[bcowen]

Tried reheating the pins - tube did not respond to treatment. Tried whacking it but no response to shock treatment. Another pretty tube decoration...
The only thing I can see is a thickening on one spot of one of the filament heating rods.

Bummer. Such nice tubes...one of my favorites.

 

[bcowen]

Tried reheating the pins - tube did not respond to treatment. Tried whacking it but no response to shock treatment. Another pretty tube decoration...
The only thing I can see is a thickening on one spot of one of the filament heating rods.

I've never bought from this vendor, and it may be one of those "too good to be true" situations, but....you never know. Might be worth an email to check it out.

https://vacuumtubes.net/prices.htm

 

[mordy]

I've never bought from this vendor, and it may be one of those "too good to be true" situations, but....you never know. Might be worth an email to check it out.

https://vacuumtubes.net/prices.htm

Thanks - you are probably right about your premonition. Look at post #1085:

https://www.head-fi.org/threads/for-6as7g-tube-rollers-here.410326/page-73

I really don't like vacuumtubes.net at all. They push off crap as "tested and certified" more often than I can to experience ever again. They'll never get another dollar from me.

 

[leftside]

Thanks - you are probably right about your premonition. Look at post #1085:

https://www.head-fi.org/threads/for-6as7g-tube-rollers-here.410326/page-73

I really don't like vacuumtubes.net at all. They push off crap as "tested and certified" more often than I can to experience ever again. They'll never get another dollar from me.

Also unlikely to be in stock. Often a bait and switch, but doesn't hurt to ask I guess.

 

[Xcalibur255]

It could be a heater to cathode short. This seems to be the most common way for these voltage regulator tubes to go, and is the culprit behind the string of blown up headphones from 5998 tubes too. Sometimes the tube is still functional but you'll get this pop every time it comes on bias which is of course no good. That was the case with mine. After it stuffed the left channel driver through its grill slats on my K701s I plugged in a different pair of headphones to find the amp still made music in both channels.

If your headphones are ok then I think you got pretty lucky.

 

[mordy]

It could be a heater to cathode short. This seems to be the most common way for these voltage regulator tubes to go, and is the culprit behind the string of blown up headphones from 5998 tubes too. Sometimes the tube is still functional but you'll get this pop every time it comes on bias which is of course no good. That was the case with mine. After it stuffed the left channel driver through its grill slats on my K701s I plugged in a different pair of headphones to find the amp still made music in both channels.

If your headphones are ok then I think you got pretty lucky.

I was lucky but I was listening via speakers. The pop was not super loud which may have been a mitigating factor as well.
I once had a tube headphone amp used as a preamp and plugged into the equalizer circuit of a receiver and blew out a circuit board in the receiver - twice. Until I figured out that the tube amp manufcturer warned against such a connection...
And I blew a driver in a Beyerdynamic T1 from a faulty TS 12SN7 BGRP.
I guess that all avid tube rollers experience these things sooner or later....

" I am drawn to tube amplifiers because of the inconvenience, unpredictability and expense."

 

[mordy]

For the artistic steampunk people out there a collection of 18 non-usable industrial sculpture tubes:
https://www.ebay.com/itm/284280388973?hash=item42306e7d6d:g:DVUAAOSwNxteq3Fo

Not sure if the rolls of toilet paper are included....but I agree with industrial sculpture.

 

[Xcalibur255]

There are some extremely desirable DHTs in that photo. Such a pity they're display only pieces now, though I certainly hope the seller is sure of that. Some of these tubes will test low and still make beautiful music in an amp for years in that condition.

Quite a few of these look like 45s or one of its cousins with similar size and shape plate. Always wanted a pair of those Eveready Raytheons.........

I get the feeling the toilet paper was to place the tubes in which didn't pan out because they probably sunk further into the roll than desired. As for why they are still in the photos in spite of that....... is certainly a choice.

 

[mordy]

Does anybody have any experience with a 9pin tube said to be similar to the C3g - the D3a:

 

[Xcalibur255]

It's popular in the DIYaudio community and considered an excellent driver for some DHTs such as the 300B. No personal experience to speak of though.

 

[dminches]

A lot of those DHTs look like RCA/Cunningham 112A, 01As, etc. Those are really nice tubes and are very cheap. I use them in my DAC.

 

[hodgjy]

I really don't like vacuumtubes.net at all. They push off crap as "tested and certified" more often than I can to experience ever again. They'll never get another dollar from me.

I can confirm. They sold me some real garbage in the past and gave me terrible grief when I tried returning the questionable tubes. They'll never get another dollar from me. I can also confirm that their inventory list is not accurate and they get super upset when you ask them to actually confirm their stock before ordering.

 

[Xcalibur255]

IMO when it comes to tube sellers you have to consider how their business is oriented. vacuumtubes.net is and wants to be a wholeseller. They don't really want to cater to audiophiles and their specific needs/concerns, although clearly they dabble in it a bit because there's money to be made. Then you have places like Brent Jesse who will take the time to honor specific requests and do detailed testing including curve tracing to make sure the tubes are what you expect. The difference is reflected in the pricing. The wholesellers have lower prices because aren't adding service on top of things, they just pick a box and ship it out the door. They're naturally annoyed when asked to do extra things because that's not really how they have their business setup to operate. Spending time on special requests means they sometimes don't make money on that sale at the wholesale prices they use.

I'm not defending anybody here at all, just musing a bit on why we tend to see two clearly different pricing structures in the world of tube resale.

Then there's eBay which kind of exists in both worlds at the same time......

 

[mordy]

IMO when it comes to tube sellers you have to consider how their business is oriented. vacuumtubes.net is and wants to be a wholeseller. They don't really want to cater to audiophiles and their specific needs/concerns, although clearly they dabble in it a bit because there's money to be made. Then you have places like Brent Jesse who will take the time to honor specific requests and do detailed testing including curve tracing to make sure the tubes are what you expect. The difference is reflected in the pricing. The wholesellers have lower prices because aren't adding service on top of things, they just pick a box and ship it out the door. They're naturally annoyed when asked to do extra things because that's not really how they have their business setup to operate. Spending time on special requests means they sometimes don't make money on that sale at the wholesale prices they use.

I'm not defending anybody here at all, just musing a bit on why we tend to see two clearly different pricing structures in the world of tube resale.

Then there's eBay which kind of exists in both worlds at the same time......

I have noticed that wholesalers that sell on eBay have higher prices than buying from them directly (more than the eBay fees).
In addition to wholesalers and tube sellers that cater to individuals you have my favorite sellers: regular people who for some reason have tubes to sell. Sometimes somebody is selling off their grandfather's radio repair shop or a box of tubes from a garage sale etc etc.
This is where you can find the real bargains - a pair of BGRP TS 6SN7 for $14.99, or a WE 421A for $9.99...
I actually saw these but was out too late.
If you arm yourself with knowledge about rebrand names or tube construction details you can pick up bargains by looking for rebranded tubes or tubes without a brand listed on them.

 

[Monsterzero]

WE 421A for $9.99