Waves / Abbey Road J37
User Guide
5
•
Bias
refers to the inaudible ultrasonic high frequency tone (usually a sine wave ranging from 40
kHz to as much as 100 kHz) that’s added to improve the fidelity of analog magnetic recordings.
Magnetic tape has a nonlinear response at low signal strengths, so the bias increases recording
quality by pushing the signal upward into the linear zone of the tape's transfer function. The J37
plugin includes a Bias level control.
•
Speed
refers to the speed at which the tape moves across the heads. The J37 lets you choose
between 15 ips (inches per second), which delivers better high frequency response and less
THD (Total Harmonic Distortion), and 7.5 ips, which delivers somewhat tighter low frequencies
at the price of reduced high frequency. .
•
Tape Formulas
refers to the chemical structures of the different tape media developed by EMI
and modeled for the J37 plugin.
o
EMI TAPE 888 (early ‘60s) – Considered “lo-fi” and “grainier” compared to the other
formulas, with more distortion between 1 kHz and 8 kHz.
o
EMI TAPE 811 (mid to late ‘60s) – Offers better high frequency response and slightly less
distortion than the 888 formula.
o
EMI TAPE 815 (early ‘70s) – Delivers flatter high frequency response and less distortion
than the 811. Recommended when minimal coloration is desired.
These tape formulas were developed during the 1960s and 1970s, when recording levels were
considerably lower than they are today, so pay attention to the levels at which your signal “hits the
tape.” In general, average input levels of -3 – 0 VU will ensure proper gain structure within the plugin.
1.5 Components
WaveShell technology enables us to split Waves processors into smaller plugins, which we call
components
. Having a choice of components for a particular processor gives you the flexibility to
choose the configuration best suited to your material.
J37
includes the following components:
•
J37 Mono
•
J37 Stereo
