Vinyl masters are fairly straight-forward. After mastering each track, they're assembled with cue markers and gaps into A and B sides, which are then sent to a lathe mastering engineer, where a lacquer is cut to RIAA specifications and is used to make pressing plates.

Masters for a vinyl are typically done to these standards but can be adjusted to requirements from the lathe engineer:

• Sample rate / Bit depth: 48kHz / 24 bit
• Volume peak / Loudness: -0.4dB / -11 to -14 lufs (ITU-R BS.1770-3 standards)

Tape masters are similar to vinyl. After mastering, tracks are assembled with cue markers and gaps into A and B sides, which are used to make a master tape and/or sent for duplication.

Although a big fan in the '80s and '90s, I no longer recommend using Dolby or dbx noise reduction. Both require a deck with those options on playback. Few of the current ones available offer them and playback on decks without sound worse than no NR.

I can dub masters on Ferro / normal bias (Type I) or Chromium CrO2 / high bias (Type II) tapes. For high quality tapes on Metal (Type IV) I recommend having them made at Sky Onion done on a Sony TC-K700ES cassette deck.

This video explains everything and more that you might want to know about the cassette format.

There are generally two approaches with tapes:

(a) Those that like the saturated sound of natural tape compression. For that I generally use these specs:

• Sample rate / Bit depth: 48kHz / 24 bit
• Volume peak / Loudness: -0.4dB / -10 to -12 lufs (ITU-R BS.1770-3 standards)

(b) For cleaner sounding, more dynamic recordings, I aim for a lower average volume and more headroom:

• Volume peak / Loudness: -1dB / -14 to -16 lufs (ITU-R BS.1770-3 standards)

CD masters are one of the most time-consuming and thus costly. Mastered tracks are assembled into a standard CD format file with CD cue markers for each track, converted to 44.1k/16b format if needed.

A CD cuesheet is hand-written and used to burn a master CD-R to ensure everything is correct (and can be used for duplication if needed) and is ripped using EAC to ensure correctness and an alternative cuesheet. During this process each track is tagged with relevant info and digital signatures created, which are then uploaded to major CD metadatabases.

• Sample rate / Bit depth: 44.1kHz / 16 bit
• Volume peak / Loudness: -0.3dB / -10 to -14 lufs (ITU-R BS.1770-3 standards)

Digital masters are fairly straight-forward. Mastered tracks are faded in/out as requested. Specs reflect best practices for Bandcamp.

• Sample rate / Bit depth: 48kHz / 24 bit
• Volume peak / Loudness: -0.3dB / -10 to -14 lufs (ITU-R BS.1770-3 standards)

Streaming masters often require the most work to maximize fidelity while preventing services from applying compression and limiting as well as to avoid transcription errors when they're converted to steaming formats. I use the Loudness Penalty analysis tools and meter to ensure little to no compression will be applied while leaving enough headroom to avoid distortion if they're attenuated or limited.

Streaming masters are done to Audio Engineering Society specs (AESTD1008.1.21-9) - see "Recommendations for Loudness of Internet Audio Streaming and On-Demand Distribution" for specifics.

There's a lot of misinformation on the Internet re: streaming and while going beyond AES specs may suit certain niche genres, my years of experience show that mastering to spec is the best approach for the majority of styles of music in order to retain dynamics and avoid distortion.

• Sample rate / Bit depth: 44.1kHz / 16 bit
• Volume peak / Loudness: -1dB / -14 to -16 lufs (ITU-R BS.1770-3 standards)

Yes, Wire Recording is a real thing, pre-dating modern cassette tapes.

Unfortunately I no longer own a working magnetic wire recorder but should I be able to secure one, this service will be available again.