5U4M/5C4M Rectifiers

[72Blazer]

I'm reading some conflicting comments online about these Russian tubes.  Are they a suitable replacement for the GZ34 Tube?  For example, would they work (plug and play) in something like a Fender Super Reverb or are there other considerations/mods needed in the circuit or special PT considerations?

Thanks

[isaac_teller]

http://ds.agavaceae.ru/similar.php

[dwinstonwood]

isaac_teller, cool website. I like these graphics from the 'MK BOIZEN HANDBOEK'

[tubeswell]

English datasheets


(Edit - I wouldn't use them in a Super Reverb - not enough forward current supply and will be too 'spongey' sounding. But you could use a Sovtek 5U4G in a Super Reverb)

[HotBluePlates]

... Are they a suitable replacement for the GZ34 Tube?  ...

No, the 5C4M is barely stout enough to be a 5Y3 substitute.

[72Blazer]

Thanks for all the clarifications and tube truth data. There are some false claims out there that I came across stating the 5U4M is a direct replacement for a GZ34.

Vr
J

[tubeswell]

5U4M

What looks like a ‘U’ (Ц)  in the Cyrillic alphabet translates to a ‘C’ in the English Latin alphabet.


(And a ‘C’ in Cyrillic translates to an ‘S’ in Latin)


A 5U4 tube (English Latin), on the other hand, is not the same as a 5C4. A 5U4 can provide enough forward current to be subbed for a 5AR4/GZ34 (if there is 3A capacity on the 5V winding).

[72Blazer]

I did see where it had a rating of 3 whereas a real GZ34 was like a 1.8 or close to that. On my cell phone now so can’t really do any research. Anyway, I had bought 6 of those Russian tubes years ago because they were cheap. I’ll have to try and source a good PT to handle this rectifier and Two 6L6GCs. Any suggestions?

[tubeswell]

I did see where it had a rating of 3 whereas a real GZ34 was like a 1.8 or close to that.

If you're talking about Amps, then a 3A 5V filament would indicate its a 5U4. (A 5C4 has a 2A 5V filament)


Any PT that has a 5V 3A winding will be good for powering a 5U4 rectifier. As for the other PT specs, that depends on what you want to build.

[dwinstonwood]

So, if the graphics I posted above are correct, the big differences are with the required 5V heater current supply, and the maximum size of the first reservoir cap. The GZ34 can tolerate a 60uF, but the 5U4 should be limited to a 32uF reservoir cap.

[sluckey]

I did see where it had a rating of 3 whereas a real GZ34 was like a 1.8 or close to that. On my cell phone now so can’t really do any research. Anyway, I had bought 6 of those Russian tubes years ago because they were cheap. I’ll have to try and source a good PT to handle this rectifier and Two 6L6GCs. Any suggestions?

I would mount them on a plaque and hang it in a dark corner of my workshop. And use more familiar tubes with good published data sheets for amp building.

[HotBluePlates]

So, if the graphics I posted above are correct ...

72Blazer was asking about the Russian 5Ц4М, which he also wrote as "5U4M" but is properly transliterated as "5Ch4M" because "Ц" is pronounced "Ch" as in "Chechnya" (Цецня).

Thanks for all the clarifications and tube truth data. There are some false claims out there that I came across stating the 5U4M is a direct replacement for a GZ34.

There is an American tube called "5Y3" that is the smallest of common 5v rectifier tubes.  It can manage 125mA of DC output current.

The Russian 5Ц4М is a "5Y3-like tube" that even says "(5Y3GB)" on the data sheet I linked earlier.  It can manage 140mA of DC output current, and has less voltage-drop than an American 5Y3.

The 5AR4/GZ34 is only slightly bigger than a 5Y3, but is capable of 225mA of DC output current.  Way stouter than the 5Y3 or Russian 5Ц4М.

The American 5U4 is physically much bigger than any of the preceding tubes, and can handle more power, too.  It can deliver 300mA of DC output current.



An American 5U4GB can handle any task a GZ34/5AR4 can do, but you must make sure the socket can deliver the extra 1A of current required by the 5U4GB.

A Russian 5Ц4М cannot survive in a socket for a 5AR4/GZ34.

[mresistor]

a lot of people got ripped off when they thought they were buying a 5Y3 and got a mislabeled 4 pin 5C4M instead .  I've got one and it says Made In England on it.