} Heritage Audio Herchild Next Gen 670N Stereo Tube Variable-Mu Compress — Pro Audio Reserve
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Heritage Audio Herchild Next Gen 670N Stereo Tube Variable-Mu Compressor Limiter

$2,999.00
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Description

Heritage Audio Herchild Next Gen 670N Stereo Tube Variable-Mu Compressor Limiter

Heritage Audio Herchild Next Gen 670N Overview

  Heritage Audio Herchild Next Gen 670N stereo tube variable-mu compressor

The Fairchild 670 Sound, Rethought for Today's Studios

Heritage Audio spent four years producing the original Herchild 670 and 660 — exacting Fairchild recreations using 22 tubes and 9 transformers — and another two years distilling everything learned into the Grandchild 670/500 series module. The Herchild Next Gen 670N is the result of all that accumulated knowledge: a full-size vari-mu stereo compressor driven by four NOS military-grade 6BA6 tubes and six newly designed custom transformers, delivering the unmistakable Fairchild warmth, glue, and program-dependent behavior at less than half the price of the flagship model.

The 670N doesn't stop at recreation. A thoroughly redesigned output makeup gain stage based on Heritage Audio's own transformer-coupled HA-880 op-amp adds level without touching the underlying tube compression character. Independent bypass switches on each channel enable instant A/B comparison. Stepped controls for every parameter make sessions fully repeatable. Six updated attack and release time constants have been refined for contemporary production demands rather than faithfully copying the original's curves.

Heritage Audio Herchild 670N five sidechain filter modes DC threshold

Five Sidechain Filter Modes and Refined DC Threshold

Where the original Herchild 670 offered four fixed sidechain high-pass frequencies, the 670N expands to five selectable filter modes covering 80 Hz, 160 Hz, 1 kHz, 3 kHz, and 5 kHz. The higher-frequency settings allow the detection circuit to respond to a narrower band of the spectrum — ideal for de-essing or taming cymbal splash on drum overheads while preserving the natural low-end behavior that defines the Fairchild character.

The progressive DC Threshold has also been recalibrated to offer a more useful working range between fully transparent compression and hard limiting. Combined with program-dependent soft-knee behavior that naturally increases ratio as signals get louder, the 670N gives you precise control over exactly how aggressively the compressor responds — from barely perceptible leveling to full vintage limiting authority.

Heritage Audio Herchild 670N LAT VERT mid-side stereo dual mono modes

LAT/VERT Mid-Side Processing and Four Operating Modes

The 670N operates in four modes. IND runs each channel independently for dual-mono tracking or parallel applications. LINK connects both channels in true stereo compression. LAT/VERT engages full mid-side processing — compressing the lateral and vertical components of a stereo signal independently for increased width, depth, and focus in mixing and mastering. LAT/VERT LINK does the same with both channels driven by an averaged control voltage.

With an input impedance of 15 kΩ, output impedance of just 50 Ω, and maximum output of +29 dBu, the 670N integrates cleanly into any professional signal chain. Self noise below -78 dBu and harmonic distortion below 0.5% at any level up to +24 dBu ensure the vari-mu character is always musical rather than coloring unexpectedly. Handbuilt in Heritage Audio's factory in Madrid, Spain. As an authorized dealer, Pro Audio Reserve ensures you receive a genuine Heritage Audio product backed by full manufacturer warranty and long-term support.

Highlights

  • Full-size stereo Fairchild 670-style vari-mu compressor at accessible price
  • 4 NOS military-grade 6BA6 variable-mu tubes and 6 custom transformers
  • Class A tube-based variable-mu compression
  • Program-dependent soft-knee behavior with progressive ratio increase
  • 6 updated attack and release time constants adapted for modern production
  • Refined DC Threshold for improved range between transparent and hard limiting
  • HA-880 transformer-coupled op-amp output makeup gain stage per channel
  • Independent bypass switch per channel for instant A/B comparison
  • 5 sidechain filter modes: 80 Hz, 160 Hz, 1 kHz, 3 kHz, 5 kHz
  • Four operating modes: IND, LINK, LAT/VERT (mid-side), LAT/VERT LINK
  • Stepped controls for every parameter — fully recallable sessions
  • Input impedance: 15 kΩ | Output impedance: 50 Ω
  • Maximum output: +29 dBu
  • Self noise: less than -78 dBu
  • THD: less than 0.5% at any level up to +24 dBu (no compression)
  • Frequency response: 20 Hz – 20 kHz (±0.5 dB)
  • 6U rackmount, handbuilt in Madrid, Spain

Heritage Audio Herchild Next Gen 670N Specifications

Specification Details
Compressor Type Tube variable-mu compressor/limiter
Number of Channels 2 (stereo)
Circuit Design Class A, tube-based, handwired
Tubes 4 x NOS military-grade 6BA6 variable-mu pentodes
Transformers 6 custom transformers
Output Makeup Gain Stage HA-880 transformer-coupled op-amp (per channel)
Frequency Response 20 Hz – 20 kHz (±0.5 dB)
Self Noise Less than -78 dBu
Harmonic Distortion Less than 0.5% at any level up to +24 dBu (no compression)
Input Impedance 15 kΩ
Output Impedance 50 Ω
Maximum Output Level +29 dBu
Time Constants 6 stepped attack/release settings (adapted for modern production)
Sidechain Filter Modes Off, 80 Hz, 160 Hz, 1 kHz, 3 kHz, 5 kHz
Operating Modes IND, LINK (stereo), LAT/VERT (mid-side), LAT/VERT LINK
Channel Bypass Independent bypass per channel
Analog Inputs 2 x XLR
Analog Outputs 2 x XLR
Rack Spaces 6U
Power Source Standard IEC AC cable
Manufactured Madrid, Spain

What's in the Box

Included Items
Heritage Audio Herchild Next Gen 670N Stereo Tube Compressor/Limiter
Power Cable
User Manual
Shipping

Shipping & Returns

  • We deliver all US orders in 3–5 business days
  • Free cancellations
  • Returns accepted within 30 days (unused items)

Order Confirmation

Once your order is placed, you will receive an order confirmation email. This confirms that we have received your order and have pre-authorized your credit card for the purchase. After confirming availability with our suppliers, we will proceed accordingly:

  • If your item is available and ready to ship within 1–2 business days, we will process the charge and arrange for shipment.

  • If your item is on backorder or unavailable, the pre-authorization will be voided and you will be notified by email.

  • Please note: While most items ship out within 1–2 business days, total delivery time is typically 3–5 business days, depending on your location and carrier handling.

Order Shipment

If your item is in stock and your payment has been processed, your order will typically ship within 1–2 business days. Total delivery time is approximately 3–5 business days from the date of order. Once shipped, you will receive tracking information at the email address provided during checkout within 24 hours of dispatch.

If you have not received tracking information within 3–5 business days of placing your order, please contact us at support@proaudioreserve.com.

The Distributor-Direct Advantage

To ensure you receive the most recent hardware revisions and 100% factory-sealed units, Pro Audio Reserve utilizes a Distributor-Direct fulfillment model. Unlike big-box retailers that may ship "floor models" or gear that has been sitting in general-purpose warehouses, your equipment is pulled directly from the primary manufacturer hub, serialized, and dispatched. This process ensures the highest level of quality control for professional-grade recording equipment.

Shipping Policy

We currently offer free shipping within the United States only. If the checkout process on our website allows you to enter a shipping address and complete your order, your location is eligible to receive delivery.

Changing Shipping Address

If you need to change your shipping address after your order has been processed or shipped, we will do our best to accommodate the request. Please note that address changes may result in delivery delays. Any additional costs incurred due to address changes, including carrier fees or rerouting charges will be the responsibility of the customer. No exceptions.

Shipping Times

All shipping times provided are estimates and should not be considered guarantees. Most orders ship out within 1–2 business days from the time payment is processed. However, total delivery time is typically 3–5 business days, depending on your location, carrier performance, and supplier fulfillment timelines.

We work closely with our vendors to ensure timely deliveries, but please note that supply chain disruptions, high-demand periods, or weather events may occasionally cause delays beyond our control.

  • To avoid misunderstandings: The “shipping time” refers to the total time from order placement to final delivery, not just when the item leaves the warehouse.

  • Cancellations: If you choose to cancel your order because it has not arrived within the estimated delivery window, you may be responsible for applicable shipping charges, restocking fees, warehouse handling costs, and other related fees.

  • Chargebacks: Customers who initiate chargebacks due to shipping delays without contacting us first may be held legally responsible for losses. We strongly encourage open communication so we can resolve any delivery concerns directly and efficiently via our Atlanta-based support team.

Delivery Options

  • Threshold Shipping: Your item will be delivered to your front door, porch, garage, or a covered entryway.

 

Why Buy From Us

We get it. You've got a lot of choice when it comes to online retailers.
Here's why we think you should shop with us at ProAudioReserve.

  • Free Shipping USA wide. 
  • 30 Day Easy Returns. Not happy with your product, we'll take it back noquestions asked.
  • Great Service. We pride ourselves on the best service, anywhere.

Reviews
Description

Heritage Audio Herchild Next Gen 670N Stereo Tube Variable-Mu Compressor Limiter

Heritage Audio Herchild Next Gen 670N Overview

  Heritage Audio Herchild Next Gen 670N stereo tube variable-mu compressor

The Fairchild 670 Sound, Rethought for Today's Studios

Heritage Audio spent four years producing the original Herchild 670 and 660 — exacting Fairchild recreations using 22 tubes and 9 transformers — and another two years distilling everything learned into the Grandchild 670/500 series module. The Herchild Next Gen 670N is the result of all that accumulated knowledge: a full-size vari-mu stereo compressor driven by four NOS military-grade 6BA6 tubes and six newly designed custom transformers, delivering the unmistakable Fairchild warmth, glue, and program-dependent behavior at less than half the price of the flagship model.

The 670N doesn't stop at recreation. A thoroughly redesigned output makeup gain stage based on Heritage Audio's own transformer-coupled HA-880 op-amp adds level without touching the underlying tube compression character. Independent bypass switches on each channel enable instant A/B comparison. Stepped controls for every parameter make sessions fully repeatable. Six updated attack and release time constants have been refined for contemporary production demands rather than faithfully copying the original's curves.

Heritage Audio Herchild 670N five sidechain filter modes DC threshold

Five Sidechain Filter Modes and Refined DC Threshold

Where the original Herchild 670 offered four fixed sidechain high-pass frequencies, the 670N expands to five selectable filter modes covering 80 Hz, 160 Hz, 1 kHz, 3 kHz, and 5 kHz. The higher-frequency settings allow the detection circuit to respond to a narrower band of the spectrum — ideal for de-essing or taming cymbal splash on drum overheads while preserving the natural low-end behavior that defines the Fairchild character.

The progressive DC Threshold has also been recalibrated to offer a more useful working range between fully transparent compression and hard limiting. Combined with program-dependent soft-knee behavior that naturally increases ratio as signals get louder, the 670N gives you precise control over exactly how aggressively the compressor responds — from barely perceptible leveling to full vintage limiting authority.

Heritage Audio Herchild 670N LAT VERT mid-side stereo dual mono modes

LAT/VERT Mid-Side Processing and Four Operating Modes

The 670N operates in four modes. IND runs each channel independently for dual-mono tracking or parallel applications. LINK connects both channels in true stereo compression. LAT/VERT engages full mid-side processing — compressing the lateral and vertical components of a stereo signal independently for increased width, depth, and focus in mixing and mastering. LAT/VERT LINK does the same with both channels driven by an averaged control voltage.

With an input impedance of 15 kΩ, output impedance of just 50 Ω, and maximum output of +29 dBu, the 670N integrates cleanly into any professional signal chain. Self noise below -78 dBu and harmonic distortion below 0.5% at any level up to +24 dBu ensure the vari-mu character is always musical rather than coloring unexpectedly. Handbuilt in Heritage Audio's factory in Madrid, Spain. As an authorized dealer, Pro Audio Reserve ensures you receive a genuine Heritage Audio product backed by full manufacturer warranty and long-term support.

Highlights

  • Full-size stereo Fairchild 670-style vari-mu compressor at accessible price
  • 4 NOS military-grade 6BA6 variable-mu tubes and 6 custom transformers
  • Class A tube-based variable-mu compression
  • Program-dependent soft-knee behavior with progressive ratio increase
  • 6 updated attack and release time constants adapted for modern production
  • Refined DC Threshold for improved range between transparent and hard limiting
  • HA-880 transformer-coupled op-amp output makeup gain stage per channel
  • Independent bypass switch per channel for instant A/B comparison
  • 5 sidechain filter modes: 80 Hz, 160 Hz, 1 kHz, 3 kHz, 5 kHz
  • Four operating modes: IND, LINK, LAT/VERT (mid-side), LAT/VERT LINK
  • Stepped controls for every parameter — fully recallable sessions
  • Input impedance: 15 kΩ | Output impedance: 50 Ω
  • Maximum output: +29 dBu
  • Self noise: less than -78 dBu
  • THD: less than 0.5% at any level up to +24 dBu (no compression)
  • Frequency response: 20 Hz – 20 kHz (±0.5 dB)
  • 6U rackmount, handbuilt in Madrid, Spain

Heritage Audio Herchild Next Gen 670N Specifications

Specification Details
Compressor Type Tube variable-mu compressor/limiter
Number of Channels 2 (stereo)
Circuit Design Class A, tube-based, handwired
Tubes 4 x NOS military-grade 6BA6 variable-mu pentodes
Transformers 6 custom transformers
Output Makeup Gain Stage HA-880 transformer-coupled op-amp (per channel)
Frequency Response 20 Hz – 20 kHz (±0.5 dB)
Self Noise Less than -78 dBu
Harmonic Distortion Less than 0.5% at any level up to +24 dBu (no compression)
Input Impedance 15 kΩ
Output Impedance 50 Ω
Maximum Output Level +29 dBu
Time Constants 6 stepped attack/release settings (adapted for modern production)
Sidechain Filter Modes Off, 80 Hz, 160 Hz, 1 kHz, 3 kHz, 5 kHz
Operating Modes IND, LINK (stereo), LAT/VERT (mid-side), LAT/VERT LINK
Channel Bypass Independent bypass per channel
Analog Inputs 2 x XLR
Analog Outputs 2 x XLR
Rack Spaces 6U
Power Source Standard IEC AC cable
Manufactured Madrid, Spain

What's in the Box

Included Items
Heritage Audio Herchild Next Gen 670N Stereo Tube Compressor/Limiter
Power Cable
User Manual
Shipping

Shipping & Returns

  • We deliver all US orders in 3–5 business days
  • Free cancellations
  • Returns accepted within 30 days (unused items)

Order Confirmation

Once your order is placed, you will receive an order confirmation email. This confirms that we have received your order and have pre-authorized your credit card for the purchase. After confirming availability with our suppliers, we will proceed accordingly:

  • If your item is available and ready to ship within 1–2 business days, we will process the charge and arrange for shipment.

  • If your item is on backorder or unavailable, the pre-authorization will be voided and you will be notified by email.

  • Please note: While most items ship out within 1–2 business days, total delivery time is typically 3–5 business days, depending on your location and carrier handling.

Order Shipment

If your item is in stock and your payment has been processed, your order will typically ship within 1–2 business days. Total delivery time is approximately 3–5 business days from the date of order. Once shipped, you will receive tracking information at the email address provided during checkout within 24 hours of dispatch.

If you have not received tracking information within 3–5 business days of placing your order, please contact us at support@proaudioreserve.com.

The Distributor-Direct Advantage

To ensure you receive the most recent hardware revisions and 100% factory-sealed units, Pro Audio Reserve utilizes a Distributor-Direct fulfillment model. Unlike big-box retailers that may ship "floor models" or gear that has been sitting in general-purpose warehouses, your equipment is pulled directly from the primary manufacturer hub, serialized, and dispatched. This process ensures the highest level of quality control for professional-grade recording equipment.

Shipping Policy

We currently offer free shipping within the United States only. If the checkout process on our website allows you to enter a shipping address and complete your order, your location is eligible to receive delivery.

Changing Shipping Address

If you need to change your shipping address after your order has been processed or shipped, we will do our best to accommodate the request. Please note that address changes may result in delivery delays. Any additional costs incurred due to address changes, including carrier fees or rerouting charges will be the responsibility of the customer. No exceptions.

Shipping Times

All shipping times provided are estimates and should not be considered guarantees. Most orders ship out within 1–2 business days from the time payment is processed. However, total delivery time is typically 3–5 business days, depending on your location, carrier performance, and supplier fulfillment timelines.

We work closely with our vendors to ensure timely deliveries, but please note that supply chain disruptions, high-demand periods, or weather events may occasionally cause delays beyond our control.

  • To avoid misunderstandings: The “shipping time” refers to the total time from order placement to final delivery, not just when the item leaves the warehouse.

  • Cancellations: If you choose to cancel your order because it has not arrived within the estimated delivery window, you may be responsible for applicable shipping charges, restocking fees, warehouse handling costs, and other related fees.

  • Chargebacks: Customers who initiate chargebacks due to shipping delays without contacting us first may be held legally responsible for losses. We strongly encourage open communication so we can resolve any delivery concerns directly and efficiently via our Atlanta-based support team.

Delivery Options

  • Threshold Shipping: Your item will be delivered to your front door, porch, garage, or a covered entryway.

 

Why Buy From Us

We get it. You've got a lot of choice when it comes to online retailers.
Here's why we think you should shop with us at ProAudioReserve.

  • Free Shipping USA wide. 
  • 30 Day Easy Returns. Not happy with your product, we'll take it back noquestions asked.
  • Great Service. We pride ourselves on the best service, anywhere.

Reviews