The extreme left side of the panel houses switches for Eq In/Out and Power, apart from these the two channels, mounted one above the other, are identical as are their controls. Starting from the right hand side of the module:

Input Level sensitivity is controlled by three sets of rotary controls, first a rotary switch for the course sensitivity with 5dB steps, secondly another rotary switch for the fine sensitivity in _dB steps and finally a continuously variable control with ±1dB range which is only in circuit when the Vari push switch has been pressed and is illuminated.

The first section of the Eq is for the High frequency section. This has a shelving characteristic of the Baxandall variety with switched rotary controls for both frequency , boost and cut .
The next two section, HMF and LMF are identical except for their frequency ranges. All the controls on these fully parametric stages are multiposition rotary switches. The boost and cut controls have the same sensitivity as the HF section, with frequency and bandwidth switches for each stage.

The last section of the Eq is the mirror of the first, the LF section is another shelving stage with rotary switches for both boost , cut and frequency selection .

There are two further rotary switches for the High and Low pass filters, with a fixed slope rate and switched selection of turnover frequency.

Below the filter switches there is a Phase Reverse switch and an Overload indicator, which will light whenever the signal level reaches or exceeds +20dB, which is 6dB prior to the onset of clipping.
The left hand end of the panel houses two further large push switches, the uppermost of these is the Power switch, which is lit when the unit is active.

The lower large push switch is the Eq In/Out switch . This has two modes of operation, the switch will latch, electronically, when pushed putting the Eq in-circuit and light the LED, a further push will unlatch and take the EQ out and the module back to bypass (this is a relay bypass). An alternative mode is to press and hold the switch, with gives a momentary action to the Eq In state which will become bypass when the switch is released. This allows the In/Out switching to be stable and momentary from the same switch.

Blue 315 MKII Isomorphic Mastering Equaliser

The extreme left side of the panel houses switches for Eq In/Out and Power, apart from these the two channels, mounted one above the other, are identical as are their controls. Starting from the right hand side of the module:

Input Level sensitivity is controlled by three sets of rotary controls, first a rotary switch for the course sensitivity with 5dB steps, secondly another rotary switch for the fine sensitivity in _dB steps and finally a continuously variable control with ±1dB range which is only in circuit when the Vari push switch has been pressed and is illuminated.

Filters

There are two rotary switches for the High and Low pass filters, with a fixed slope rate and switched selection of turnover frequency.

EQ

The first section of the Eq is for the low frequency section. This is a shelving variety with switched rotary controls for frequency , boost , cut , Q ( bandwidth ) along with a frequency range push button switch .
This stage can also be switched from shelving to a fully parametric bell stage .

The next two section, HMF and LMF are identical except for their frequency ranges. All the controls on these fully parametric stages are multiposition rotary switches. The boost and cut controls have the same sensitivity as the LF section , with frequency and bandwidth rotary switches for each stage.

The last section of the Eq is a high frequency mirror of the first i.e., another shelving/bell stage with rotary switches for boost , cut ,
Q ( bandwidth ) and a frequency range push button switch .

The link switch , when engaged , allows both corresponding upper and lower EQ push button functions to be switched in and out simultaneously E.g., engaging the low-mid parametric stage high range switch on the upper channel will cause the corresponding lower channel low-mid parametric stage high range switch to be engaged . Pressing either switch again will cause both to be switched off .

Phase , Overload & Master In

Below the filter switches there is a Phase Reverse switch and an Overload indicator, which will light whenever the signal level reaches or exceeds +20dB, which is 6dB prior to the onset of clipping.
The left hand end of the panel houses two further large push switches, the uppermost of these is the Power switch, which is lit when the unit is active.

The lower large push switch is the Eq In/Out switch . This has two modes of operation, the switch will latch, electronically, when pushed putting the Eq in-circuit and light the LED, a further push will unlatch and take the EQ out and the module back to bypass (this is a relay bypass). An