What if you run the output threw the tone cap?

[BowerR64]

I use to be into R/C cars, not the toy ones but the high end ones you race competitively. I remember for a while there was alot of noise generated from the motor and one of the things that slowly became normal was using small capts to reduce the noise from the motor.

Can this be done to a pickup? A motor is very similar to the way a pickup works it uses coils and magnets. Im not real sure how the caps help reduce the noise but i remember it really did help radio glitching specialy on a noisy track.

 

[Artie]

Re: What if you run the output threw the tone cap?

Technically, it would work, but not the way you want. A small motor like that has brushes, and as the armature spins, arcing occurs. The arcing generates broadband RF. This was the basis of early radio tranmission. They'ld just hit a "key" that would generate a strong spark. The RF part of that spark could be detected miles away. If you've ever had an AM radio on during a thunderstorm, you know what I mean.

The problem with the noise a pup makes is twofold. Much of it is 60hz, and the RF part gets demodulated by the coil and thus, becomes AF. (Audio frequency) Any cap value that would remove that, would also remove the pickups signal. That is, in fact, what a tone control does, to a controlled degree.

Artie

Edit: To answer the question in your title, you can definitely do that. A cap is just a high-pass filter. You'ld just be filtering out the lows instead of the highs, depending on what value cap you selected. Thats the basis for my 59 de-mud mod.

 

[BowerR64]

Re: What if you run the output threw the tone cap?

See thats whats weird, when i got into car stereos i noticed that all the tweeters have these caps and i remember thinking to myself, whats that thing doing so i removed it and then the speaker had more bass. The cap cut the low end out so it only put out a high end frequency and didnt blow.

So for a while i ran the output of the pickup threw the cap because i thought thats what gave the bridge that thin edgy sound.

Then my dad told me thats not how it works, the cap is bleeding off the high end and im just all confused how and why it works. When its going threw the pot the cap makes the sound warm, yet on the speaker the cap takes the warm bottom out.

 

[Artie]

Re: What if you run the output threw the tone cap?

A capacitor passes high frequencies, and blocks low frequencies. The point at which that happens is determined by the value of the cap. Look at this diagram:

On the pickup, the cap "passes" the highs to ground. They're still there. They just circulate around the pup and never make it out to the jack. The pot, (not shown), is a valve that controls how much makes it to the cap.

On the tweeter, the opposite happens. The cap is in series and blocks lows, and passes highs threw it to the tweeter.

Make sense?

Artie

 

[BowerR64]

Re: What if you run the output threw the tone cap?

So if its paralell with the pickup itcuts the highs, and if its series it cuts the lows? or that just works on speakers?

 

[Artie]

Re: What if you run the output threw the tone cap?

Exactly. Thats the whole basis of my 59 de-mud mod. Its a certain cap value in series with the red and white wires. Just remember, for blocking lows, you'ld use a completely different value than for damping highs.

 

[JHN]

Re: What if you run the output threw the tone cap?

I tried with the search engine but did not find any value-frequency analogy for either parallel or serial connection.Is there any,or a not painfully difficult equation for this?

 

[SpiderVenom]

Re: What if you run the output threw the tone cap?

*brain explodes*