Tube Rolling w/Crack

[Paul Birkeland]

Let it run overnight and see if that resolves the issue.  Arcing can sometimes be gas in the tube, and getting it nice and hot for a long period of time can resolve the issue.

[Doc B.]

The sad reality these days is that a lot of "untested" tubes have been tested. They just failed the test. Caveat emptor.

[Kitchener]

The sad reality these days is that a lot of "untested" tubes have been tested. They just failed the test. Caveat emptor.

But have they been double tested?
-or tripple tested even?
It is the only way to be sure.

[BZ58]

Caveat emptor /ˌkævɛɑːt ˈɛmptɔːr/ is Latin for "Let the buyer beware"

Looked it up. Today I learned.

[InnerTube]

Could anyone help me with a determination if the 6C5G can be used as a direct replacement for the 6080 in the Crack.  Thanks in advance, JS

[Doc B.]

Not even close.

[InnerTube]

Thanks for the quick answer.  It is great to have this resource.

[Paul Birkeland]

Could anyone help me with a determination if the 6C5G can be used as a direct replacement for the 6080 in the Crack.  Thanks in advance, JS

A pair of them would probably work in place of the 12AU7, but it would take a really unusual adapter or a much larger chassis plate.

[rabele]

Loving my Crack! Aptly named too as you've definitely gotten me hooked on the sound and the hobby.  Speedball ordered.  Using HD600s and an Apogee Groove DAC.

Regarding rolling, would it be appropriate to add "M8136" and "VX8136C" to the list of 12au7-equivalent tube types?  I believe these are additional British designations (if not identical to?) "CV4003".  Stumbled across these while researching the codes of a Mullard I bought (full code is 631 R4I3, FWIW).

My kit came with a nice RCA 12au7 and I've also tried a modern Electro-Harmonix (which sounds better than I was expecting for the price and provenance).   Can't say I loved the winged C/SED/Svetlana 6H13C I got as a backup for the JAN Philips 6080WC that came with my kit.  It sounds loose or rough to me, YMMV.

Thanks again for the kit and the community,
rabele

[adeep42]

Have really enjoyed my Crack+Speedball for some time mostly with Tung-Sol 6520 and NOS Mullard 12AU7. After reading so many posts about 6SN7s and adapters, I couldn't help myself. Got the Garage adaptor and picked up a 1951 National Union Blackglass from Brent Jesse. Really enjoying the combo. With my HD650s audio seems "rounded" and musical with plenty of detail and definition. The adaptor seems well made and certainly doesn't distract from the appearance of the Crack.

[dasman66]

Let it run overnight and see if that resolves the issue.  Arcing can sometimes be gas in the tube, and getting it nice and hot for a long period of time can resolve the issue.

Just dropping a note... I let it play music for about 8 hrs a few days ago and the problem seems solved.  Hasn't arc'd at all since then.   I have it paired with either a Mullard CV4003 or CBS 5814A (until I figure out which I like better).

Thanks for the suggestion!

[BZ58]

I recently received this tube in the mail. It’s a Chatham 5998, and "650" with the letter J is printed on the base. It has a clear top. The description stated that it has "triple mica, black plates and twin bottom D getters.”

Are bottom or top getters better? Or does it make a difference? It sounds great. Just curious about some details. Also would like to know what year this tube was made in.

There’s so many variations of the Tung Sol and Chatham versions of this tube. I’ve searched through this and other threads to learn about these tubes. I’ve read the 116 pages in this thread.

[InnerTube]

A pair of them would probably work in place of the 12AU7, but it would take a really unusual adapter or a much larger chassis plate.

Thanks very much for your helpful reply, JS

[Paul Birkeland]

Are bottom or top getters better? Or does it make a difference?

The getter is just a little piece of metal that holds the barium as the tube is assembled. The barium is drawn off the getter and onto the glass near the end of the manufacturing process, and after that the metal shape referred to as the getter serves no purpose!

The getter shape and position is brought up mostly as an identifying mark.

[attmci]

I recently received this tube in the mail. It’s a Chatham 5998, and "650" with the letter J is printed on the base. It has a clear top. The description stated that it has "triple mica, black plates and twin bottom D getters.”

Are bottom or top getters better? Or does it make a difference? It sounds great. Just curious about some details. Also would like to know what year this tube was made in.

There’s so many variations of the Tung Sol and Chatham versions of this tube. I’ve searched through this and other threads to learn about these tubes. I’ve read the 116 pages in this thread.

Nice clear top bottom getter 5998 close to WE421.

50th week of 1956. I could be wrong.