Bendix 5992/6V6

[teleblueman]

I know tone is in the "ear" of the beholder, but holy cow! $200.00 apiece on average?? Has anyone here ever verified these are so much better than any other NOS power tube out there? Or, is it just their scarcity that drives the price?? Vintage tube collectors with disposable income??

 

[theprofessor]

I'd like to know, too! They'd better be life-changing at that price, right? There may be some folks here who have tried them. Perhaps @Opaltone or @slider313 or @DaveKS . But if no one shows up on this thread with information, you might search at The Gear Page. Those guys hang out over there, too, and there are many others. It seems to me that a lot of the tube aficionados are over at TGP.

 

[Ringo]

You can buy a couple sets of nice NOS USA made 6V6s for that, I can't imagine that they would be that much better sounding.

 

[Bendyha]

I picked this one up very recently for about $15 on E-Fray, as noone else seemed to spot what it realy was. I haven't tested it yet though, looks like it will end up in a single-ended amp. There is no markings or references to Bendix on it, it has been rebranded RSD, which was the East-Germany central supplier of Army electronics....hows that for down-grading for you ! Now that I know they exist, I will keep an eye out for more. Makes me wounder how many were in the shipment, and the date..end of 1984.
I love the drawing on the Bendix Data-sheet.

 

[theprofessor]

I picked this one up very recently for about $15 on E-Fray, as noone else seemed to spot what it realy was. I haven't tested it yet though, looks like it will end up in a single-ended amp. There is no markings or references to Bendix on it, it has been rebranded RSD, which was the East-Germany central supplier of Army electronics....hows that for down-grading for you ! Now that I know they exist, I will keep an eye out for more. Makes me wounder how many were in the shipment, and the date..end of 1984.
I love the drawing on the Bendix Data-sheet.

Very nice find, Bendyha! Let us know what the test results are and how it sounds. Like you, I love that drawing!

As I said before, I've not heard one of these. @Opaltone once sent me some notes in which he listed the Bendix 5992: "Bendix 5992 – Clear, fluid, refined, a bit more “tame” than other 6V6 types. Reported to sound better when cold-biased (more raw and bright; warmer-biased makes them darken and smooth out)" He notes on TGP in 2015: "Well, not everybody agrees on what constitutes the "best." I find 5992 to be too smooth and tame for my taste, but they do have a certain clarity to them. I much prefer less costly Ken-Rad 6V6GT, which bring more rich harmonic content to the fore, with even greater clarity." (https://www.thegearpage.net/board/i...65-fender-deluxe.1549737/page-2#post-19664229)

 

[theprofessor]

Also, OP: someone asked a similar question on TGP in 2014: https://www.thegearpage.net/board/i...thoughts-on-this-tube-in-guitar-amps.1514796/

 

[DaveKS]

From Brent Jesse's web site.

5992This is a military/industrial version of the 6V6GT, is probably the best sounding 6V6 tube you will ever get your hands on, and is rather rare. I have only seen versions made by Bendix, but GE lists it in their Characteristics book so they must have made some as well, or relabeled the Bendix military surplus tubes. The US Air Force was supplied these as spares from the Sperry Gyroscope Co, and they have the 5992 number taken off, and the Sperry part number on the base. These are real Bendix tubes, as Bendix Red Bank was the ONLY manufacturer of this incredible tube. These have rugged brown micanol bases, heavy glass, a short boxy black plate structure, three mica spacers and dual top mounted D getters. The brown bases can vary in color from beige down to rich mahogany and sometimes have varying shading on the same base. This is probably the ultimate holy grail tube to have in the 6V6 world, but their scarcity today keeps them in a fairly obscure corner of that world. Clients tell me these blow away even the NOS RCA blackplate greyglass tubes! They are indeed awesome, and will never be made again. All of these tubes glow blue inside and have slightly longer warm-up time than the 6V6GT, this is normal. They are plug and play compatible with any 6V6 type tube, with normal bias checks and/or adjustments as you would do whenever replacing any power tubes. Also, all of these tubes have various colors to the base, ranging from light tan to dark brown, and often mottled. This is also normal! These are worth seeking out as they are built like a tank and may outlast both you and your amp!

 

[Old Tele man]

Back in the hey-day (of vacuum tubes), Bendix/Red Bank tubes had an extremely good "reliability" reputation, ie: they worked exactly as specified and (usually) outlasted their guaranteed MIL-SPEC "operational" lifetimes.

More info: http://www.timeelect.com/vacuum-tubes-tc-myths-and-snake-oil-marketing.html

 

[anonymous]

Why are the Bendix "Red Bank" tubes so highly coveted? Two reasons.

One is that they sound great. In Vacuum Tube Valley (VTV) #10, a highly regarded vacuum tube reference, they did a big high-fi shoot-out with 6V6 tubes and the Bendix 5992 clobbered the rest. This makes it very valuable for the audiophile crowd but, VTV also knows guitar amps have different needs and they also did a big guitar amp shoot-out in the same issue and greatly preferred the RCA 7408 over the Bendix 5992. The ability to distort is not anything an audiophile would want and why so highly regarded, such as on Brent Jessee's audiophile tube page.

Two is that they were built in the military, such as for rockets, such as ICBM's (see VTV #5). They are near indestructible, so audiophiles can get great sound and a very long tube life. Price and desirability go up even more.

With that said, I've tried 5992's in tube amps and they sound really good. A much better deal in Bendix tubes for guitar amps, by far, is using the 6106 in place of a 5Y3 rectifier. The Bendix 6106 is near indestructible, will last much longer than the amp, and sound great to boot.

 

[anonymous]

Also, with the high price fakes are everywhere. Brent Jessee is a trusted source, as is Upscale Audio.

Bendix tubes were only made in the US and had a distinctively mottled base made of micanol (looks somewhat like mica, though the color can vary a bit).

They also have a blue glow when used and I have only seen that in real Bendix 5992 tubes.

 

[mherrcat]

I bought a Bendix 5Y3GT about a year or so ago. Long warm up time and it starts out with kind of a bluegreen filament glow. (I thought something was wrong with it at first!) Really cool. They are supposed to last forever. Built like a tank.

 

[anonymous]

Glad you mentioned that. I've been using Bendix 6106 in place of a 5Y3 for so long I've forgotten they take a full minute to warm up. Some may think they're broken when they're just getting started.

 

[charlie chitlin]

I picked this one up very recently for about $15 on E-Fray, as noone else seemed to spot what it realy was. I haven't tested it yet though, looks like it will end up in a single-ended amp. There is no markings or references to Bendix on it, it has been rebranded RSD, which was the East-Germany central supplier of Army electronics....hows that for down-grading for you ! Now that I know they exist, I will keep an eye out for more. Makes me wounder how many were in the shipment, and the date..end of 1984.
I love the drawing on the Bendix Data-sheet.
View attachment 430045View attachment 430047

Someone please explain how this is something other than a 6v6gt when it has that printed on it.

 

[slider313]

Someone please explain how this is something other than a 6v6gt when it has that printed on it.

Really? Did you examine the drawing above? Have you ever seen a 6V6GT built like that?

 

[anonymous]

Someone please explain how this is something other than a 6v6gt when it has that printed on it.

Fair question. The Bendix 5992 is similarly rated to a 6V6 electrically, hence the interchangeability, but overbuilt in the extreme to withstand much harsher mechanical & electrical operating conditions and stresses. Something like a model rocket to a Saturn V (they may have been used in Saturn V’s).

 

[teleblueman]

I picked this one up very recently for about $15 on E-Fray, as noone else seemed to spot what it realy was. I haven't tested it yet though, looks like it will end up in a single-ended amp. There is no markings or references to Bendix on it, it has been rebranded RSD, which was the East-Germany central supplier of Army electronics....hows that for down-grading for you ! Now that I know they exist, I will keep an eye out for more. Makes me wounder how many were in the shipment, and the date..end of 1984.
I love the drawing on the Bendix Data-sheet.
View attachment 430045View attachment 430047

I have seen single Bendix tubes on e-Bay periodically for relatively cheap. Would it be O.K. to try a couple in My deluxe, or do they need to me "Matched" or have specific date codes?

 

[anonymous]

I have seen single Bendix tubes on e-Bay periodically for relatively cheap. Would it be O.K. to try a couple in My deluxe, or do they need to me "Matched" or have specific date codes?

Bendix 5992 can certainly be used in place of 6V6, but needing matched pairs or not depends upon the construction of your amp. Electrically matched tubes would always be preferred, needed or not.

Be careful. There are a huge number of fakes and near-dead, if not completely dead, tubes being sold as NOS. In that case, matching dates won't help. I've never seen a Bendix 5992 later than from the 1960's (I understand the plant closed in the 1970's), so any later dated tubes are highly suspect. If you really want to try I'd recommend getting from a well-respected dealer (assuming they have any, they're pretty rare).

 

[Bendyha]

Be careful. There are a huge number of fakes

I'm not aware of any fakes that look to be constructed the same way as the originals, which are quite unmistakably individual in the way they are made. Have you? If so I would like to see a photo of one. Being so excesivly well constructed, one would think any firm capable of copying that construction would in there own right be building a very good tube.

 

[anonymous]

Bendyha, you are absolutely correct. There is no other 6V6 tube made like a Bendix 5992 and fakes aren't constructed anything like it (just like normal 12AX7's being relabeled and passed off as ECC803S tubes, though only the ECC803S has a frame grid construction to eliminate microphonics). Checking the photos carefully can help identify the real thing.

But I have gotten a few, real, Bendix 5992 tubes off the site that can't be mentioned and instead of NOS they were dead or near dead. Hence the warning.

 

[Mountain Jammer]

Bendyha, you are absolutely correct. There is no other 6V6 tube made like a Bendix 5992 and fakes aren't constructed anything like it (just like normal 12AX7's being relabeled and passed off as ECC803S tubes, though only the ECC803S has a frame grid construction to eliminate microphonics). Checking the photos carefully can help identify the real thing.

But I have gotten a few, real, Bendix 5992 tubes off the site that can't be mentioned and instead of NOS they were dead or near dead. Hence the warning.

I paid top dollar for a "NOS" one that buzzes horribly. My tech says it's on its last legs. Bummed.