There was enormous interest in the latest Soulnote P-3 flagship preamplifier, which uses a unique and custom-made RSR-2-12D highest quality glass tube-enclosed reed relays and newly developed satellite-grade ultra-high-precision naked foil resistor, etc. so here is a detailed breakdown of the unique features and highlights of this unique preamplifier from Japan.
■Type-R circuit adopted for non-feedback balance amplifier
The output line amplifier is equipped with the discrete non-feedback balance circuit “Type-R circuit” that made a debut with the S-3, fully tuned for the preamplifier.
In addition, the newly developed ultra-precision naked foil resistor is introduced. Demonstrate an amazing amount of information, a sense of SN, drive capacity.
■High-end fixed resistance switching type volume
The highest volume is born by the best possible method and the best parts. Ultra high precision naked foil resistor is fully introduced to the resistor. Also, for the switching relay, we have newly developed an ultra-low loss custom relay RSR-2-12D (reference soul note relay) and adopted it. The volume of 144 steps is constructed in 0.5 dB steps. Even if the volume is turned down, the freshness is not lost and the sound is not lost.
■ GND switching type input selector
One of the biggest factors that deteriorates the sound quality in the preamplifier is the problem of GND loops and noise mixing when connecting many source devices. In order to eliminate this problem, we adopted a method to switch not only the signal side but also the GND so that the unselected equipment is in a state where the connector is unplugged. Moreover, in order to avoid the influence by a relay contact, RSR-2-12D is also fully adopted as the selector.
■ Complete twin monaural construction
The so-called twin monaural construction is used for the left and right channels, using two identical input/output terminal boards, circuit boards, power supply circuits, power supply transformers, relay drive circuits, and relay power supplies. In addition, the power supply for the microcomputer is completely separated, including the transformer. Furthermore, the control signal of the relay, which is the only contact point with the signal system, is completely separated by the photo-coupler.
■ GND floating
We succeeded in completely floating each of the three GNDs of the left and right GNDs and the control system GND by having three chassis insulated by ceramics for the three systems of the left and right channels and the control system. .. Although it is possible to connect each GND by setting the rear switch, you can experience the amazing phenomenon that “the sound field spreads surprisingly in three dimensions and all the sounds start singing organically” by making the GND floating. ..
■ Super strong power transformer
As the analog power transformer, a large-scale non-impregnated toroidal transformer of 280VA on one side is adopted. Including the control system transformer, SOUL NOTE has the highest capacity in the history of A-2 equivalent to 600VA in total. As for the transformer, the audible drive capacity improves in proportion to the regulation improvement brought about by the large capacity. The driving power of P-3 changes the grade of power amplifier and speaker.
■Vertical mount of transformer
By making the mounting direction of the transformer perpendicular to the board, the direction of harmful leakage flux is made parallel to the board, thus preventing jumping into the circuit.
■ 3-point spike grounding
With three spikes directly connected to each of the three power transformer bases, the harmful vibration of the transformer is eliminated before propagating to the chassis.
■Double bearing & flywheel type optical rotary encoder
The flywheel effect of the large volume knob made of solid aluminum and the two large bearings used to eliminate mechanical backlash have created a moist and heavy volume control feel.
■ AV bypass function
For each XLR and RCA system, AV bypass setting that fixes the volume and outputs with zero gain can be set.
■ Floating structure
The Type-R board and top cover have a floating structure that is not mechanically fixed. By releasing from mechanical stress and harmful air dump effect, the sound quality and sound field that are fresh and natural, close to the state where the top cover is opened, are acquired.
■ GND anchor
The left and right side metals are insulated from the main chassis by ceramic washers, and the left and right GNDs are directly connected. This further enhances the effects of the left and right GND floating (a vast sound field and transparency).
■ Multiple unit connection function
Multiple units can be linked by UART communication. By setting the master and slave, all slaves will follow the master’s setting. At this time, it is possible to add a difference to the master volume on the slave side. With this function, for example, the volume control of the multi-amplifier by the digital channel divider becomes possible after DA conversion. Of course, due to the floating control system GND, problems such as GND loops due to connection do not occur.
■ About RSR-2-12D (reference soul note relay)
Further customized and based on an ultra-low loss glass tube-enclosed reed relay that exhibits performance similar to that of a mercury relay. This is our original custom relay, which has been finished to the level of sound quality comparable to that of wires. The P-3 uses 94 relays per unit.
■ About ultra-precision naked foil resistors
Based on satellite-grade ultra-high-precision foil resistance with excellent temperature characteristics, further customized with particular attention to sound quality. In order to eliminate dumps and habits caused by molds and dips, we made it naked and independently developed a resistor with the highest sound quality. The P-3 uses 156 resistors per unit.
■Specifications
- Input XLR 4 lines RCA 4 lines
- Output XLR x3 RCA x1 (XLR and RCA are selectable)
- Total harmonic distortion 0.0015% (1.5Vrms)
- Frequency characteristics 2Hz to 1MHz (±3.0dB)
- Residual noise 13μV (20kHz L.P.F.)
- Maximum output 21Vrms
- Maximum gain 11 dB
- Power supply voltage AC100V 50/60Hz
- Power consumption 20W
- Maximum external dimensions Main unit: 454(W)×170(H)×430(D)mm
- Mass about 25kg
- Accessories Remote control, spike, spike receiving board, power cable
- JAN Code Premium Silver: 4580197835884 Premium Black: 4580197835891
■ Accessories
Spike receiving board, spike, remote control, power cable
■Notice about products
About the temperature
For SOULNOTE products, the circuit current is decided with the highest priority on sound quality and safety. Generally, the higher the transistor temperature, the better the performance and the better the sound quality.
Therefore, all SOULNOTE products have a higher transistor temperature setting within the range where there is no problem. Therefore, compared with general products, the set temperature is higher, but it is not abnormal.
About anti-vibration case
As a result of placing the highest priority on sound quality, SOULNOTE products do not intentionally provide vibration isolation for the top cover and chassis.