Mentor SET 300B/2a3 Power Amplifier


Stereo 300B Power Amplifier – ideal for mating with matching Mentor Pre-amplifier.

SKU: 300B-MENTOR Categories: , , ,


ANK is proud to announce The Mentor 300B/2A3 SET Power Amp that can be configured for either 3.5w or 8W triode configurations.

Some Amazing features such as:

5u4g Tube Rectification with Mundorf Film power supply caps

Configurable Filament board for 2.5v to 5V operation

AudioNote Tantalum Resistors 1W ,2W

AudioNote Copper Film caps 

6sh7 driver PCB

Optional QuadC cores (  or triple) along with massive EI cores all custom made

8.5w  300B SET or 3.5w 2a3 mode

Customers requested a serious pure 300B SET Power amp in an enclosed chassis with massive Quad C core output transformers as an ideal mate to their  Mentor Pre-Amplifier . The combination of the two will create the most incredible experience in Single Ended Triode Amplification.

For 300B or 2A3 PURISTS looking for a pure power amp configuration with Ccore output transformers the Mentor SET Power amp is a great choice – Couple if with our prestigious Mentor Pre-amplifier for the ultimate pre and power combination


The 300B section is all hardwired with our TAG strip configuration for the large 300B cathode resistors and bypass capacitors


Check out the massive QUAD C core outputs for our top of the range version of the Mentor SET – you have to experience to believe!


the Driver board for the 6sh7 componentry makes for easy construction – large 2oz copper traces along with big foot prints for 1 and 2w resistors and large FILM capacitors


A fairly easy build compared to a kit1 for example – the kit is well layed out




The ultimate DIY 300B SET Power Amplifier comes in our Mentor chassis and can be built for 2a3 operation. Using the 6sh7 driver tube and 5u4G rectifier . The classic zero feedback Single ended triode operation delivers 8.5w of pure SET sound – Massive output transformers in three levels deliver incredible Performance!

Enjoy the finest single ended 300B power amplifier with unlimited upgrade potential!


Check out our Build Manual before you buy! you can download it off the Manuals menu on the website home page or go directly her

Mentor 300B SET Manual 

Hi-Res Gallery 



The Mentor set comes in three configurations – out entry level uses the large EI core transformers found on the kit1 classic , the second level uses out triple c core output transformers ( 8 & 15) found on our kit1 -10 product and then we made a quad C core for single 300B exclusively for this product for third level configuration!


Mentor SET 300B/2a3 8.5W EI Core
Mentor SET 300B/2a3 8.5W Triple C Core
Mentor SET 300B/2a3 8.5W Quad Core


Power 8 Watts Single Ended Triode, zero feedback
Output Tubes 2 x 300B
1st Stage Gain 6SH7
Rectifier Tube 5U4GB
Outputs 1 x Stereo Pair 4, 8, 16 ohms
Recommended Speakers min 88dB
Width 53cm
Height 20cm
Depth 45cm
Weight 18kg
Chassis 3mm Aluminum with Black Powder Coat