NAT Signature Phono

Vacuum-based inverse network (Vacuum RIAA by NAT) Tube Phono Stage NAT set a new standard in phono with its state-of-the-art product, thanks to a new approach: a vacuum-based inverse RIAA network in the new Signature Phono model - Vacuum RIAA. A standard inverse RIAA network uses a resistor or, even better, an inductor as the main component in the signal path! NAT uses a vacuum field medium instead. The Signature Phono stage contains 10 vacuum triode tubes in a full zero-feedback configuration. The Signature Phono is a fully balanced phono stage from input (for MC mode) to output! It is possible to switch from balanced to unbalanced operation (on the rear panel). The AC input power is filtered and fully regulated by the Signature Phono's separate cord-conditioner unit. An extremely high-energy power supply (over 320 J) is used to power the low-noise, high-gain triode tubes! These are N.O.S. (New Old Stock) grade tubes. A premium genuine Oyaide input power connector is also used! There is no need to use any additional power cord! The separate cord-conditioner replaces the power cord in the best possible way! There is also an internal input main phase detector (L detection). It is in the form of an LED indicator positioned on the separate cord-conditioner chassis! Hand-coiled output transformers and inter-stage chokes (4 separate magnetic units) create the simplest possible signal path in the Signature Phono! The magnetic material used inside the unit is the best possible by today's audiophile standards - nano-crystalline! The specially designed output transformer in the Signature Phono can be reconfigured from pure single-ended (RCA) to pure balanced (XLR) operation! Low-output MC cartridges are boosted by NAT's premium fully balanced, hand-coiled nano-crystalline setup transformers. Selectable load resistance (in six steps - 50, 100, 200, 500, 1k, 2k) is available for different cartridges! The signal-to-noise ratio is excellent because the input MC transformers are almost noiseless! With an output impedance of 300 ohms, the Signature Phono can easily drive any long interconnect cable. High-quality gold-plated Teflon (PTFE) insulated connectors are used for both input and output. Each Signature Phono is a handcrafted and finely tuned device with a minimum burn-in test period of 100 hours. The quality of the electronic components used inside the Signature Phono is very high - military-grade 0.1% tolerance capacitors, high-grade electrolytic capacitors with over 320 J of energy from the main capacitor, Vishay 0.1% resistors, electrolytic capacitors rated for an operating temperature of 105°C, silver-OFC wired input for the MC stage...

Frequency Response 10 Hz to 100 kHz Noise < -84 dB "A" weighted Gain 42 dB MM standard + 6 dB MM HIGH + 14 dB MC (TOTAL 62 dB or 56 dB as an option) RIAA Accuracy +/- 0.4 dB Channel Unbalance < 0.1 dB THD & N < 0.1 % Input Impedance Selectable (50, 100, 200, 500, 1k, 2k) for MC, 47k as standard for MM Stereo Separation > 96 dB Tube Complement 10 x nuvistor low-noise triodes Phase Status (non-inverted) 0 degrees Output Impedance < 300 ohms @ 1 kHz Power Requirements 100 VAC to 240 VAC @ 50 to 60 Hz, max. 60 VA Dimensions Main unit: 19" (483 mm) wide x 16.5" (420 mm) deep x 6.6" (168 mm) high P.S. unit: 10.8" (275 mm) wide x 6.9" (175 mm) deep x 2.8" (70 mm) high NET Weight approx. 53 lbs. (24 kg) unpacked with cord-conditioner TOTAL Weight approx. 75 lbs. (34 kg) packed