[Dubstep Girl]

Hello all,

I have acquired this Marconi/GEC? U52 5U4G thinking it might be a copy. A member here thinks it is genuine, so am posting it here for the wider community’s thoughts. The photos are the best I can do, but it has smooth anode plates with a cup getter, and obviously a straight brown base rather than curved. I believe it’s genuine, can anyone add to this? Any idea date of manufacture? Thanks.

U52 curved base only!!!! any other is not it

 

[Tubegear]

The cup getters are indeed strange

I bought several RCA 5R4GY from Langrex several years ago. Really nice performers for the money. I examined the photos and one of my tubes as best I could and they are identical in every feature but for the getter and glass etching. The getter location is the same but my examples have D getters(?). Getters aside, these tubes could have been produced on identical machines to the same specs.

​

I agree but the cup getters on this BVA 5U4G are strange. I have never seen these type of getters on an American tube. I do own several American type 80 rectifiers but these have foil getters if I remember correctly. Maybe need to check again.

 

[JTbbb]

The cup getters are indeed strange

I agree but the cup getters on this BVA 5U4G are strange. I have never seen these type of getters on an American tube. I do own several American type 80 rectifiers but these have foil getters if I remember correctly. Maybe need to check again.

Well it seems, along with help from others, that we are sort of settling on this tube http://www.r-type.org/exhib/acb0025.htm it is the getter that is troublesome, and possibly the Marconi lettering. I bought this tube as a job lot with 4 KT66’s (it was the KT66’s I wanted and all untested, bought as seen) I knew nothing about the rectifier until I had bought them. They all were filthy and after cleaning look new and unused! Two original boxes too.

Anyways, they have all gone for testing and when back I will doubly check the getter and get a good photo of it.

Edit :- My tube tester is going to check the heater current draw. Should be 5A not 3A. Testing on calibrated AVO VCM163

 

[spiderking31]

Have you ever heard a Takatsuki TA-274B?

I own the Takatsuki 274B, and it’s an amazing tube! Now I’m using Bendix 6106 and a Mullard 5AR4 4 notch tube

 

[tholt]

Of the Mullard 5AR4 black base (non-metal) versions, is there a consensus which sounds the best? I've seen regular or "fat" bases, no-notch, 4-notch or 7-notch. From what I understand, the fat base no-notch ones are the oldest. Is this the best option to look for?

 

[CAJames]

Of the Mullard 5AR4 black base (non-metal) versions, is there a consensus which sounds the best? I've seen regular or "fat" bases, no-notch, 4-notch or 7-notch. From what I understand, the fat base no-notch ones are the oldest. Is this the best option to look for?

IMO yes, the fat-base smooth-plate (no-notch) are the best. Also the most expensive.

 

[tholt]

IMO yes, the fat-base smooth-plate (no-notch) are the best. Also the most expensive.

Cool. Dude you're in Lompoc? I graduated from Cal Poly and lived in the SLO area for 20+ years. Love it there

 

[CAJames]

Cool. Dude you're in Lompoc? I graduated from Cal Poly and lived in the SLO area for 20+ years. Love it there

Guilty as charged .

I grew up LAish but moved up here 30+ years ago (after a brief stop in Santa Barbara). I have a bunch of family and friends in SLO/Cayucos/Cambria. It is a slice of heaven for sure.

 

[tholt]

It is a slice heaven for sure.

It is that for sure. NorCal, SoCal, and central coast is the little idyllic patch in the middle.

 

[tholt]

Here is some info I found to follow up Mullard GZ34 black base on some things to look for. To sum – fat base, smooth edge and code f31 (made between 1958 - 1962) being the oldest.

https://forum.polkaudio.com/discussion/181086/rectifier-tube-which-mullard-gz34
http://www.tube-classics.de/TC/Tubes/Valvo GZ34/GZ34.htm

 

[ardbeg1975]

I own the Takatsuki 274B, and it’s an amazing tube! Now I’m using Bendix 6106 and a Mullard 5AR4 4 notch tube

I second the praise of the Tak 274B. I'm running one in an icon HP205D and it complements the 205Ds very well.

 

[BlakeT]

Black & White photo filter seemed appropriate, since these are both 1942 vintage, Valvo G2504 mesh plate in front, and Valvo G2504 solid plate in back.

 

[tholt]

This wonderful bit of history arrived a few days ago and I've been enjoying it from the first time I turned it on (Mogwai SE Rev 2)

Seller wasn't sure on the year but I'm guessing it's early 50s? GEC labeled Brimar 5U4G, grey plate cup getter. Sound seemed to really open up immediately. I've been steadily tube rolling around it so can't make a ton of detailed observations, but judging from what I'm hearing so far and all the comments/comparisons here, I'm certainly content for now.

The other rectifier I'm interested in is a Mullard or perhaps Valvo/Philips 5AR4. Any thoughts on how that would compare sonically and otherwise to the GEC 5U4G?

 

[Dubstep Girl]

This wonderful bit of history arrived a few days ago and I've been enjoying it from the first time I turned it on (Mogwai SE Rev 2)

Seller wasn't sure on the year but I'm guessing it's early 50s? GEC labeled Brimar 5U4G, grey plate cup getter. Sound seemed to really open up immediately. I've been steadily tube rolling around it so can't make a ton of detailed observations, but judging from what I'm hearing so far and all the comments/comparisons here, I'm certainly content for now.

The other rectifier I'm interested in is a Mullard or perhaps Valvo/Philips 5AR4. Any thoughts on how that would compare sonically and otherwise to the GEC 5U4G?

this is the better sounding one for sure, lovely tube

 

[ChJL]

I'm officially at the headache level stage. The power supply of the amp I'm looking at has one GZ34/274B rectifier tube.
They sell some at their shop so they could put in following cheaper models:
# Shuguang 5AR4 (GZ34)
# Sovtek 5AR4 (GZ34)
# Tungsol 5AR4 (GZ34)
# Genalex GZ34

and one more expensive:
# Full Music 274B N

so which one would you (experienced) "rollers" use?

my headache stems from looking into:
Birmar, Mullard metal base, 3 types of Psvane, Elrogs, Taks...

Which option would be a good starting point for a beginner? Just get any cheaper option and take time to look into it later on?