George Massenburg Labs GML 2032 Microphone Preamplifier / Parametric Equalizer The Model 2032 Microphone Preamplifier / Parametric Equalizer is a single-channel, multi-input device for high-resolution studio and remote applications. Incorporating the renowned 8300 preamplifier and reference-standard 8200 equalizer, the Model 2032 inherits over thirty years of GML engineering excellence. This transparent class-A discrete design with internal supply delivers reliability, musicality, and precision.
INTRODUCTION Combining the features of the GML flagship 8200 Parametric Equalizer and 8300 Transformerless Microphone Preamplifier, the Model 2032 embodies the legendary detail and accuracy for which GML is renowned.
•• Flexible routing: Single-Channel, Independent, Inline Insert configurations •• High-pass Filter; selectable 40 Hz, flat, 100Hz •• Front panel Phantom and Phase illuminated switches •• Front panel EQ IN and Insert illuminated switches •• Overload (OL) indication LED •• Power status LED •• Low-noise, highly regulated internal linear power supply •• Modern surface-mount construction, yielding maximum precision, manufacturability, and reliability •• No internal signal interconnects; high-qua
OPERATION The Model 2032 Microphone Preamplifier / Parametric Equalizer offers exceptional flexibility and sonic accuracy when dealing with a variety of signal sources and conditions. Allowing quick adjustment of any critical parameter, the operation of the Model 2032 remains straightforward despite an extensive feature set. Indeed, a reduction in apparent complexity is achieved by taking a building-block approach to operational analysis. I.
A particularly wide range of gain settings (10dB through 75dB of gain) is available for both preamplifier inputs of the Model 2032. This feature accommodates a broad array of input signals, from extremely "hot" microphone inputs to extremely "low" MI inputs, which are often neglected by professional peripheral audio processing devices. Indeed, the minimal 20dB of gain found in most microphone preamplifiers can be excessive in certain circumstances, and decreases the possibility of optimized gain staging.
III. Parametric Equalizer The EQ section of the Model 2032 Microphone Preamplifier / Parametric Equalizer offers precision and adaptability when sculpting the response of any source. Its operational characteristics, duplicated from the Model 8200 Parametric Equalizer, have been honed through many years of use in the most critical recording and mixing situations and have proven both reliable and remarkably accommodating.
IV. Insert A portion of the Model 2032's allure is the flexibility accorded the user in determining the signal routing of the preamplifier and equalizer sections. This functionality is incorporated in the front panel Insert control, an illuminated pushbutton switch that activates a precious-metal contact signal relay. Specifically, the Insert function allows the user to configure the Model 2032 for Single Channel, Independent, or Inline Insert operation (see Configuration illustration).
MODEL 2032 FRONT PANEL DIAGRAM A. Source determines which input the preamplifier section utilizes, either MIC or MI. B. P48 applies 48V Phantom power to pins 2 and 3 of the mic INPUT XLR. C. Gain sets the coarse gain in precise 5dB steps, from 15dB to 70dB. D. Fine provides a continuously variable amount of gain, from –5dB to +5dB. E. Filter regulates the high-pass filter mode of operation, optionally 40Hz, flat, or 100Hz. F. EQ IN engages the parametric equalizer.
MODEL 2032 BACK PANEL DIAGRAM A. City of Los Angeles, UL, and CE standards require these safety statements. “WARNING – To reduce the risk of fire or electric shock do not expose this device to rain or moisture.” “CAUTION: Risk of electric shock. This unit contains no user-serviceable parts—do not open. Refer service to qualified personnel only.” B. The Grounds terminal block gives a common point of continuity to the electronics ground (upper) and the chassis ground (lower).
SPECIFICATIONS* INPUT Input Impedance Mic: 1 kΩ balanced Insert In: 20 kΩ balanced MI: 1 MΩ unbalanced (tip "hot") 1 CMRR, 20 Hz to 20 kHz Mic: >80 dB Insert In: >50 dB CMRR, 100 Hz and 10 kHz Mic: >80 dB Insert In: >40 dB 2 Maximum input before clipping Mic: +17 dBu Insert In: +21 dBu MI: +8.5 dBu THROUGHPUT 3 PREAMPLIFIER MIC INPUT 4 -0.1 dB / +0.002 dB, <10 Hz to >200 kHz -0.01 dB / +0.002 dB, 20 Hz to 40 kHz 5 -3 dB at 310 kHz and <<10 Hz 6 <0.0025% Harmonic distortion at +20 dBu, 20 Hz to 30 kHz <0.
Specification Notes * All tests conducted at the GML laboratory using the Audio Precision System Two Cascade Dual Domain (AP S2C), or else as noted. Unless otherwise specified, all tests include AP S2C residual measurement and were conducted under the following conditions: Rs=40Ω, RL=100kΩ, <10Hz to >500kHz analyzer bandwidth. GML reserves the right to make changes to these specifications and/or any of its products as it deems necessary.
FORM FACTOR One channel, multi-input, gain, filter, parametric equalizer with insert capability Preamplifier section Two inputs: MIC (balanced, XLR), MI (unbalanced, 1/4”; Tip = Signal, Sleeve = Ground) Input Source control: MIC or MI Gain control: 10dB to 70dB, 5dB steps Fine control: -5dB to +5dB, continuously variable Phase switch, illuminated pushbutton: in-phase (LED off), phase reverse (LED on) P48 switch, illuminated pushbutton: phantom on (LED on), phantom off (LED off) Filter -- Second-order Butter
DESIGN On the surface it is not eminently evident just how much "new" design is represented in the Model 2032 Microphone Preamplifier / Parametric Equalizer. Indeed, the equalizer section has been barely modified from the reference-standard Model 8200 Parametric Equalizer, while the Model 8300 Transformerless Microphone Preamplifier is largely copied in the preamplifier section.
passive elements. This attention to detail partially elucidates the quality found in the Microphone Preamplifier / Parametric Equalizer. These component choices, coupled with superior design techniques and a proclivity towards innovation, combine to make the Model 2032 a most powerful, flexible, and transparent single channel processor. Another feature that distinguishes the Model 2032 is its inherent dynamic range.
POWER SUPPLY Integral to the superb quality of all GML products is the power supply, an internal power supply in this case. No piece of electronic equipment can operate as designed without an adequate power supply; however, many contemporary processors do not feature a supply that can provide clean, quiet power without unduly heating the device. The Model 2032 internal supply excels in this respect, maintaining the ability to deftly react to highly transient signal content and extreme circuit actions.
TROUBLESHOOTING Note: This unit is a highly sensitive device that includes many complex circuits. THIS UNIT CONTAINS NO USER-SERVICEABLE PARTS. Warning: Risk of electric shock if top cover is removed. In the event of unit operational failure, contact GML Service and Technical Support. Refer to the "Contacts" page of this manual, or for more current contact information, check the web site.
CONTACTS General Information: GML, LLC. 615.790.1016 (ph) 615.794.4802 (fax) www.massenburg.com Service and Technical Support: GML, LLC. Franklin, TN 615.790.9946 (ph) www.massenburg.com Engineering: GML, LLC. Attn: Jeffrey Warren, Chief Engineer Franklin, TN 615.790.9946 (ph) email: gmleng@earthlink.net Pricing/Ordering: USA Sales Office: TransAmerica Audio Group Las Vegas, NV 702.365.5155 (ph) sales@transaudiogroup.
NOTICE OF COPYRIGHT AND OWNERSHIP All designs, circuit board artwork, front panel artwork, text contained herein and therein, and all other intellectual material is the sole property of George Massenburg Labs, LLC (and/or GML, Inc.). Unauthorized use, distribution, reproduction, etc. is strictly prohibited. GML intellectual property is protected by U.S. and international copyright laws. Violators will be prosecuted to the fullest extent of all applicable laws.
ADDITIONAL GML PERIPHERALS Model 2020 High Resolution Discrete Input Channel Model 2030 Mastering Dynamic Gain Control, Series III Model 8200 Parametric Equalizer, Series II Model 8300 Transformerless Microphone Preamplifier Model 8355 Power Supply Model 8900 Dynamic Gain Control, Series III Model 9015 Power Supply Model 9500 Two Channel 5-Band Parametric Mastering Equalizer HRT 9100 Mixer HRT 9145 Multi-Output Power Supply Model 9550 Two Channel Digital Noise Filter Model 9560 Digital Noise Filter w/ Macin
P/N 2032-SG-001 CONFIGURATION I. Single Channel Operation OUTPUT INPUT 1 2 3 PREAMP 2 PARAMETRIC EQUALIZER HPF 2 1 3 INSERT OUT MIC INSERT SOURCE MI CONFIGURATION II. Independent Operation INSERT OUT INPUT 1 2 PREAMP 3 2 HPF 1 1 3 INSERT IN OUTPUT 2 2 PARAMETRIC EQUALIZER 3 1 3 MIC INSERT SOURCE MI CONFIGURATION III.
P/N 2032-BD-001 MODEL 2032 MICROPHONE PREAMPLIFIER / PARAMETRIC EQUALIZER BLOCK DIAGRAM All Routing Options 70dB CW +5dB CW S4 GAIN SOURCE MIC 1 15dB 3 1 S1.A MI INPUT 2 meter INSERT -5dB 2 OL INPUT 1 FINE INPUT GAIN +BALANCING HPF (musical instrument) 2 CW 3 40Hz 100Hz 1 FLAT P48 PARAMETRIC EQUALIZER S7.B S5 S3 OUTPUT S7.A INSERT IN (2nd order Butterworth) S1.
P/N 2032-RS-001 SOURCE SELECT GAIN P48 MIC 60 -4 -4.5 65 20 15 70 dB 3 0 4 dB .5 3 1.5 6 9 .3 5 INSERT 12 15 3 1 6 12 0.4 .14 SHELF OL 8 Hz x100 0 dB BOOST .5 3 6 33 4 .2 15 CUT .8 1 2.5 2 .15 100 Hz EQUALIZER LOW-MID BOOST 9 FLAT 2 3 0 dB 6 40 Hz 1 -5 LOW CUT -1 -3 55 -3.5 30 PHASE EQ IN high-pass -2 50 25 MI FILTER FINE 40 45 35 1.5 6 .3 9 1 12 6 12 0.4 8 .14 15 15 kHz Q HIGH-MID 0 dB BOOST 3 6 33 4 .15 4 3 2 .2 9 CUT 2.
