• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

who made this 2a3 ?

rifraf50

Member
2015-09-19 10:28 am
hi , happy new year everyone !!!

This 2a3 looks Russian , perhaps 2c4c ? but I just cant find anything that looks identical ….the box is a plain white box with a marker pen "2a3"

It looks tidy in the manufacture , I have come across 5 of these …..

The getters look similar to those on my Melz 6sn7's

Perhaps a diy expert may know it …..cheers
 

Attachments

  • 100_3748.JPG
    100_3748.JPG
    585.2 KB · Views: 334
  • 100_3749.JPG
    100_3749.JPG
    473.7 KB · Views: 337
  • 100_3750.JPG
    100_3750.JPG
    551.4 KB · Views: 328
  • 100_3751.JPG
    100_3751.JPG
    604.4 KB · Views: 318
  • 100_3752.JPG
    100_3752.JPG
    532 KB · Views: 310
  • 100_3753.JPG
    100_3753.JPG
    608.6 KB · Views: 117
Last edited:

Parafeed813

Member
2012-08-15 8:24 am
My guess is it is Chinese, Shuguang.
It's been over 20 years since I worked on an amp with those, but the brown smudges that appear on the top during use were quite common with those.
The Russians I only know from pictures, but the bottom of the glass of those seem to be more round, while the Chinese have a more straight inclination to the base.
 
Last edited:
Cheapest Chinese from the past

My guess is it is Chinese, Shuguang.
It's been over 20 years since I worked on an amp with those, but the brown smudges that appear on the top during use were quite common with those.
The Russians I only know from pictures, but the bottom of the glass of those seem to be more round, while the Chinese have a more straight inclination to the base.

They look like the old Cheapest Chinese tubes. I bought 10 for $15 each and they were gassy and short lived. Fun to play with though. Respect the 15W dissipation or they go quick.
 
Yes, old Shuguang. I have several that are exactly like these. Mine are somewhere around 15 years old, and all are still alive.

I have been abusing a pair at 380 volts and 60 mA for several months in my new TSE-II board. No sign of ill effects yet and I'm getting almost 6 watts out of them. They were a 15 year old NOS pair though.

They came in plain white boxes with bubble wrap sleeves. Most of the ink stamped printing on the box is gone, but it was blue. The tubes still have their white paint lettering, but they haven't been used. The 300B's that I got at the same time have lost their printing from the tubes and boxes. They are well used but still good.