Summit MPC-100A Operating Manual

Summit Audio Model MPC-100A

Mic Preamp/ Compressor

Operating Manual

IMPORTANT!: CAREFULLY READ THE ENTIRE INSTRUCTION MANUAL BEFORE HOOKUP OR OPERATION OF THE MPC-100A.

WARNING!: HIGH VOLTAGE. THIS UNIT CONTAINS NO USER SERVICEABLE PARTS. SERVICING SHOULD ONLY BE DONE BY QUALIFIED SERVICE PERSONNEL OR FACTORY. DO NOT OPERATE THE MPC-100A WITH THE COVERS REMOVED.

Summit Audio, Inc. 1183 Baltic Suite A

Gardnerville. NV 89410

Product Introduction

The Summit Audio MPC-100A Mic Preamp/ Compressor-Limiter is a single channel tube preamp and tube compressor/limiter all in a two-space rackmount unit. It accepts line, microphone, and Hi-Z input signals. The preamplifier provides a warm yet crisp vacuum tube tone. The compressor/limiter section has very fast attack times, making it ideal for optimizing signal prior to entering the digital domain. In addition to having superb sound and a user friendly interface, the MPC-100A has the robust build quality consistent with the Summit Audio family of products.

Features include:

Mic, Line and Hi-Z inputs

“Clean” to “Saturated” tube sounds

Tube drive indicators

Unique Hi-Z instrument DI with impedance matching control

Two stages of tube amplification

3 position “smart” attack and release switches

High quality true VU meter

Continuously variable level control

+4 dB balanced and –10 dB unbalanced outputs (useable simultaneously)

Stereo linkable to another MPC-100A or TLA-100A

Jensen Mic transformer

990, discrete output stages

Hand crafted in the USA

Having found this manual, carefully unpack the MPC-100A and it’s power cord. Save the carton and packing material should it be needed for future shipping. Before powering the unit, read this manual. Please observe the cautions for HIGH VOLTAGE. Proceed by doing the following:

1. Set the line voltage switch to the proper position

2. Determine the proper fuse size by referring to the specifications

3. Check for pilot illumination when powered up

THE CONTROLS

1. Line/Mic/48 3 position switch selects the input being used, line or mic, and also

engages the phantom power +48 volts for condensor microphones

2. Pad/-20 2 position switch engages 20 dB of input signal attenuation

3. Phase/180 2 position switch engages a 180 degree phase shift of the signal

4. DI Input 1/4" mono jack accepts Hi-Z instruments such as electric guitars

and basses; a direct input into the preamp tube, bypassing the input transformer

5. Loading variable resistor for impedance matching of the Hi-Z input (range is 10k to 1M ohms); adjust for desired upper harmonic content in guitar sound

6. Gain 12 position rotary switch controls signal gain in the input preamp only

note: for Hi-Z input only top 7 positions have any effect (as shown in blue)

7. OL left yellow LED indicates preamp vacuum tube saturation; when

LED is blinking, the tube is just entering soft clipping

Compressor Section Controls:

8.Gain variable resistor controls compressor vacuum tube gain

9. OL right yellow LED indicates compressor vacuum tube saturation; when

LED is blinking, the tube is just entering soft clipping

10. A.C. Threshold variable resistor sets the signal amplitude threshold, above

which compression engages

*NOTE!!! A setting of 10 yields the least compression, whereas a setting of 0

yields the most compression

11. Slope variable resistor controls the magnitude of compression (sometimes

referred to as ratio); a setting of 10 yields maximum compression, whereas a setting of 0 yields the least compression

12. Attack 3 position switch selects fast, medium, and slow compression response

time to input signal peaks; this is how fast the compression can kick in

13. Release 3 position switch selects fast, medium, and slow compression release

time; this is how long it takes the compressor to stop attenuating signal

Output Section Controls:

14. Output variable resistor controls overall output signal level; this is a post-

preamp and post-compressor gain control preceding the 990 discrete solid state output

note: this feature enables the user to saturate both the preamp tube and the compressor tube while still maintaining a proper signal level sending to other devices - i.e. recording media

15. Level/G.R. 2 position switch selects the VU meter's mode of operation;

in level mode, the meter indicates peak amplitude of output signal; in G.R. mode, the meter indicates the gain reduction is being applied to the signal

note: this meters right to left from 0 VU

16. Link/In/Bypass 3 position switch selects stereo linked compression, compression

engaged, or bypass compressor (preamp by itself)

note: when linking two MPC-100A's for stereo operation, the unit which is set for the most compression will act as the controller for both units; also, a 1/4" mono connection is required between units

Back Panel Connections:

Mic Input female XLR jack for microphone signal in

Line Input female XLR jack for line level signal in (Pin 3 is + of balanced pair)

Side Chain 1/4" stereo jack for balanced signal in for ducking and d'essing

Stereo Link 1/4" mono jack to connect two MPC-100A's for stereo compression

-10 dB Output 1/4" mono jack for low level -10 dB unbalanced signal out

+4 dB Output male XLR jack for pro level +4 dB balanced signal out (Pin 3 is hot)

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