How-To: Make your own graphite resistors from pencil lead

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By Sean Michael Ragan
Posted 2009/12/22 @ 9:16 am
Category Education, Electronics, Music, Science

Some audiophiles apparently think graphite resistors “sound better” than metal oxide or wound wire resistors. Whether that’s science or just myth, I don’t claim to know, but making one’s own resistors is pretty cool either way. Troels Gravesen’s tutorial shows you how. [via Hack a Day]

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6 Responses to How-To: Make your own graphite resistors from pencil lead

vivi on December 22nd, 2009 at 10:03 am said:

Won’t anybody tell him that the standard, cheapest resistors are made of carbon ? ^^

Different resistors types do have various noise and inductance characteristics however. Checking the manufacturers datasheets for actual data might be a good idea, as un-audiophile-like as it may be.

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Audiophol on December 22nd, 2009 at 10:03 am said:

Alas, the clay included in standard pencil and the sand included in the manufacture cause the resulting sound to be muddy and grainy.

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Simon on December 22nd, 2009 at 10:08 am said:

I am glad you have “sound better” in quotes and that the article takes a similar approach to that claim.

I see to recall exploding pencil leads by short circuiting them across power supplies (maybe it was, very dangerously, the 230v mains?) at school.

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erikscott on December 22nd, 2009 at 11:18 am said:

The cheap resistors for sale now are metal film types. It’s (slightly) difficult to find carbon composition ones because they’re noisy, and they have a tendency to change value as they age. Adding noise to a signal definitely changes the sound (grin). It could remind you of how stuff sounded on 1930s gear, then nostalgia kicks in, and the next thing you know you’ve convinced yourself you like it better. I’m going to call this one “Plausible”.

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anachrocomputer on December 22nd, 2009 at 1:32 pm said:

Tim Hunkin did a really good demonstration of a pencil lead as a resistor, in his series “The Secret life of Machines”. It was the episode about the light bulb, where Tim connects a pencil lead to his arc-welder, and turns it up. Followed by a few sparks flying when he uses the still-live arc welder clamp to brush away leftovers of carbon from his steel work surface! I think the graphite lead actually worked quite well as a light bulb filament, when enclosed in an evacuated milk bottle.

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Noah Buddy on December 22nd, 2009 at 11:40 pm said:

Similar to Simon’s comment, another way to clean the wax off of the ends would be to use a power supply with controllable current.

It does take some practice to do it without breaking or burning up the pencil lead.

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