Inovative Audio Manufacture

Phono Stage

Vacuum I.N.

Full Battery Powered Vacuum Tube MM Phono Stage

Our flagship phono stage!


NAT set a new standard in phono stage state-of-the art product by new approach-vacuum based inverse network realised in model Vacuum I.N. . Standard inverse network is based on RC or even better LCR type as main part of the signal path. NAT put vacuum field medium instead. Vacuum I.N is based on 14 vacuum tubes in full absolute zero feedback configuration to form uncompromised MM phono stage!


Battery supply for plate voltage is used for the low noise triode tubes that lasts over 10 000h. All tubes are by military and N.O.S. (new old stock) type. Even all tubes filament are powered by batteries!

Hand coiled output transformers as well as input and output chokes (6 separated magnetic unit) form in Vacuum I.N.  simplest signal paths as possible! Magnetic material is the best possible by today audiophile standard: nano-crystalline!

Special constructed output transformer is possible to reconfigurated from pure single-ended (RCA) to pure balanced (XLR) operation in Vacuum I.N. .

System of battery charging is fully automatic.

AC voltage (for battery charging and logic) is filtered in Vacuum I.N. by separate ultra low magnetic radiated transformers/power supply units.

Vacuum type (NAT original approach) equalization is applied regarding the philosophy of zero feedback. Signal-to-noise ratio is excellent, partly thanks to battery supply.

With lower output impedance than standard, Vacuum I.N. may easy drive interconnect cable of reasonable lenght.

Best quality gold plated teflon (PTFE) based PCB is used in Vacuum I.N. MM phono stage.

High quality gold plated teflon isolated connectors, both input and output are used in phono stage.

Each Vacuum I.N. is hand crafted device with burn in test period of over  100 hours.

Quality of electronic components that is used inside Vacuum I.N. are at high level - military grade capacitors as well as tubes, teflon based gold plated PCB, high grade batteries, Vishay 0.1% resistors, electrolytic capacitors for 105Cof operating temperature, all signal magnetic unit based on nano-crystalline core ...

Vacuum I.N. device works properly at world wide AC line voltage from 100 - 250 VAC, 50 - 60 Hz (different voltages set in factory only).

To confirm, Vacuum I.N. represent new original innovative approach by NAT globally and set a new standard for phono reproduction-ONE OF A KIND UNIT!

 Find a new dimension in phono reproduction!

Technical Specification
Name Value
Frequency Response 10 Hz to 100 kHz
Noise < -85 dB "A" weighted
Gain > 41 dB MM
RIAA Accuracy ± 0.4 dB
Channel Unbalance < 0.1 dB
THD & N < 0.08 %
Input Impedance 47 kohms ( 100 kohms option )
Stereo Separation > 96 dB @ 10 kHz
Tube Complement 14 x nuvistor triode
Phase Status (non inverted) 0 degree
Output Impedance < 800 ohms @ 1kHz
Power Requirements 100 VAC to 240 VAC @ 50 to 60 Hz, max. 30 VA
Dimensions 19" (483 mm) wide x 17.4" (442 mm) deep x 6.7" (171 mm) high
NET Weight approx. 88 lbs. (40 kg) unpacked
TOTAL Weight approx. 110 lbs. (50 kg) packed in flight case


Design Features

- vacum based inverse network - Vacuum I.N. - original approach by NAT
- absolute zero feedback - pure class "A" (unique construction)
- zero capacitor on signal path
- all pure triode tube configuration
- full battery powered supply (that include all tubes filament)
- fourteen (14) vacuum tube (7/channel) MM phono stage
- military grade all nuvistor triode (N.O.S.) vacuum tubes - over 10.000h of lifetime
- premium nano-crystalline hand coiled double chokes per channel
- premium nano-crystalline hand coiled output transformers per channel with dual separated connection (selectable XLR or RCA)
- separate conditioner - low density (two) power transformers for recharge control and logic circuit
- full automatic battery charge
- soft start operate function
- teflon insulated gold plated PCB
- teflon insulated gold plated RCA and XLR connectors
- hand assembled all modulated chassis
- anodised 0.6"(15mm) thick aluminum front panel
- extensive used computer numeric control machines (CNC)

Specifications are subject of change without notice

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