User`s manual
Section 1  Description 
This section provides a general description of the 176 Tube Limiting Amplifier. Please 
review this information before installing or operating the 176. 
1.1  Your Limiter 
The 176 Tube Limiting Amplifier is designed to provide the quintessential character of 
vintage tube compression in the modern recording studio environment. It is modeled 
after the superb UA 176 limiter and adds new features and conveniences. The Retro 176 
uses high quality components that should provide many years of trouble-free service. 
Your limiter has been through a full burn-in and testing procedure at the factory. 
Ease of use is key with user-friendly front panel controls and easily recallable settings. 
No matter what settings you use, the great sonic traits of the 176 will enhance your 
recordings. 
1.2 Applications 
The Retro 176 is designed for great versatility in many applications. Because of the way 
real tube compression handles dynamics, the 176 enhances dimension, depth and detail. 
Independent tracks such as vocal, bass, acoustic guitar, piano fill out nicely without harsh 
restraint. The 176 is great for tracking, mixing and multibuss compression applications. 
Possibly the best application for the 176 is use on the stereo buss, buffing it to a glossy 
finish. The Retro 176 adjusts tone in a way that equalization cannot. 
1.3  Specifications 
Frequency Response  Flat within 0.5 dB from 20-20,000 Hz. 
Harmonic Distortion    Below 1% from 20-20,000 Hz at 0-15 dB Gain Reduction 
Noise Level      Greater than 76 dB below normal operating level 
Gain Reduction    20 dB of available gain reduction 
Maximum Gain    32 dB with input and output controls set maximum 
Input Impedance    600 Ohms - floating transformer balanced 
Output Impedance    600 Ohms - floating transformer balanced 
Minimum Input Level   –26 dBm@2:1 ratio –12 dBm@12:1 ratio 
Normal Operating Level  +4 dBm 
Maximum Operating Level  +20 dBm 
Maximum Operating Temp.  55° C 
Physical Dimensions    Standard 19” rack mounted. 2U, 3.5” high, 9.5” deep 
Power Requirements    40 Watts at 115/230 VAC, 50/60 Hz. 










