Positive Feedback : " Midwest Audio/NAT/Legacy/Triangle Art: I went to this room to hear the AURALiC and Invicta Mirus DACs, but when I sat down they were playing large scale orchestral music on the big-dog Triangle Art turntable. The Legacy Aries loudspeakers sounded very good with unrestrained dynamics even in the small room. One of my favorites stops for sure.
Trade ins considered.
NAT Audio Signature Phono Stage. This phono stage is world class and the battery powered, zero feedback, all tube design brings the music alive. You will be awestruck! Come audition now at Midwest Audio. Paypal adds 2.9% Very good condition well cared for. Approx two years old. Sounds
I am also an authorized dealer for Legacy Speakers, Auralic, Resonessence , PS Audio, Verastarr, Labs,Oracle and Triangle Art.
From NAT Audio
Signature Phono Vacuum RIAA Battery Powered Vacuum Tube Phono Stage
NAT sets a new standard in state-of-the art phono stages by using a new approach: a vacuum based inverse RIAA network in the Signature Phono. ( Instead of the standard inverse RIAA network based on resistors or better inductors for the main part in the signal path) NAT uses a Vacuum field medium instead. The phono stage contains 10 vacuum tubes in full zero feedback configuration.
The battery supply is used for the military grade ultra low noise nuvistor 6S51N-B & 6S53N-B triodes with approximately 20 000h of life time as well as for the output controlled high current tube-6S19P-V all by military and N.O.S.
Battery charging is full automatic.
Low output MC cartridges are amplified with the dual gain amorphous step-up transformer.
Passive RIAA equalization is applied using the philosophy of zero feedback. Signal-to-noise ratio is impressive (over 90dB), partly due to the battery supply.
With output impedance of around 900 ohms Signature Phono will easily drive any interconnect cable of reasonable length.
High quality gold plated teflon isolated connectors, both input and output are used in phono stage.
Each Signature Phono preamplifier is a hand crafted device with a burn in test period of 100 hours.
Frequency Response 5 Hz to 100 kHz
Noise 96 dB at 10 kHz
Tube Complement 2 x 6S19P-V (N.O.S.) + 8 x nuvistor triode (10 in total)
Phase Status (non inverted) 0 degree
Gain 38 dB MM + 20 dB MC HIGH + 6db MC LOW (TOTAL 64dB)
- vacuum based inverse RIAA network-original approach by NAT
- absolute zero feedback
- pure class "A"
- triode based configuration
- battery powered supply
- 10 (ten) vacuum tube based phono stage
- military grade nuvistor triode (N.O.S.) vacuum tubes-up to 20.000h of lifetime
- military grade high current triode output controled 6S19P-V (N.O.S.) vacuum tubes
- premium amorphous input step-up transformers (with dual gain possibility)
- low density low capacitance additional separate power transformer module
- full automatic battery charge
- soft start operate
- teflon insulated RCA input & output connectors
- gold plated sockets
- hand assembled all modulated chassis
- anodised 0.6"(15mm) thick aluminum front panel
- extensively used computer numeric control machines (CNC)
Michael Fremer Stereophile Review Excerpts:
everything most listeners would want from a phono preamp:
top-quality rhythmic agility; taut, believable pacing; a rich midrange; and
the kind of crystalline clarity and transient speed on top I expect from the
best solid-state phono preamps, but free of etch and grain. The bass
remained tight, deep, and nimble. The NAT was quiet, ultradynamic, exciting
to listen to over the long run, and it let me see way into the musical picture.
I found it harmonically well structured as well-as you’d hope to hear from
tubes, but without sounding too lush or ripe.
The NAT presented images in bold relief, but with believable edge
definition on a big, spacious soundstage that made me want to stick my
head in it and get lost. It was equally effective with all genres of music,
producing velvet where velvet was required, sandpaper when that was
Excerpts from 6Moons:
The most striking characteristic of the NAT is its completely silent operation despite being a tube unit. Compared to even the quietest solid-state phono preamp I reviewed, the NAT went further in providing the famous “blacker than black” background which by itself does not mean much except that it enables soundstaging and imaging to go much farther than any of the other units tested. Instruments seemed to float in the room sized and contoured exactly as they should be. Instruments and voices were not chiseled like they sometimes are with solid-state electronics which operate on the sharper end of neutrality. Instead they had this very gentle halo one hears in natural acoustics where each instrument is easily identified and located yet gently overlaps with and transition into its neighbors. On that front, the NAT completely eclipsed the Esoteric E03 and Flight Phono which sounded two-dimensional by comparison (and neither are poor in absolute terms but the NAT was simply exceptional).
What silence of operation also brings to the table is quite impressive transparency. Although the Esoteric E03 seemingly retrieves more information from the grooves, it is not as tonally developed as the NAT, offering a slightly drier presentation of those details and one with more insight into the transients than harmonics. The Serbian allows the harmonics to develop further. The NAT does not apply the same rigor to how it portrays the first micro second of the notes and impacts. Hence it sounds slightly more laid back. In turn it offers a much more complex harmonic picture than the E03, revealing that a piano is not just strings but all sorts of wooden resonances too which arise from the instrument's body (the E03 reveals it too but not at the same level of complexity).
When cueing up Ella and Louis, I was given another perspective into the NAT's strengths. Triodes just seem to have a magical effect on voices and brass instruments by infusing them with a life that you don't get with transistors. When you combine one of the finest jazz voices of all times with Armstrong's enticing trumpet, the NAT shines and offers its very best. The only way I can describe the effect is by speaking of dimensionality. Both Ella's voice and Louis' horn seemed to move forward in the music (not as in "aggressive" but forward as in "closer") and instead of being mostly two-dimensional, they occupied a 3-D space between the speakers. I've never heard this effect with anything but triodes and the Signature Phono offered it in spades. The E03 was flatter and two-dimensional by comparison and somewhat drier. You could hear a phenomenal level of detail and insight into the performance but with the NAT, you could hear a singer.