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Features of StereoKnight Magnetic passive


Silverstone Magnetic Passive Preamp series

  • Ultimate Silverstone-Silver

Upgrade version of Reference Silverstone-B&R by using 4 silver wired transformers in both input and output.

Contact for the quote and customerization




What is a Passive Preamp? what does Magnetic Passive mean?

To some audiophiles, a Passive Preamp sounds odd and mysterious; but to some senior hifi guru, Passive Preamp may represent a pure and simple pursue of the extrem high fidelity. Anyway, what is a Passive Preamp? Simply to say, passive here means no active circuitry, i.e. no connection to AC wall power, in short, no power supply. But now days, the request of convenience, for example, the need of remote control function has narrowed the concept of passive. Maybe no power on audio circuit is more precise defination to the word "Passive". Passive Magnetic is the high level type of Passive Preamp. Magnetic refers to the use of multi-tapped attenuation transformers instead of resistive volume control devices. However, design and manufacturing of this type of transformer is quite a complicated work. Also being a high end audio transformer supplier, StereoKnight has dedicated to the research and manufacturing of audiophile grade transformer for years. Housed inside refined high quality aluminum alloy chasis, StereoKnight presents one of the best Passive Magnetic Mreamplifiers in the market.

Why Passive Preamplifier

To audio fundermentalist who pursue flawless neutral sound without any contamination from the devices, the passive is The One. Theoretically, all that's required for a passive pream is then the naked functionality: source selection and volume control via signal reduction only. Ideally, a well designed and built Passive Preamp is supposed to link the source and amplifier with necessary controls over the signal. Any altering, rendering, and amplification would be considered detractive, however, as a qualified link device, it should also be a good match electronically both to source device and amplifier.

Why Passive Magnetic Preamplifier

Entry level Passive Preamp usually refer to resistive passives which suffer impedance mismatches and concomitant frequency response aberrations depending on setting and cable load. Traditional Passive Preamplifiers impose large impedance values with additional resistance in part of accomplishing attenuation. It requres the source to provide the power to drive the volume control's resistance. By comprison, transformer-based attenuation with its electromagnetic coupling does not rely on the addition of resistance. The transformer itself has very high impedance across the audio band. Accordingly, very little of the source's output power is lost and only the very low winding resistance appears in series with the source prior to the preamplifier's output. Thus the source only needs to drive the load and cables connecting to and from the Passive Preamplifier. However, as the Passive Magnetic Preamplifier's attenuation is increased (preamplifiers in most systems end up cutting the signal by 20dB or more at all times), the output impedance rapidly falls to very low values. This in turn translates into much improved ability to drive a load or cable. In fact, a transformer simply takes the drive ability of the source and passes it through with either a slight decrease over the source when any significant attenuation level is used. The use of transformers dramatically improves on the ability of the Passive Preamplifier to drive cables (and loads) compared to traditional designs. In addition, the use of transformers will actually improve the ability of the source to drive its cables as well, which explains the experiences of senior audiophiles who found the use of the Passive Magnetic Preamplifier to be a substantial improvement over using no preamp at all.

Great features of StereoKnight Silverstone Magnetic Passive Preamplifier

The StereoKnight Silverstone series is fully transformer-balanced input to output design. Internal hookup wiring is silver, the standard transformer windings are copper but silver versions are available. Both RCA and true XLR (balance) input and output are equipped or optional. RCA solution should be sufficient for most serious systems. The Silverstone-Balance is the expert to supply best but affordable full balance solution while Silverstone-B&R adds the great versatility (multiple XLR and RCA in/out and convenience (remote control function and LCD display).                 

As a serious high end Passive Preamplifier, the StereoKnight passive is essentially unbreakable. There are no coupling capacitors to age or blow up, no resistors to fail. The StereoKnight units are true isolation transformers with separate primary and secondary windings. Gain in most preamps is redundant when the majority of amplifiers are driven to full output by the source voltage. Superior amplifiers don't need assistance from preamps except for the bare functionality of attenuation and input switching. If you already own a high level amplifer, the StereoKnight will be the best match to make your amp shinning. With full bandwidth regardless of setting and no impedance problems, this is a passive that doesn't sound flat, boring and bereft of life, especially by full balance pass.

Silverstone-Balance features

  • Totally Passive design with zero distortion, no compromising!
  • Ture balance input/output design with four transformers which isolates components, break ground loop problem and reduce noise.
  • Duall mono, dual volume switch.
  • Dual 6/0 dB switch on Silverstone-Balance
  • Seiden quality 33 position stepped attenuator.
  • 3 RCA input, 3 XLR input
  • 2 RCA output, 2 XLR output
  • Input selector (3)
  • Point to point hand wiring with Teflon coated solid core copper wires.
  • Full Heavy duty refined aluminum alloy faceplate and knobs; beautiful Acrylic made body for best cosmetic and isolation.
  • Dimensions: 14" W x 10" D x 6” H
  • Weight: 20 lbs net; 25 lbs shipping weight
  • Warranty: 3 years parts and labor

Silverstone-B&R features summary

Silverstone-B&R is an enhanced balance version of Silverstione with great versatility and convenience features. "B" means balance, and "R" indicates remote control function. The use of 4 transformers attenuation is now with upgraded 33 steps selection instead of 24 steps in previous model. Execpt for the mulptiple XLR and RCA in/out in rear part of the unit, the new style of the front panel with LCD display window plusing the great build quality bring a quite stylish vision to the full alluminum alloy body. 9V DC powered remote control function for source selection and volume is a 'non-passive' features without distracting the audio signal passing but a great convenience to users.
  • Ture balance input/output design with four transformers attenuation which isolates components, break ground loop problem and reduce noise
  • 33 step volume attenuation with remote control based on 33 transformer output terminals
  • 9V seperate DC powered remote control functon for source selection and volume
  • 3 single-ended or RCA input, 2 balanced or XLR input
  • 2 single-ended or RCA output, 2 balanced or XLR output
  • Point to point hand wiring with Teflon coated solid core copper wires.
  • Full Heavy duty refined aluminum alloy body, faceplate and remote wand
  • 6dB passive gain, so low gain amplifiers can be driven to their maximum efficiency by components that otherwise might require active boosting
  • Dimensions: 18" W x 12" D x 7” H
  • Weight: 25 lbs net; 30 lbs shipping weight
  • Warranty: 3 years parts and labor


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Copy right® 2007 Stereoknight HiFi Technology LLC. All right reserved, the art of design & engineering / 7890 Grove Ct. E. / Germantown, TN, USA 38138 
Phone: 1-901-283-0073 / Fax: 1-901-248-6866 / email: info@stereoknight.com / sales@stereoknight.com