What's in your bag, Corey Schreppel?

Corey Schreppel is an audio engineer and Technical Director at Minnesota Public Radio|American Public Media (MPR|APM). He has mixed episodes for In the Dark from APM Reports, recorded in the field with Performance Today, and often records in-studio music sessions for The Current. Corey is known at MPR for his ability to use technology to optimize workflow and simplify the production process. In this month’s “What’s in your bag?,” Corey shares the gear he uses to edit and mix in the field.

I’ve been an audio engineer for nearly 15 years, cutting my teeth on tape machines in parallel with audio software like Pro Tools, Nuendo, Logic, Adobe Audition, etc. As technology has advanced, field/mobile rigs have become exponentially more powerful for high-level production outside of the studio. I committed to this idea early on and developed a portable post-production kit that can handle nearly everything thrown at it, whether it be broadcast and podcast editing, music mixing and mastering, or sound design for film.

While my kit for field recording includes the usual suspects (shotgun and stereo mics, wind protection, Sound Devices recorder, backup batteries, memory cards, etc.), this kit specifically focuses on post-production work like editing, mixing and file delivery. It’s also a Swiss Army knife that’s great for emergencies when you need to connect to various audio interfaces or need to charge that “mission critical” device.

With the advent of USB Type-C, which can handle USB and Thunderbolt 3 protocols in addition to power transmission on the same connector, my kit has slimmed down even further.

Here’s what I carry:

Core components

The core of Corey Schreppel’s field production kit. (Corey Schreppel/MPR)

  • 13-inch MacBook Pro w/ TouchBar
  • 9.7-inch iPad Pro
  • Logitech MX Master Mouse
  • Portable USB 3.0 drives
  • Anker 20100mAh USB-C battery pack. Loads of capacity to charge my laptop, phone and tablet simultaneously. Multiple charges on smaller devices if I’m not using my laptop. This came in handy when a host needed a clock during a live event broadcast. I was able to power my iPad for more than three hours, which displayed an atomic clock app at full brightness. I keep a standard lightning cable, micro USB cable, and a USB-C cable in this case.
  • AudioEngine USB DAC. While most MacBook headphone jacks are more than sufficient, I prefer to have something that can drive my headphones a little more efficiently and accurately. This DAC (digital-to-analog converter) does the job really well. (Editor’s note: Carrying a separate DAC like this is an easy way to upgrade the sound quality of your computer audio monitoring setup. As you’ll see below, Corey also invested in very nice headphones, which typically have the biggest impact on monitoring quality, followed by the DAC.)


  • Shure SE-215 in-ear monitors are my go-to headphones on the road. They’re relatively cheap ($99), incredibly durable, sound great, and isolate extremely well (great for planes, coffee shops, windy mountaintops).
  • Beyerdynamic DT 1770 PRO. If I’m in a moderately noisy-to-quiet environment (office desk, hotel room), I’ll do all of my mixing and editing on these. They isolate well, are comfortable and have a wonderful frequency response for a pair of closed-back headphones. They’re not cheap, but since I don’t travel with studio monitors, it’s one of the best investments I’ve made to ensure my mixes are balanced well.

Tech/Cable/Media Case

Adapters, cables, USB drives, batteries and storage found in Corey Schreppel’s field production kit. (Corey Schreppel/MPR)

Everything below is housed in a $10 Amazon Basics travel case.

  • iLok for Pro Tools and other software authorizations.
  • iLok (spare) in case the first iLok breaks or is lost. I subscribe to iLok’s Zero Downtime program where I can call and have my software licenses immediately transferred to a spare iLok when I’m in the field. (Editor’s note: All of you Pro Tools users out there, take note. Keeping a spare iLok is a very smart idea!)
  • Anker USB 3.0 + USB C power brick which can charge up to four devices via standard USB in addition to my MacBook Pro via USB-C. Great for charging phones, tablets, hotspots, and audio interfaces (that use separate USB charging).
  • HooToo USB-C hub. This is a great solution for the entry-level 12-inch MacBook that only has one USB-C port. This device allows you to connect standard USB devices, has pass-through power, and a video output for projection or an external display. I use it for the SD card reader function with my 13-inch MacBook Pro as it doesn’t have a built-in card reader (my biggest complaint about the new Apple laptops).
  • 2 USB 3.0 Mini to USB-C cable These are used for my external SSD drives and replaced the original hard drive cables – no dongles here!
  • 2 USB 3.0 to USB-C adapters. Takes a standard USB cable and converts it to USB-C.
  • 2 USB-C to USB 3.0 adapters. Takes a USB-C cable and converts it to standard USB.
  • USB C to C cable. For charging my MacBook Pro off the Anker power brick or the standard AC adapter.
  • 6-inch USB to Lightning for iPhone/iPad charging and syncing.
  • 6-inch USB to Micro-USB for various device charging and connections.
  • 6-inch FireWire 400 to 800 cable. FireWire is on its way to the “Great Cable Bin in the Sky,” but I always find myself needing one of these a few times a year to connect older Sound Devices to Macs when other methods can’t be used.
  • 1-foot Cat6 cable. I work frequently with the Avid S3L console for live event recordings for broadcast. All of the interconnects are Cat5e and Cat6. While it’s short, it’s great in a pinch to test and troubleshoot intermittent connections between boxes in the field. (Editor’s note: The Cat6 cable is a piece of gear that’s quite specific to Corey’s job, but there’s a good lesson here: Corey might rarely use this problem-solver, but he’s always got it with him, just in case.)
  • 2 32GB SD Cards. For field recorders (primary and backup).
  • SD to CF adapter. Allows me to use SD cards in a Sound Devices 722 recorder. This isn’t technically supported by Sound Devices, but I’ve never had an issue with it. It allows me to offload files much more quickly than using a CF reader. Recordings are always backed up to the recorder’s internal drive as well in case something goes wrong. I have not gotten this to work in the 788 or newer 600-series recorders.
  • 64 GB USB 3.0 thumb drive. Great spare for file transfers.
  • Headphone splitter. So my producer/host and I can both listen to my mix before delivery.
  • Measuring tape for setting microphone stereo arrays for music recording or calculating distances for input delays on live consoles and field recorders.
  • iPhone Lightning earbuds + 3.5-millimeter adapter. Always great to have a spare!
  • 0.3-meter Apple Watch charging cable. Keeps my watch smart on the road.


In a majority of cases, I’m traveling with my remote recording rig in a small or medium rolling Pelican case. However, this entire kit fits into my everyday bag, which is one of two bags: a Timbuk2 Classic Messenger (medium) or a Timbuk2 Armory Backpack. The messenger has a 21-liter capacity and the backpack has a 26-liter capacity. Both bags have loads of organization and accessory pockets and are lightweight, weather resistant and durable.

I’ve had luck with camera backpacks with dividers and specific organizer inserts, but usually find myself gravitating back toward bags with a larger bucket and smaller accessory pockets and storage. Water bottle holders are a must!

What’s in your bag? is a regular series about the tools used by people in public media. We all use the basics (like a mic and headphones), but the way we personalize our kits is where things get interesting — and where we can learn from each other.

Whose bag should we open next? Let us know at trainingteam@npr.org or on Twitter!

Rob Byers was a Production Specialist with the NPR Training team, where he focused on audio engineering.