equivlent of FU-50

[siliconray]

Hello all! it seems that most Chinese tube has equivlent part made in USA, soviet or Europe, for example 6N8P = 6SN7. Did you know what is the equivlent of FU-50? I'm making a FU-50 SE, and want to find a equivlent tube to compare the differences.

[AndreasS]

Hello,

equivalents are german LS50 and russian ГУ50.

Andreas

[kenpeter]

Did China also copy the military socket with spring loaded door on top?
Sadly, I only have one, and the ГУ-50 tube inside is missing the knob...

Grid - Screen Alignment (X-Rays)
My XRay upskirt shots of the Russian version begin at post #34...

[v4lve lover]

SRS552M east german GU50

have a good one

[siliconray]

Kenpeter, yes there're military socket.

These are my tank version FU-50

[Wavebourn]

Originally Posted by siliconray

Hello all! it seems that most Chinese tube has equivlent part made in USA, soviet or Europe, for example 6N8P = 6SN7. Did you know what is the equivlent of FU-50? I'm making a FU-50 SE, and want to find a equivlent tube to compare the differences.

There were no American equivalents of German LS-50.
Wikipedia article about the tube has very good information about it, unlike many other articles related to tube amps: GU-50 - Wikipedia, the free encyclopedia

Edit: on your online store you call it triode. It is not true; the tube is pentode.

[siliconray]

Thanks Wavebourn. I found a lot of useful document on wiki about FU-50.

I just finished assemblying my first FU-50 tube amp. It's a bit rediculous that I haven't build a FU-50 amp by my own hands althouth a lot of kits have been sold from our store.

I have to say FU-50 is really awesome. The sound is warm and clear, much better than 6P3P. I know why there's a knob on the top of the tube..it's very very hot when working. You can pull it from the socket by the knob without hurt the fingers :-)

Next I will try to get at least 2 LS50 to replace FU50 on this amp to make a compare. I found it's hard to find LS50 in China. There're some sellers on ebay, I think I can get a few from Europe.

I really like this amp. I will take it home to replace the FU-50 with my current KT-88 push-pull amp.

[ThorstenL]

Hi,

Originally Posted by siliconray

Hello all! it seems that most Chinese tube has equivlent part made in USA, soviet or Europe, for example 6N8P = 6SN7.

There is some interesting history here which I am still researching, my understanding so far...

The chinese military electronics industry was build up by russia after the communist defeated the kuomintang and founded the PRC. This covers mostly the Northern Provinces. There is even an interesting military electronics factory in Beijing that was build by East Germany in Bauhaus style, it now a famous art gallery area called 798 Art Zone. I do not know what was made there, it may very well also have been tubes.

The whole northern tube industry as a result makes mostly russian designs on originally russian tooling and even with the exact same type number as the russian tubes (but the cyrillic lettering has been romanised. There are a few key omissions, for example the russian 6922 analog called 6N23 was introduced AFAIK after the China/Soviet relationship cooled and only the earlier 6N11 is made in china, while the 6N11 was discontinued in Russia.

It appears some US trained Engineers at the same time set up a US influenced operation in Nanking around 1948/49 which made copies of US Tubes, I have encountered very old NOS Nanking 5U4 and 2A3 that look exactly like US tubes. Why they remained in production in China is a mystery to me, but there they where...

Until the opening up to the West in the 80's that was it, but chinese tube factories where quick to recognise the export potential and started mainstream US Tube copies (some better than others).

Meanwhile the origin of the Russian tubes is also interesting.

Pre WW2 many tubes where US copies, however following WW2 soviet russia acquired in various ways (including wholesale de-montage of factories then shipped eastwards to russia, including any employees that could be found pressed into service and "accommodated" in the Gulags) much of Germany's WW2 Tube technology (as well as much other German technology).

At the same time russia had also received large numbers of US military gear via lend-lease which needed of course US tubes to run. So both East German factories where making copies of US Tubes as war-reparations to soviet russia and russian factories where also producing them, so they too became used by the russian electronics industry and where given russian type numbers. Soviet Russia would alter pass this bewildering mix of american and german designs on to the Chinese.

It was not well into the 1950's that soviet russia started to produce truly indigenous designs, though many of these can also be seen as copies of American and German tubes. Few if any of these designs made it to china though.

Ciao T

[Jaap]

You can find fascinating litarature on this site; Introduction page

For instance about the first analog computer, invented in WW2 for the purpose of steering the German V2 rocket to London.

If you use the search function on the site with "LS50" you will for instance find stuff in which this tube was used

[kenpeter]

Originally Posted by siliconray

Kenpeter, yes there're military socket.

These are my tank version FU-50

Yes, exactly the socket I tried to describe.