AM Hi-End AM R-S
To some audiophiles, a Passive Preamp sounds odd and mysterious but to some experienced audiophiles, passive pre-amplification may represent a pure and simple method of obtaining high fidelity. Anyway, what is a Passive Preamp?
Simply, a passive means no active circuitry, no connection to AC wall power, no internal power supply. Nowadays, at the request of convenience, the need of remote control function has narrowed the concept of passives.
In today's modern era 'no power on the analogue circuit' is probably a more precise way to describe a modern 'Passive Pre.
Passive Magnetic - is a high level type of Passive Pre. 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 task.
With Audio Music also being a high end audio transformer supplier, which has dedicated many years of research and manufacturing tomaudiophile grade transformers. Housed inside refined high quality aluminium alloy chassis, with our knobs AMR-S presents one of the finest sounding and value for money Passive Preamplifiers in today's market period!
Why Choose A Passive Preamplifier?
For the audio fundamentalist who pursues a flawless neutral sound without any contamination from their devices, the passive is the preamplifier of choice. Theoretically, all that's required from a passive preamp is source selection and a volume control via signal reduction. Ideally, a well designed and built Passive 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 A Passive Magnetic Preamplifier?
Entry level Passive Preamplifiers usually refer to resistive passives which suffer impedance mismatches and concomitant frequency response aberrations depending on settings and cable load. Traditional Passive Preamplifiers impose large impedance values with additional resistance in part of accomplishing attenuation. They require the source to provide the power to drive the volume control's resistance.
By comparison, 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 greater improvements in its ability to drive a load or cable.
In fact, a transformer simply takes the drive ability of the source and passes it through with only 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 experienced audiophiles who have found the use of the Passive Magnetic Preamplifier to be a substantial improvement over using no preamp at all.
The AMR-S is fully transformer-balanced input to output design. the standard transformer windings are copper but silver versions are available. Both RCA (unbalanced) and true XLR (balanced) inputs and outputs are equipped or optional. RCA solution should be sufficient for most serious systems. However for the discerning audiophile an XLR or combination of XLR and RCA inputs and outputs for convenience can also be specified.
Above information taken from AM Hi-End Website.