Terms & conditions

Updated August 28, 2020

Pricing per song


Price / song

Total Price

Total Price


(max 2 persons)



1 song




2 songs




3 songs




4 songs




5 songs




6 songs




7 songs




8 songs




9 songs




10 songs
























11 songs or more, add €50 per additional song

The song prices are for separate songs of up to 10:00 min each. Longer songs will have an additional cost of €20 for every started 10 minutes extra in length.


Important recall notice

  • Recall ‘original mix’, upon client’s request = free of charge within 1 month after session start date
  • Recall ‘revised mix’, upon client’s request, with the same mastering setting = €25 per additional version
  • Remaster ‘revised mix’, upon mastering engineers request = free of charge within session
  • Remaster ‘revised mix’, upon client’s request = €50 per additional master within 1 month after session date
  • All recalls or remasters +1 month after session start date = new session


Important stem mastering notice

  • Instrumental stem + vocal(s) stem can be a winner if that extra dB in the end is important (think EDM)
  • The final master is not necessarily better when you allow access to (more) stems
  • The glue of exported stems may not be as musical as one stereo mix export, please provide that as well
  • Only EQ and compression will be used, special FX are for mixdown
  • Be careful when using mix bus compression if you prefer stem mastering as your final step
  • Stem mastering is not there to skip the mixdown stage
  • The sum of the stems is your mix
  • A good mix is a good mix
  • Just to be sure: the focus is mastering, not mixing



Booking and Payment

Before your session: invoice info such as name, address, VAT/BTW number and contact info must be available.
After your session: master copies for release will only be delivered after we have received full payment for all work completed.

Heavy deadline?

Ask your invoice-reference in advance and transfer the amount due before your session.

Note that the -JM CHECK- files are watermarked or may contain drops/cuts made on purpose and are therefore not suitable for release. The check files are WAV 44.1k-24b loudness limiting quality, lossless audio.



Ways of working together

Administration: contacts for updates

During the sessions, we might want to communicate about that background singer in the front. Please provide us with the contact info (email and phone number) of the producer and mixing engineer, just in case of a problem.

Attended or Unattended?

…It’s where you feel the most comfortable to judge masters.

Attended: you’re welcome during the setup of the session.

Once the chosen path is clear, it’s easier to judge the masters in your comfort zone.
Please also note that it can be easier for the mastering engineer to stay in the zone during an unattended session, mostly resulting in a more coherent EP/album because of less distraction.

Unattended? Don’t worry!

Check files will be uploaded to an online server during your session so you have the possibility to follow your session in your comfort zone. This way you can check the masters on a setup you know and trust and provide us with feedback almost instantly.



File delivery

  • Make sure you check your exported final mixes BEFORE the mastering session to avoid the cost of unnecessary recall setup costs to replace wrong mixes/masters afterwards.
  • Please send in your songs with final track order, correctly named as “01_Title Song (mix1)” or “12_TITLE SONG (mix3546)”, correct use of capitals included.
  • Make sure you export to an uncompressed lossless format like WAV, AIF or DSD.  NO MP3 or other lossy format!
  • The sampling rate must be the same as your DAW session.
  • Please give export with dither to 24bit a check. It can sound wider, more focused and open.
  • Leave some silence before and after your song and don’t use fade-in or fade-out. Export may eat the first important milliseconds of your kickdrum if you export from the very start of your song.
  • Don’t use a limiter on your mix just to make it loud. Of course you may send your (clients) listening version as well to give us an idea of your intentions or what the band/artists approved the mix on. There could always be a chance we start from there… Peak level around -1dBFS is acceptable, don’t crush.
  • If you have used reference tracks during the previous production process or you like to sound as close as possible to band -X-, please send us a link from QOBUZ music or a high-quality reference track in WAV.   NO MP3, YouTube or Spotify link please, unless you’re a lo-fi lover.
  • Don’t forget to send in your vocal-up, instrumental, radio-edits… BEFORE your session if you like to have extra versions.
  • Did you check your mix in mono?



ISRC codes

ISRC codes are welcome prior to your session.
What is an ISRC code? Please visit: www.isrc.ifpi.org

To get your code, please visit and contact:




When you send in your mixes for mastering, please provide the info attached and where applicable, with correct spelling and capitalisation:

  • Artist/band:
  • Album/ep:
  • Songs for mastering: Track order + Title(s) + mix info: ##_title (mix##)
  • ISRC code(s):
  • Genre:
  • Cover artwork 1400×1400:
  • Release date:
  • Contact A&R (e-mail, mobile):
  • Contact producer (e-mail, mobile):
  • Contact mixing engineer (e-mail, mobile):
  • Studio(s):
  • Invoice info (name + address + BTW-VAT-TVA,Europe only):
  • Deadline:




Responsibility for acceptance / quality control

All masters are checked for errors before delivery, but it is your responsibility to independently Quality Control the state of the data produced by us before reproduction. We accept no responsibility for any technical flaws and imperfections or errors of commission or omission in respect of any matter or thing arising from the production of the data. Receipt of the master is your acknowledgement that you discharge us at Jerboa Mastering from any proceedings, costs, or any sorts of claims. Listen carefully to all files delivered before sending them in for production / duplication.





Some more info


CD premaster

We provide you with a ‘musically loud’ premaster that is conform within your genre.
The -Jerboa Mastering Check files- (-JM CHECK-) provided over Dropbox to approve your masters are WAV44.1K-24b loudness limiting versions.
Note that the -JM CHECK- files are watermarked, may contain drops made on purpose or miss the outro.

Loudness Limiting?

  • Best known from the CD format and the Loudness war
  • Still in use by most radio broadcast stations
  • Soundcloud is one of the last streaming services using this
  • The loudness war ideology is ‘the louder your track, the better it will sound to your listeners’ but there is a limit:
    • Musically Loud?
      …intro – VerSe – CHoRUS – OutroTOO LOUD?
    • TOO LOUD = when instruments and vocals stop breathing

NOTE that each song has its own loudness potential:

  • Arrangement and key of the song
  • Vibe and energy of the song
  • Production, recording & mixdown quality

Single Mastering approach vs Album/EP Mastering approach

Short term listening: 90% of the listeners choose louder over dynamic in a quick A/B comparison, whether or not it actually sounds better… but after roughly 20 seconds they are used to the volume and only sound-quality remains…
Advertisement-hyper compression is acceptable for 10 seconds, not for 3 minutes or 1 hour.

Long term listening: (micro-)dynamics are less fatiguing and therefore more enjoyable and interesting to listen to. It can make the difference between eject after track 5 or an album on repeat.

SO: please think twice before asking to go from ‘Musically Loud’ to ‘TOO LOUD’.



Next to the WAV44.1k-16b CD Quality files we provide you with high resolution files WAV44-24, WAV44k-24b, WAV48k-24b and WAV96k-24b.
These may be used for Qobuz, compilation albums, DVD, streaming services that don’t use Loudness Normalization (to-date) or archiving.



A folder with MP3 files of the CD master will be included in case you will insert a download card within the vinyl sleeve. Note that you have to ask your vinyl manufacturer for this service and upload these files to their server. These files are also usable for promotion.


Next to the WAV44.1k-16b Quality Streaming files we provide you with high resolution WAV44k-24b, WAV48k-24b and WAV96k-24b streaming files. 

Briefly, this is a low-, mid- or high-resolution master as above with less limiting and a greater peak headroom between -1dBTP and -1.3dBTP. These STREAM masters are to send to streaming services that use Loudness Normalization. 


IMPORTANT NOTE: Streaming Services normalize loudness to their standards upon playing only. The source file is intact as it means no additional files need to be stored in case they change the loudness spec. Hence upon downloading you’d get the original loudness of the file. -14dB LUFS is the average loudness most services use as a playback level today and they only put your music down in volume, not up. The streaming masters we provide will not have the -14dB LUFS top but a little higher in volume because of these reasons. This means, we don’t limit more than necessary, but also not less.  Just in balance with what the song, EP or the album needs to have the best focus and translation overall conform within your genre.   



Loudness Normalization?

This is the process used to make music play back at a consistent volume to maintain a constant perceived loudness. This is implemented so that the listener isn’t always reaching for the volume control.
Loudness Normalization is used by Spotify, YouTube, Apple Music, Tidal, Deezer, and some other streaming services.


Mastered For Apple Music – “Apple Digital Masters”

Jerboa Mastering is an official Apple approved mastering studio and is on the “Apple Digital Masters” Providers List.


Vinyl Premaster

Briefly, this is a high-resolution WAV96-24 master with less limiting to send to your preferred vinyl cutting engineer to create the Vinyl Lacquer or DMM.  It comes with a Timing sheet inside.


Be aware of these limitations



(Some side notes concerning the quality of your test pressing and final quality of your vinyl record)

  1. CUTTING ENGINEER: The know-how of the Cutting Engineer is as important as any other audio engineer involved on your project. Please choose a qualified one for your final transfer,
  2. CUTTING GEAR: quality of the Cutting Lathe / Cutting Head / Cutting Medium (hard or soft Lacquer vs DMM Direct Metal Master do make a difference,
  3. QUALITY OF THE VINYL POLYMER: This is the basis for the vinyl record. They may use recycled polymer for your test pressing or color disk what may result in more cracks and crackles. The less clean and pure the vinyl polymer, the more distorted the microscopic grooves will be.
  4. PRESSING machines: not all pressing plants have the same quality gear to press vinyl disks.

How much audio to put on a side:

33 rpm

45 rpm


05 min


13 min

11 min


20 min

14:30 min








higher RPM = better high end, more detail, less distortion
longer times = lower audio quality, less bass and lower volume




Please use one of the following three credits for your sleeve notes:

  • Mastered by Frederik Dejongh at Jerboa Mastering
  • Mastered by Frederik Dejongh
  • Mastered at Jerboa Mastering

Please avoid the use of ‘Mastered by Jerboa’, because Jerboa is the alias of Frederik Dejongh as a musician.





All the gear used at Jerboa Mastering is carefully selected. Some of these devices are useless on their own, but priceless in combination with other ones. All the (vintage) transformers react to the load of the next and previous gear in line, they all have their sweet spot and their do’s and don’ts. All gear is used in certain combinations, a certain manner and a certain order: this works wonders, and makes Frederik Dejongh reach the goals he envisions.


Macchine per caffè

  • DALLA CORTE Super Mini
  • MAZZER Mini (grinder)
  • MORTIER coffee



  • KII AUDIO Three BXT Reference System
    (serial number 1 & 2, A 7000Watts full range system considered to be the best available reference system worldwide to date)


ADDA conversion

  • LAVRY AD122-96MX (The Rolls Royce of all A to D converters)
  • MERGING premium DA8P & AD8DP (DSD audio)


Equalizers and compressors

  • AMTEC 099 compressors (Fairchild 660)
  • ANAMOD ATS-1 Analog Tape Simulator
    (full option)
  • ARREL AUDIO ML-116 Monster Line Mastering Equalizer
  • BUZZ AUDIO REQ-2.2 ME Mastering Equalizer
    (with active low band cards and Lundahl LL1684 amorphous core transformers)
  • DANGEROUS Bax Equalizer
  • KNIF Eksa+ Equalizer
  • LIVIO ARGENTINI LA-117 – Mastering Equalizer
  • MANLEY Stereo Variable Mu® compressor (modified)
  • MASELEC MLA-3 compressor
  • MASELEC MPL-2 limiter
  • RUPERT NEVE DESIGNS Portico II Master Buss Processor
  • SHADOW HILLS Mastering Compressor (modified)
  • TUBE TECH HLT2AM Mastering Version Equalizer (modified gold plated switches)