The preamplifier, key element in the system, is mandatory to take advantage of analog sources like vinyl discs and to use the digital to analog converters at full resolution.
The impossible had to be made possible: to insert an element and not to lose any detail of sound.
The research and the development of the PRS1.5 actually took us many years…
|JMF Audio had designed excellent preamplifiers in the past. One of them has even become legendary in Asia. However the new challenges for the ultimate reference JMF Audio preamplifier were extremely severe:
1. For sound quality the goal was to equal a fixed passive attenuator carefully designed by JMF Audio.
Point 1. was a test that none of the preamplifiers we tested passed successfully. (obviously, we thought)
The PRS1.5 eventually saw the light. Not only it is the only preamplifier to successfully fulfill point 1, but it also surpasses by far this target ; mostly thanks to the hand calibrated input/output stages and impedance matching provided by JMF Audio’s SSA Super Symmetrical Analog technology!
|The PRS1.5 is a dual mono, fully balanced design that embeds the innovative CSV volume control !
> CSV is a fully passive volume control system based on a digitally controlled switches network.
> CSV by concept features zero noise, zero distortion, zero phase shift, infinite headroom!
> CSV is sealed and shielded in a massive tooled block of aluminum with the JMF Audio logo engraved on.
> CSV features a quadruple redundancy for an expected life time superior to the best potentiometers.
> CSV is input and output buffered in the PRS1.5 by JMF Audio’s SSA Super Symmetrical Analog technology.
After selection on technical aspects, refined selection on measurement, the final decision on absolutely all the audio components that the PRS1.5 contains has been taken after long listening tests in the newly built JMF Audio’s studio. The audio boards were designed in the great JMF Audio’s tradition (PGP gold) and have benefited of the results of the now JMF Audio’s 30 year experience in audio. They are mounted on a suspension system that makes them quasi acoustically floating and immune to vibrations.
The integrated power supply, free of radiation, is double shielded and located next to the audio circuits for an instantaneous energy delivery following JMF Audio’s proprietary DUAL-STAR-POWER concept. Before delivery every PRS1.5 undergoes a burn-in phase and a listening test with comparison to our reference.
|Beside being the most transparent preamplifier,
the PRS1.5 is the ultimate JMF Audio HQS power amplifiers’ driver !
|Balanced inputs||3 (IN0, IN1, IN2)|
|Unbalanced inputs||3 (IN3, IN4, IN5)|
|Balanced outputs||2 (OUT1, OUT2)|
|Unbalanced outputs||1 (OUT3*)|
|Volume display|| to |
|Relative gain setting between sources||[-9] to [ 6] display for -9 to +6dB gains|
|Source display||[i0] to [i5]|
|*Out3 can be set to follow the volume control
or set as direct (DI) for a tape loop
or to drive a headphone amplifier
|[di] display on selection,
recalled by a dot light on normal use
|Ground connection (earth)||dia. 4mm banana type|
|Remote control||IR, all functions using MBR-1|
|Massive aluminum volume control button / double bearing / massive aluminum compartment / smooth rotation|
|Massive anodized aluminum chassis, mounted on special damped and anti skidding JMF Audio feet|
|Gold plated analog mono boards embedding CSV and mounted on suspensions for acoustical isolation|
|Input impedance||> 5k ohm / XLR and RCA inputs|
|Maximum input level||+22dBu XLR bal / +16dBu RCA|
|On normal output OUT1 (OUT2), at volume max:|
|Bandwidth||1Hz .. 100kHz (+0.0 / –0.1dB)|
|20Hz ..20kHz (+0.0 / –0.0dB)|
|Signal to noise ratio||> 130dB (+22dBu 1kHz narrow band)|
|128dBA typ. (+22dBu 1kHz in / bw. 22..22k Hz)|
|THD+N||0.0005% typ. (+22dBu 1kHz in / bw. 22..22k Hz)|
|Crosstalk left/right||< -120dBA|
|Output impedance||50 ohms|
|Maximum gain output/input||0dB (XLR bal in) +6dB (RCA in)|
|Volume control range||70 steps of 1dB|
|Volume control step precision||better than 0.05dB above volume |
|Volume control left/right level mismatch||< 0.1dB above volume |
|Specific to modular output OUT3:|
|Maximum gain in variable mode (at volume max)||0dB (RCA in) – 6dB (XLR bal in)|
|Output impedance in variable mode||50 ohms|
|Gain in direct mode (DI)||0dB (RCA in) – 6dB (XLR bal in)|
|Output impedance in direct mode (DI)||600 ohms|
|Power consumption||< 25W in operation (< 1W in standby)|
Buka jam 10.00 s/d jam 17.30 , Minggu & Hari Besar Tutup