658 | | Mixer controls |
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659 | | -------------- |
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| 658 | Input preamp / output amp gain control |
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| 659 | -------------------------------------- |
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| 660 | |
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| 661 | On the Fireface-400 the gain of the mic/instrument preamps and output |
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| 662 | amplifiers can be set. Mic channel gain is in steps of 1 dB from 10 dB up to |
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| 663 | 65 dB, with 0dB also available. Instrument input gain ranges from 0 dB to |
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| 664 | 18 dB in 0.5 dB steps. Output gains range from +6 dB down to -58 dB in |
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| 665 | steps of 1 dB, with compete "mute" also available. |
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| 666 | |
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| 667 | The gains are set using the register at 0x801c0180. |
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| 668 | |
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| 669 | bits 31-24: |
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| 670 | bits 23-16: channel being set (0=mic1, 1=mic2, 2=inst3, 4=inst4) |
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| 671 | bits 15-8: |
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| 672 | bits 7-0: the gain value |
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| 673 | |
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| 674 | For mic channels the gain value is the dB value. For instrument channels, a |
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| 675 | value of 2G is written for a gain value of G (thereby allowing a stepsize of |
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| 676 | 0.5 dB). For output gain, 0 = +6 dB, 0x3b = -53 dB, 0x3f = mute. |
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| 677 | |
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| 678 | The definition of the "channel being set" is as follows. |
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| 679 | 0 = mic input 1 gain |
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| 680 | 1 = mic input 2 gain |
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| 681 | 2 = instrument input 3 gain |
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| 682 | 3 = instrument input 4 gain |
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| 683 | 4-9 = analog outputs 1-6 level |
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| 684 | 10-11 = phones output level |
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| 685 | 12-13 = SPDIF output level |
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| 686 | 14-21 = ADAT outputs 1-8 level |
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| 687 | |
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| 688 | |
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| 689 | Firefice-400 mixer controls |
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| 690 | --------------------------- |
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| 691 | |
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| 692 | The Fireface-400 matrix mixer is controlled using a block of registers |
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| 693 | starting at 0x80080000. An 18x18 matrix mixer is implemented allowing any |
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| 694 | hardware input to be sent to any device output. Pan control is effected by |
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| 695 | manipulating the "left/right" controls within an output pair. |
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| 696 | |
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| 697 | For each input channel block the order of channels is Analog 1-8, SPDIF 1-2, |
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| 698 | ADAT 1-8. |
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| 699 | |
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| 700 | 0x80080000 - 0x80080044: input channel sends to Analog 1 output. |
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| 701 | 0x80080048 - 0x8008008c: playback channel sends to Analog 1 output. |
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| 702 | 0x80080090 - 0x800800d4: input channel sends to Analog 2 output. |
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| 703 | 0x800800d8 - 0x8008011c: playback channel sends to Analog 2 output. |
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| 704 | : |
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| 705 | 0x80080990 - 0x800809d4: input channel sends to ADAT 8 output. |
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| 706 | 0x800809d8 - 0x80080a1c: playback channel sends to ADAT 8 output. |
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| 707 | |
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| 708 | 0x80080f80: matrix mixer analog 1 output fader |
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| 709 | 0x80080f84: matrix mixer analog 2 output fader |
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| 710 | : |
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| 711 | 0x80080fc4: matrix mixer ADAT 8 output fader |
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| 712 | |
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| 713 | Each fader control ranges from 0x00000000 (-inf) through 0x00008000 (0.0 dB) |
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| 714 | up to a maximum of 0x00100000 (+6.0 dB). The precise scale is still to be |
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| 715 | worked out: -52.7 dB appears to correspond to a value of 0x0000004c, -46.6 dB |
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| 716 | is 0x00000099. |
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| 717 | |
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| 718 | When setting the output fader controls, the associated output amplifier |
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| 719 | gain control (see previous section) are generally kept in sync. That is, if |
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| 720 | register 0x80080f80 (analog 1 output fader) is set to 0 dB, so is the analog |
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| 721 | output 1 level via register 0x801c0180. |
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| 722 | |
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| 723 | |
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| 724 | Fireface-800 mixer controls |
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| 725 | --------------------------- |
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