Chassis Design with Jon Erickson February 16, 2017 12:35
We audio nerds love to talk about particular parts and circuitry—transformers, op-amps, discrete vs integrated, passive vs active, etc—but we rarely discuss the biggest part and the one we actually interface with the most: the chassis.
In this episode of our resurrected podcast, I talk to Jon Erickson about the ins and outs of chassis design and manufacturing.
Jon Erickson has been involved with some of the most delicious-looking audio gear on the market: the A-Designs Pacifica preamp, JHS Pedals' line of 500-series modules, and his flagship Tonecraft 363 DI/preamp.
"Explain Like I'm 5": Why Is Pro Audio Gear So Expensive? (Podcast #13) February 27, 2015 17:17
Sticker shock is a common malady in the recording world. It takes a lot of money to outfit and maintain a studio. But why?
What are the factors that drive the price of professional recording gear?
Why does gear cost so much more than the sum of its components?
Are the prices justified, or is someone getting ripped off?
In this month's podcast, Peterson and Chris discuss what goes into the cost of a piece of gear, and how you can short-circuit some of these costs by doing it yourself.
"Explain Like I'm 5": Filters (Podcast #12) January 29, 2015 14:32 3 Comments
How do filters work?
As audio engineers, we use filters every day. We're all intimately familiar with high-pass, low-pass, band-pass, shelf, etc. filters. But how do they actually work in analog gear?
The basic operating principles of analog filters are actually very simple. In this quick (10 minute) podcast, Peterson and Chris explain the very basics of high-pass and low-pass filters so that any 5-year-old could understand.
“Explain Like I’m 5″: Audio Levels (Podcast #11) December 11, 2014 20:22 8 Comments
What's the difference between "pro" and "consumer" line levels?
Is it ok to plug an instrument into a line level input?
What's the difference between peak and RMS levels?
In the long-awaited return of our "Explain Like I'm 5" podcast series, Peterson and new DIYRE team member, Chris, explain the basics of audio levels.
- Can you damage equipment by plugging the wrong thing in?
- In analog audio Volume = Voltage
- The difference between peak and RMS volume
- RMS is a way of measuring AC as if it were DC
- The most common levels you'll encounter in the studio:
- +4dBu, pro line level (1.22V)
- -10dBV, consumer line level (.316V)
- Mic level
- Instrument level
- Tangent: why are microphone output levels so low?
Talking Tubes with DW Fearn August 26, 2014 12:07 1 Comment
Download the mp3 or listen on iTunes .
- How Doug pieced together his first console from standalone amplifiers
- What happened when he replaced that tube gear with a solid-state console
- "We couldn't admit that it didn't sound good, so we just got used to it."
- How a demo tape from college in 1966 led him back to building tube amps
- "We didn't listen to recorded music in my household... live music was what I was exposed to. So when the time came to build a mic preamp, that's the sound I had in my mind."
- Tubes vs transistors: why it's all about headroom
- Even vs odd harmonics and how they relate to tubes vs transistors
- "The less you torture it, the better it's going to sound. So you keep the signal path as simple as possible."
- What Doug's new product design process looks like
- The one equalizer that knocked DW Fearn out
- DW Fearn refuses to wrestle a piece of gear into existence
"Explain Like I'm 5": Impedance (Podcast #9) July 18, 2013 16:20 10 Comments
When I sent out the newsletter announcing the last "Explain Like I'm 5 Podcast," I asked which audio topics you wanted to hear explained to a 5-year-old. As as result I now have a list of over 25 topics for future shows! But the response I got the most was "impedance."
One reader even taunted me: "Haha, explain impedance like I'm five..good luck with that ;)" Challenge accepted, buddy!
Impedance is one of those audio concepts that comes up at almost every recording session or live sound gig, even if you're not aware of it. Grasping the basics of input and output impedance can make you aware of potential problems before they happen, and help you problem solve more quickly and confidently. And the truth is that the fundamentals of impedance are simple enough that you can learn them from a 15-minute podcast.
In today's ELI5 podcast, I begin with a discussion of acoustics before moving to electronics to show you that you already know more about impedance than you probably think. I go on to cover exactly what input/output impedance specs mean, illustrate the concept of impedance with examples from the studio, and explain what impedance mis-matches can do to your sound.
Do you understand impedance now? How easy was the podcast to understand? Is there any other topic you'd like to hear explained as if to a 5-year-old? I welcome your feedback in the comments.
"Explain Like I'm 5": Balanced vs. Unbalanced Connections (Podcast #8) July 11, 2013 12:30 8 Comments
This podcast marks the first of a new series in which I attempt to explain complex audio subjects so that a 5-year-old could understand them.
In this first "Explain Like I'm 5" podcast, I tackle the important subject of balancing. What is the difference between balanced and unbalanced connections? How does balancing work? Why do we need balanced connections?
In less than 15 minutes, I answer these questions the way I wish someone had for me: assuming no electronics knowledge, sticking to the basics, and using only terminology that a musician would understand.
In order, I discuss:
- What are balanced and unbalanced connections?
- How can I identify the difference?
- Why are there these two types of connections in the studio?
- How does balancing reduce noise?
- What is Common Mode Rejection Ratio (CMRR)?
- If balanced connections are so great, why isn't everything balanced?
Mic Preamps and Surface-Mount Parts with Expat Audio March 14, 2013 14:15 2 Comments
In this month's DIY podcast, I talk to Dafydd Roche of Expat Audio about their new Eden Mic Preamp.
Download the mp3 or listen on iTunes .
Dafydd and I get into some good stuff about mic preamp and general audio design, including:
- The difference between surface mount (SMD/SMT) and through hole components in terms of sound and performance.
- Are SMDs good for audio? Should we audio folks resist industry's march toward all surface-mount parts?
- The concept of "parasitics" in audio electronics design and when their effects can be critical.
- Dafydd gives us a guided tour of the Eden circuit from the input to output jacks--a great way to get a grasp on the basics of mic preamp design.
"Everything You Always Wanted to Know About Audio Electronics..." Part 2 December 31, 2012 12:42 2 Comments
Our resident electronics expert, Duncan Gray, is back to answer your audio electronics questions! Duncan and I recorded two hours of answers last week to the questions you asked in the original "Everything You Always Wanted to Know About Audio Electronics..." post.
So to spare you the tedium of digging through 120 minutes of audio to find the answer to your questions, we've split our conversation up into smaller, more easily digestible podcast. Stick with us until the 33 minute mark, where we answer my favorite question so far that gets to the heart of the amazing relationship between audio and analog electronics.
Download the mp3 or listen on iTunes .
In today's 45 minute segment we cover:
- "What troubleshooting process do you recommend when your PCB-based project isn’t working?"
- "What audible impact does input/output impedance have on the connected equipment. The effect it has upon the amount of voltage transferred is clear, however a more comprehensive explanation on how impedance can alter the sound of interfaced equipment would be hugely appreciated."
- When impedance can be negligible and when it can have a huge impact on sound.
- "Capacitors have been causing me headaches for a while now. In pedals for guitars, tone circuits for guitars, audio paths for pre’s, and so on, it always seems like folks go the extra mile to use film caps. Why? Isn’t a cap a cap a cap? Putting aside electrolytics for the moment, and voltage limits, why would anyone use one style (ceramic, mica, polyester, polypropylene) over another for audio purposes?"
- Why Duncan would avoid ceramic caps in the signal path "like the plague."
- Duncan ranks types of film capacitors in terms of their suitability to audio.
- "What parts are most/least to susceptible to heat damage from soldering?
- Using a hemostat to protect your components while soldering.
- Straight 5" Hemostat (Amazon affiliate link that benefits DIYRE.)
- "What do you think the top five safety rules are when building audio gear , whether tube or solid-state?"
- Which voltages are dangerous? Which are fatal?
- How to protect yourself from the circuit, and how to protect the circuit from you.
- "Can you clarify and explain the correlation between audio frequencies & amplitude, and their electrical counterparts current, voltage, and resistance… In other words what does a change in resistance, current, or voltage do to sound waves."
- The "magic of math": how sound and analog electronics are deeply analogous.
- Sound and AC voltage: same concepts, different medium
- Using the concept of "silence" to better understand electrical "ground."
Podcast #5: Is Open Source the Way Forward for DIY Audio? November 14, 2012 13:33 5 CommentsDIY audio folks like to share--that's what makes us a community. My kits and the DIY Project Directory are possible because others have shared their research, schematics, designs, etc. without any legal limitations. In turn, I document my projects so that anyone who cares to can learn from, tweak, or improve upon them. So, while the greater audio world remains largely closed, with patents, secrecy, and lawyers protecting intellectual property, our little DIY corner is very much an "open source" environment. But unlike explicitly open-source communities such as Wikipedia or GitHub, our openness is not formalized into licenses or explicitly agreed upon. In podcast #5 I talk Eric Jennings of Pinocc.io, an open-source, wireless hardware platform, about how an open source approach might look for the DIY audio community. Topics discussed include:
- Is openness a viable way forward for the DIY audio world?
- What exactly does open source mean for a hardware-based industry?
- Does open source encourage cloners and copycats?
- How can audio designers protect their work without patents?
Being a DIYer, Studio Owner, and Engineer with Marc Alan Goodman of Strange Weather Brooklyn June 22, 2012 16:22 3 CommentsOne thing I often wondered when I first got into DIY was whether any "real" producers and engineers built their own gear. So I was thrilled to visit Marc Alan Goodman at his studio Strange Weather in Brooklyn to see his DIY gear and talk to him about how DIY fits into his career as a successful studio owner and engineer. We recorded some video of Marc's DIY gear which you can see below.
After my camera ran out of batteries, we sat down and chatted about lots of DIY stuff.
- Becoming your own studio tech
- The ecstasy and agony of trying to do everything yourself
- Marc's involvement in the Harrison Ford Filter project
- Marc's thoughts on the LAZ EQN, Neve-style EQ (of which he built 16!)
- How DIY is as old as the profession of audio engineering
- DIY: business or hobby?
- Electricity as the true medium of a recording engineer
- The vintage U87 project (of which he built 3!)
"Everything You Always Wanted to Know About Audio Electronics" Answers Podcast! (pt. 1) June 11, 2012 11:13 9 Comments
Last week, I put out the call for you to ask "Everything you always wanted to know about audio electronics, but were afraid to ask." The response was awesome, and a tad overwhelming: almost 50 questions! I want to sincerely thank all of you who posed questions, we got some great stuff. On Saturday our volunteer expert, Duncan Gray, joined me to answer your questions podcast style.
Here's what we covered in chronological order:
- How Duncan got into audio electronics (as usual, it involved breaking something)
- Circuit talk:
- What does class-A mean? Why is it desirable?
- How do I measure the total current draw of modules in a 51x rack?
- How do I choose the right power supply for a given DIY project?
- What's the difference between an LC and RC filter?
- What happens to the Q, or bandwidth, in a swinging input EQ topology?
- What's the simplest way electronically to make a noise?
- Why do parts of a circuit go to ground?
- How should I ground inside the box?
- What is star grounding?
- Coloration talk:
- Is there really a difference between NOS and new transistors?
- How do you know if a device needs recapping?
- Discrete vs. monolithic opamps?
- How close can we get to replicating vintage gear?
- What does a good preamp do that I can't just do in post production?
- How do I get my foot in the door doing audio design?
- The incredible learning resources at HyperPhysics
What Makes API Gear Sound So Good? With Jeff Steiger of CAPI May 12, 2012 17:30 9 Comments
Jeff Steiger of CAPI and I get nerdy about various vintage audio and DIY topics, including:
- Why create a company dedicated to vintage API gear? Why not Neve, SSL, etc.?
- Will we ever see ClassicAPI kits in a 1RU rack format, instead of 500-series?
- Why does old API gear sound so good when it's specs are so bad?
- The sonically stunning Gar2520 opamp
- Jeff's new, two-stage preamp design, the VP28
- How Jeff tried to cram a full API console strip into one 500-series slot.
- "Inventory management is a bitch."
- How DIY gear is beginning to penetrate the big-budget recording world.
- Are we seeing a return to the early days of recording when many engineers built their own custom gear?
DIY Condenser Microphones with Scott Helmke May 05, 2012 13:28 8 CommentsToday, I discuss the ins and outs of making your own condenser microphones with Scott Helmke, creator of the popular Alice Microphone project. Scott walks us through how he designed the Alice microphone, including some practical tips for making your own mic bodies and headbaskets.
- How Scott developed the Alice mic
- The brilliant Mic Builders Yahoo group.
- The Transound TBS-165A condenser capsule
- What happened when Scott swapped electrolytic for film capacitors in the Alice circuit.
- Tips for DIY mic bodies and headbaskets. The McMaster-Carr store is your friend.
- What to look for in a headbasket mesh material.
- "Somewhere between sculpture and audio."
- Scott's most recent project: a linear microphone array for piano.