User Guide
Mic-PreEminence
Microphone Preamplifier
Issue 5, April 1994
© 1994 Studio Technologies, Inc.
5520 West Touhy Avenue
Skokie, Illinois 60077 U.S.A.
Telephone (847) 676-9177
Fax (847) 982-0747
www.studio-tech.com
50101-494, Issue 5
Page 1: ...PreEminence Microphone Preamplifier Issue 5 April 1994 1994 Studio Technologies Inc 5520 West Touhy Avenue Skokie Illinois 60077 U S A Telephone 847 676 9177 Fax 847 982 0747 www studio tech com 5010...
Page 2: ...nstallation 7 Operation 8 Technical Notes 10 Circuit Description 11 Troubleshooting 13 Appendices Appendix A Specifications 16 Appendix B Enabling the Output Coupling Capacitors 17 Appendix C Replacin...
Page 3: ...bal anced outputs use monaural inch 2 conductor jacks tip and sleeve and have a nominal output level of 10dBv Connect your selected Mic Pre Emi nence line outputs to the line inputs of the next device...
Page 4: ...rior high performance circuits not found in other audio equipment By building a dedicated microphone preamplifier we were not hampered by the cost restrictions that console manufacturers have We think...
Page 5: ...pment Connecting the Unit to Power The Mic PreEminence may be operated from mains power of either nominal 115Vac or 230Vac 50 60Hz Units shipped to North America are factory selected for 115V operatio...
Page 6: ...ntains a phantom power switch When this switch is in the ON position 48Vdc is applied via 6 81k ohm resistors to pins 2 and 3 of the associated microphone input connector This 48Vdc power should allow...
Page 7: ...t level and the gain selected by the gain control In the likely case of wanting an average output level of 4dBu you would have 26dB of headroom The gain control is really intended to match the input l...
Page 8: ...ut Capacitors The microphone input is capacitor coupled to the input stage to block phantom power that may have been selected The 100uf electrolytic capacitors used in this location are a low leakage...
Page 9: ...sion circuitry We want as little done to the input signal as is required It is possible to implement a low pass filter by adding inductors in series with the input signal Only if there is an RF proble...
Page 10: ...noise A transistor array package feeds two high slew rate opera tional amplifiers in a non differential configu ration The input is capacitor coupled to block the 48Vdc phantom power that may be pres...
Page 11: ...The following procedures must be performed by a qualified technician Operating the Mic PreEminence with the top and or bottom cover removed ex poses the technician to points in the power input sectio...
Page 12: ...pots serve a dual function setting the input common mode rejection and the output circuit level bal ance From now on we will refer to this procedure as setting the CMR common mode rejection Input com...
Page 13: ...traces The two AC voltage levels should be equal within 20 percent of each other This step confirms that the output is bal anced If not go back to step 3 and again perform the CMR adjustment 11 Connec...
Page 14: ...0kHz bandwidth 150 ohm resistor on input Frequency Response 0 1 5dB 20Hz to 60kHz 40dB Gain 0 0 5dB 10Hz to 90kHz 68dB Gain Gain Range 12 to 68dB related to balanced output Slew Rate 20V usec Distorti...
Page 15: ...start with the letter R followed by a number Two ID numbers are found for each output channel 4 Carefully cut out the appropriate 0 ohm resistor jumper wire s with diagonal cutting pliers 5 Return the...
Page 16: ...s are about the size of watt resis tors they are very easy to handle and install The following procedures must be performed by a qualified technician Operating the Mic PreEminence with the top and or...
Page 17: ...es Inc replaced at no charge provided that the product is re turned shipping prepaid to the manufac turer Information on obtaining service is available by contacting the dealer from whom the product w...
