Logarithmic vs. Linear

It’s a fairly ongoing debate truth be told, with plenty of contradicting information on the subject (in part due to a change in coding in the early 90s muddying the water, as well as different standards set by different companies in the modern day, and of course – personal taste) but we’ll try to remain impartial on this one and explain the advantages and pitfalls of each style.

Linear pots (usually Alpha B) gives a true representation of the output, (so 1 on the dial is 10% of the output, 5 is 50% and 10 is 100%). For this reason you’ll find them used all over the place, (rightly or wrongly) doing a variety of jobs,

Logarithmic (alpha A or Audio Taper) are a little bit more specialised. They offer very narrow control range. Electrically speaking, by running though 1 – 6 on the dial, you cover 0% - 15% on the output, then tracking from 6 – 10 covers a much larger range from 15% - 100%.

Probably the easiest way to explain the whys and what fors, is to break down the pots into real life situations you’ll find in your guitar.

Volume control

Linear

As a volume control, you’ll mostly find linear pots on Import guitars. In this case, a true representation of output lends itself really well to bedroom playing. It’s purely aimed at a target market looking to keep the guitar quiet and controllable, hitting low volumes during practise.

Logarithmic

You’ll mostly find logarithmic pots on higher end instruments acting as the volume – in these cases the guitar is obviously targeted at gigging musicians. The guitars never going to be played quiet for extended periods so a log pot actually gives a nice “sweep” at the top end which lends itself to moving through different volumes whilst playing (moving from 10 to 8 on the dial will pretty much half the volume). This gives a great effect when used in combination with true amp overdrive.

Relation to our hearing

Obviously if you play on 10 constantly, its not going to make much difference, the arguments only really start when you’re changing volume.

The main point to take into consideration is that the human ear works on a logarithmic scale. So whilst moving through volumes during playing, it pays to try to match the way the ear works. The problems start when you consider that our hearing is far superior to anything electrical, so the “curve” of a log pots output never really matches up perfectly, so although the sweep feels more natural, it’s still not perfect. Speaking personally, I try not to think of the curve as matching our hearing, instead I think of it as a “sensitive” control that allows better control at high volumes through less movement.

The pitfalls

The downfall of this “theory” is that it flags up the log pots main cause of concern. Most of the numbers on the dial (1-6) only give access to a very low output. This leads us back to the way the ear works – you can hear a pin drop just as well as you can hear a jet engine, the ear should be able to pick out the lower volume sound the same way it picks the higher volume, and your brain should tell you its quieter.

Unfortunately, its not that clear cut, and this isn’t a perfect world, and although some people can either live with this feature (even use it to their advantage), others find the lower volume settings next to useless and the sudden drop off (usually between 6 and 7) quite annoying (some describe it as acting as a kill switch – basically muting the guitar)

So linear volume then?

On the back of this – the linear pot seems the natural solution, but as with most things, it just isn’t that simple. Although the linear pot is great for low volume playing, and it’s easy to see where you are etc – they sweep in a way that isn’t conducive to human hearing. It sounds like its jumps from one setting to the next, and the ear finds it rather unnatural.

But not all is lost

Fortunately, “sweeping” from low volume to high volume still sounds perfectly fine on a log pot, but moving around at low volumes is still something that’s never been quite perfected as yet. Luckily, its not something most of us do.

In Conclusion

In closing on the volume topic – if you like making use of volume control whilst playing, then logarithmic control is probably your best bet thanks to the more natural curve of the output, but if your looking for a straight forward control solution at set volumes, where dial position represents the output, then linear pots are a great solution.

TONE

Coming Soon

250K or 500K?

As a quick and easy rule of Thumb, we use this guide.

1Meg = very bright sounding
500K = bright sounding
250K = warm, vintage sounding

Problems can arrise when your running a Humbucker in the same guitar as a Single Coil, but these are the results we've found.

1Meg = bright HB, shrill SC
500K = warm HB, bright SC
250K = muddy HB, warm SC

Basically, you'll always suffer slight compromise by running single coils next to humbuckers when it comes to pots. The saving grace is that 90% of use have been to too many gigs to notice any real differance. Comes down to a litle bit of audio snobbery at the end of the day, which is never a bad thing.

All the best

Axesrus