ASM164 Summing Mixer

The API ASM164 is a 16-channel rackmount analog summing mixer designed to bring the renowned API summing sound to professional and project studios. Inspired by the summing section of API's The BOX console, it offers a streamlined yet powerful way to achieve warm, punchy, and clear mixes. Each of the 16 input channels features balanced line-level connections, an API 2510 opamp, and an assignable pan control, allowing for precise stereo imaging. The mixer includes two stereo program buses (Mix-A and Mix-B) with independent inserts, giving engineers flexibility for external processing such as EQ and compression. Additionally, the ASM164 offers high-quality API 2520 opamp-driven transformer-coupled outputs, ensuring the signature depth and character that API gear is known for.

Designed for seamless integration into various workflows, the ASM164 provides comprehensive rear panel connectivity, including balanced DB-25 and XLR connections, making it easy to interface with patch bays, DAWs, and other studio gear. A dedicated External Input (EXT IN) allows additional stereo signals to be summed into the mix, while the Mix-A to Mix-B summing option enables parallel processing for added creative control. High-precision VU meters ensure accurate level monitoring, and a detented level control system provides precise recall of settings. Whether used as a standalone summing solution or combined with multiple units for expanded channel count, the API ASM164 delivers the classic analog warmth and detail that API consoles are celebrated for, all in a compact and efficient format.

• 16 Summing Inputs " Each with balanced connections, inserts, pan control, and LED metering.

• Dual Stereo Mix Buses (Mix-A & Mix-B) " Independent level controls, inserts, and routing options.

• Mix-A to Mix-B Summing " Enables flexible signal routing and parallel processing.

• Balanced External Input " Assignable to Mix-A and Mix-B for additional mixing options.

• High-Quality API Sound " Uses API 2510 and 2520 opamps with transformer-coupled outputs.

• VU Meters with A/B Selection " Allows monitoring of output levels with a +10dB boost option.

• Comprehensive Rear Panel " Includes DB-25, XLR, and TRS connections for easy integration.

• External Power Supply " Provides stable and efficient performance.

AUDIO PERFORMANCE:

• Input Impedance: 30K Ohms (balanced)

• Mix Output Impedance: 75 Ohms (transformer-coupled, balanced)

• Max Input Level: +28 dBu

• Max Output Level: +28 dBu

• Frequency Response: ±0.5 dB from 20 Hz to 40 kHz

• THD+N: < 0.02% @ +4 dBu, 1 kHz

• Signal-to-Noise Ratio: -112 dBr

INPUT CHANNELS (1-16):

• Balanced, line-level, low-impedance inputs

• Connectors: DB-25 (8-channel standard pinout)

• API 2510 input opamp (same as API "The BOX")

• Balanced insert send and return

• Insert switch with illuminated indicator

• 31-step detented level control (-∞ dB to +6 dB)

• 0 dB bypass option for all channels

• Continuously variable pan control with center detent

• 4-segment LED level meter per channel

• Assignable to Mix-A and/or Mix-B stereo buses

EXTERNAL INPUT (EXT IN):

• Stereo balanced, line-level, low-impedance input

• Connectors: 3-pin female XLR (1=G, 2=+, 3=-)

• 4-segment LED level meter

• Assignable to Mix-A and/or Mix-B buses

• Fixed unity gain (0 dB)

SUMMING MIX BUSES (MIX-A & MIX-B):

• Independent stereo summing buses

• Balanced insert send and return for each mix bus

• Insert switch with illuminated indicator

• 31-step detented mix output level control (-∞ dB to +6 dB)

• Balanced, transformer-coupled, low-impedance stereo XLR outputs

• Mix-A to Mix-B summing for flexible routing

• API 2520 opamp and transformer mix output circuits

MIX OUTPUT VU METERS:

• High-quality stereo analog VU meters

• Assignable to Mix-A or Mix-B via switch

• +10 dB meter shift option

REAR PANEL CONNECTIONS:

• Power: 6-pin DIN external power connector (threaded, locking)

• Channel Inputs: DB-25 (balanced, line-level)

• Channel Insert Send/Return: DB-25 (balanced, line-level)

• External Input (EXT IN): XLR Female (balanced)

• Mix Outputs: XLR Male (balanced)

• Mix Insert Send/Return: ¼" TRS (balanced)

ADDITIONAL FEATURES:

• Cascade multiple ASM164 units for expanded channel count

• Compatible with professional patch bays

• Designed for high-end studios, project studios, and production environments

• Provides the classic "discrete" API analog summing sound

WEIGHT & DIMENSIONS:

• Actual: 12 lbs (5.5 kg)

• Shipping: 17 lbs (7.7 kg)

• Dimensions: 19" x 3.5" (2U) x 11.25" depth

• Shipping Dimensions: 21" x 8" x 14.5"