nano-At SE 300B or PX25 Tubes

KR Audio 300B


KR Audio 300B

KR 300B Balloon high power triode.  This high power, triode delivers 6-12 Watts of pure class-A  power. Visually stunning (early balloon glass shape) and fully  compatible with all classic 300B tube amplifiers.

This new production tube is very attractive and a great performer, close to the sound of the WE300B

KR Audio PX25


KR Audio PX25

KR PX25 Balloon high power triode.  This high power, triode delivers 6-8 Watts of pure class-A  power. Visually stunning (early balloon glass shape) and fully  compatible with all classic PX25  tube amplifiers.

This new tube is very attractive and a great performer, perforamnce and sound equivalant to the Vintage Osram & Marconi production .

Western Electric New Production


The Original and Simply the best 300B, all the others have had to follow.

KR Audio PX25 or Full Music PX25 SE Triode Amplifier @ 6 watts , This circuit with 6N6P Fixed bias is also available with SE300B for 10 watts


This tube has a long and venerated history as one of the best performaing directly heated triodes ever made, it was the British answer to the 300B

Its characteristic sound is a stunning midrange, liquid smooth with excellent low frequency performance and very sweet and extended high frequencies, a personel favourite.

6-8 watts output suited to 93 dB/1 watt speakers and above .

If you are a Lowther Owner you will love this Amplifier, as it provideds a perfect platform for speed and transparancy with no harshness at all.

Also perfectly suited to horn drivers and full range drivers like Fostex etc.

SS Hexfred or GZ34 rectifier option for power supply.

Yamamoto mA panel meter to check current for PX25 tubes.

6922, ECC88, 6N6P, E88CC Family of tubes can be used as the driver , front ended tube.

A new circuit has been designed for the PX25 Amplifier using Constant Current Source Devises on both plates of the input tubes  to provide a very low distortion circuit, with great clarity and presence.

A wide band input transformer is used for fully balanced input option

A fully Professional Design with XLR and RCA inputs. The integrated option is dual input RCA only

The Speakon termanals are a very robust and solid connector in the professional audio arena provided excellent mechanical stabilty and audio clarity .

Traditional Binding posts from CMC are an option.

CMC RCA inputs.

Neotech OCC wire,Dale&Caddock Resistors.

The latest low ESR Vishay Power Supply Capacitors.

Teflon Coupling Capacitors used , simply the best sound,exceptional clarity and very neutral.

Analogue mA Meter

Available with Amorphous or Nanocrystalline Output Transformers

Please read tech notes under More! TAB 


SE 300B , M19 Electra-Print Standard or Option 1 - Amorphous or Option 2 -Finement

NEW RELEASE SE 300B with E280F in Triode mode for driver tube with Anode Choke Load.

Nano-AT SE 300B , uses a E280F  input tube running in triode mode, 

 Using Plate Chokes on the Anode of the E280F, to ensure the coupling capacitor is always charged for very low distortion and excellent dynamics to drive the grid of the 300B output tube .

The E280F input tube has more than enough drive to enable full output power from a DAC or CD without a pre amplifier.

With only a single stage driver ! coupled to the 300B the simplest and purest path possible.

Featuring Teramoto Finement " Nanocrystalline Cut C core  Output Transformers @ T1.3 Tesla , Simply the Best currently available in the Audio World easily matching Level 5 of Audio Note.

NPA Amorphous Double C core , is our Level 4 Option with outstanding performance. 

Electra-Print M19 is our Level 3 Option, great bass and very musical , an all round performer , flat from 20Hz - 28Khz.

Rectification is by GZ34 for low voltage drop ,giving excellent bass extension with all film capacitors in the power supply.

Charming Music Company - CMC- USA RCA inputs and extra thick copper plated GAOFEI speaker binding posts, or copper terminal speakON connectors.

The SE300B produces 8 watts of output in Cathode Bias for a Warmth and Naturalness of timbre .

This provides unparalleled performance creating a massive sound stage , with powerful drive characteristics presenting a lifelike performance .

Bass is solid and tuneful ,very quick dynamics providing an excellent platform for a lush and full Midrange and Crystal Clear high's ,with the added touch of natural warmth and timbre which is very enticing. 

Level 3 :M19 Electra Print Output Transformers ,in production for over 30 years and have been used by Eddie Current ( Moth Audio ) DeHavilland,Wellborne Labs, Cyrus Brennan,Modwright and many others to great success.

There is plenty of information on the Web regarding the long history and great performance of Electra- Print 

Level 4 : Amorphous Double C Core Output Transformers are excellent at detail retrieval , frequency extension is a real strength for these. 

They have good solid bass, very clear midrange and extended high frequency performance.

Level 5:   Teramoto Finement Nanocrystalline Output Transformers  are the most detailed and analytical sounding transformers I have ever heard.

Leading edge detail, micro dynamics and the all important PRAT are ever present.

Fast transient recoveries are a real strength of this design as Nanocrystalline is a hyper efficient metal, so recovery is very quick from demanding bass notes, they do not get muddled or wooly sounding ,often found in Single Ended Amplifiers with cheaper output transformers.

Midrange Clarity is unrivalled with Finement, as are the super extended highs.

We have chosen the coupling capacitor very carefully with this design to give lifelike presence and warmth to vocalists.

Bass is very tuneful and solid, not just a one note thump but characterised by the snap !on the snare or kick in the bass drum with real presence and decay.

Nanocrystalline metals can be produced by rapid solidification from the liquid using a process such as melt spinning. This often produces an amorphous metal, which can be transformed into an nanocrystalline metal by annealing above the crystallization temperature. - Wiki - 

More info on Technical Note's and the More Tab.

Please refer to More TAB for technical details and Signature Series Output Transformers, POA.

.A TKD stepped attenuator is Available with dual switchable inputs on the Integrated model.

A fully Balanced differential XLR input is also available as an option for those who need it  


Output Tube choices are :

Genalex 300B Standard Issue , or 

KR Audio 300B 

Western Electric 300B  

ER Elrog 300B POA

Rectifiers GZ34 standard issue

TKD Stepped Volume Control 

Dale Non Inductive WW Resisters
TKD Non Magnetic Resistors
Caddock Thick Film Resistors

ClarityCap TC2 Terminal PSU Capacitors
CDE/UNL Film Capacitors
Neotech OCC  solid copper wire in the signal path & multi stranded OCC Teflon for high voltage DC.
GAOFEI Speaker Binding Posts 

Electra Print Plate Chokes 

Siemens Epcos  - MKV   Film & Oil  Coupling Capacitors
CMC RCA inputs
5mm thick alloy water cut top and bottom plates with thick powder coat finish.
Russian Birch Plywood, hand rubbed shellac light or dark finish and Natural Wax coating.

you can request custom colours at $200 extra charge

please email us with requests for consideration

Electra-Print M19

Electra- Print Potted M19 Copper or PSSS Silver Secondary

Solid silver performance:

Silver wire audio transformers have been known for a long time to improve audio response and clarity.  Silver's higher sensitivity to flux change (200%)  reproduce's lower level information produced by the output stage. The resulting increase of the low level higher harmonics  from various musical instruments. ElectraPrint Audio has developed  Partial Silver Stranded Secondary (PSSS) to reduce cost but retain performance of solid silver . Source  Electra - Print

Very Flat Frequency response

We Pot these large transformers to fit nicely on our custom Australian Made Chassis.

Jack Elliano guarantee's all his transformers after careful winding and testing to always exceed 25Hz-20KHz -1dB.

Copper secondaries are an excellent performer and PSSS Silver even better.

We as many others have found typical in circuit response is 15Hz-28Khz -1dB and very clean square wave performance.

Masters of Bass !!

See how they stack up against the competition.

Find out more

Finement C core


Termamoto Nanocrystalline Finement C core

These output Transformers are Custom Wound by Mr Suzuki for Teramoto.

Multifilar Layering for extended frequency response .

At Tesla T1.3 this metal is characterised by excellent detail retrieval, very low distortion and up to 1/5 the core loss of Iron based metal's like M6 GOSS 


Amorhous C cores

These cores are custom wound for the ultimate performance

At Nano AT we have Amorphous Double C cores custom wound to our design requirements for extended bandwidth and crystal clear presentation with very low distortion for the ultimate experience .

Nanocrystalline is a re refined version of this metal .


Our Brands

Teramoto, Western Electric, NP Acoustics , Electra-Print, Furutech, CMC

More to come .

Jensen JT-11P-1HPC


Wide Band Balanced Input Transformer option

Line Input Transformer


Typical Application

•   Ideal for balancing any high-impedance unbalanced input

•   Wide bandwidth: -3 dB at 0.25 Hz and 80 kHz

•   Recommended for levels up to +19 dBu at 20 Hz

•   High input impedance: 14 kΩ

with 10 kΩ load

•   High common-mode rejection: 124 dB at 60 Hz

This transformer is designed for use in wideband line input stages. Distortion 

remains very low and CMRR remains high, even when driven by high source 

impedances. The primary is fully balanced and its terminals may be reversed 

to invert polarity, if required. A 30 dB magnetic shield package is standard.


Other models available

Customers have questions, you have answers. Display the most frequently asked questions, so everybody benefits.


Nano AT SE 300B

WE300B tubes included 2019

A number of 300B and 274B options will be available when this model is released  in early 2019 .

Seen here with Genalex 300B Standard Issue or a choice of >>>>>>>

Western Electric , KR Audio and Elrog 300B will be options for 300B's in 2019 

Interstage and Anode Chokes & Audiophile Parts we use in Bespoke Builds at Customers request

Custom Made Hitachi Metals Glassmet Interstage Transformers and Anode Chokes


Hitachi Metglass Amorphous Cut C core double bobbin Interstage Transformers and Anode/Plate Chokes 

NP Acoustics Interstage Transformers


NP Acoustics  Amorphous Interstage Transformers 

Electra Print Anode Chokes


Electra- Print Anode /Plate Load Chokes as seen in our Electra Print  Transformer 300B based builds 

Teramoto Finement Nanocrystalline Anode and Power Supply Chokes available in our Bespoke Builds


CMC-805-2.5CUR-G thick gold plate RCA sockets


Audiophile Quality CMC RCA inputs  

New and Vintage Audiophile Parts


We have a stock available for bespoke builds of new production and  NOS vintage audiophile parts.

Neotech OCC wire, Silk and Teflon Tubing ,Dale Non Inductive Wire Wound Resistors. 

TKD and Dale Metal Film Resistors.


Oil and Film Capacitors .

Black Gate Capacitors , NOS Red Cerafine Capacitors.

Sprague as seen in Yamamoto Amplifiers 

V735P V710P ,Dearborn & Sprague 730P