Sure. I own a small company which designs and manufacturers amplifiers. Prior to that my primary job was recording engineer and did service work on the side. My education came from maintaining and repairing studio equipment which was a "by ear" rather than "by calculus" affair. Keeping up with some consoles is somewhat like painting a bridge where when you finish painting one side you start right over at the other side because its started to rust. Some consoles generate so much heat that by the time youve finished capping it, you start back over, its a constant job on some designs which are imo abysmal because of that. Sometimes in the middle of sessions channels fail and need fixing. Sometimes the caps you have on hand to do an immediate repair may have the exact value and rating but are different that the channels next to it and when you put the channel back in the board you get an engineer, an assistant, a producer all telling you it sounds different to the point that you pull the channel and put it at the other end of the bucket because it wont work in stereo because of the caps you put in it, which were the exact value that ya took out. Works fine, measures to spec, just sounds different. How different? Eh, different enough that your stereo image is wack with closely matched mics. You go through this exercise a few times in your life and you'll never have a conversation like this again... What really piqued my interest in this years ago was prototyping an EQ with a decade that had pet caps in it, then putting in polypros once we built the board and measuring a different frequency response as well as different corner freqs. put in pet's that we had on hand which matched what was in the decade and magic, back to what we had before. Whats funny is that in our professional circles we never have these debates. People will talk a bunch of drunken shit at a trade show and not once in my life have I heard another manufacturer be dismissive about capacitors beyond poking fun at the hifi crowd. The amount of user evidence out there is staggering. You can look at professional recording forums and read threads about why does new gear X not sound like old gear X. As surface mount becomes more and more of an unescapable reality for manufacturers, users now sit and ask why the new small signal amp in brand x sounds different than the old one, and not the old one from the 60's. The old one from 2001. In some cases the answer is simply because the type of cap that is available for coupling in some surface mount designs today are all ceramic. And no matter how good COG is, it is never, ever going to sound like the old (old meaning what you could buy 5 years ago) film caps that are not available in surface mount. These are recording guys whose only job is to listen and they arent tech's at all. They dont know about caps and mostly dont pretend to either, they just know they had a ten year old amp in their console fail, got a replacement from the manufacturer and now the thing sounds different. And its the same exact amp, made from the same drawing, fabricated by the same board house that has been doing the work for ages. The only difference is the new amp is surface mount construction where the old one was through hole and the component selection is different because of that. same transistors spec'd to the same hfe, similar enough layout, only thing is different is the caps, theyd been using metal film resistors for years. I can go on an on... We dont sit around and wonder if caps sound different. We dont sit around and hear a difference and then "dont trust our ears" and second guess the universe. We sit around trying to identify what made the old gear that everyone is fiending after sound the way it does and do our best to make new designs that satisfy the expectation of engineers who use all this old stuff. If caps didnt have an inherent sound 1. any half idiot could make good sounding gear and ALL the cheap stuff that gets made overseas using the cheapest components possible to save money would ALL sound exactly the same as the high end designs they have cloned and 2. we would save literally hundreds of man hours a year by being blessed with the opportunity to open a distributors catalog, randomly pick any one of the hundreds of different ".01uf/250v" cap that comes up in a search, put it in the circuit and know it will work and sound the same, because caps apparently have no sound. This is not how it works. Anyway, this is an absurd depth to go to to suggest to people that it is worth some time to listen to a cap in a guitar. I have no horse in this race, its your guitar, your tone, your world. I like coming on here to learn about les pauls because it's my preferred instrument and this message board is an excellent barometer to judge the failures and success of gibson's marketing which is insightful for what we do now. Coming from a world of recording guys, which is a world of listeners (not to instruction from the internet, but to sound coming out of speakers) its odd to make a suggestion to hey dude, clip some leads in your guitar and have a listen to then be brought to task by prove it to me guy. Try it, dont try it, who cares. Watching people discourage others from even listening out of curiosity is just an odd thing and why I post this crap. Maybe all the caps you "tested" sound the same. I know I have been in that boat time and again. Its a lot easier to find 10 caps that sound the same than 4 that sound different. Also please consider, Im not trying to convince people of a single thing. Seems like the people that have their mind made up should get a high five, it's for everyone else who's on the fence. Have a listen. You might find something you like better than the disc cap in your guitar. you might not either but at least you discovered for yourself and didnt have to take my or some other guy's word for it.