Sprague vs. Mullard "Mustard" cap in a Tonebender Mark II

[mordechai]

I'm building up a TB Mk II on vero (first time doing it that way), and I"m trying to use as many vintage, high end parts as possible.  I have ordered one of those enormous Mullard "Mustard" caps for the 100n cap between Q1 and Q2, but I have a feeling it just won't fit onto the board I've prepared.  I also have a few old Sprague Orange Drop caps of the same value, which I think WILL fit. 

I want to get as authentically "vintage" as possible, and I've seen both the Mullards and Spragues used in old units...but mostly the "Mustard" caps in the 100n position between Q1 and Q2.  All other things being equal, will these caps significantly affect the tone in notably different ways?

[stallik]

IMHO, old caps have much mojo. Mojo is the addition of extra noise and lowered accuracy due to the age of the component which is well past Its sell by date. The visual look of these old caps is what makes them sound better.
Recreate a vintage pedal by all means but why not lower the noise floor by using modern components? Having said that, I popped some new electrolytic caps into old paper cap sleeves and one listener swore that the 'old' caps sounded better.

[merlinb]

All other things being equal, will these caps significantly affect the tone in notably different ways?

No.
Mallory 150s, Mullard mustard caps, and Orange Drops (up to 1000V rated) are all plain-Jane metallized polyester caps, the same as any cheap plastic caps.

[thermionix]

I'm not sure, but I think the mustards might be film and foil.  They are good caps, but obviously not magic.  In tube amps, I prefer mustards (and most others) over orange drops, but in pedals I usually use the cheap green mylar chicklet caps.

[Electric Warrior]

Right, Mustards are film and foil, but Sola Sound rarely used them. The 0.1µF usually was a metallized polyester film cap made by Iskra, the 0.01(5)µFs were mostly either Wima TFM (also metallized poly) or Iskras (metallized poly or styroflex).

Marshall used a 0.1µF in their version of the Supa Fuzz, though..

[mordechai]

Right, Mustards are film and foil, but Sola Sound rarely used them. The 0.1µF usually was a metallized polyester film cap made by Iskra, the 0.01(5)µFs were mostly either Wima TFM (also metallized poly) or Iskras (metallized poly or styroflex).

Marshall used a 0.1µF in their version of the Supa Fuzz, though..

So, in your view, if I used some decent Panasonic or Topmay reddish-brown chicklet types or some Greenies for the 100n interstage and 10n output caps, the tone difference won't really be discernible compared to the vintage, "chiq" Mallory, Sprague or Mullard caps -- provided my other components meet vintage specs for the circuit?  This is because, mustard caps notwithstanding, poly film is poly film at the end of the day?

[merlinb]

This is because, mustard caps notwithstanding, poly film is poly film at the end of the day?

Yes. And because the signal voltages in a pedal are too small to induce polyester capacitor distortion, and even if it did it would be masked by all the distortion happening in the amp and speaker.