the fact that I was *sure* it was sounding *different* (forget better or worse for the moment) and yet when I did the A/B comparision with another media/source/connection combo, the differences all but vanished.

I'm not saying there aren't still differences, given the variables, there must be some, it's just that they aren't the very noticable ones I thought I heard initially.

[dave2010]

Steve

It was exactly the switching between different sources which eventually decided me to take the DACMagic I borrowed back.

My initial impressions were "wow" - that sounds good, but eventually I started comparing the sound with different inputs, and directly from my CD player and Logitech/SB3, and when I decided I really couldn't reliably tell which way the switches were set - that's when I finally gave up. There was a significant aural difference on the USB input though - but at the time I didn't think I needed that.

I think you're right to point out the need for caution, though sometimes we may just decide we want the stuff anyway.

[Themis]

Frankly, tracking subtle differences is very (*very*) hard... Sometimes the more you try to identify them, the more the seem to disappear. :( I have come to the conclusion that some differences can only be noticed on the long term.

Nevertheless, most of the time, the initial impression still proves right. ;)

[dave2010]

Dimitri

Nevertheless, most of the time, the initial impression still proves right. ;)So I should have kept the DACMagic then? I suspect not, and I do think there's more detail with the Caiman, though sometimes I think it's not as sweet as I'd like.

[Themis]

DimitriSo I should have kept the DACMagic then? I suspect not, and I do think there's more detail with the Caiman, though sometimes I think it's not as sweet as I'd like.
The sweetness is the up-sampling feature.
You can do like me : have an upsampling and a non-upsampling dac (or a dac with defeatable upsampling), like this, I switch depending on my mood. ;) V-Dac is a cheap upsampling dac (if I'm not mistaken).

[Ali Tait]

Frankly, tracking subtle differences is very (*very*) hard... Sometimes the more you try to identify them, the more the seem to disappear. :( I have come to the conclusion that some differences can only be noticed on the long term.

Nevertheless, most of the time, the initial impression still proves right. ;)

Agreed.I can form an impression within seconds that often holds after days.Not always,but often!

[jandl100]

Frankly, tracking subtle differences is very (*very*) hard... Sometimes the more you try to identify them, the more the seem to disappear. :( I have come to the conclusion that some differences can only be noticed on the long term.

Nevertheless, most of the time, the initial impression still proves right. ;)

I think that rapid ABABAB comparisons can be misleading and can substantially underplay differences.

I was comparing the DAC section of my Arcam DV29 player with my Theta DAC last night - each plugged into a different input on my amp so a single press of a remote control button swapped between the two.

Rapid A/B comparisons usually resulted in a "it sounds the same" result .... but leaving each one playing for just a minute or so and then swapping back and the superiority of the Theta DAC became pretty damn obvious! (Darn - I was hoping to be able to sell the Theta! :eyebrows:).

[Primalsea]

It definitely a case of sum over averages when comparing hifi. I find that I have to listen to something for days to get a good idea of how it compares. During this time I have to swap for long periods. There has only been a few times when a change has been obvious and oddly mostly never on my own system!

[Themis]

I think that rapid ABABAB comparisons can be misleading and can substantially underplay differences.

I was comparing the DAC section of my Arcam DV29 player with my Theta DAC last night - each plugged into a different input on my amp so a single press of a remote control button swapped between the two.

Rapid A/B comparisons usually resulted in a "it sounds the same" result .... but leaving each one playing for just a minute or so and then swapping back and the superiority of the Theta DAC became pretty damn obvious! (Darn - I was hoping to be able to sell the Theta! :eyebrows:).
Yes, that's what I mean ! :)

[Vincent Kars]

One day I run into a post made by a guy working for Fraunhofer.
If he compares codecs for transparency, he uses samples of 2-3 sec max.
Otherwise you auditory memory will fail you!

Perception (One day I run into a post made by a guy working for Fraunhofer.)