Jewellworks
Tele-Holic
ive heard electrolytic's arnt good for tone section. there are so many cap types (film, silver mica, ceramic, poly) what works best for audio filtering?
what type capacitors are best for tone controls?
- Thread starter Jewellworks
- Start date
Swirling Snow
Tele-Afflicted
Any non-polarized cap will work. Most people can hear no difference.
I use poly film because they're cheap and +-5%. They're not very pretty, if that's a concern, and I don't think there's any special magic properties ever attributed to them.
Ceramics are super popular for guitars. They're also easier to read at a glance than the film (at the least the ones I have, which have tiny tiny writing on a tiny edge).
Ceramics are super popular for guitars. They're also easier to read at a glance than the film (at the least the ones I have, which have tiny tiny writing on a tiny edge).
In an amp? Ceramic disc and poly/film/dip caps are good. Electrolytic caps are used as voltage reservoirs and for coupling/decoupling between circuit stages in amps. In the tone circuit however, caps are audio filters. That's the difference.
You can use silver micas for low-capacitance requirements, but they cost more. They're not necessarily better for this application but many amp builders use them because they're used in high-end audio and other applications where stability and low loss are critical.
In realty, a guitar amp is not that critical about caps. Polys and ceramics are plenty accurate and stable. Spending more money does not get you moar toanz when it comes to caps.
You can use silver micas for low-capacitance requirements, but they cost more. They're not necessarily better for this application but many amp builders use them because they're used in high-end audio and other applications where stability and low loss are critical.
In realty, a guitar amp is not that critical about caps. Polys and ceramics are plenty accurate and stable. Spending more money does not get you moar toanz when it comes to caps.
In a passive tone circuit in a guitar, any signal that goes through the cap goes to ground, so you aren't going to hear any difference the material makes. It's a drainpipe. Whether it's pvc or copper or whatever isn't going to affect the flavor of the water.
Edit: Hey look, I'm in the DIY Amp forum! Never mind.
Edit: Hey look, I'm in the DIY Amp forum! Never mind.
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I'm not an amp builder but I know for guitar tone controls the cap type is completely irrelevant. If you wanna pay for anything, pay for tight tolerances. I presume the same can be said for caps used in similar situations within an amp, and remember the whole system is lo-fi so I'd bet the audiophile hype can be disregarded.
Sort of related, Brian Wampler has a great video somewhere on youtube demonstrating the tube screamer circuit on a breadboard. He switches out components with varying tolerance stack ups and it explains away any and all differences between all TS type pedal circuits. Again, pay for tight tolerances if anything, so you "know" how much the cap's nominal value affects the given circuit.
Sort of related, Brian Wampler has a great video somewhere on youtube demonstrating the tube screamer circuit on a breadboard. He switches out components with varying tolerance stack ups and it explains away any and all differences between all TS type pedal circuits. Again, pay for tight tolerances if anything, so you "know" how much the cap's nominal value affects the given circuit.
Assuming we're talking amps in this forum, and noting I don't take cap wars seriously: At least for audio filtering in an amp, we have some objective criteria. Is it quiet, is it stable, does it have *measurable* filtering qualities?
First, a question. I've read someone smart (no longer recall who) saying that for very small caps on pots, polypropylene was objectively better than polyester. Sadly, they didn't explain why they said that. Anyone know more?
Second, a couple ideas I've "heard inferred" -- some may be well-known facts, some may be pure fairy dust. Silver micas are felt to be *potentially* noisy, some more than others, maybe even within the same brand/batch. CDs are said to be unstable over time -- a common point is they're affected by humidity.
Some high-end users say that *polystyrene* caps sound smoother, less grainy, than silver micas in 'treble' and 'bright' slots. (I've used several, and they do sound great. Better? No idea).
And (this is either the most scientific or the most bogus, you choose) some say *NOS* CDs have 'comb filter' qualities that actually gave vintage amps part of their sound.
mountainhick
Tele-Afflicted
In amps there are numerous and entirely common uses of ungrounded tone caps in line with the signal.
This is an amp forum.
cousinpaul
Friend of Leo's
I use ceramics in my guitars but I know some people who swear by PIO. I've had a block logo Dist+ going on 40 years or so. It's all CD and I detect no degradation. As far as amps go, I've got a tweed copy capped with Mallory 150s and SOZO electrolytics. Pretty standard stuff... My other amp is a Quilter head I'm assuming is stuffed with SMD components. I don't lose sleep over it but sometimes wonder about the tolerances of the tiny SMD components. I can tolerate them in my laptop or phone but they creep me out in an OD pedal. Go figure...
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Hmm, electrolytics? Maybe "tone section" is ambiguous. When you said silver mica etc, I thought you meant little bright and treble caps, but maybe you mean big caps like Fender's 'bass' and 'mid' caps, where electrolytics are used most commonly? Can you clarify -- before the guitar guys take over the thread completely?
mountainhick
Tele-Afflicted
The problems with "What's new" feeds.before the guitar guys take over the thread completely?
tubedude
Tele-Afflicted
Fender, or any mfgr, doesn't use electrolytics in bass or mid caps. They used foil caps or metalized film. Most amps now use metalized film (smaller, cheaper) for those positions and ceramic or silver/mica for the treble and high bypass positions.Hmm, electrolytics? Maybe "tone section" is ambiguous. When you said silver mica etc, I thought you meant little bright and treble caps, but maybe you mean big caps like Fender's 'bass' and 'mid' caps, where electrolytics are used most commonly? Can you clarify -- before the guitar guys take over the thread completely?
Paul G.
Friend of Leo's
Polypropylene is harder to spell than polyester, so it must be better. QED.
TequilaCaster
Tele-Holic
Some builders use Polyamorous caps, which is where they parallel two or more caps of different types to makeup the desired capacitance value, in order to add some spice and swing to the amp.
tubedude
Tele-Afflicted
I see this in power supplies where a "fast" cap foil/film is paralleling an electrolytic, or in audiophile amps, using sometimes three caps in parallel of decreasing value. Say a 10uF electrolytic, a 1uF foil/film, and a 10nF polystyrene.
TequilaCaster
Tele-Holic
I have seen it on a couple of Dumble schematics, notably for coupling caps, but also in the tone stack. But who the heck knows if those schematics were accurate. But yes, the technique is often seen in audio power supplies.
jonrpick
Friend of Leo's
Some builders use Polyamorous caps, which is where they parallel two or more caps of different types to makeup the desired capacitance value, in order to add some spice and swing to the amp.
Actually I'm pretty sure Ken Fisher did this in his Trainwreck amps!
One that will fit inside the control cavity.
