Useful Arts SFP-30

• Fabricant : Useful Arts
• Modèle : SFP-30
• Catégorie : Préamplis à lampes
• Fiche créée le : 22/01/2019

Préampli micro à lampes rackable, version 1 canal du SFP-60

Each gain stage is single-ended, inherently class A.

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Audio Magnetics (Input and Output Transformers, Plate Inductor) custom wound by 

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Output Transformer with 50% nickel core

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Frequency response is flat within 2dB from 20Hz-30KHz:

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Each channel of the SFP-30 features 4 switches:

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• High Pass Filter

• Input Pad

• Phase Reverse

• Phantom Power

• Absolutely no signal passes through these switches, because we hate the noise that develops over time in even the most expensive switches.  Instead, the front panel switches control sealed, gold-plated relays to ensure years of operation without pops and clicks.

• The input and output levels of the triode stages of the SFP-30 are separately controllable by detented attenuators, and combined with the color control, the SFP-30 provides just over 55dB of useable gain.

• The rear panel is simple: it offers a voltage selector for 115/230 volt operation in the IEC fuse block.  The gold-plated XLR connectors are on the front panel.

• The only active devices in the signal path are the three tube gain stages, consisting of 1 EF806 and 1 ECC82 per channel.  We use new-manufacture JJ tubes for long life and easy replacement.

• Each channel features an output level VU meter, which is op-amp buffered to ensure that the signal is not loaded by the meter.

• The audio power supply features a toroidal dual-primary transformer and linear regulation for lowest noise.