Detail 01
Six original and four variable time constants
Provides ten timing options for configuring the compressor's response.
Product detailSKU #1500000441405
Undertone AudioUnFairchild 670M II Compressor
1/4
Independent shopping perspective
The Korena take
Undertone Audio’s UnFairchild 670M II is a dual-channel tube compressor for rack-based recording setups. Its ten time-constant options cover gentle level control through much heavier compression, while the MS function and sidechain processing expand how you can shape a recording. True bypass makes it straightforward to compare processed and unprocessed signal paths. It is an 8U, 37.4 lb. unit with analog XLR connections, so plan the rack space and installation around it.
Strong match
Who this is for
- Studio setups needing dual-channel compression with MS processing and sidechain control.
- Recording work that moves between restrained level smoothing and more forceful compression.
Consider the trade-offs
When to look elsewhere
- Small racks or portable setups with no room for an 8U, 37.4 lb. processor.
What matters in use
The specifications, translated
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 02
MS function and sidechain processing
Adds mid/side operation and sidechain-based control to the compression workflow.
Detail 03
Analog XLR input and output
Uses XLR connections for its audio I/O.
Final check
Know before you order
- 01Requires 8U of 19-inch rack space.
- 02The unit weighs 37.4 lb.
- 03Audio connections are analog XLR.
Product questions
Before you decide
Straight answers to the questions shoppers most often ask about this product.
01Is the UnFairchild 670M II a stereo unit?
It is specified as a dual-channel compressor and includes an MS function.
02Does it have a bypass mode?
Yes. It includes true bypass.
Reference
Full specifications
The complete catalog record, organized around the decisions musicians make when comparing gear.
1 detailsSound
- Impedance
- 2.5 kOhms (input); 200 Ohms (output)
2 detailsConnections & power
- Input Connectors
- Analog XLR
- Output Connectors
- Analog XLR
2 detailsSize & weight
- Weight
- 37.4
- Unit Weight
- 37.4 lb.
6 detailsOther
- Rack Spaces
- 8U
- Tube Complement
- 6386-LGP, ECC83, ECC83-S, ECC99
- Channels
- Dual-Channel
- Compression Type
- Fairchild-Style
- Tube or Solid State
- Tube
- Chassis
- 19 inch Rack-Mount
