Capacitors question - DS1 Keeley Mod

[maurice]

I'm looking to mod my Boss DS-1 with the Keeley Seeing eye & ultra mods.  I'm using this as a guide http://www.instructables.com/id/Modify-Your-Boss-DS-1/?ALLSTEPS

I have all of the components as existing parts within my supplies but all my caps are ceramic or electrolytic.

Would using ceramic for all the caps be suitable or would I need to order film caps?

Here's the mod parts list (caps only):
1.0uF 50V Stack Metal Film Capacitor x 4
0.1uF 50V Stack Metal Film Capacitor x 5
0.047uF 50V Stack Metal Film Capacitor x 1
47.0pF Capacitor x 1
220pF 50V Monolythic Ceramic or 220pF 500V Silver Mica Capacitor X1 (I'd go with the ceramic one, its

[GibsonGM]

I'd get the film caps, bud.  Ceramics are sorta "limited" in their quality...they exhibit distortion at certain frequencies. Now, there are arguments about whether we hear this much or not, and some like that distortion in certain places...but I'm pretty sure this mod intended to NOT have the grainy distortion of ceramics, LOL...use the list to order.  Probably < $5, just have to wait for them to arrive (the hardest part!).

[maurice]

OK, thanks.  I have a couple of follow up question whilst looking to order the film caps.

1) Do they have to be metal film or will polyester film suit?

2) I've read that using caps higher than 50v can suck the tone.  is this true?

...Of course poly caps and metal film caps above 50v are easy to source.

Note - I'm in Australia and looking on ebay/aliexpress as a primary source if that makes a difference (Jaycar is a rip)

[PRR]

> Do they have to be metal film or will polyester film suit?

Two different questions. A cap is sandwich of conductor and insulator.

The conductor is usually metal (electrolytics use a semi-liquid on one side). You may be linking at "metalized", the metal is not honest foil but a thin spray of metal; this is fine for our audio purposes.

The insulator may be glass, ceramic, mica, paper, paper/wax... but in sizes 0.05uFd to 1uFd we today often favor some kind of plastic. Poly this or poly that is not a critical thing for basic pedal building.

> I've read that using caps higher than 50v can suck the tone.

Always interesting to hear what you can "read" on the internets.

"Over-volt" caps tend to be larger (and cost more). Yes, if you find a 400V 10uFd foil/film cap and use it in a high-impedance point, the sheer size of the cap will spew treble to the world more than a small cap. But it really has to be "OMG big!" to make a problem. (I once did use OMG! input caps on a build, they dominated the layout, but I knew the treble-suck would be supersonic in this low-impedance node.)

Think like the greats. Nearly all classic pedals were originally (and still) built with low cost parts.

I would discourage "ceramic" above 1nFd because it "can" have a "sound" and not always sweet. One problem is that modern ceramic is the cheapest cap over a range of sizes, and comes in funny names like "multi-layer stack" without clearly saying which type of ceramic it is. It may help to know what "pedal caps" look like, shop for those, avoid funny things that belong in cellphones.

[GibsonGM]

> Do they have to be metal film or will polyester film suit?

Think like the greats. Nearly all classic pedals were originally (and still) built with low cost parts.

[maurice]

Awesome, thanks guys!

So in summary, poly with any voltage would be ok?

[bluebunny]

So in summary, poly with any voltage would be ok?

Yes, unless you find some unlikely beast with a rating lower than your 9V power supply (I've seen 6.3V electrolytics, but I think film this low would be physically difficult).