MPR ESSOR MPRESSOR
The information in this document is subject to change without further notice and shall not be deemed as an obligation or warranty of any kind by the manufacturer. No warranties, express or implied, are made with regard to the quality, suitability or accuracy of this document. The manufacturer reserves the right to change the contents of this document and/or the associated products at any time without the provision of prior notice.
WARNING: High Voltage • Risk of electric shock. • Do not open chassis. • Refer service to qualified service staff only. • Before connecting the device to the main power supply, check if the right voltage is selected. • Replace fuse with the same type and value only. • This device must be connected to ground. • Do not use a damaged power cord. • Never place containers with liquid, e.g. beverages or a vase, on the unit. • Do not expose this device to rain or moisture. • Do not use this device near water, e.g.
Dear friend of audio culture, First of all, we would like to thank you sincerely for choosing the mpressor as your new compression tool. We believe this is a true step forward. Instead of a further copy of concepts that were invented several decades ago, you now have an absolutely contemporary tool for processing dynamics at your disposal.
BASICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Signal Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BASICS Controls Both channels of the mpressor are absolutely identical regarding their electronic design. Therefore both sides of the front panel have exactly the same controls and switches. Continuative information on the specific functions can be found on the pages in brackets.
EQ Freq: the center frequency of the Niveau Filter. Around this reference point, bass is boosted and treble is cut or vice versa. (pp. 11, 21) x10: shifts the frequency range of the Niveau Filter. The printed values from 26 Hz to 2.2 kHz are multiplied by 10 to 260 Hz and 22 kHz. (pp. 11, 21) GR Limit: margins the control voltage. This innovative limiter is not placed in the audio path as usual, but in the control circuit of the compressor. (pp. 11, 23) On: activates the Gain Reduction Limiter.
BASICS Connectors Please pay attention to operate the mpressor with the correct voltage setting for your country and the proper pin assignments on the XLR connectors. Mains module This module combines the line cord connector, the on/off switch, the fuse holder with integrated 230/115 VAC voltage selector and a line filter for providing the transformer with clean current.
Link Mode In link mode, both channels of the mpressor can be coupled and operated with the controllers and switches of the left control panel.
BASICS Auto Fast The attack time parameter is a very crucial factor for the control behavior of a compressor. Therefore choosing the right setting is very important, but depending on the dynamic progress of the source material this can be a difficult task – no matter if you are processing single channels or complete mixes.
Gain Reduction Limiter A specialty of the mpressor is the Gain Reduction Limiter for the control voltage of the compressor. This limiter is not placed in the audio path where you would usually find it, but in the control path of the compressor. When it is activated, it limits the control voltage according to the setting of the controller. This means: No matter how high the input level might become – the amount of gain reduction will never exceed the value which is set with the GR Limit controller.
SCENARIOS -5 -8 9 -17 -18 dB 1,0 1,0 SC Extern 0,01 6,0 6,0 Hi dB 150 ms 200 260 12 52 1k3 26 Hz 2k2 1k2 11 9 1,2 1,5 21 0 dB 1:X -4,0 4,0 6,0 Gain 3,0 5 2,0 0,5 On 1,0 EQ Gain 3,0 6,0 Left Link On Hi dB 150 ms 200 260 450 Hz 5 ms 11 1k2 9 x10 2k2 5 -2,0 1,2 -4,0 1:X 4,0 6,0 Gain 3,0 2,0 0 dB -1,0 -3,0 10 1,0 1,5 21 -0,3 1,3 Anti Log 3 19 10 1,6 GR Limit 13 15 17 1k3 26 930 5,0 Ratio 2,0 600 7 Auto Fast 700 28 380
-5 -8 9 -17 -18 dB 1,0 1,0 SC Extern 0,01 6,0 6,0 Hi dB 150 ms 200 260 12 52 1k3 26 Hz 2k2 1k2 11 9 1,2 1,5 21 0 dB 1:X -4,0 4,0 6,0 Gain 3,0 5 2,0 0,5 On 1,0 EQ Gain 3,0 6,0 Left Link On Hi dB 150 ms 200 260 450 Hz 5 ms 11 1k2 9 x10 2k2 5 -2,0 1,2 -4,0 1:X 4,0 6,0 Gain 3,0 2,0 0 dB -1,0 -3,0 10 1,0 1,5 21 -0,3 1,3 Anti Log 3 19 10 1,6 GR Limit 13 15 17 1k3 26 930 5,0 Ratio 2,0 600 7 Auto Fast 700 28 380 12 EQ Freq
SCENARIOS -5 -8 9 -17 -18 dB 1,0 1,0 SC Extern 0,01 6,0 6,0 Hi dB 150 ms 200 260 12 52 1k3 26 Hz 2k2 1k2 11 9 1,2 1,5 21 0 dB 1:X -4,0 4,0 6,0 Gain 3,0 5 2,0 0,5 On 1,0 EQ Gain 3,0 6,0 Left Link On Hi dB 150 ms 200 260 450 Hz 5 ms 11 1k2 9 x10 2k2 5 -2,0 1,2 -4,0 1:X 4,0 6,0 Gain 3,0 2,0 0 dB -1,0 -3,0 10 1,0 1,5 21 -0,3 1,3 Anti Log 3 19 10 1,6 GR Limit 13 15 17 1k3 26 930 5,0 Ratio 2,0 600 7 Auto Fast 700 28 380
-5 -8 9 -17 -18 dB 1,0 1,0 SC Extern 0,01 6,0 6,0 Hi dB 150 ms 200 260 12 52 1k3 26 Hz 2k2 1k2 11 9 1,2 1,5 21 0 dB 1:X -4,0 4,0 6,0 Gain 3,0 5 2,0 0,5 On 1,0 EQ Gain 3,0 6,0 Left Link On Hi dB 150 ms 200 260 450 Hz 5 ms 11 1k2 9 x10 2k2 5 -2,0 1,2 -4,0 1:X 4,0 6,0 Gain 3,0 2,0 0 dB -1,0 -3,0 10 1,0 1,5 21 -0,3 1,3 Anti Log 3 19 10 1,6 GR Limit 13 15 17 1k3 26 930 5,0 Ratio 2,0 600 7 Auto Fast 700 28 380 12 EQ Freq
SCENARIOS -5 -8 9 -17 -18 dB 1,0 1,0 SC Extern 0,01 6,0 6,0 Hi dB 150 ms 200 260 12 52 1k3 26 Hz 2k2 1k2 11 9 1,2 1,5 21 0 dB 1:X -4,0 4,0 6,0 Gain 3,0 5 2,0 0,5 On 1,0 EQ Gain 3,0 6,0 Left Link On Hi dB 150 ms 200 260 450 Hz 5 ms 11 1k2 9 x10 2k2 5 -2,0 1,2 -4,0 1:X 4,0 6,0 Gain 3,0 2,0 0 dB -1,0 -3,0 10 1,0 1,5 21 -0,3 1,3 Anti Log 3 19 10 1,6 GR Limit 13 15 17 1k3 26 930 5,0 Ratio 2,0 600 7 Auto Fast 700 28 380
-5 -8 9 -17 -18 dB 1,0 1,0 SC Extern 0,01 6,0 6,0 Hi dB 150 ms 200 260 12 52 1k3 26 Hz 2k2 1k2 11 9 1,2 1,5 21 0 dB 1:X -4,0 4,0 6,0 Gain 3,0 5 2,0 0,5 On 1,0 EQ Gain 3,0 6,0 Left Link On Hi dB 150 ms 200 260 450 Hz 5 ms 11 1k2 9 x10 2k2 5 -2,0 1,2 -4,0 1:X 4,0 6,0 Gain 3,0 2,0 0 dB -1,0 -3,0 10 1,0 1,5 21 -0,3 1,3 Anti Log 3 19 10 1,6 GR Limit 13 15 17 1k3 26 930 5,0 Ratio 2,0 600 7 Auto Fast 700 28 380 12 EQ Freq
REFERENCE THD Analysis This diagram shows the FFT spectrum with a sine wave of 1 kHz at 0 dBu. The additionally generated second and third harmonics at 2 kHz and 3 kHz which make the processed signals sound richer and more interesting become very obvious here. These harmonics are generated in the transconductance amplifier stages of the mpressor. Their amount is dependent on the input level: the higher it is, the more harmonics are produced.
Attack Here we see how a burst signal (a sine wave which is boosted by 20 dB for a period of 400 ms in this case) is used to demonstrate the effectiveness of the attack controller. The different curves show how fast the jump in level is reduced by 10 dB. When fast settings are applied, the reduction only needs a few milliseconds. Longer settings, on the other hand, do not only need a longer period of time, but also produce a smaller overall amount of decrease in level.
REFERENCE Release This figure is based on a very fast attack time which produces -6 dB of gain reduction. The burst lasts for 50 ms and then follows the release phase with its time parameter set to different lengths. The linear characteristic of the release curve is easy to see here. Arising from the circuit used for this process, the attack time has to be added to the release time.
Ratio The mpressor is a typical hard knee compressor, which can be seen in this diagram very obviously. Compression directly starts with the full adjusted ratio in the very moment the input signal passes the threshold point. Compared to a soft knee characteristic, this kind of compression is more on the noticeable and audible side. The figure also shows the negative ratios: The characteristic curve bends and returns back down.
REFERENCE EQ Gain Low This measurement shows different settings of the EQ gain controller between middle and fully counter-clockwise position at a center frequency of 1.5 kHz. The diagram shows the effectiveness of the filter: The lower frequencies are boosted up to 6 dB, then the curve crosses zero at the center frequency. The high frequencies are attenuated at the same time, and in the extreme setting of the controller even a 6 dB low pass filter is available.
GR Limit Envelope Here, a burst signal is used to demonstrate the effect of the Gain Reduction Limiter. While the lowest curve represents the maximum amount of gain reduction in this example, the other curves show the reduction that is influenced by different settings of the now activated limiter.
APPENDIX APPENDIX – Technical Data & Level Problems Technical Data 24 Frequency response: <10 Hz – 33 kHz (-3.0 dB) THD+N @ 0 dBu, 20 Hz - 22 kHz: THD+N @ +10 dBu, 20 Hz - 22 kHz: 0.04 % 0.33 % Noise floor, 20 Hz - 20 kHz (A-weighted): -84.0 dBu Dynamic range, 20 Hz - 22 kHz: 109 dB Maximum input level: Maximum output level: +25 dBu +27 dBu Input impedance: Output impedance: 10 kOhm 68 Ohm Input pin assignment: 1. Ground 2. Positive 3.
Warranty Conditions and limitations The mpressor is covered by a limited warranty for a period of 2 years against defects in parts and labor from the date of purchase. Natural wear is not covered by this warranty. elysia will remedy problems caused by material or workmanship either by repair or replacement to restore the product to full performance without charge for parts and labor. Repairs or replacements will not extend the warranty period.
dB Lo dB Hi 6,0 On 17 21 26 90 28 36 52 Hz 100 70 Attack 2k2 1k3 700 450 x10 EQ Freq 140 150 Auto Fast 200 260 0,01 ms 13 1,0 5,0 8,0 19 17 21 600 380 dB 11 9 0 1,5 3 5 On GR Limit 0 3,0 0,5 1,0 5,0 10 dB 4,0 6,0 20 17 13 10 Gain -3,0 -2,0 -1,0 -0,3 1,2 1:X -4,0 2,0 1,3 1,6 2,0 Release Ratio 930 Anti Log ms 1k2 85 150 13 5 50 15 7 12 26 Left Link Right -5 dB dB 1,0 1,0 16 0 Lo 2,0 6,0 4,5 3,0 14 9 5 -15 -13 6,0 4
