The product looks nice, feels strong, and works fine.
DigiFi No. 22 Balanced Drive Compatible Headphone Amplifier and More Added
Product Details
(Please note: I will be away from Friday, March 13th to Sunday, March 15th. Shipping will resume on or after Monday, March 16th. Thank you for your understanding.)
I am listing the Stereo Sound DigiFi No. 22 headphone amplifier with balanced drive capability.
Additionally, I am including two NC3MXX connectors for making balanced cables, and three operational amplifiers (op-amps) in addition to the one that comes with the unit for testing unbalanced audio output.
■Main Unit
- Product Name: Stereo Sound DigiFi No. 22 Headphone Amplifier with Balanced Drive Capability
*Note: The Burr-Brown OPA2134PA op-amp for unbalanced output is already installed from the time of purchase.
- Accessories: Screws for board mounting
In addition to the above, the following items are included:
- NEUTRIK NC3MXX Connectors (2 pieces)
- Color Rings (1 orange, 1 gray)
- Op-amps (3 pieces): JRC 4558DD, 4556AD, 2114DD
(These three op-amps were purchased separately by me for unbalanced drive. Separate op-amps are required for balanced drive.)
Purchased approximately 5 years ago. The contents were opened to confirm them, but the unit has never been used, and I have not had the opportunity to use it since. Therefore, I have decided to list it now. The included NC3MXX connectors, color rings, and JRC op-amps are all unused.
*Pets: None
*Smoking: None
Below is an excerpt from the product's original sales description:
- Main Unit Dimensions: 75 x 75 x 29mm (Width x Depth x Height)
- Weight: 55g
This is an analog input headphone amplifier with switchable input terminals: a stereo mini (3-pole) jack with volume control and RCA terminals. The output features a 3-pin XLR balanced terminal and a 3-pole stereo mini jack. It operates with a 13V boost drive, capable of driving various headphones, and also includes an impedance switching function.
The op-amp used is Burr-Brown's OPA2134PA, described as exceptionally luxurious for a magazine freebie. In its standard configuration, it only supports unbalanced drive, but balanced drive becomes possible by adding op-amps separately. The unit is equipped with slots for adding op-amps.
Daily Cleaning: Use a soft brush or damp cloth to gently wipe away dirt. Avoid harsh chemicals. For mesh areas, use diluted mild detergent and a soft brush.
Drying: Air dry in a cool, shaded place after cleaning. Avoid direct sunlight or high heat, which can cause fading and glue deterioration.
Storage: Stuff with paper to maintain shape when not in use. Store in a dry, ventilated area to prevent mold. Rotate between multiple pairs to extend lifespan.
Usage Notes: Designed for basketball. Not recommended for hiking, long-distance running, or other specialized sports where different performance features are required.



