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AUDIO FORUMS >> Replacement Tubes >> Decware branded 5U4G
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Message started by ChrisC on 11/11/22 at 19:18:54

Title: Decware branded 5U4G
Post by ChrisC on 11/11/22 at 19:18:54

Anyone know where these are sourced? I assume Steve and the Elves have not (yet) expanded into in-house tube production...

ChrisC

[smiley=tunes51.gif]

Title: Re: Decware branded 5U4G
Post by Carlsbad on 11/13/22 at 20:13:27

I've been waiting for this thread. Nice looking tube and attractively priced compared to Sophia or EML.

If I still had Rachael I'll have already ordered one to test.

Jerry

Title: Re: Decware branded 5U4G
Post by Showme on 11/15/22 at 01:18:15

It would be nice if Steve would step up and give us a little background on this new item.

Title: Re: Decware branded 5U4G
Post by CAJames on 11/15/22 at 03:19:10

Just FWIW here is a post Steve made a while back regarding current production rectifiers. Emphasis added by me.

Quote:

Posted by: Steve Deckert Posted on: 06/23/20 at 06:08:32

Some great feedback regarding quality tubes...

...here is some of what I know that you should know:

Current production vs. New Old Stock. In my experience the only consistently solid tubes on the market today come from Russia. Brands like Mullard, Tungsol, Electro Harmonix, Sovtek, Svetlana. The rights to these brand names have been acquired over the years by New Sensor Corp in the USA, who is predominately a tube supplier for the music industry / guitar amps. They own or partially own factories in Russia.

Decware purchases it's Russian tubes direct from Russia in bulk with the exception of the larger output tubes (EL34/KT66/KT88) which are current production branded tubes imported into the USA. All of the the Russian tubes that we purchase direct from Russia are N.O.S. Russian Military Grade tubes. Many of them have Gold grids, thick glass, high G ratings for missile use, and longer life, in some cases 10,000 hours. These are ultra-hi-end tubes in disguise and have always been. To hear how good these tubes are you have to install an American New Old Stock rectifier tube.

My experience with Boutique Chinese brands is mixed. The sound is good, the reliability and or consistency is ridiculous. I have been purchasing samples of these fancy tubes as they come out over the past many years and I have an entire collection of crippled tubes. Even KT88's that cost $1600 a quad drifted out of usable tolerance within days and had to be replaced.

New Old Stock is the real deal. Those who like to push the envelope of what is possible with their amplifier will often go down this path with no regrets. For one thing, the tubes not only sound better, but often last longer, in some cases like with rectifier tubes up to 10 times longer.

Rectifiers are a subject all in their own. Russian rectifiers are acceptable, everything else is a no-go from a reliability standpoint with some rare exceptions that are very pricey. My advise to all Decware amplifier owners is to find yourself a New Old Stock 5U4 or a 5R4 that has never been used and comes in it's original un-molested box. Consider the current production rectifier tube we ship with the amp the best sounding and most attractive option that will last long enough for you to find a real N.O.S. replacement.

Finding N.O.S. tubes is easy, even on eBay there are millions. Since you only need one or two you will have more to choose from than you know what to do with. Finding quantity of these tubes is another story. If Decware could secure reliable inventory of 1000's of N.O.S. rectifiers, it is an investment we would gladly make but in 25 years is has yet to happen. Because we can't find N.O.S. tubes in large quantities, even batches of 100 would be gone in less than 30 days, we feel there is no point in even trying.

For the customer it is easy, just find a N.O.S. 5U4 tube on eBay that is unused, and in it's original box for $40 and it could easily last for 10 years or more and sound better the entire time.

As an amplifier designer, it is possible to create circuits that baby the rectifier tube by limiting inrush current, using smaller capacitors, running higher voltages with a choke and so on. Correctly done, this can make a Chinese rectifier tube last the full rated 500 hours or more. The problem with this is that it changes the sound quality of the amplifier well outside what we find acceptable. So, we have to make a choice, do we design tube amplifiers to baby the crappie rectifier tubes being made today, or do we design amplifiers to use REAL tubes. Of course the answer has to be REAL tubes, because we make real amps.

Title: Re: Decware branded 5U4G
Post by ChrisC on 11/17/22 at 01:07:34

here;s the answer:

https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1668549964

Title: Re: Decware branded 5U4G
Post by fridays on 11/22/22 at 16:35:57

I’m confused one post Steve’s letter, say they aren’t very good, another post says they are great?

Title: Re: Decware branded 5U4G
Post by CAJames on 11/22/22 at 17:05:33

Quote:

Posted by: fridays Posted on: Today at 16:35:57

I’m confused one post Steve’s letter, say they aren’t very good, another post says they are great?

I don't want to speak for Steve, but this how it looks to me. Decware needs to provide current production rectifiers to it's customers. They would prefer to source them from Russia, but that is no longer possible and the only other option is China. So now they are selling an attractively Decware branded 5U4G, but I don't think the message from the post I quoted has changed. The "problem" with Chinese tubes isn't that they sound bad, it is the lifespan is very highly variable. Sometimes you hit the jackpot and get one that last years, other times it is weeks. FWIW my advice is the same as Steve's: Get a NOS USA rectifier as soon as you can. It will probably sound better and almost certainly last longer. There is a very helpful thread further down the forum that discusses how to do that:

https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1605822949

Title: Re: Decware branded 5U4G
Post by Tony on 11/22/22 at 17:07:30

Hey Fridays,

Here is my take. The post by CAJames is from Steve from a while ago, before the current Decware tube was available. In it, Steve suggests finding a known NOS tube for best results.

I think the newer recommendation, just being offered this month, is for the Decware 5U4G tube, which Steve is thumbs up on as it meets his standards.

For me, that would be the difference.