Anyone try Synergistic Research PHT...

All I say is that there IS observer bias, and it works in a major way to affect our sense of things. Where did I say that I can measure it or know for sure the degree to which it has affected a review? If you thought I meant to say that, or anything like that, you are mistaken. But just because we cannot fathom someone else's observer bias does not negate its effect on his or her review or opinion. Having said that, is it not logical that spending a substantial sum of money to purchase a device would tend to cause the buyer to be subconsciously biased in favor of the device? Thus I think cost has a predictable effect on subconscious bias. Likewise, the color and feel of an object will affect our perceptions of it. (For example, is the faceplate gold, silver, or black? Is it made of really thick heavy metal or flimsy looking? Are the knobs "really cool"? Any or all of such factors may affect one's opinion of the sonics, up or down.) So, here is how I use the notion of observer bias as regards audio: I take anyone else's opinion of an audio device with a large grain of salt. If ten out of ten knowledgeable listeners agree, then I might sit up and take notice of the device, or ignore it, depending upon the consensus of a quorum of persons I trust.

"Where did I say that I could measure it or know for sure the degree to which it has affected a review?"

In your first post. I never said you could measure it or know for sure, but you appear to be implying, in a strong manner, your prediction that there will be a positive bias.

"11-17-14: Lewm
I have read several glowing subjective "reviews" of this item, and I will predict that you will be swamped with similar."

Read down a bit further, and you get to your famous quote, that implies the positive reaction is due to listening bias. Just to be clear, I'm not saying that can't or doesn't happen, I'm saying that a positive reaction in the above example is not the only reaction. The reaction could just as easily be negative. We just don't know. Why get so worked up over the whole issue?

I've been watching this thread in amazement and quite surprised in the emotional outcries it caused, which was unintended on my part.

Well, I tried the blue velvet PHT today. The device weighed around 0.015g. I heard no discernible difference at all. Had a friend of mine blind me and put the device on and off without my knowing which was which. We did not account for its weight effect on VTF due to the changing out sequence. Cart was a Dyna XV-1t. We then did it on my friends system too on a Lyra Atlas. Same result - no appreciable difference in sound. Bottom line is when you have your cart dialed in properly, I'm doubting one would even desire a tweak such as the PHT. At least the blue one. Of course, everyone's system and listening preferences (and probably bias too) will vary.

"Of course, everyone's system and listening preferences (and probably bias too) will vary." You forgot aural acuity, critical listening aptitude/experience, familiarity with real instruments/vocals in a live venue and(perhaps) ear wax. There are a plethora of variables! Synergistic offers a money-back satisfaction guarantee. Any Dollar-induced bias should be subtracted from the opinion equation, as it won't cost you anything, not to like it. Then again; those with the preconceived notion that it can't possibly make any difference, already have a built-in, set in concrete, bias against such tweaks.

"Then again; those with the preconceived notion that it can't possibly make any difference, already have a built-in, set in concrete, bias against such tweaks."

Yes, but in a case like that, you are moving away from what we are discussing here with listening bias and moving into other areas. A view like that is more of a ego/personality issue. I think its likely that someone with such an extreme position, can hear a difference, but will not admit it. You don't see too many people like that here on Audiogon, which is why I like this site over the others. The other sites are overrun with that type of thinking. They call themselves objectives. I call them super subjective. If we had this same discussion on a site like Hydrogen Audio, they would have shut it down after the first couple of posts and kicked us all off. lol.