When introduced in the late 1960s, Sprague Orange Drops set the standard for "modern" capacitors in appearance and performance (they are now made by Cornell Dubilier). As some of the first readily available, high quality capacitors in values suitable for audio use, the Orange Drops achieved wide spread uptake among electronics manufacturers, including amp makers. This is probably one of the reasons why they are associated with vintage tone.
The tonal reality is that there are no measurable differences between the various types of capacitors of the same value in audio applications;
- high quality;
- consistent/accurate values;
- look impressive.
- bulky, so hard to use where space is limited.
Beware of knock-offs
Just because a capacitor is orange in colour, doesn't make it a Sprague Orange Drop. Buy from a quality Cornell Dubilier reseller like element14.com or specialist suppliers like those found on Amazon.