[avahifi]

Can a 10 percent value difference be audible?

It certainly can be, depending upon the circuit design.  For example, normally there is more than one pole point in a given circuit and good design will set up one pole to be dominant for stability reasons.  Inadvertently making one pole point 10 percent higher, and another 10 percent lower may very well drive a unit into instability.  You will hear this big time.

Regards,

Frank Van Alstine

[JohnR]

Thanks, I was referring to this statement:

You also risk changing the phase gain characterises of the two channels, and if they do not tightly matched, imaging is screwed.

[WEEZ]

NOTE: This will be a non-technical post

Many times, it seems that when 'technical' guys and 'subjective' guys get into discussions..here in The Lab, or elsewhere....many times they seem to talk 'past' each other. 

In a former life, I had the opportunity (privilege) of managing a project where the staff were all engineers. (At times, it was like herding cats  .) We were designing and marketing an electrical product for a specific application where the end user had specific performance goals that needed to be achieved. In the end, two different proposals were made to the customer...both of which met the objective. The customer did his own evaluation of both. One cost 3% more than the other. Guess which one he chose? Answer: he didn't choose. He deferred to our recommendation. Which did we recommend? The one that cost 3% more, of course. (hell, we weren't stupid )

Seriously though; there is a small builder of amps out there (sturgus and Scott F know who I'm talking about ) who will sell you an amplifier with 'good' curcuits and parts at a base price. He will sell you 'upgrade' versions of that same amplifier with 'premium' parts (in varying degrees) up to approx. 4 times that base price. "4" times you might ask? Wow, that's a lot, you say. Yup. But the choice in parts (and hence the price) is the result of not only higher cost parts, but the time and effort that went into testing and matching those parts. And then evaluating the final product all over again. I'm sure once the engineering work is done (overhead?) he would much rather sell the 'premium' version(s)...but I'm sure he sells all versions.

What's my point?  I guess it's partly that I would rather trust the designer AND my own ears when I buy something...not 'experiments' by novices randomly swapping parts. For the record...some 'premium' caps DO seem to sound better. And resistors too...but I'll leave the engineering to the experts.

WEEZ

[Occam]

.....
Mr. F. you stand before a mountain you haven't begun to climb yet you somehow feel you are qualified to comment.

Indeed, Scott will never be the electrical engineer that you are. Conversely Daryl, you stand before a itsy bitsy hummock of dirt that you seem unwilling to transverse. While I do admire your Einstein like ability to solve problems via thought experiment, audio really isn't cosmology/theoretical physics; conclusions really can be tested empirically, with little effort.

Do you really think it out of place if I don't believe you unless you have quantifiable reasoning?

I would prefer quatifiable measurements, as opposed to your quatifiable reasoning. Then again, thats just me.....
Nor would I expect anyone to believe you without some empirical verification of your assertions.
Given your reasoning on signal coupling capacitors, I'd assume you'd believe that a 220uf UCC SMG 50v electrolytic would make a better coupling cap than a .47uf Rifa/Evox 50v MMK metalized polyester cap  into a 47k load????. (same voltage, and approx equal size) Slap it between a dc coupled pre and a dc coupled amp and you could actually hear the fruits of your quantifiable reasoning. A single 4pdt(center off) switch would allow you to compare SBT, in stereo, between  electrolytics and that cheap film cap, or between the electo and a straight wire. Although empirical verification is boring and trivial, some here might benefit tremendously from such efforts
I find your posts interesting and unique in perspective.