AUDIO FORUMS >> Replacement Tubes >> 5R4WGA

Message started by RobLikesTubes on 01/10/07 at 15:17:12

Title: 5R4WGA
Post by RobLikesTubes on 01/10/07 at 15:17:12

Can this  tube  be  used  in a  C-Select  as a  5u4 substitute ?

Title: Re: 5R4WGA
Post by Mike W on 01/10/07 at 17:04:52

The 5R4 is built somewhat like a 5U4, however the 5R4 operates at lower load currents. So yes it can be used but the term substitute should be used loosely.
I am sure someone who is more knowledgeable than me will weigh in on this one.

You will hear a difference. In one of my amps I actually prefer the 5R4 to the 5U4. Many Zen C owners like the sound of the 'Tater Masher' which is a 5R4WGB.

Title: Re: 5R4WGA
Post by rayd on 01/10/07 at 21:31:56

Courtesy of Bo-(ead)  :D from a past thread many moons ago:

Rectifier tubes for Zen Select:
(Low voltage = mellower, less aggressive)
-25v      5Y3
-15v      5R4, 5R4-G
0         Stock - 5U4-G
0         5U4-G, -GA, -GB [G=800ma-max, GA=900ma-max, GB=1000ma-max]
+5v       GZ32 (Mullards own, 5V4 substitute)
+10v      5V4
+10v      5V4-G
+10v      5V4-GA
+30v      5AR4 / (GZ34)
(Higher voltage = Dynamic, more aggressive)

Title: Re: 5R4WGA
Post by rayd on 01/10/07 at 21:39:52

I tend to lean towards the RCA 5U4GB. Seem to listen to it the most.

Just noticed I have an RCA 5R4GYB. I'll have to pop it in sometime and see how I like it.

- Ray

Title: Re: 5R4WGA
Post by Chris K on 01/11/07 at 03:35:51

5R4 in a Select is not the same as using a 5R4 in a Zen "C".
Zen "C" is spec'd for 5Y3 and a 5R4 is a bump up in voltage.
In a "CS" or "Select" 5U4 is the spec'd rectifier and it is substantially higher voltage than the 5R4. So in that instance 5R4 would be a step down in terms of voltage. Not saying a step down in sound mind  you. Just that my best guess is that 5R4 would "relax" a Select a little. I found though that in my Zen "C" 5R4WGB (masher) sounded the best of any rectifier.
If you want to maybe try a Mullard NOS GZ32. Some have said a 5AR4 would work in a Select but IMHO too much for a Select.

Corrected above: "CS" or "Select" oops!

Title: Re: 5R4WGA
Post by selmerdave on 01/11/07 at 21:04:31

5R4WGA (RCA) is one of my favorite rectifiers for my Select EX.


Title: Re: 5R4WGA
Post by Joel on 01/12/07 at 01:56:04

Just in case somebody is getting the "willies" about trying different rectifiers.

From the dark ages -

Started by sargon | Post by Steve Deckert
There is an error on the Schematic from the standpoint that we ship the SE84C with a 5Y3GT.  It is compatible with 5Y3GT, 5AR4, 5U4.  The resistors on pin two are lower values and a different type on the SE84CS not due to voltage differences but to achieve the desired signature.


Title: Re: 5R4WGA
Post by Chris K on 01/12/07 at 18:04:08

SO Joel that would mean different rectifier + given resistor value would = different signature. All true but even Ed V. and Steve D. say a 5AR4 is too high a voltage for a stock "C". It will do OK in a "Select" though. Oh I'm not saying anything would happen in a "C" with a 5AR4 but if I still had my "C" I would NOT put in a 5AR4 ever. A Zen CS Select is a different story. The power supply component values are different enough to take advantage of the 5U4. 5Y3 sound very good in a "C" not in a Select though and not many use that low V in a Select.

Title: Re: 5R4WGA
Post by Joel on 01/12/07 at 19:45:09

Those were Steves' words, not mine, saying a 5AR4 was okay in a C. I have used them in my CEX.

Title: Re: 5R4WGA
Post by Andy831 on 02/16/07 at 07:20:09

I have now tried the 5U4GC, and also the GZ32 (Mullard) and I prefer the GZ32 in my select.

Has anyone tried a 274B ? My "new to me" 20 month old Select is apparently shipping to me with this
Rectifier tube, I await its arrival with interest  [smiley=cloud9.gif]

Title: Re: 5R4WGA
Post by veryoldcat on 02/16/07 at 07:47:40

Some folks have raved about the 274b in a Select, but I haven't tried it. If recollection serves, there is some chance the 274b won't live as long as other rectifiers in the CS, but an expert is needed to confirm this.

My personal dead center favorite is the Mullard gz32! I've tried quite a few 5u4's of excellent lineage, and they're good, but clearly not as liquid as the the gz32. The 5u4's are much more aggressive sounding, and more fatiguing to my ear.

My second best fav to the gz32 is the RCA 5v4 (electrically similar). Not as liquid as the gz32 but darn nice.

Don't care much for the 5r4 or 5ar4 in the CS (or my csp either).


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