Technical Articles

A collection of technical articles from over the years. They’re all PDF files. Clicking on the title will probably bring up the article in your web browser, or you can right-click and download the file for off-line reading.

  • Mixer Anatomy 101 – What the knobs and buttons do. The emphasis of this article is on learning how to figure that out yourself by studying the block diagram. What better way to learn than to walk through a couple of different block diagrams?
  • Headphone Amplifiers – Not all headphone amplifiers are the same, and some differences are subtle but important. This article was written originally as a handout for the PreSonuSphere Users’s Conference (that’s why the PreSonus headphone amplifiers are described first) but there are examples from other manufacturers as well that point out the differences in how the outputs relate to the inputs. This isn’t a shootout or a review. Its intent is to help a user decide which type of headphone amplifier is right for his application and what specific features to look for when making a choice.
  • Gain Structure – How all the various gain and level adjustments in an audio system interact.
  • All About Equalizers – Peaking, shelving, Q, British. Improve your EQ IQ
  • Compression Exposed – What a compressor really does
  • Much About Mic Preamps – This is actually a mash-up of two Recording articles, one from 2001, and the other a few years later when the editor asked me for a new article about preamps for the new crop of readers. There’s some duplication, but also some things appropriate early on which new readers tend not to care about. But YOU do, don’t you?
  • Using a Stereo Microphone – I originally wrote this article for Studio Projects as an application note for their LSD-2 stereo microphone, so that’s what’s used as the example for coincident stereo mic setups. Read about X-Y and M-S techniques including methods for decoding and manipulating the left/right sound field.
  • Catching some ZZZZZs – All you need to know about impedance to hook things up right
  • The Ins and Outs of Gozintas and Gozoutas – Mic, Line, XLR, TRS, levels, impedance, balanced, unbalanced – all about the inputs and outputs of audio equipment
  • Signals from Source to DAW in two parts: Part 1 and Part 2 – This is a fairly complete article about interfacing audio to a computer. It was written for the Recording Magazine reader who knows enough about computer audio to get MP3 and videos playing through the built-in sound card, and now wants to start recording. Part 2 didn’t get published until a few years after it was written, and the magazine version of this part got a fair amount of editing and updating. This is the original version. The magazine version is still available on Recording’s web site in the Resources section. You might want to give it a look as well.
  • Patchbays – Let’s get normal for a change. All about patchbays When you need one, jacks, plugs, normals, planning, and wiring.
  • Pin 2 Hot – What’s hot and what’s not, about polarity, balanced, and unbalanced connections
  • Grounds and Shields – Got hum? Here’s why.
  • Electrical Power – Safety precautions, distribution, wiring, protection from surges,  spike, and power failures, effective grounding
  • Latency In a DAW – Everybody wants to know if their DAW-based recording system has too much latency, how they can tell if they if have too much latency, and what to do if the have too much latency. This article is what it all means, and how to formulate a latency battle plan.
  • Lies, Damn Lies, and Specifications – How much do you really know when you look at a spec sheet? What’s important and why, and what the numbers mean.
  • When Good Things Go Bad – Troubleshooting – Stuff breaks, or sometimes things just quit working. It’s important to be systematic when troubleshooting. Here are some tips and good places to start.
  • Balanced vs. Unbalanced Connections – What these terms really mean, configurations, how to identify what you have, and how to best mix balanced and unbalanced devices in a system.
  • DB-25 Audio Snake Pinouts – There are several different wiring conventions for the 25-pin D-subminiature connector (DB-25) often used for connecting a multi-channel input or output to the outside world. TASCAM’s convention is most common for analog connections, but many different pinouts have been used for digital connections. There may be others, but these are what I could find when I was researching the subject for an article a while back.
  • Meter Madness – All about level meters, analog and digital, VU, dBu, and why zero isn’t zero any more.
  • Tips For Using a Handheld Recorder – To you, it’s a recorder with a built-in microphone. To me, it’s a microphone with a built-in recorder. Some mistakes to avoid and some good things to remember. This is an evolving article that I originally wrote for a music camp workshop. The link is to the original student handout with a couple of updates, with the latest at the top. You might want to read it backwards to see where we’re coming from.
  • Magnetic Sound Recording – This is a detailed article that apparently was part of a training manual for a German news organization. I’ve been meaning to re-work an old article of mine on tape recorder alignment because it’s something that’s asked about every now and then, but it’s been on the back burner for a long time now. I ran across this article and it’s very complete. If you need to learn how to to set up a tape deck or learn how it works, this article will tell you. I don’t plan to get into the habit of re-publishing the work of others here, but I expect that an easier-to-find version of this work will be appreciated.
  • Mackie Compact Mixer Reference Guide – Some history: Mackie commissioned me to write this back in 2001. They knew that nobody reads the manuals, and worse, nobody keeps the manuals. They wanted a manual that everyone would keep as a general reference. The original intent was for it to be everything you’d need to know about any mixer. A copy would be included with each of Mackie’s mixers, along with a quick start guide for that particular mixer. The idea was that the quick start guide would show you where, for example, the Auxilary Send knobs were, and if you needed to learn what to do with those knobs, you could go to the reference guide. Well, when they realized that a 300 page book, while it would look impressive on an engineer’s bookshelf, was too expensive to give away with every mixer, they offered a printed copy for sale (I think it was $30) and posted the individual chapters on their web site as PDFs, both as reference material and if you wanted to print up your own copy of the book. Since Mackie totally reworked their on-line support, it’s no longer there. I’ve posted a copy here because I think it’s still useful and people are asking me about where they can get it.
  • Talkin’ Taters – It’s time for a bit of whimsy here. Engineer/Producer Sylvia Massy has made her reputation (aside from some good engineering) by coming up with unexpected and novel studio techniques. She describes what she calls a “potato filter,” electrically connecting a potato in series with an amplifier’s speaker leads for an unusual sound effect. This led me to some experiments to see, first, what kind of sound she was talking about, and second, what’s the technical side. Read my lab notes and be amused and amazed.
  • How To Bake a Tape – I wrote this article around 1990 when sticky shed syndrome, the adopted name for when recording tape becomes gooey. It can foul a tape deck’s heads and guides quickly, causing havoc in playback. The common solution to this problem was to “bake” the tape by holding it at a constant temperature of around 130°F for several hours, letting it cool down slowly, and most of the time the tape will be playable again after you clean up your gooey tape deck.

    I originally posted it, long before this web page existed, to the Josephson Engineering web site, since David Josephson hosted the Ampex mailing list (he still does) and that’s where people were talking about tape problems. It never occurred to me to post it here for a couple of reasons. First, now this isn’t such an esoteric things and there’s lots of good (and some bad) info on the WWW. Second, by the time I started putting articles up here, there’s been a lot more deep study of the problem and, while the procedure still works most of the time, there’s some incorrect information there. We’ve learned, for example, that the problem isn’t caused by the tape absorbing water as explained here, but rather that the problem is caused by molecular breakdown of the binder that holds the oxide to the tape. Heating doesn’t drive water out of the tape,. it causes the binder components to re-combine, and that’s the real fix.

    When a long time friend, AES colleague, and sometimes audio historian told me that he sometimes cites my original article but it’s no longer linked on the Josesphson web site (it’s still there if you know the URL) and suggested that I post it here where it will be easier to find. OK, says I. I’ve posted it here with its original ASCII art drawing of the cardboard box and hair dryer which was the classic setup as described in an Ampex technical paper, but be warned that this is a historical document. It’s unlikely that you’ll ruin a tape by following the procedure  here, but that we know more now than we did then.

  • Specifications – This is a series of articles about specifications, each with its own link. I wanted to call this “Demystifying the Spec Sheet, but the editor renamed it “Specifications – Removing The Mystery, so I kept it. A follow-on series, Trust But Verify, explains how you can test your gear and compare its performance to what the manufacturer claims.
  • Trust But Verify – This is the practical side of the Specifications articles, where you can learn how to measure some of the things on the spec sheet, or things not on the spec sheet. These aren’t lab quality tests, but by making these measurements with software and hardware that you already have, you can see if a product lives up to its claims or determine what’s wrong if something doesn’t sound right.
    • Trust But Verify – 1 Measurement concepts, measuring frequency response and distortion using the (free) Room EQ Wizard program.
    • Trust But Verify – 2  Measuring voltage and gain. You might need to buy a multimeter, but it’ll come in handy for a lot of things besides checking out your specs. This article includes a section about digital multimeters that will help you to pick out one to meet your needs.
    • Trust but Verify – 3  It’s About Time – Using an oscilloscope (software if you don’t have the hardware) to measure frequency and phase. Measuring your DAW’s actual latency.

Acknowledgment and Thanks – While most of these articles were originally published in issues of Recording Magazine that are now out of print, some of them are still available, as well as many other excellent technical articles, through the Resources section of the magazine’s web site. Check it out, and encourage them to get me to write some more stuff for them. Hey, you might even want to subscribe. (this isn’t an ad, but a way to say thanks for giving me the opportunity to put down on paper the things that I’ve learned over the last umpteen years)