Tube Rolling w/Crack

[attmci]

Not a real bendix 6080. It has been listed on eBay for long long time.
Bendix is a rare tube.

Read my previous post and get some hints.

[JamieMcC]

i am looking at this tube on ebay:
http://www.ebay.com/itm/Good-TungSol-6080WB-Graphite-Anode-Twin-Triode-Vacuum-Tube-5-/151673051637?hash=item23506b19f5:g:ZhoAAOSwpDdVSuGU

basically after reading the review on this site:
http://the-key.enix.org/~krystal/review-tube-bottlehead.html

i decided to give the Bendix 6080wb Slotted Graphite Cross Column a try. (since i am really going for the large sound stage). but the original review photos are no longer available. so i don't know if the tube in the auction above is indeed the "slotted graphite Cross colum" or just a solid graphite.

can someone confirm?

thanks

That is a solid Graphite plate tube not the slotted ones I have come across a number of different Graphite shaped solid column tubes  cross, round, semi oval. They are normally found branded Tungsol, Chatham or Bendix irrespective of the branding to my knowledge they were all manufactured by Bendix.

They are nice sounding tubes, I have had a couple of NOS ones in the past that have had a tendancy to give loud pops through the headphones during their warming up phase this effect dissapered after a numer of hours use but was a bit scary.

The domino plate 5998 is definitly the better tube and I expect you will be able to pick up one for a similare price you just need to be paitent they do turn up.  You would also be able to pick up a GEC or Mullard 6080 for less which are both very good options.


You might like to try the E80CC as a driver instead of a 12au7 a cheap Tungsram with the holes in the side will cost a lot less than a premium 12au7 I liked them immensly and prefered them to some highly rated and expensive 12au7 options. The E80cc are also long life tubes 10,000 plus the 12au7 life span is more often given seen around 2500hrs.  They are a straight swap for the 12au7 and work well there is even a really inexpensive (couple of dollars) resister switch mod detailed on the forum which allows fine tuning the Speedball voltages for running the E80cc in the sweet spot.

Link for details and impressions of the mod

http://bottlehead.com/smf/index.php?topic=5989.0

[howzz1854]

thanks guys. sorry you'll have to be patient with me. as i just started rolling tubes last week. 

so is THIS what i should be looking for if i wanted a slotted graphite Bendix 6080wb?

and i'll be sure to keep my eye out for a TS 5998 Domino plate in the future.

[attmci]

thanks guys. sorry you'll have to be patient with me. as i just started rolling tubes last week. 

so is THIS what i should be looking for if i wanted a slotted graphite Bendix 6080wb?

and i'll be sure to keep my eye out for a TS 5998 Domino plate in the future.

Yes.

[howzz1854]

Jamie did you say the E80CC is a direct replacement for the factory driver tube? if so, i think i can get my hands on a gently used on through the forums. and how would you describe the sound of the E80CC compare to a stock 5963 which came with my stock crack. as i understand the 5963 is a computer tube version of the 12au7. thanks!

EDIT: and thanks for the response attmci

[JamieMcC]

Jamie did you say the E80CC is a direct replacement for the factory driver tube? if so, i think i can get my hands on a gently used on through the forums. and how would you describe the sound of the E80CC compare to a stock 5963 which came with my stock crack. as i understand the 5963 is a computer tube version of the 12au7. thanks!

EDIT: and thanks for the response attmci

Yes PB has confirmed its ok to use.

 I would say it a fast open and clear sounding tube with better resolution than any 12au7 I have tried (and I have rolled a lot) it also has superb sound staging. Well worth a try if you can get a used one at a decent price the only 12au7 I have that came close was the Mullard CV4003 box plate (British 12au7 equivalent) which is highly regarded the E80cc is half the price just as good if not better and will last four times as long!

http://www.ebay.co.uk/itm/Mullard-12AU7-ECC82-CV4003-tube-/121935877158?hash=item1c63f1d426:g:cZoAAOSwxp9W9afD

http://www.tubemaze.info/tungsram-e80cc/

[howzz1854]

Thanks Jamie!

[howzz1854]

Lee,

i got some backup replacement JAN Sylvania 6080WB arrived in the mail today. and sure enough they do look identical down to the rods and details.

thanks so much!. now at least i have a backup and baseline to work with.

i also bought some 2nd hand TS 6080WB from a forum member on HeadFi. it was a package deal that includes a Phillips E80CC, Amerpex ECC82, and a Mullard ECC82. i have no idea what the latter two were, but since it's a good package deal i just told the guy i would pick them all up. the TS 6080WB looks to be a solid graphite, but oh well, be nice to experiment.

 

[Rhok]

the only 12au7 I have that came close was the Mullard CV4003 box plate (British 12au7 equivalent) which is highly regarded the E80cc is half the price just as good if not better and will last four times as long!

Although I have not tried a E80CC (might have to soon) I have tried several Mullard variants, and also found the CV4003 box plate to be excellent, however.. I recently acquired a Brimar CV4003 and I found it notably, maybe even substantially better than the Mullard. It's paired with a TS 5998.

[howzz1854]

guys, is there a spec on how much voltage the power tube socket can support? is it 3v? i understand that a single 6080 or 6AS7 is 2.5v. i am just wondering how high the crack can support.

[Paul Joppa]

I will assume you are asking about current in amperes, not voltage.

The sockets per se are not rated for current capability. It's the power transformer which has limits, due to heating. Heating increases as the square of the current, so there is not much wiggle room.

The PT-3 power transformer can supply 3.5 amps maximum. From this you must subtract the current of the driver tube heater - 12AU7 is only 0.3 amps, but a 5687 for example is 0.9 amps. The remainder can be used to heat the power tube.

[howzz1854]

yeah, you're right. silly me. i meant Amp. lol.

this is good info. i've been reading up a lot about using different tubes, or two lower power tubes through a converter. so i was just wondering how much power the crack can support. sounds like there's not much room above the stock configuration.

in your opinion, and i won't hold it against you or anyone. but what's the worse case scenario when someone overloads the transformer. in an exaggerated example, say if someone were to put a hypothetically 5 amp powertube into the socket, and knowing that the transformer in this case only supports up to 3.5amps. what's the worse case scenario? i heard that the transformer can catch fire. but will it take the headphone with it?

basically i've been reading up a lot on using two lower amperage tubes in place of one power tube, but there's a chance that the total amperage in place of the power socket will exceed the stock 6080 slightly, which i believe to be 2.5 amps.

like all things, i always try to read up and research as much as possible before doing anything. information is friend.

btw, and is that 3.5 amp based on a 12 volt draw?

[Paul Joppa]

When a transformer overheats, the usual failure is that of the insulating materials - internal short circuits of various sorts. That includes shorts to the core and chassis, making it a major safety risk. Don't do it!

[Paul Birkeland]

btw, and is that 3.5 amp based on a 12 volt draw?

The winding is a 6.3V winding which will supply 3.5A. 

There's a little bit of current headroom on that winding, but since you haven't been specific about what you're up to, we can't weigh in to say whether or not you will damage your transformer.

-PB

[howzz1854]

Thanks guys.

basically through a friend's recommendation, i started looking into the possibility of using two tubes that'll possibly result in 3 amps total at the power socket. so sounds like it might still be under the ceiling of 3.5 amps total if i keep the driver slot with 12AU7 or E80CC, which both are 0.3 amps.

i just don't want to damage my brand spanking new HD800 S. that's my biggest concern. will over loading the transformer result in damaging the headphone? not that i am looking to kill my amp or being suicidal with the amp. but in my case it's easier to replace an amp than another HD800 S.

thanks!