Mainstream Phono Stages Incorporating Premium Branded PCB Parts - Do They Exist?

@ lewm

Thanks for the thoughts, but it seems odd to me that you would jump to such conclusions with so little information.

To address each point:

1st - Yes, I do know exactly which Caps were installed.

2nd - Yes, I do.  The difference in SQ created by the new caps is profound, not subtle. (strike two)

3rd - The original caps were the standard caps for this Ayre Acoustics V-5xe (~ $5K Stereophile "Class A') amp.  This preamp was, and still is, very well regarded.  The new, higher-line caps only made it better.  So, again, it is not clear why you would suggest that they 'might have been 'very low grade' (strike three).  

If you want a photo of the new caps, just send a PM.

Returning to @Wescoman's original question, my answer remains that the original manufacturer may be a great source for identifying higher-line parts (often from that manufacturer's higher product-line), and thus, maintain the intended SQ qualities. 

Furthermore, because these 'higher-line' were originally evaluated by the manufacturer, in their topologies, they may actually sound better than other, random premium-branded parts.

. 

I did not come to any conclusion. I was speculating. Sorry to have offended you. Glad you’re happy.

I extend my sincere thanks to everyone who replied.  The myriad (and scope) of responses reflect a keen interest in the topic.  As a result, I'm better informed and acknowledge my naïveté regarding audio equipment design, product manufacturing, and quality control initiatives impacting signal quality.  The cost/benefit analysis and technical knowledge required to be successful in the business is substantial.  I learned much from the discussion.  Much appreciated!   

My Experience had and the one which produced a Phonostage that I was not only happy to support being built, but also extremely satisfied with owning. Took place when I rolled the dice on two components. 

I bought in a Copper Foil Cap' at a value the EE was extremely reluctant to use, and Z Foil Resistors that the EE was reluctant to use because of cost in relation to parts and discard from matching. 

The Copper Cap's produced the smile, usually seen when things liven up.

The addition of the Z Foils produced the Cheshire Cat Grin, that is the sign I am selling my soul to get this one. 

In my case the addition of a Particular Brands Design for a Resistor brought the End Sound to one I was not willing to be without. 

This Phon' has been demo'd to quite a few individuals who have been very vociferous with appraisal given. I would suggest the Subjective Evaluation is more of a Collective Evaluation, where findings are notable. 

Pindac, if you are referring to copper foil in oil capacitors, especially those marketed under the Jansen (sp?) or AN name, I have found them to be unreliable when asked to tolerate voltages that are "high" in a tube circuit, but well within their stated ratings. Thus there is no excuse. I have had two catastrophic failures, and now I don’t use them. In a solid state design, where voltages are much lower and way below the voltage rating, perhaps there is no danger. Otherwise, yes, they sound good.

The Z foil resistors I believe are the same as the TX2575 resistors I mentioned, I think.  I associate them with Vishay and used to call them "nude Vishay" resistors.  Somehow Texas Instruments markets them at least in the US. Historically, I think they are like Vishay S102 resistors which have/had a plastic casing around the resistive element.  Turns out they sound much better "nude". But very expensive.