Jasmine LP2.5DU MM/MC Phono Preamplifier
The Jasmine Audio LP2.5DU phono stage uses two independent power supplies to minimize crosstalk and noise, and maximize signal integrity. The single-ended class-A circuitry uses no negative-feedback. RC attenuation is used for the RIAA network. The LP2.5DU has two sets of RCA inputs, and can easily meet the requirement of systems with two turntables, or two arms on one table. The inclusion of variable loading and capacitance makes it a good match for many different cartridges. Several layers of shielding is used to isolate the circuit from EMI/RFI. Every choice for the Jasmine LP 2.5DU was made with the goal of exceeding performance of the best available units.
The LP2.5DU is a natural progression of the LP2.0MKII, with upgraded components, dual inputs, better regulated power supply, and the result is a quieter background than LP2.0MKII. The Jasmine LP2.5DU was designed with high end audiophiles in mind.
Download: Jasmine LP2.5DU User's Manual
- Independent separate power supplies
- Multiple layers of mixed materials are used to prevent electromagnetic interference
- Hand matched 2SK170 J-FETs are used for low-noise amplification
- A single-ended, class-A , zero-negative-feedback circuit for wide frequency response and excellent dynamic performance
- High-precision components are used, to more effectively reduced distortion and background noise.
When it comes to longevity, reliability and ease of repair, you can rest easy. All the parts are easy to get, though your local Radio Shack would have to special order a few of them. For instance, the low voltage polypropylene coupling capacitors are available through all audiophile parts dealers (Parts Connexion, Michael Percy, etc..), and could be changed for super-high-priced boutique parts from Mundorf (just for an example). The low voltage polypropylene capacitor is probably the least likely part to fail in the entire unit. Polypropylene capacitors are self-healing, and the voltage ratings of these capacitors allow a very large safety margin. As power supply electrolytic capacitors age (15-20 years), they start to lose their effectiveness. After repairing and modifying audio electronics for years, electrolytic capacitors are the most likely parts to fail, in all classes of electronics, other than vacuum tubes. The capacitors used by Jasmine are all normal electrolytic capacitor values, available through every electronics parts dealer in the world. The rectifiers and regulator chips are also standard parts. The only part that would take a few days to acquire would be the 2SK170 transistors, which aren't stocked by the big parts suppliers like Mouser and Digikey.
The units are easy to work on, and I can maintain them for customers. Any competent tech can work on these (they are simple analog circuits--no proprietary chip sets or digital circuits are involved). Because they are simple, with 3 transistors in the gain path, reliability is very good.
MM = 55dB; MC = 70dB ( Suitable for 0.1mv ~ 0.5mv output MC cartridges)
|Freq. Response :||10Hz ~ 60KHz|
|Input Terminals:||2 Sets of RCA (MM or MC, selectable, and MC load selectable)|
|Output Termianls:||1 Set of RCA|
|RIAA EQ compliance:||- 0.03 ~ +0.15dB (20Hz ~ 20KHz)|
|THD:||< 0.01 (20Hz ~ 20KHz)|
|S/N:||MM > 90dB , MC > 85dB|
|Output Level :||10V (Max)|
|Input Impedance:||MM = 47K ohm|
MC = 50/100/250/1K ohm selectable
|Power Consumption:||6 Watt ( MAX)|
|Unit Size:||185 x 205 x 65 mm|
280 x 280 x 300 mm