Heritage Audio / Grandchild 670

The Heritage Audio/Grandchild 670 is a 500 series tube compressor.

～500 series size “Fairchild”～

■Thorough quality control
Recreate the impact and excitement of the Herchild Model 670 with the 500 series module. A stereo Variable Mu tube compressor fits in just 2 slots.

The Grandchild 670 is packed with four 6BA6 (5749) NOS tubes, three specially designed transformers (one for each channel and one for the sidechain), and the carefully selected components and circuitry you need to capture that elusive sound. We achieved the tone and response you were looking for in an affordable size.

Like the Herchild, it features an INPUT GAIN control with a 20 dB adjustment range, an AC threshold, a time constant switch with five attack and release options, and a DC threshold (a unique curve adjustment that combines controls) with access to a progressive ratio. Adjusting the DC Threshold provides a nice combination of ratio and knee, giving you the flexibility to go from hard limiting to extremely smooth and transparent light compression. It also features a 3-position high-pass sidechain filter to reduce low-frequency effects in the detection circuit, making it ideal for modern productions.

Since this unit is a stereo unit, the sum of the two channels determines the amount of gain reduction for both channels, ensuring a stable stereo image. The attractive, vintage-inspired front panel features not only a gain reduction meter, but also a highly visible 3-position switch that shows active/bypass/off status, resulting in a clear and beautiful design.

Achieving an intimate, classic sound that connects your mix musically and warmly envelops you isn't easy, but the Grandchild 670 does it perfectly. Heritage Audio engineers responded with a determination to achieve the rich, classy, ??and elegant tone of “Fairchild.” By using four 6BA6 (5749) tubes and three transformers, every signal you put into the Grandchild 670 will sound better.

input impedance
15 kΩ

Output impedance
50Ω

output level
+29 dBu

frequency response
20Hz ~ 20kHz ±0.5dB

self noise
-78 dBu or less

harmonic distortion
<0.5% at any level up to +24 dBu output (no compression)

size
180 mm (W) x 133 mm (H) x 75 mm (L)

weight
1.12Kg

Current consumption
Over 200 mA per slot (1 rail) (+16V / -16V) *Total per unit: Approx. 400 mA