Mark Hammer BBD article in Premier Guitar

[g1]

Way to go Mark, great article!

Behind the Bucket Brigade | Premier Guitar

[Chuck H]

Not even a pedal guy. Had a good time reading the whole thing

We could have done without the picture

JK! Making the forum proud!

[tboy]

I just now finished reading it. Way cool, Mark!

[oc disorder]

Agree with all comments above. Well rittin ! We all obviously need a psychologist to s'plain complikated stuff to us...

"We could have done without the picture " Well it kinda suits the "about the author" particularly the carefully chosen text delay
just after ....He gets up in the morning and thinks........ !

[Mark Hammer]

Not even a pedal guy. Had a good time reading the whole thing

We could have done without the picture

JK! Making the forum proud!

Thanks, fellas. You should have seen the picture I tried to get them to use. Lucky for you that Shawn Hammond told me it was too grainy. There are some things you can't unsee.

Shawn "spiced up" the language in a few places, but didn't take anything away from the content or clarity, so it all worked out. T'was a pleasant experience all round, and Shawn was very complimentary and easy to work with. I gather submissions are more likely to come in promptly and on time when they're not coming from gigging musicians, so he was appreciative of the change. We'll see if I get any more work from them out of this. I'd kind of like to do a short-run column directed at older and newly-retired players who are dusting off their guitars in storage, trying to get their chops back again, and reclaiming their youth. Nobody really publishes anything directed at that crowd....MY crowd.

[Chuck H]

Well it got me excited. Now I want one of those pedals! Maybe I'm weird, but Something about a string of capacitor buckets appeals to me more than digital. Of course everyone here over the age of 35 (and that's probably most of us) have owned one or more of these devices and liked them. Nice work whipping up the interest. I hope that the visitation of older technologies and the specific nuances they bring to guitar tone will always be a part of this genre and articles like yours (and the savvy to get them published) help to keep it that way

[rjb]

Great article. I learned a lot. However, I do have a niggle over one word:

Now let’s talk about the second kind of noise. We may think of BBDs as providing a seamless, continuous representation of the input signal, but in actuality there are teensy-weensy steps between each successive sample, and those can create the illusion of high-frequency content riding on top of the actual signal. This is referred to as aliasing noise.

Aliasing happens when your signal has components above 1/2 the clock frequency and you hear the difference between those components and the clock. Like, if your clock is 10kHz, and your (non-low-pass-filtered) guitar signal contains harmonics at 6kHz, you'll hear noise at 10kHz-6kHz = 4kHz.
Aliasing - LabWindows/CVI 2012 Help - National Instruments

Would the "right" term be quantization noise?
Quantization noise is related to the error generated when a continuous signal is sampled into discrete steps.
But that term usually applies to rounding error between the analog input voltage to an ADC and the output digitized value.
There must be a proper term for BBD stair-step jaggies noise- but I'm pretty sure it's not aliasing noise.


Later,
Mr. Noodge

[nickb]

Great article. I learned a lot. However, I do have a niggle over one word:

Aliasing happens when your signal has components above 1/2 the clock frequency and you hear the difference between those components and the clock. Like, if your clock is 10kHz, and your (non-low-pass-filtered) guitar signal contains harmonics at 6kHz, you'll hear noise at 10kHz-6kHz = 4kHz.
Aliasing - LabWindows/CVI 2012 Help - National Instruments

Would the "right" term be quantization noise?
Quantization noise is related to the error generated when a continuous signal is sampled into discrete steps.
But that term usually applies to rounding error between the analog input voltage to an ADC and the output digitized value.
There must be a proper term for BBD stair-step jaggies noise- but I'm pretty sure it's not aliasing noise.


Later,
Mr. Noodge

It's analog so there is no quantization at all Go analog!

[Mark Hammer]

A fair criticism. There was actually a lot that I had to leave out, since I was given a target of 2500-4500 words. It obviously wasn't going to be a treatise on sampling theory, and had to be accessible to typical readers of the magazine and those with less technical knowledge. I guess my criterion would have been "Is this more information, explained more clearly, than you'd get from the average music-store salesperson, or ad copy?". And the answer for me was "Yes".

Is aliasing the wrong term, though? Personally, I think not. Maybe artifactual noise would have been closer to ideal, but aliasing isn't that far off. I'll leave it to the EEs to arm-wrestle over. I'm just a psychologist.

But thanks for the comment and compliment.

[rjb]

It's analog so there is no quantization at all Go analog!

There is no quantization- but there is conversion of a smooth signal into one that looks like a bar chart.
The "jaggies" (technical term ) introduce high frequency content, which you filter out with a LPF.
I think we all agree on that.

I guess my criterion would have been "Is this more information, explained more clearly, than you'd get from the average music-store salesperson, or ad copy?". And the answer for me was "Yes".

And I wholeheartedly agree.

Is aliasing the wrong term, though? Personally, I think not.

Here I have to disagree.
Aliasing has a specific meaning, and is unrelated to "stair-step hiss" (another technical term ).
Aliasing is more like heterodyning- an input frequency is converted (i.e., "aliased") to a lower frequency which is the difference between the original and the clock frequencies.
You stick a LPF before the BBD to prevent aliasing, and a LPF after the BBD to remove the "jaggy noise".

There was actually a lot that I had to leave out, since I was given a target of 2500-4500 words.

So, just leave out the sentence "This is referred to as aliasing noise."


- rjb
AKA Noodge the Niggler