DIY Recording Equipment Podcast

Latest Episodes:

"Everything You Always Wanted to Know About Audio Electronics..." Part 2 Dec 31, 2012

Show notes

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.

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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."

Is Open Source the Way Forward for DIY Audio? Nov 14, 2012

Show notes

DIY 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?

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Being a DIYer, Studio Owner, and Engineer with Marc Alan Goodman of Strange Weather Brooklyn Jun 22, 2012

Show notes

One 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.

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Topics covered:

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) Jun 11, 2012

Show notes

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.

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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

Again, many thanks to Duncan and those who asked questions. Stay tuned for pt. 2, when we'll talk about troubleshooting, safety, reference levels, and impedance.

What Makes API Gear Sound So Good? With Jeff Steiger of CAPI May 12, 2012

Show notes

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?

Download the mp3 file or listen on iTunes . Thanks for listening. If you enjoyed the show, subscribe to the podcast!

DIY Condenser Microphones with Scott Helmke May 05, 2012

Show notes

Today, 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.

Download the podcast Topics discussed:

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.