Fredenstein Bento 8 - 500/600 Series Rack
Bento 8 features a complete linear power supply consisting of a mains transformer and linear regulators. This topology yields the cleanest power to your modules.
Usually linear power supplies can't deliver high output currents, but Bento 8 outputs +/-16V DC 2A and +48V DC 0.25A, 500mA per slot, that's ample power for the most demanding 500 series modules! Another drawback of linear supplies is that they are prone to introduce hum from the mains transformer directly into input and output transformer inside modules, especially when plugged into the slot closes to the supply. Bento 8 incorporates extensive shielding of the mains transformer to eliminate induced hum
Fredenstein MAGIC PRE Overview
Outfitted with a vintage vacuum tube for metering, the Fredenstein Magic Pre is a 500 Series microphone preamplifier offering striking visual and sonic appeal for producers, musicians, and engineers. The discrete signal path features input and output transformers as well as Fredenstein's specially designed OPA2 opamp, allowing it to impart a smooth tone along with high-performance noise and distortion specs. A simple press of the Color switch adds harmonics based on select tube circuits, a great way to enhance the sound of your source in a hurry.
The Magic Pre utilizes a single knob to provide a gain range of +15 to +70 dB, so it can adequately serve dynamic, ribbon, or condenser microphones. A front-panel 1/4" jack is provided for direct connection of an unbalanced Hi-Z instrument such as an electric guitar, bass, or keyboard. The pad switch can be used to attenuate the input signal by 20 dB to prevent distortion when tracking loud instruments such as drums. The Magic Eye tube meter opens and shuts to indicate output levels between -15 to +15 dBu.
The preamp follows what may be thought of as a very traditional topology that uses input and output transformers. Both are high-quality, American-made transformers. The steel-core output transformer in particular is a very important sound-shaping component whichhelps produce a smooth vintage sound without being dark or mushy.
A single discrete amplifier is used for the active gain element, and there are no chip based amplifiers in the signal path. To achieve a high level of performance, the circuit is based on Fredenstein's OPA2 discrete audio operational amplifier. As in all Fredenstein products, the OPA2 is not a copy of an older design, but is a completely new design manufactured in SMT technology with matched and integrated dual input transistors to guarantee vastly improved specifications compared to older designs. The OPA2, in the tradition of similar modules, is socketed and can be exchanged without tools. The industry-standard pinout makes it compatible with many other amplifier modules.
The Color switch is intended to produce some tube-like harmonic content that, while not calling attention to itself, can bring some sounds to life and bring them forward in the mix to sound more detailed and dimensional. While the color circuit does increase distortion, the audible effect is subtle enough that few people would ever describe the effect as distorted.
In addition to its standard 500 Series mic input, the Magic Pre offers a front-panel 1/4" Hi-Z instrument input with an impedance of 2 megohms. The rear microphone input is automatically disconnected when a plug is inserted in the DI connector.
The face of the Magic Pre sports dedicated switches for 48V phantom power, color, and a -20 dB pad.
The Magic Pre's most obvious feature is the green, glowing, Magic Eye vacuum tube for output level indication. This vintage 6E5C vacuum tube complements the rich vintage character of the preamp. The eye closes near optimal output levels.
The Eye is wide open (about 90° unlit and 270° softly glowing green) when there is no signal, and it begins moving 30 dB below dBFS or clipping (-15 dBu output). The Eye closes as the signal level increases and the two edges gradually approach each other until they overlap slightly. Where they don't quite overlap or where the Eye closes completely represents +15 dBu typically and is analogous to a bar graph meter going into the yellow. This may be considered a near optimum level. When there is noticeable overlap, consider it similar to going into the red and levels may be too hot.