This Buzz Audi DBC-20 is a new take on vintage audio compression with a gain reduction element of silicon diodes in a transformer coupled balanced bridge arrangement.
The DBC-20 audio path uses our Class A discrete amplifier design in a balanced configuration from input to output, but for extra colour in this unit, we have a radio steel laminated transformer of our own design to couple into the diode bridge element. This overall combination produces a desirable compression character that can best be described as tight, colourful and rich with harmonics.
DYNAMIC RATIO POWER
In the style of compressors from the 60's, the DBC-20 incorporates a self-adjusting ratio whereby the compression ratio is progressively increased with deepening gain reduction. This feature allows for the control of very dynamic signals (such as vocals) in a seamless fashion and is also a very desirable characteristic when used on complex percussive material.
This compressor is easy to get happening with six switched attack and release times covering a wide range, including an interesting auto release mode. Big knobs are provided for the amount of compression and the output gain control. The compressor can be switched to a Soft mode whereby dynamic peaks are partially retained. Another switch introduces a high pass filter to the side chain to lower compression sensitivity at low frequencies which is useful on the mix bus. The large knobs with pointers allow for accurate resetting of the compressor and the fast response 15 LED bar graph meter accurately displays gain reduction.
controls and functions
Gain - variable pot that adds gain at the output to correct for lost level with 15dB range. Compression -variable pot that sets the amount of compression. Attack - rotary switch with 6 settings, FAST (less than 0.5mS)-5mS-10mS-15mS-25mS-50mS. Release - rotary switch with 6 recovery time settings, 50mS-100mS-200mS-400mS-600mS and AUTO. Hard/Soft -adds dynamics in soft mode for times when light compression is required. Flat/Bass - reduces compression sensitivity at low frequencies. Bypass/Engage - hard wire unit bypass to compare compressed and uncompressed signals.
There is also a handy power On/Off switch and the Link A/B which provides for stereo tracking to prevent image shift when used on the mix buss.
Maximum Input Level: +27dBu
Maximum Output Level: +27dBu
Noise; -80dBu (measured A Weighted with 10dB gain applied).
Gain; variable 0dB to +15dB
Frequency Response: 6Hz to 400kHz measured no gain reduction.
Harmonic Distortion; At +10dBu input level, no gain reduction; 0.28% @ 100Hz, 0.25% @ 1kHz, 0.15% @ 10kHz
Harmonic Distortion; With 10dB gain reduction (Release set to 400mS); 1.5% @ 100Hz, 0.5% @ 1kHz, 0.5% @ 10kHz
Standard Operating Level; +4dBu
Size; 1 Unit 19" rack mount, (482Wx44Hx250D).
Power requirements; 230V/115V selectable, IEC detachable power cable.