225P Polyester Film / Foil type capacitors
!!!!!!! DON’T BE FOOLED BY UNKNOWLEDGABLE OR DISHONEST SELLERS !!!!!!!
NOT Type 715P Polypropylene, which are cheaper from Sprague!
I could sell 715P, and my cost is about 20% less. I don’t because 225P is a far better cap.
!!!!!!! DON’T BE FOOLED. CHECK IT OUT FOR YOURSELF !!!!!!!
See Vishay’s website for the data sheets for 225P and 715P to see what I am talking about (Vishay bought Sprague in 1992, and still produces both types of caps)
http://www.vishay.com/docs/42016/225p.pdf
DON'T PAY 8-10 BUCKS A PAIR FOR CAPS THAT ARE CHEAPER FROM THE SUPPLIER, AND AREN'T THE TYPE USED BY YOUR GUITAR MANUFACTURER!
*A note about 400V vs 200V. Just like certain sellers are claiming that 225P caps are not Film / Foil, other sellers are claiming that since you don't have 400V running through your guitar, you don't need 400V caps. While it is true that a guitar's signal is only a small voltage, it is also true that the physical size of the dielectric material has a huge effect on the tone. These are big and beefy in size, but not too big to fit like some 600v caps may be.
There is also talk of Polypropylene caps (like 715P) being "similar" to Mylar caps, but having an extra extended temperature stability up to 105C. I can guarantee that if your guitar ever reaches 105C, you won't be playing it anymore. As far as being "similar", "copy" instruments are similar to the originals, but that doesn't make them sound like the originals.
715P caps are great for high heat applications (like in amplifiers), where the warmer sounding 225P won’t hold up, but using a Polypropylene Cap (715P) in a low heat application like in your guitar is a compromise.
One more note before I get off of my soapbox. Polypropylene is definitely a more stable capacitor material than Film / Foil Mylar, and both are more stable than paper in oil caps like Bumblebees or Vitamin Qs. Stability doesn't necessarily equal tone. If you are upgrading your caps, I'm pretty sure you are looking to improve your tone.