Winged "C" (SED) 5U4-G Black Plate Rectifier Vacuum Tube

5 Reviews
Out of Stock
SKU: RU-5U3C-Black
USD $‎49.95
Incredibly rare and considered to be one of the best 5U4G rectifier tubes made. This NOS Winged "C" 5U4G / 5U3C (5U3-S) vacuum tube has black-plate construction and was made from the late 1950's to early 1960's. This tube is labeled with its Russian name 5U3C but is an exact replacement for any 5U4-G tube.

Other SED tubes5U4 Types

Additional Information and Downloads

What does "NOS" mean, anyway?:

Commonly known as "NOS," the term New Old Stock simply refers to tubes that were made years ago but have never been used. Much like antiques, "NOS" tubes are currently not being manufactured and this means their supply is dwindling while the price continues to rise.

For most NOS tubes we have a variety of brands available. Typically these are the common brands such as RCA, Sylvania, GE, Raytheon, etc. However, there are instances where lesser known brands are in stock. If you have a particular brand you prefer you can simply request it in the Order Comment box when you place your order.

Warranty Information and Return Policy

Warranty Period: 3 months

All our tubes are guaranteed for 3 months from the date of purchase. (Any exceptions will be noted on that tube's Warranty tab)

If you receive a tube that does not perform to the manufacturer's specifications, please do the following:

- contact us to get a return authorization
- return it via regular mail within 90 days from when we shipped it, and we will provide an exchange or refund of the full purchase price of the tube.

Returns not related to warranty or defect will be considered at our discretion, and are subject to a 15% restocking fee.

We can not accept returns that don't have an authorization, are past 3 month, or are returned improperly.

These guidelines may be updated without notice.

Ratings & Reviews

5 reviews

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A very good rectifier, better than a Sophia Aqua Blue. Very, very natural especially in the high frequencies.


Plugged in my Decware SE34I. A bit bright, but much more transparent and natural compared to the Sophia Aqua Blue. I actually cannot go back to the Sophia which sounds artificial now. It can be aggressive in the treble if something else in the chain is not correct. The best with my nos RCA, the later being more balanced overall.

Bright sounding


This rectifier tube is very bright in my system, to much to live with. If you have a dark sounding amp then this my be your ticket, otherwise you will likely do better with some NOS 5U4G's..

Increased air, space, and depth


Just plugged this in to my Decware SE34I.4 and my first impressions are coming in. There's immediately a greater sense of air and space around the music compared to the Valve Art 274b. Only gripes so far would be that it's maybe even too much air for me. If your amp lacks highs extension, this might help you but for my ears I feel this might get fatiguing and hope it will smooth out with some break in. It also sacrificed a bit of the lower mid range punch to get the highs.

That said, it's smooth and grain free. Will report back with any changes post break in.

Winged "C" (SED) 5U4-G Black Plate in Woo Audio WA6


Absolutely transparent in my Woo Audio WA6 headphone amp, revealing BIG differences between various driver tubes. Haven't wanted to put my $160 Sophia Princess 274B back in. Great service from Richard, fast delivery also.

Winged "C" (SED) 5U4-G Black Plate Yaqin 300b


What can I say. Wow.