Designed to Make Music
LKV Makes the Phono 2-SB Even Better
LKV Research has made its great-sounding phono preamp, the Phono 2-SB, even better in two audibly important ways: (1) the already very quiet 2-SB now has an even lower noise floor; and (2) the 2-SB now incorporates a version of the excellent, jfet-based third gain stage originally designed for LKV’s state-of-the-art Veros One phono pre.
The 2-SB is LKV’s state of the art phono preamplifier, designed to enable your system to convey to your ears the emotion, drama and beauty of the music on analog LP recordings. It has every element needed to amplify and equalize with great fidelity the minute voltages produced by the cartridge as it traces the grooves on your vinyl records.
Very low noise and distortion allows all of the low level detail and subtle information encoded on the LP to flow to the rest of your system and to your ears. This information conveys much of the meaning and emotion of the music and contributes to creating a believable soundstage and solid, palpable images. The 2-SB achieves these very low levels of noise and distortion through good design:
- Multiple stages of power supply noise control using resistor/capacitor filters, capacitance multipliers and modern IC regulators to create very smooth, quiet power rails.
- Ultra low noise active components (jfets and bipolar transistors) biased into their quietest operating ranges.
- Cascode amplification circuits and active current sources to assure low distortion in each amplification stage.
- Differential (balanced) amplifier circuits to block incoming noise.
- Signal path capacitors using accurate polypropylene dielectric to pass the musical signal without smearing.
- Four-layer circuit boards to keep signal paths short and improve grounding.
- Three grounding options to minimize noise and avoid ground loop hum in a variety of systems.
Dynamic headroom. Headroom is essential for accommodating the wide dynamic swings of music without strain or compression. In the 2-SB, it is achieved by using relatively high power rail voltages (+32v, -12v), biasing the active devices properly, and carefully adjusting the distribution of gain among amplification stages.
All discrete, Class A gain circuitry with zero loop feedback. While op amps and other circuits using feedback and “push-pull” amplification can produce good results, the best, most transparent, relaxed, musical sound still comes through well designed circuits, like those in the 2-SB, that achieve low noise and distortion without loop feedback.
Accurate RIAA equalization. The 2-SB uses a highly accurate RIAA filter, composed of precision metal film resistors and polypropylene capacitors, to compensate for the boost of high frequencies and attenuation of the low end that is imposed when LPs are made. This accuracy is essential if the listener is to hear a valid reproduction of what the microphones at the original performance heard.
Flexibility. The 2-SB is designed with great flexibility to allow it to function properly in a wide variety of systems and to accommodate most cartridges and turntables. Click on the Operating Adjustments button for details.
Listening. The final selection of components and the balance among the foregoing attributes was arrived at through many hours of careful listening and modifying numerous prototypes. The result is the Phono 2-SB, which we believe will deliver on our claim that it is “designed to make music.”
Try it in your system and we think you will agree. But, if you don’t, return it within 30 days for a full refund of the purchase price. You pay only the shipping.
Reviewers' Reactions to the LKV Phono 2-SB
Michael Fremer titled his Phono 2-SB review “Affordable Excellence” and concluded that very positive review by saying, “So, is the LKV Phono 2-SB 'an overachiever and a ridiculously great value for the money'? In a word, 'Yes.'"
Harry Pearson describes the Phono 2-SB as “… a great phono stage at a quite reasonable price.” Originally published on HPSoundings.com.
Tom Lyle says that the Phono 2-SB is “… one of the best phono preamplifiers I've ever had the pleasure of using in my system.”
Scott Hull awarded the Phono 2-SB a Part Time Audiophile “Best of 2013” and more recently said that, “Overall, the 2-SB seems to fall on the warm-side of sonic neutrality, with excellent dynamics and detail retrieval. It is, in a word, excellent.” Also read "An Analog Twist: Bob’s Devices 1131 Step Up Transformer" using the 2-SB.
Enjoy the Music bestowed a Blue Note Award on the Phono 2-SB, honoring it as a “Best of 2013.”
Scott Dorsey describes the Phono 2-SB as one of the three most exciting things he saw and heard at the Capital Audiofest.
Art Dudley reported that at Capital Audiofest “New Hampshire-based LKV Research demonstrated their 2-SB solid-state phono preamplifier ($2500, direct) and a prototype of their forthcoming line-level preamplifier, to very good effect.”
Balanced Out – 40/50/59dB
SE Out – 34/44/53dB
+3dB Gain Mod:
Balanced Out – 43/52/62 dB
SE Out – 37/46/56 dB
+6dB Gain Mod:
Balanced Out – 46/55/65 dB
SE Out – 40/49/59 dB
Varies from 50 to 47K ohms depending on cartridge load setting.
Balanced Out – Less than 150 ohms.
SE Out – Less than 75 ohms.
Signal to Noise Ratio (unweighted audio band (20Hz-20KHz), inputs shorted):
60dB s/n at High Gain, Ref. to 0.5 mV input.
80dB s/n at Lo gain, Ref. to 5mV input.
Total Harmonic Distortion (THD), High Gain at 1KHz:
Balanced output: 0.008% at 2.0V output.
Single Ended Output: 0.008% at 1.0V output.
RIAA Equalization Error:
Less than +/-0.1% from 20 Hz to 50 KHz
Crosstalk (5mV input at 10 KHz, one channel driven, Balanced and SE):
Better than -90dB (Right to Left and Left to Right)
Fuse: 1.5 Amp , 250 VAC, Fast Acting
*These specifications are subject to revision based on further product testing and development.
The LKV Phono 2-SB is a very flexible component designed with numerous adjustments that make it suitable for use in virtually any Hi-End audio system.
Phone 2-SB Operating Options
Phone 2-SB Owner's Manual