Carvin EQ2015 & EQ2030 Dual Graphic Equalizers - Operating Manual
Introduction
The Carvin EQ2015 and EQ2030 are professional dual graphic equalizers designed for a wide range of audio applications including recording, sound reinforcement, and home audio systems. The EQ2015 offers 2/3 octave equalization, while the EQ2030 provides finer 1/3 octave control. Both units feature extended frequency response, wide dynamic range, low noise operation, 15dB boost/cut per frequency band, low interaction between frequencies, and dual sweepable High and Low cut filters. They are built for ruggedness and reliability, ensuring years of professional service.
Receiving Inspection
Upon receiving your unit, inspect it for any damage that may have occurred during shipping. If damage is found, notify the shipping company and Carvin immediately. Save all original packaging materials for potential future returns or shipments. Keep your invoice as it is required for warranty service.
Record the serial number on the enclosed warranty card for your records.
Interface & Operation
The EQ2015 and EQ2030 are designed to be inserted into an audio signal path at any point where a nominal "line level" signal is present. They are not suitable for very low level signals (e.g., microphone preamps) or very high level signals (e.g., loudspeaker outputs), as this may cause damage. The units offer balanced XLR and unbalanced 1/4" connections for compatibility with professional audio equipment.
Applications
Recording Studio Applications
In the studio, these equalizers are ideal for correcting control room monitor frequency response to achieve a neutral, "colorless" sound. They can be placed between the mixer's control room outputs and the stereo power amplifier inputs. They can also be patched into individual mixer channels or subgroups for tone shaping.
Sound Reinforcement Applications
For live sound (PA systems), the EQ2015 and EQ2030 are used to equalize main and monitor speaker systems, correct for room acoustics, and control feedback. A common technique for feedback control involves raising the system level to the point of feedback, identifying the ringing frequency, and reducing that slider. This process is repeated to achieve a stable system. The units can be inserted between the mixer/monitor outputs and the power amplifier inputs. The sweepable low-cut filter can protect woofers from subsonic transients, and the high-cut filter can protect tweeters from ultrasonic oscillations.
Guitar & Bass Amps
Guitar and bass players can integrate these equalizers between their pre-amp and power amp for enhanced tonal control. Using A/B boxes allows for additional channel-like flexibility.
Home Hi-Fi Application
These equalizers are suitable for home Hi-Fi systems, allowing users to achieve a highly accurate frequency response in their listening room. They can be connected to a tape monitor loop on an integrated receiver/pre-amp or placed between a separate pre-amp and power amp. They can also be used for home recording to equalize material being recorded or for making tape dubs of older recordings.
Micro Toroid Supply
Each unit features a built-in Micro Toroid power supply with precision voltage regulators. This design provides excellent noise and hum rejection, allowing the equalizers to be placed near sensitive equipment without interference.
Technical Specifications
MODEL EQ2015 SPECS:
| Parameter | Value |
|---|---|
| Input Type | Balanced and unbalanced via male and female XLR connector or 1/4" phone jack |
| Input Impedance | 20 KΩ balanced, 10 KΩ unbalanced |
| Maximum Input Level | +20 dBv balanced or unbalanced |
| Output Type | Balanced and unbalanced via male XLR connector or 1/4" phone jack |
| Output Impedance | 600 Ω balanced |
| Maximum Output Level | +20 dBv (7.8 Vrms) into a 600 Ω load or greater (Unbalanced), +26 dBv (15.6 Vrms) into a 600 Ω load or greater (Balanced) |
| Input Gain Control | +6 dB to full attenuation |
| Boost/Cut | ±15 dB, +20 dBv into 600 Ω |
| Center Frequencies | 25, 40, 63, 100, 160, 250, 400, 630, 1k, 1.6k, 2.5k, 4k, 6.3k, 10k, and 16 kHz ± 5% |
| Filter Type | Active bandpass filters (no inductors) |
| Frequency Accuracy | ±5% of nominal center frequency |
| Frequency Response (centered) | ±1 dB, 10 Hz to 45 kHz |
| Bandwidth (-3 dB points) | 7 Hz -85 kHz |
| Harmonic Distortion | <.01% THD, 20 Hz to 20 kHz |
| Noise (unweighted, 20 kHz BW) | 104 dB below full output |
| Slew Rate | 9 volts per microsecond |
| Power Requirements | 120 VAC, 60 Hz, 1/4 A, 5x20 fuse (US); 230 VAC, 50 Hz, .125 A, 5x20 fuse (Export) |
| Package | 2 rack spaces |
| Dimensions | 19"W x 6"D x 3 1/2"H |
| Net Weight | 10 lbs. |
MODEL EQ2030 SPECS:
| Parameter | Value |
|---|---|
| Input Type | Balanced and unbalanced via male and female XLR connector or 1/4" phone jack |
| Input Impedance | 20 KΩ balanced, 10 KΩ unbalanced |
| Maximum Input Level | +20 dBv balanced or unbalanced |
| Output Type | Balanced and unbalanced via male XLR connector or 1/4" phone jack |
| Output Impedance | 600 Ω balanced |
| Maximum Output Level | +20 dBv (7.8 Vrms) into a 600 Ω load or greater (Unbalanced), +26 dBv (15.6 Vrms) into a 600 Ω load or greater (Balanced) |
| Input Gain Control | +6 dB to full attenuation |
| Boost/Cut | ±15 dB, +20 dBv into 600 Ω |
| Center Frequencies | 25, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1k, 1.25k, 1.6k, 2k, 2.5k, 3.15k, 4k, 5k, 6.3k, 8k, 10k, 12.5k, 16k and 20k ± 5% |
| Filter Type | Active bandpass filters (no inductors) |
| Frequency Accuracy | ±5% of nominal center frequency |
| Frequency Response (centered) | ±1 dB, 10 Hz to 45 kHz |
| Bandwidth (-3 dB points) | 7 Hz -85 kHz |
| Harmonic Distortion | <.01% THD, 20 Hz to 20 kHz |
| Noise (unweighted, 20 kHz BW) | 104 dB below full output |
| Slew Rate | 9 volts per microsecond |
| Power Requirements | 120 VAC, 60 Hz, 1/4 A, 5x20 fuse (US); 230 VAC, 50 Hz, .125 A, 5x20 fuse (Export) |
| Package | 3 rack spaces |
| Dimensions | 19"W x 6"D x 5 1/4"H |
| Net Weight | 13 lbs. |
Front & Rear Panel Controls
Front Panel Controls
- 1. PEAK OVERLOAD LED ⚠️: Indicates signal levels approaching clipping (distortion). Brief illumination at musical peaks is normal; constant or frequent flashing requires input gain reduction.
- 2. GAIN CONTROL: Adjusts signal levels between the equalizer and connected equipment, from full attenuation to +6dB gain.
- 3. FREQUENCY BAND SLIDERS: 15dB boost/cut per frequency band. Features a positive center detent for a precise "flat" setting.
- 4. EQ BYPASS SWITCH: Allows A/B comparison of the equalized signal with the original source.
- 5. SWEEPABLE LO CUT FILTER: Range of 10 Hz to 230 Hz. Functions as a subsonic filter to protect amplifiers, reduce stage rumble/wind noise, or minimize 60-cycle hum. A recommended setting is 35 Hz.
- 6. SWEEPABLE HI CUT FILTER: Range of 6 kHz to 45 kHz. Useful for reducing hiss in low-frequency content or as an ultrasonic filter (20 kHz and up) to protect high-frequency drivers from damaging oscillations. A recommended setting is 20 kHz.
Rear Panel Connections
- 7. AC POWER CORD & MAIN POWER FUSE: Use grounded outlets. Replace fuse only with the specified type and value (120 VAC: 1/4A, 5x20mm; 230 VAC: .125A, 5x20mm).
- 8. CHANNEL 1 (2) 1/4" PHONE JACK INPUT: Accepts balanced or unbalanced signals. For balanced signals, tip is signal +, ring is signal -, sleeve is ground.
- 9. CHANNEL 1 (2) XLR INPUT CONNECTOR: Accepts balanced or unbalanced signals. Pin 2 is signal +, pin 3 is signal -, pin 1 is grounded.
- 10. CHANNEL 1 (2) 1/4" PHONE JACK OUTPUT: Outputs balanced or unbalanced signals. Pin 2 is signal +, pin 3 is signal -, pin 1 is ground.
- 11. CHANNEL 1 (2) XLR OUTPUT: Outputs balanced or unbalanced signals. Pin 2 is signal +, pin 3 is signal -, pin 1 is ground.
- 12. OUTPUT XLR GROUND LIFT SWITCH: Defeats pin 1 ground on the XLR output to help eliminate ground loops (AC hum).
Diagram Description (Figure 1)
Figure 1 illustrates common connection scenarios for the EQ2015 and EQ2030:
- Recording Studio: Shows a mixer's control room outputs feeding into the EQ's inputs, with the EQ's outputs then connecting to a stereo power amplifier's inputs.
- Sound Reinforcement (Live PA): Depicts a mixer's main outputs going to the EQ's inputs, then to a main power amplifier and finally to the main speakers. A separate path shows mixer monitor outputs feeding an EQ (or directly to a monitor power amp), then to monitor speakers.
- Home Hi-Fi: Illustrates connecting the EQ between a receiver/pre-amp's tape output and tape input, or between a stereo pre-amp and stereo power amp.
Using the EQ2015 & EQ2030
These equalizers are powerful tools for shaping audio. For precise adjustments, especially in live sound or studio monitoring, using a spectrum analyzer with a pink noise test signal is recommended. This helps achieve a flat frequency response by allowing visual adjustment of each frequency band. The manual also mentions an "impulse response" technique as a more advanced alternative.
The document includes frequency response graphs (Figure 2 and Figure 3) illustrating various settings and band responses.
Safety Instructions & Warranty
Important Safety Information:
- ⚠️ Risk of Electric Shock: Do not open the unit. Refer servicing to qualified personnel.
- Keep the appliance away from water and moisture.
- Connect only to the specified power supply type.
- Ensure grounding and polarization are not defeated.
- Protect power cords from damage.
- European Safety Instructions: Conductor colors for AC power cords are specified (Green & Yellow for Earth, Blue for Neutral, Brown for Live). A warning is issued regarding modified UK mains plugs.
Limited Warranty:
Carvin products are guaranteed against failure for one year from the date of purchase, unless otherwise stated. Carvin will provide free service and parts under warranty, but shipping costs are the customer's responsibility. The warranty does not cover damage from natural disasters, accidents, abuse, misuse, or failure to follow instructions. A copy of the original invoice is required for warranty verification. Carvin is not liable for incidental or consequential damages.
Help Section: Basic troubleshooting tips are provided, including checks for power issues and fuse replacement.
Replacement Parts Lists
Detailed replacement parts lists for both the EQ2015 and EQ2030 are included in the original document, specifying component references, descriptions, Carvin part numbers, and quantities. These lists are valuable resources for service and repair.
