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 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 .
The Original and Simply the best 300B, all the others have had to follow.
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.
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
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
Please read tech notes under More! TAB
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
COMPONENTS AND BUILD
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.
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
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.
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
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 .
Line Input Transformer
1:1 FOR 'BALANCED BRIDGING' INPUTS
• 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.
Customers have questions, you have answers. Display the most frequently asked questions, so everybody benefits.
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
Hitachi Metglass Amorphous Cut C core double bobbin Interstage Transformers and Anode/Plate Chokes
NP Acoustics Amorphous Interstage Transformers
Electra- Print Anode /Plate Load Chokes as seen in our Electra Print Transformer 300B based builds
Audiophile Quality CMC RCA inputs
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