Upgrading Quicksilver preamp or amp caps -- warranty impact?

If I were a mainstream mfg, I too would likely focus on Reliability, Availability, and Cost to stay in business. All key factors. As long as the "standard" version lasts and sounds "good enough" for 95% of the mainstream consumers, it keeps variation away, keeps costs down, and makes the product more affordable for consumers. Makes good business sense. Let the other 5% of DIY’ers do what they want to do and take on the risk themselves, etc etc. Less headaches for the manufacturer. It also comes down to those who want upgraded vs. standard. Standard works fine. And, sometimes changes or upgrades don’t always work better, fwiw.

as mentioned, the manufacturers can not afford to install high end copper foil caps, they retail price increase would just be too much. Also if you want to go further, replace the bias and plate load resistors with wire wound. will make the amp much quieter, and let more micro detail come through. But again, not cheap.

@hilde45 I have reached out to Mike recently about using lower gain tubes and have not as yet heard back. 
Let us know if you do. 
P.S. I may be putting my current version of his Line Stage Preamp up for sale soon as it’s not a good fit for my system.

@johnss My system is very, very quiet. I guess units can differ.
@gochurchgo If you put your line stage up for sale, I bet it goes quickly!

If you work on the amp changing caps, if its not done at the factory you void the warranty plain and simple. To get around this problem we offer coupling cap options. We use the copper foil V-Caps as they are some of the most neutral made, and have the further advantage of reliability.

That latter aspect is important. We've auditioned a lot of parts and one thing I've noticed is that while nearly all of the paper and oil capacitors sound excellent, over time they can develop a slight amount of electrical leakage. In an amplifier circuit this can throw off the operating point or bias of the circuit! That in turn can fry power tubes and output transformers- definitely not for the faint of heart to put it lightly.


So you might want to consider that when looking into boutique capacitors.