Nattawut Uamkruea, blogger and audio gear maker who passionate in vacuum tube, audio & music.
Producing electronics projects since high school. Seriously upgrade and modify vintage audio equipment for “Real Sound” concept.
He is a co-founder of Soundaries and Sentimental Studio, all audio solution provider.
Experienced and lively explore the listening rooms & audio shops in Japan as his most favorite to do.

Tuesday, February 2, 2016

Tuesday Tube : Western Electric 418A

Main reason that select this tube to work as driver for my amplifier

because it is a Western Electric tube that look like an expensive WE437A too much.

WE418A is an indirectly heated tetrode tube. Use 9 pin Magnoval socket.

Same base and bulb like WE437A and WE436A too.

Frame grid construction.

Square getter.

I've found this copper tube shield in ebay, it's look tight and rigid.

Keep it for my WE437A triode tube in the future. ;)

Tube shield inside with spring all around. Great design and usable.

Later version of WE418A had smoke glass and different font.

When I made a decision to use WE418A,

I'm searching more information and specification in google.

No triode curve from any sites. Only question but no answer.

Until I've found triode curve from project in MJ Audio magazine for February 2015 !!!

Plate Characteristic for triode connection of WE418A tube.

Characteristic & typical operation.

Sound of WE418A in triode connection so flat and powerful, 

easily match with almost power tube especially directly heated triode.

You can get the same feeling like looking and listening to WE437A. ;)



  1. Hi Nattawut,

    Nice article. Do you happen to have any reference or triode curve of WE 436A?

    1. Hi Heng Gin Loo,

      I will let you know if I find 436A curve.