[SHIMACM]

Is there a difference in sound from graphite slotted plates to solid graphite plates?

 

[bcowen]

Oh my friend, don't be sorry.

Incidentally, I bought this pair advertised on ebay.

https://www.ebay.com/itm/MATCH-PAIR-BENDIX-CEA-JAN-6080WB-5998-6AS7-421A-GRAPHITE-PLATE-TUBES-7/124539785804?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

It cost me $ 135 + $ 39 in shipping.



Do you think it was a business?

There is a tube that the key was fixed, but it is so difficult to find those pipes that I decided to take a chance.

A broken guide pin is not a show stopper as long as the glass is intact and is not all that uncommon. Will probably become even more common as these tubes continue to age and the base material gets even more brittle with time. I've broken a couple guide pins myself being careless removing the tube, but since I had the pin I just glued it back on. Easy enough to see the orientation based on the marks on the tube base where it broke off. Sounds like they already repaired the one you're getting so no worries, but it never hurts to have a couple of these in the stash bin just in case:

https://www.ebay.com/itm/2-8-PIN-PO...159498?hash=item4da87badca:g:BbwAAOSw3Y9eZLur

 

[raindownthunda]

Is there a difference in sound from graphite slotted plates to solid graphite plates?

I've spent a good amount of time with both versions and have not been able to perceive any sonic difference. If anything, the solid graphite plates take a bit longer to warm up to sound their best, but the slotted versions take a good amount of time as well... The solid versions are typically the best value since people want to pay more for the rarity, especially when the pretty red Bendix logo is fully intact

 

[SHIMACM]

A broken guide pin is not a show stopper as long as the glass is intact and is not all that uncommon. Will probably become even more common as these tubes continue to age and the base material gets even more brittle with time. I've broken a couple guide pins myself being careless removing the tube, but since I had the pin I just glued it back on. Easy enough to see the orientation based on the marks on the tube base where it broke off. Sounds like they already repaired the one you're getting so no worries, but it never hurts to have a couple of these in the stash bin just in case:

https://www.ebay.com/itm/2-8-PIN-PO...159498?hash=item4da87badca:g:BbwAAOSw3Y9eZLur

Thank you for the link.

I was a little worried, because in the upper mica of the second tube it seems to be cracked.

But as I knew if I didn't buy another one I would buy it, I decided to take a chance.

Does anyone know what is the useful life of Bandix?

I heard that it is a tube that has a longer life than the other 6080. Is it true?

 

[therremans]

Thank you for the link.

I was a little worried, because in the upper mica of the second tube it seems to be cracked.

But as I knew if I didn't buy another one I would buy it, I decided to take a chance.

Does anyone know what is the useful life of Bandix?

I heard that it is a tube that has a longer life than the other 6080. Is it true?

I also noticed that and was going to mention it to you, but wasn’t sure if it was just the photo. Inspect it and if it’s true, you have a grounds to get a partial refund or whatever the seller decides. I owned one with a badly cracked mica, it was in two pieces. It worked but I returned it

 

[attmci]

Is there a difference in sound from graphite slotted plates to solid graphite plates?

The Jedi will tell you the difference. At least, I hope so.

I hate to compare different tubes.

 

[Paladin79]

Measure the voltages in the tube sockets on both amps, and let us know.

Glowing too bright sometimes is not a good thing, tube could be overloaded and has reduced lifespan.

I run 5998's in the Incubus I designed as a standard, the tubes do well in the amp and I use them more than any other. I also studied tube theory in college and certainly understand tube parameters, tube brightness was never discussed. Oh and I have quite a few of those amps in the hands of people who own 5998's. Tubes can fail and lose vacuum with age, it is part of dealing with them. They have a finite existence. Oh and I donated four of the amps for 6sn7 comparisons and the Tung Sol 5998 has been the power tube in those for nearly two years.

As Mr. Cowen pointed out it is less common on many US tubes but there can be poor solder within tube pins. We are often dealing with tubes that are 50 years old, and older. I just got a pair of power tubes of WW 2 vintage, NOS, original boxes. One was good, the other did not maintain vacuum.

 

[PsilocybinCube]

I run 5998's in the Incubus I designed as a standard, the tubes do well in the amp and I use them more than any other. I also studied tube theory in college and certainly understand tube parameters, tube brightness was never discussed. Oh and I have quite a few of those amps in the hands of people who own 5998's. Tubes can fail and lose vacuum with age, it is part of dealing with them. They have a finite existence. Oh and I donated four of the amps for 6sn7 comparisons and the Tung Sol 5998 has been the power tube in those for nearly two years.

As Mr. Cowen pointed out it is less common on many US tubes but there can be poor solder within tube pins. We are often dealing with tubes that are 50 years old, and older. I just got a pair of power tubes of WW 2 vintage, NOS, original boxes. One was good, the other did not maintain vacuum.

I suspect my issue was a tube issue with the BHC. I replaced the Chatham 5998 with a Chatham 6as7g and also went back to a melz 6sn7 and everything worked fine. I also tried a 12bh7 and 12au7 and those worked fine, too.

I've had a TS 5998 stuck in the Incubus for the better part of 2 months and no issues. I pretty much only roll drivers in that amp now.

Upon closer inspection, the 5998 that had had issues on the BHC does have some broken glass in it, though I know that's not always a deal breaker. I may try to resolder for grind and giggles and see what happens!

And @cddc I will check voltages and post them in the BHC thread in case that's an issue.

 

[bcowen]

I suspect my issue was a tube issue with the BHC. I replaced the Chatham 5998 with a Chatham 6as7g and also went back to a melz 6sn7 and everything worked fine. I also tried a 12bh7 and 12au7 and those worked fine, too.

I've had a TS 5998 stuck in the Incubus for the better part of 2 months and no issues. I pretty much only roll drivers in that amp now.

Upon closer inspection, the 5998 that had had issues on the BHC does have some broken glass in it, though I know that's not always a deal breaker. I may try to resolder for grind and giggles and see what happens!

And @cddc I will check voltages and post them in the BHC thread in case that's an issue.

Not to be unduly risk-averse here, but if there is visible broken glass you could have elements touching each other and/or have shifted close enough together for current to flow between them where it shouldn't (inter-element leakage). A high current leakage path or a dead short could put the amp at risk depending on how tolerant it is of dealing with such faults. My recommendation would be to get that tube tested (in a tube tester) before risking any further trials in either amp. Just FWIW.

 

[Paladin79]

Not to be unduly risk-averse here, but if there is visible broken glass you could have elements touching each other and/or have shifted close enough together for current to flow between them where it shouldn't (inter-element leakage). A high current leakage path or a dead short could put the amp at risk depending on how tolerant it is of dealing with such faults. My recommendation would be to get that tube tested (in a tube tester) before risking any further trials in either amp. Just FWIW.

I am rebuilding my tube tester or I would be glad to help. I started working on mine but other projects got in the way.

 

[bcowen]

As Mr. Cowen pointed out it is less common on many US tubes but there can be poor solder within tube pins. We are often dealing with tubes that are 50 years old, and older. I just got a pair of power tubes of WW 2 vintage, NOS, original boxes. One was good, the other did not maintain vacuum.

I'm up to 6 Tung Sols (and derivatives like Chatham) now that have had pin solder issues. I have limited experience with Melz tubes, but usually suspect a Foton before I even plug it in. I'm beginning to get that same immediate suspicion with Tung Sols. Maybe just (bad) luck of the draw, but beyond the Fotons and TS's I've had only one other tube to date with pin solder issues, and that was a '52 Sylvania Bad Boy.

 

[Paladin79]

I'm up to 6 Tung Sols (and derivatives like Chatham) now that have had pin solder issues. I have limited experience with Melz tubes, but usually suspect a Foton before I even plug it in. I'm beginning to get that same immediate suspicion with Tung Sols. Maybe just (bad) luck of the draw, but beyond the Fotons and TS's I've had only one other tube to date with pin solder issues, and that was a '52 Sylvania Bad Boy.

I do have one 5998 that gives me issues in the Incubus, I will have to re-solder the pins later on. Right now I am trying to finish up a lacewood Incubus amp and yes I will use a 5998 in it, with a rare Melz solid plate 1578 for my personal testing. This is a loaner amp so it will most likely go out with RCA 6as7G or Flying C Svetlana and maybe a 50's Foton.

 

[gibosi]

I'm up to 6 Tung Sols (and derivatives like Chatham) now that have had pin solder issues. I have limited experience with Melz tubes, but usually suspect a Foton before I even plug it in. I'm beginning to get that same immediate suspicion with Tung Sols. Maybe just (bad) luck of the draw, but beyond the Fotons and TS's I've had only one other tube to date with pin solder issues, and that was a '52 Sylvania Bad Boy.

I have a number of BG/RP Tung-Sols that have that "shhhh" sound I associate with a poor cathode connection. I suspect mine may need pins re-soldered...

 

[Paladin79]

I have a number of BG/RP Tung-Sols that have that "shhhh" sound I associate with a poor cathode connection. I suspect mine may need pins re-soldered...

I have been known to help out on occasion, are you talking 6sn7 or 6080 equivalents? Without my tube tester working I have to be careful what I try to do right now. Maybe @bcowen will give me a tube tester out of pure kindness.

 

[gibosi]

I have been known to help out on occasion, are you talking 6sn7 or 6080 equivalents? Without my tube tester working I have to be careful what I try to do right now. Maybe @bcowen will give me a tube tester out pure kindness.

These are Tung Sol BG/RP 6SN7 types, two are 6SN7 and one is 12SN7. (I can run 6SN7, 12SN7 and 25SN7 using a selector switch).

And thank you.