nano-At SE 300B or PX25 Tubes Choices

Genalex 300B


EML 300B -XLS -16 watts


Western Electric 300B New Production


KR Audio SE - PX25 / 6 Watts or SE-300B /10 watts XLR input


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

Its sound is characterised by a stunning midrange, with excellent low frequency performance , very sweet and extended high frequencies, a personnel favourite.

6 watts class A output suited to 93 dB/1 watt speakers and above .

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

Also perfectly suited to horn drivers and full range drivers like Fostex or Contrast Audio Line of Speakers.

SS Fully Regulated power supply.

PCC88 / ECC88 with Constant Current Power Supply

A new design for a balanced input for both the 300B or PX25 Amplifier using Constant Current Source Devises on both plates and heaters of the input tubes, to provide very low distortion, with great clarity and presence.

A pair of wide band input transformers are used for fully balanced operation.

This design utilises a set of small PCB's to fit a new small form chassis for those with limited space.

300B with Very low distortion .

    THD @ 1 W, 1 kHz 0.25%

  THD@ 10 W, 1 kHz 1.5%

     M19 - 20Hz-25KHZ -1dB 

Designed for the Professional Audio Studio with XLR Balanced and RCA inputs, Speakon & Binding Posts

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

Traditional Binding posts from CMC are an option.

XLR & RCA switchable inputs.

Neotech OCC input wire, Dale Resistors.

The latest low ESR Mundorf Power Supply Capacitors.

Teflon Coupling Capacitors used  &  Yamamoto Analogue L/R mV Meter

Available with M19, Amorphous or Teramoto FINEMET® Output Transformers

More information and images soon.


new release of custom made FINEMET® C core transformers 2020

FINEMET® is a Registered trademark of Hitachi Metals, a Nanocrystalline of exceptional quality.

Performance under more TAB.

FINEMET® is a registered trademark of Hitachi Metals. This Nanocrystalline is characterised by very low distortion and insertion loss with up to 1/5 the core loss of Silicon Steel. As an ouput transformer has a large impact on a tube Amplifiers performance FINEMET® has no real equal and is simply the best !


SE 300B , M19 Electra-Print or FINEMET® output transformers

NEW RELEASE SE 300B with E280F or 6E5P , 8 watts standard or 16 watts EML 300B- XLS tube.

Nano-AT SE 300B ( 8 watts ), uses a E280F  or a new option of a 6E5P  input tube running in triode mode, 

 Using Constant Current on the Anode of the E280F, or Cascode Current source on the 6E5P option to ensure the High End Teflon coupling capacitor is always charged for very low distortion and excellent dynamics to drive the grid of the 300B output tube .

The E280F or 6E5P option 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 FINEMET® ,Nanocrystalline Cut C core Output Transformers @ T1.3 Tesla , Simply the Best Metal currently available, or

Electra-Print M19  with Silver Secondaries, great bass, excellent full midrange , very detailed high frequencies and very musical , an all round performer , flat from 20Hz - 25KHz.

 Five fully regulated power supply with the SE 300B Amplifier. 

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 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. 

 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 and we use the PSSS silver or solid silver secondary option which is a step above the main copper secondaries option  most manufacturers use.

:   Teramoto FINEMET®  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 is 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 FINEMET® , 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 

Teflon  Coupling Capacitor  or  Siemens Epcos  - MKV - Your Choice.
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


Nicely Potted M19 Silver

Partial Silver or Full 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 . 

Amplifiers with these have Solid Silver Internal Hook Up Wire in the Signal Path. 

Very Flat Frequency response

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

These transformers after carefully wound  and tested to always exceed 25Hz-20KHz -1dB.

Partial Silver or Solid Silver Secondaries.

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

Masters of Bass !! Lush Midrange and very detailed High Frequencies as you would expect with Silver. 

See how they stack up against the competition.


6E5P Tube

New 6E5P in Triode Mode option for all SE300B models now.

Our PSSS/Solid Silver SE300B  amplifier range now uses this tube for its enhanced linear qualities , large current drive and very low distortion.

More to Follow

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 .

25Hz - 50 KHz -1dB

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.

These come as a standard issue or Signature Series.


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 .


Finement SE300B

SE 300B Finement ,Nanocrystalline, E280F or 6E5P input tube with TKD Volume Control and dual RCA

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.


Amorphous Transformers SE 300B

A number of 300B output options .

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

Western Electric , KR Audio and Elrog 300B are options for 300B's  , please email for details.

Some of the Parts we use Below



High End Volume Control from TKD for very even tracking and for added transparency in the signal chain a step up from the normal Blue Alps most commonly used in many production amplifiers.

Toroidal Power Transformers


High Quality , low noise Torodial Power Transformers now used in the new Silver Series SE 300B and SE PX25

Electra Print Anode Phase Splitting Transformers for Push Pull Designs


Nickel Phase Splitting Transformers 

Teramoto Finement Nanocrystalline, Anode and Power Supply Chokes, available in our Signature Series Builds. POA


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


Audiophile Quality CMC RCA inputs  

Mundorf Silver Gold Hook Up Wire


Mundorf Silver Gold Hook up wire for our PSSS and Silver Secondary Transformer Based Amplifiers.