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Safe rectifier roundup (Decware input pending) (Read 11538 times)
marky
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Re: Safe rectifier roundup (Decware input pending)
Reply #15 - 01/12/13 at 12:16:55
 
I finally ordered the philips rectifiers and reading L Soths observations
in the above were very helpful in decision making. In fact I`m getting
warmed to the Philips brand. The miniwats always look enticing.
Riz, I did read that a user of the EML got 600 hrs out of the tubes before they went on the blink whereas they should last 1000`(s) +. So you could take a flier, if it`s just the tubes that go and no damage elsewhere....
In the info they provide they mention some component changes inside the amp and also they had to change or add extra heaters because of problems. I think if you wait they will eventually fix all the bugs.
Lotta money for a punt.
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« Last Edit: 01/12/13 at 12:22:23 by marky »  

Decware: Rachaels x 2 bridged, CSP2+, ZP3, ZMC1, DSC i/c`s, DHC-1 pw/cbl`s. Roksan Radius/Nima/high def cabl & M.Benz LP s , Rega P3,RB300 (silver Litz), Rega wall mount, DV 20XL, Nakamichi LX5, M/L aeon i`s, Townshend Isolda sp/cbl`s, Isotek mains sub
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JD
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Re: Safe rectifier roundup (Decware input pending)
Reply #16 - 01/12/13 at 16:07:52
 
those phillips are a great rectifier you won't be disappointed.  I have to say that my fav rectifier so far is nos 1953 rca 5r4gy that i picked up from cryoset that is currently in my csp2+.  Running early 50's rca 5u4g rec's on my torii.  240 seems too much to spend on a rectifier.  money might be better spent on a couple great nos input tubes...telefunken, amperex,mullard, ediswan etc.

JD
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Rizlaw
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Re: Safe rectifier roundup (Decware input pending)
Reply #17 - 01/13/13 at 01:02:17
 
My mind is melting with this 5U4G rectifier issue.

I just went back to the EML 5U4G technical spec page. As I posted yesterday (Reply 7 & 9), EML spec'd their 5U4G at "33uF for 1st capacitor connected to plates" (that was on Jan. 11, 2013).

I also posted the email response I received from EML's Jac van de Walle where he confirmed the EML 5U4G had a max capacitor value of 32/3 uF and the 5U4GB (an electrically different tube) was 40 uF (see my Reply 12 this thread).

This evening, Jan.12, 2013, I went back to the same EML spec page and guess what, EML changed the max safe capacitor value for the 5U4G from 33 uF to 40uF! I sure wish I had saved a copy of yesterdays EML 5U4G web page. So maybe they caught an error because of my inquiry and fixed it? Fair enough.

But, according to Mr. de Walle's email of 1/11/13, the 5U4G and 5U4GB are electrically different tubes, so how can they have the same capacitor value when he stated different values in his email to me? Perhaps another error regarding the 5U4GBs correct max capacitor rating?

As Mr. de Walle's email also mentions, the photo of the SE34I.3 on the Decware site shows a 5U4GB rectifier being used.

So as Dr. Szell (Laurence Olivier) asked Dustin Hoffman in "Marathon Man": "Is it Safe?" the EML 5U4G that is.

P.S. I'd prefer not to have my teeth probed without anesthetic on this one. Grin
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System 1: Computer/Linux OS > Audiophileo 2 > W4S DAC-2 > Woo WA-2 / CSP3 > Taboo III > Omega 3E / LCD-2.1/ Beyer DT-990/DT-1350
System 2: Yamaha PX-2 (Shure Ultra) / Oppo DV983H > Classe CAP2100 > Thiel 7.2
System 3: Fisher:R200/X202B > Magnapan MMG
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clowkoy
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Re: Safe rectifier roundup (Decware input pending)
Reply #18 - 01/13/13 at 10:04:57
 
There is actually a very simple solution to your problem: change the first capacitor to a polypropylene 3.9uf, like a Mundorf or Clarity cap. I've done this on my CSP2+ to accept a Sophia 274b. I didn't hear any difference in sound or increase in hum. A polypropylene cap is much better than those $2 stock Lelon caps. A mundorf costs $90.
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Rizlaw
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Re: Safe rectifier roundup (Decware input pending)
Reply #19 - 01/13/13 at 19:14:05
 
Clowkoy, my apologies in advance for this long winded reply. It's more, or less, a summary of everything I've said before and where, in my thinking, I'm at now on the subject. I'm hoping it will be my last post on the subject.

Quote:
Clowkoy
There is actually a very simple solution to your problem: change the first capacitor to a polypropylene 3.9uf, like a Mundorf or Clarity cap.


Clowkoy, the problem to which you refer (rectifier tube/amp compatibility) IMO, is not just my problem, it's a problem for anyone who owns or contemplates purchasing a Decware SE34I.3 and contemplates tube rolling. At this point, at least for me, the jury is still out on whether it's the amp or the particular tube that's at the rooThere is no mention of any other type of 5U4 tube, i.e., 5U4GA, GBt of the problem in the first place. This is assuming there is a problem at all! Until I hear more from Steve, I shall reserve judgment. (skip to the last paragraph if you don't care to read any further)

As for replacing caps, that, IMO, could and probably would void the lifetime warranty, not to mention compromise Steve's intended design goal for this amp. While I may be somewhat ignorant about the internal workings of tube electronics, I get the feeling that changing a cap in a preamp is less problematic (read dangerous) than doing so in a power amp.
There is no mention of any other type of 5U4 tube, i.e., 5U4GA, GB
In the end, I have to believe that Steve knows how to build a proper amp for the tubes he selects and that he knows how to select caps with proper values so that those tubes operate correctly, within their intended specifications (NOS or current tubes), and without flashing issues (all this, notwithstanding what EML's Mr. van Walle implied in his email to me yesterday. See Reply #12 above).

Carefully reading the the Decware web site "Specifications" on rectification for the SE34I.3:

Quote:
Rectification    5U4G tubes


There is no mention of any other type of 5U4 tube, i.e., 5U4GA, GB
and the pdf "Owner's Manual" for the SE34I.3 "Rachael":

Quote:
There are also some compatible substitutes that you can try which include 5Y3GT and
5AR4. The 5AR4 is an indirectly heated rectifier with a soft start up so it may be a bit
more expensive than the 5Y3GT and 5U4. A popular rectifier tube that many people try
to substitute is the 274B. There are different manufactures and different types of 274B
rectifier tubes. Of the ones we’ve examined, they all required no more than a 10uf
capacitor in the first section of the power supply. Very few tubes amps today use that
small of a value. The SE34I.3 uses a 47uf capacitor in this location which can cause
the 274B to arc on start-up and thus reduce it’s life.


you now know the following:

1. the substitute rectifier tubes which could be a problem are some 274B's. A list of know problem 274B is not given;

2. the 5AR4 or 5Y3GT tubes are compatible substitutes for the 5U4G; and

3. any "5U4G" tube will work (NOS or current) since there is nothing in the manual or spec that states otherwise similar to the caution on the 274B. There is no mention of 5U4GB which is not electrically the same as a "5U4G", although, I think, it does appear to be safe to use from everything I've learned so far. We need Steve's confirmation on this.  

What set me off on this journey was the OP's original question concerning "safe" rectifier substitutions for the SE34I.3 "Rachael". The OP wanted to know if it would be safe to substitute a 274B in place of a 5AR4/GZ34 AND his important notation of flashing problems in WOO amps which used the Sophia 274B and EML 5U4G.

To be clear, nowhere in this tread has it been stated that an EML 5U4G will flash and prematurely fail in the SE34I.3. The closest anyone in this thread has come to "suggesting" premature failure for the EML 5UG4, was "Marky" in replies #10 and 15 concerning what he read regarding the EML 5U4G tube on "other" forums, possibly with other non-Decware amps.

Nevertheless, the only reason I posted anything in this thread was because of the warning about tube-flashing of "EML 5U4G" tubes. I asked myself: why would the EML 5U4G flash in a Decware "Rachael" which is designed to accept a "5U4G"? By "a 5U4G" I am only referring to that specific tube, not to 5U4GA or 5U4GB.

When I looked at the EML 5U4G max capacitor spec on the EML web site, it was originally noted to be 33 uF and in less than 24 hours was quickly changed to 40 uF (as I noted in a post above). Both of those values were below Steve's selected cap value of 47 uF. Was this a potential flashing problem? Maybe. Lord Soth's "ballon" analogy in reply #8 on page 1, which explains how a tube can be stressed when used with a capacitor rated higher than the tube's max capacitor specification added to my concern. Adding more confusion, was the fact, pointed out by EML in their email to me, that the picture of the Decware SE34I.3 showed not a 5U4G, but rather a 5U4GB, an electrically different tube with a 40 uF cap rating. The 5U4GB is still 7 uF below the SE34I.3s 47 uF cap. Is this a problem or not?

Recognizing that tubes are tempermental beasts, and can fail at any time and for almost any reason, I am at the point of asking the following questions:

1. If the 5U4G and 5U4GB are electrically different tubes, are they safely interchangable (NOS or newer current types) in the "Rachael" in the same way 5AR4s or 5Y3GTs are safe substitutes? If not, why not?

2. If the "Rachael" is using a 5U4GB as the stock tube, rated at 40 uF max according to EML, why isn't this noted in the specifications to avoid confusion?  Steve has confirmed in an email that the rectifier he is using (without exactly specifying the model tube) is working without issues, but he can't confirm that the EML 5U4G will work because he has never tested it in the Rachael. Excluding a bad tube, why wouldn't an EML 5U4G work properly? It seems to me the specifications should state which of the 5U4 family of tubes is safe to use.

So, in the end, I believe what is needed for the SE34I.3 is more and clearer information from Steve himself. Much akin to what he provides for the Mini Torii information page (pictures and descriptions of all the compatible tubes).  
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System 1: Computer/Linux OS > Audiophileo 2 > W4S DAC-2 > Woo WA-2 / CSP3 > Taboo III > Omega 3E / LCD-2.1/ Beyer DT-990/DT-1350
System 2: Yamaha PX-2 (Shure Ultra) / Oppo DV983H > Classe CAP2100 > Thiel 7.2
System 3: Fisher:R200/X202B > Magnapan MMG
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clowkoy
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Posts: 52
Re: Safe rectifier roundup (Decware input pending)
Reply #20 - 01/13/13 at 23:41:02
 
If you really want to follow the capacitor requirement, then you only have the 5AR4/GZ34.

"So, in the end, I believe what is needed for the SE34I.3 is more and clearer information from Steve himself. " - Good luck on this. Sad
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marky
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Re: Safe rectifier roundup (Decware input pending)
Reply #21 - 01/14/13 at 00:20:03
 
This is asking questions about tubes that I haven`t got involved with on the spec sheets.
I`ve bought 12ax7`s, 12au7`s, 5u4`s, 5y3`s, 5ar4`s, and 5r4`s with all sorts of different suffixes....I just buy them put them in. So far no prob.
When I read here about the 247b`s I thought wow, yeah, must get one, they`re huge. But...they came with baggage, as in the brightest light burns half as long..possibly. I still check them out, out of curiosity. Then a couple of months ago the mesh rectifiers were mentioned. I couldn`t find them until Rizlaw brought them to light. I thought they would be old NOS at just a bit more cost but they`re new and 3-4 times more expensive.
I must say I was hoping someone would say " Oh, I use them and ...."
Are they the only makers of mesh 5u4`s ?
How new are the mesh tubes ?

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Decware: Rachaels x 2 bridged, CSP2+, ZP3, ZMC1, DSC i/c`s, DHC-1 pw/cbl`s. Roksan Radius/Nima/high def cabl & M.Benz LP s , Rega P3,RB300 (silver Litz), Rega wall mount, DV 20XL, Nakamichi LX5, M/L aeon i`s, Townshend Isolda sp/cbl`s, Isotek mains sub
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Rizlaw
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Posts: 90
Re: Safe rectifier roundup (Decware input pending)
Reply #22 - 01/14/13 at 01:27:52
 
Clowkoy,

I see you don't have faith that Steve will provide additional clarifying info. I'm sure he's a very busy fella and can't read and respond to every issue/ question posted on these forums, even though I think this topic deserves his additional attention.

I left a message on Friday (1/11/13) for him to call me about this, so far he hasn't, but I was told he was busy with a customer and Fridays are a bad day for everybody. Monday they are closed. Perhaps on Tuesday he will call. He's already told me via email that he can't comment on the EML 5U4G because he's never personally used one in the SE34I.3. When I speak to him, I'm sure he will answer and explain the concerns I have outlined in my previous "long" post.

Marky,

Decware forums don't appear to be all that active so I doubt you're going to find an answer about the EML tube here any time soon. It's just too expensive for most people to chance buying and getting an instant flash over with possibly no warranty recourse because EML thinks Decware's circuit topology for the 5U4G tube is faulty. The customer would be caught in the middle of an argument between two manufacturers, both claiming it's the others fault. I'm sure we've all "been there, done that" before in other areas.

However, as EML's Mr. van Walle mentioned in his email to me, it should work and my question to him seems to have immediately prompted a changed in the cap value from 33 to 40 uF on EMLs website for this tube. So maybe we're all worrying about nothing; maybe not.

I may just be crazy enough to eventually buy the EML 5U4G and try it after I get my own "Rachael". In the meantime, I will be ordering a couple of 5AR4s from Upscale Audio on Monday. I was wrong, it seems Upscale gives a 90 day warranty on tubes (not 30) so when I order tomorrow, I should be covered until about mid April. Hopefully, I'll get my amp in March and have a few weeks to spare for testing.
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System 1: Computer/Linux OS > Audiophileo 2 > W4S DAC-2 > Woo WA-2 / CSP3 > Taboo III > Omega 3E / LCD-2.1/ Beyer DT-990/DT-1350
System 2: Yamaha PX-2 (Shure Ultra) / Oppo DV983H > Classe CAP2100 > Thiel 7.2
System 3: Fisher:R200/X202B > Magnapan MMG
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Lord Soth
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Posts: 264
Re: Safe rectifier roundup (Decware input pending)
Reply #23 - 01/14/13 at 02:15:53
 
There are infamous tube equipment which literally eat tubes.

AFAIK, Decware amps are not designed like that.

The cap values used in their amps is pretty standard and tube friendly so you can literally pop in any of the standard NOS rectifiers such as 5Y3G to 5R4 to 5U4 to GZ34 .... Etc. Those few uF will not make any difference so quit ya yammering will ya? Wink

BTW, the ultimate rectifier is a GEC U52 or the Western Electric 274b.
These have a lower maximum uF cap rating than the standard 5U4, 5Y3 rectifiers used today. I believe that Steve designed his amps to sound fantastic based on good old American made standard rectifiers which were (and still are) cheap and easily available.
Case in point is the CSP2 amp, the US$20 5y3 sounds fantastic in this tube amp.

The cap values also have a bearing on the final sound and so based on what I've mentioned above, I don't see any fault with Mr. D's designs.

If you still insist on using one of those mesh rectifiers, I'd suggest opening a dialogue with Steve to specially accommodate that. The famous Woo Audio also made a special version of some of their amps to accommodate exotic rectifiers like the mesh plates.

However, your final sound output will be different from the original design a.k.a Mr. D's "vision".
The final sound could be better or worse.



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orangecrush
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Re: Safe rectifier roundup (Decware input pending)
Reply #24 - 01/14/13 at 02:36:06
 
Anyone know what the cap value is for the Torri?

I am still really liking those cheap Preferred Series Shugang 274B from the Tubestore.
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Rizlaw
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Re: Safe rectifier roundup (Decware input pending)
Reply #25 - 01/14/13 at 03:23:28
 
LS,

For the record, nothing I have written casts any doubt on the quality of Steve's designs (that was something EML's Jac van Walle seemed to imply in his email to me if his tube didn't work in the "Rachael." He ultimately felt it should work). I wouldn't be ordering a fully optioned "Rachael" if I had doubts.

And yes, I've already quit my "yammering" (although, I thought that what I wrote was better than simple "yammering", perhaps more like "kvetching" when something is not clear enough. Smiley

BTW, I thought you rated the Brimar 5R4GY rectifier #1 and the Philips 5R4GY #2 in your shoot out? I just checked, TubeDepot has the WE 274B for a mere $999.00, which, I imagine, is a non-starter for all but the most prosperous hardcore tube-o-philes.http://tubedepot.com/nos-274b.html

Do you promise, by all the pixie dust in NeverNeverLand that those few uFs won't make a difference. Wink
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« Last Edit: 01/14/13 at 03:26:36 by Rizlaw »  

System 1: Computer/Linux OS > Audiophileo 2 > W4S DAC-2 > Woo WA-2 / CSP3 > Taboo III > Omega 3E / LCD-2.1/ Beyer DT-990/DT-1350
System 2: Yamaha PX-2 (Shure Ultra) / Oppo DV983H > Classe CAP2100 > Thiel 7.2
System 3: Fisher:R200/X202B > Magnapan MMG
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Rizlaw
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Posts: 90
Re: Safe rectifier roundup (Decware input pending)
Reply #26 - 01/14/13 at 03:33:33
 
Orangecrush,

I know this isn't a definitive answer to your Torii cap inquiry, but Steve did state that:

Quote:
Re: Safe rectifier roundup (Decware input pending)
Reply #1 - 07/05/12 at 18:38:32  
Decware amps typically use between 33 ~ 47uf caps as the first section of the power supply filter after the rectifier tube.
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System 1: Computer/Linux OS > Audiophileo 2 > W4S DAC-2 > Woo WA-2 / CSP3 > Taboo III > Omega 3E / LCD-2.1/ Beyer DT-990/DT-1350
System 2: Yamaha PX-2 (Shure Ultra) / Oppo DV983H > Classe CAP2100 > Thiel 7.2
System 3: Fisher:R200/X202B > Magnapan MMG
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Lord Soth
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Re: Safe rectifier roundup (Decware input pending)
Reply #27 - 01/14/13 at 05:59:36
 
Hi Rizlaw,

Yes, I'm positive that you can safely use any NOS 5Y3, 5R4, 5U4, GZ34 rectifiers in Decware amps. Within each of the major families, there will be a slight variation in uF, e.g. 5U4G vs 5U4GB. This is perfectly fine.

The WE 274b and GEC U52 are really out of the "safe" range wrt uF.

The Brimar 5R4GY retails for around US$100 whereas the Philips 5R4GYS costs less than half of that. From my point of view, they are both Military grade tubes which should be able to last at least 10 years, so the cost is reasonable.
New vacuum tubes don't last as long, hence my personal adversion to forking out 200$++ for the mesh plates.

Now it's me who's doing the yammering. Wink



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Rivieraranch
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Re: Safe rectifier roundup (Decware input pending)
Reply #28 - 01/15/13 at 01:25:01
 
You boys listen to Lord South.
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DECWARE CSP2+, TABOO MK III; SE84CKC; HR1; TRAPEZIUM DESKTOP SPEAKERS; TECHNICS SL1200MK5 turntable; Ah! Njoe Tjoeb CD player; MARANTZ 2226B, 2216B receivers; SENNHEISER HD-580 headphones
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Lord Soth
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Re: Safe rectifier roundup (Decware input pending)
Reply #29 - 01/15/13 at 01:56:03
 
And I listen to Mr. Steve D.

;)
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