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SMP- 2 Two Channel Discrete JFET Mic Preamp Test Data 

 
Unless otherwise specified all tests into 10k ohm || .001 mfd load 
 

Forssell Technologies Inc

05/31/07 14:29:03

  A-A THD+N vs AMPLITUDE  

Mike Pre THD+N vs AMP.at2c

0.0001

1

0.0002

0.0005

0.001

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

%

-0

+24

+ 2

+4

+ 6

+8

+10

+12

+14

+16

+18

+20

+22

Output Level dBu

 

THD+N vs output voltage from 0 dBu to +25 dBu 

 
 

Forssell Technologies Inc

05/31/07 14:34:58

  A-A DIM IMD vs AMPLITUDE  

Mike Pre DIM vs AMP.at2c

0.0006

1

0.001

0.002

0.005

0.01

0.02

0.05

0 . 1

0 . 2

0 . 5

%

-0

+24

+2

+ 4

+6

+ 8

+10

+12

+14

+16

+18

+20

+22

Output Level dBu

 

DIM vs output voltage 

Summary of Contents for SMP-2

Page 1: ...F t Forssell Technologies Inc SMP 2 Microphone Preamplifier User Manual Forssell Technologies Inc Sandpoint Idaho USA 208 263 0286 ...

Page 2: ...n off switch and LED are also located on the front panel The rear panel contains the two input and one output XLR connectors per channel All XLR connectors are wired Pin 2 hot There is an input XLR for phantom powered mics labeled P48 and one for non phantom powered mics DC such as ribbon dynamic or externally powered condenser mics There is also an IEC AC power connector and fuse holder on the ba...

Page 3: ...f the phantom power switch is pressed in on the front panel PLEASE NOTE only one of the two input XLR connector can be used at any given time The unused XLR should have no cable plugged into it Gain control on the SMP 2 variable from a minimum of 6 dB to a maximum of 68 dB or 74 dB if high gain option is installed in 24 steps The gain control use high quality Elma switches for long life and good s...

Page 4: ...ain 68 dB or 74 dB Input Impedance 13k ohms EIN Max gain better than 128 dBu 22 Hz to 22 KHz unweighted typically 130 dBu CMRR measured at 45 dB gain better than 90 dB Frequency Response 5 Hz to 100 Khz 0 0 5 dB THD N better than 005 Maximum Output Level 24 dBu Recommended Load Impedance 600 ohms Preamp Output Impedance 49 9 ohms Power consumption appox 16 watts ...

Page 5: ...N vs AMP at2c 0 0001 1 0 0002 0 0005 0 001 0 002 0 005 0 01 0 02 0 05 0 1 0 2 0 5 0 24 2 4 6 8 10 12 14 16 18 20 22 Output Level dBu THD N vs output voltage from 0 dBu to 25 dBu Forssell Technologies Inc 05 31 07 14 34 58 A A DIM IMD vs AMPLITUDE Mike Pre DIM vs AMP at2c 0 0006 1 0 001 0 002 0 005 0 01 0 02 0 05 0 1 0 2 0 5 0 24 2 4 6 8 10 12 14 16 18 20 22 Output Level dBu DIM vs output voltage ...

Page 6: ...70 60 50 40 30 20 10 d B u 10 20k 20 50 100 200 500 1k 2k 5k 10k Hz FFT plot 0 dBu output Forssell Technologies Inc 05 31 07 14 39 56 A A FFT SPECTRUM ANALYSIS Mic Pre Dual Freq FFT at2c 150 0 140 130 120 110 100 90 80 70 60 50 40 30 20 10 d B u 10 20k 20 50 100 200 500 1k 2k 5k 10k Hz Twin Tone 17KHz and 19KHz FFT plot ...

Page 7: ... u 20 20k 50 100 200 500 1k 2k 5k 10k Hz EIN at max gain 20 Hz to 22 KHz Forssell Technologies Inc 05 31 07 14 50 11 A A FREQUENCY RESPONSE Mike Pre Freq Lo at2c 3 3 2 75 2 5 2 25 2 1 75 1 5 1 25 1 0 75 0 5 0 25 0 0 25 0 5 0 75 1 1 25 1 5 1 75 2 2 25 2 5 2 75 d B r A 20 200k 50 100 200 500 1k 2k 5k 10k 20k 50k 100k Hz Freq Response at 6 dB gain blue and 60 dB gain red ...

Page 8: ...tom power such as vacuum tube mics ribbon mics and dynamic mics You can only use of these inputs at a time Do not connect the unused input to anything cable of microphone The connector in the middle is the Direct Input Input and Output connectors are XLR 3 wired pin 2 hot The front panel mounted bicolor LED will light green when an output signal level of 5 dBu or greater is present and this LED wi...

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