# Cable capacitance?

Discussion in 'Pickups & Electronics [BG]' started by friedtransistor, Dec 31, 2013.

1. ### friedtransistor

Dec 9, 2013
I just decided to do an experiment. I hooked my cable to a 555 timer circuit, and then used capacitors to match the frequency of the cable's capacitance. My cable is about 495-500 pF, which means that a 1M resistor in series with it gives a lowpass response of about 320 Hz. Gives my guitar a jazzy tone with the resistor. Haven't tested it on my bass yet, my bass amp is out of order until I sort the mess of hair-thin traces Fender decided to coil all over the pcb for the grounding. Is there any way of getting around this high capacitance without usig a buffer? I mean, I can make a pretty mean little buffer/booster, but I'd rather not have the hassle of dealing with it. Would I need to solder resistors or caps into the plugs of the cable to counteract the cheapness? :b

Jun 25, 2008
3. ### friedtransistor

Dec 9, 2013
Sorry, I didn't explain my calculations. Guitar->short low cap cable->1M resistor->long cable under test->amp. The capacitance to ground in the cable with the resistor in series acts as a simple 1 pole RC lowpass. 1/(6.28*0.000000000495*1,000,000)=~320Hz. Unless there is a better way of measuring capacitance other than using a 555 timer wih the cable as a cap, taking the output frequency, then using other caps instead of the cable untill I get the same output, then adding up the caps. I had to use a 470pF parallel to a 15pF to get the same oscillation.

4. ### BlueTalonHappy Cynic

Mar 20, 2011
Spokane, Washington
Endorsing Artist: Turnstyle Switch
You could go wireless, that would solve the capacitance issue.

5. ### friedtransistor

Dec 9, 2013
And be way outside my realm of expenses. Idk, I've dealt with it this long, I probably just continue using it until it breaks, then move on to a low cap cable. Maybe I'll just make a buffer. Just need to order some parts, and since I got a power supply for christmas, order a dc jack. I'll have to wait, though, until I figure out what other project I want to make, so I can save on the cost of shipping. But I guess I need to tackle one thing at a time... *continues waxing guitar fretboard*

6. ### dune2k

Sep 26, 2009
Germany
Do you hear a difference when you use a shorter cable (bass -> cable -> amp)?
If not don't make up a problem where there is none.

Also: Why did you put a 1M resistor in series with it? What's the idea behind it?

Dec 9, 2013