Tube Rolling w/Crack

[SxVa]

The modifications would align the plate voltage of the 12BH7 to properly bias the 6080.  In an unmodified amp, the output tube won't bias well.  The amp will still work, but won't perform as well as it should.

Oh okay.

The signs do seem to point to it being modified, it was used and that's what the previous owner was using, it's been working for 2 years without any problems and it sounds really good to me with that tube, but... yeah it's probably best to err on the side of caution since i don't know what i'm doing.

Alright. Thanks for all the help and responses and info. I think i have enough info to begin exploring more tubes. It would've been a disaster had i not asked. I should be okay in knowing what to avoid and what to look for now.

I am changing my mind on this Tesla ecc82 though from my initial impressions. There's an overwhelming white noise to it while it's idle  compared to my other tube that's nearly silent and even though the music drowns it out it can be distracting, also there's a feeling of being what i can only describe as underwater in it's distance that i'm not liking. Cmon Yugoslavia, if you're going to use the name of the legendary Nikola Tesla you've gotta step up your game. It's not too bad for certain distorted dreampop/shoegazer/electronic music and vocals but i think i'm passing on this tube at least in combination with the 7236 Tung-Sol since that's what i tried it with i can't say if it might be better in a different setup.  First exploration tube, the pre-JJ (not JJ) Yugoslavian Tesla ecc82 is concluded to be unsatisfactory.

[Doc B.]

Try cooking that tube for 50 hours and see if it changes.  A large percentage of tubes need to be heated up for some time to get the cathode emission optimized and the noise floor minimized.

[SxVa]

Try cooking that tube for 50 hours and see if it changes.  A large percentage of tubes need to be heated up for some time to get the cathode emission optimized and the noise floor minimized.

Hmmm. Could you expand a bit on what "cooking that tube" means? Is that like a break in period torture test kind of thing? I'm assuming it doesn't mean heating it up in a skillet like some eggs.

[Doc B.]

Yup, just run it for 50 hours.

[SxVa]

Yup, just run it for 50 hours.

Alright. Thanks again. I've ran it a lot over the course of a 3 day period or so as i also use my Crack to watch movies/tv series in addition to music but i suppose i could try and give it a bit more of a push and see if there's any change.

[SxVa]

Wow. That's uncanny. Powering things up today and there isn't the same level of white noise as yesterday and things do seem less "underwater" than before and not just a perception thing it's clearly noticeable from how overwhelming it was. What the... 'twas like it was right on cue from your post. That's freaky lol.

There's still hope for Yugoslavia!

[Bluebird55]

Read the forum every now and then, first-time Bottlehead Crack (Loved the Build and it sounds great!) user looking for some tube rolling help. Maybe it's early to start tube rolling, but I live 10 minutes away from The Tube Store, and they have a great black Friday sale (40% off all items) so I figure I better start now. I don't have the speedball installed yet, but I will later, for what it's worth. I've chosen my 6080 replacement, the Winged "C" 6H13C / 6AS7G. I have narrowed things down to three options for the 12AU7 replacement:

Philips ECC82 / 12AU7
JJ ECC802-S / 12AU7 Gold
Genalex - Gold Lion ECC82 / B749

I'm not too concerned about price, but the Philips is $90, which seems like a lot, but if it has such a big difference... Demoing the tubes is also an option since they allow returns with a 15% restocking fee. But I'd like to avoid paying a 15% fee on that Philips. Hopefully, someone knowledgeable can explain the sonic differences and advantages. I am open to other options, but when it comes to the deal at The Tube Store, these are the only in stock options. Thanks in advance for the help, I'm looking forward to going even further in the DIY audio world!

[Doc B.]

I'll just throw out there that for $90 you could buy six different $15 12AU7s on ebay and roll through them to judge for yourself which works best in your system.

[Bluebird55]

I'll just throw out there that for $90 you could buy six different $15 12AU7s on ebay and roll through them to judge for yourself which works best in your system.

That’s a pretty good point, I think I’d like to stray from that one anyway. What would you recommend between the other two? I guess that’s a bit of a loaded question...

[Paul Birkeland]

I wouldn't expect either of those new production tubes to sound quite as good as the old stock tubes we provide with the kit.

For $15-25, you should be able to score a Mullard 12AU7 on eBay.

[Bluebird55]

I wouldn't expect either of those new production tubes to sound quite as good as the old stock tubes we provide with the kit.

For $15-25, you should be able to score a Mullard 12AU7 on eBay.

Would that be your top recommendation any others? What about the 6080 I had mentioned, any thoughts on that?

[Paul Birkeland]

I haven't actually listened to the newer Russian 6AS7G.

An Amperex, Mullard, Telefunken, or Siemens 12AU7 would be high on my list.  Since I'm a bit of a cheapskate, I would look for a 12AU7 made on European tooling in a different country. 

This is a nice deal Telefunken 12AU7.

[Bluebird55]

I haven't actually listened to the newer Russian 6AS7G.

An Amperex, Mullard, Telefunken, or Siemens 12AU7 would be high on my list.  Since I'm a bit of a cheapskate, I would look for a 12AU7 made on European tooling in a different country. 

This is a nice deal Telefunken 12AU7 [nofollow].

Thanks for the link - I emailed the seller about shipping to Canada. Right now, I think that’s by best option.

[attmci]

Read the forum every now and then, first-time Bottlehead Crack (Loved the Build and it sounds great!) user looking for some tube rolling help. Maybe it's early to start tube rolling, but I live 10 minutes away from The Tube Store, and they have a great black Friday sale (40% off all items) so I figure I better start now. I don't have the speedball installed yet, but I will later, for what it's worth. I've chosen my 6080 replacement, the Winged "C" 6H13C / 6AS7G. I have narrowed things down to three options for the 12AU7 replacement:

Philips ECC82 / 12AU7
JJ ECC802-S / 12AU7 Gold
Genalex - Gold Lion ECC82 / B749

I'm not too concerned about price, but the Philips is $90, which seems like a lot, but if it has such a big difference... Demoing the tubes is also an option since they allow returns with a 15% restocking fee. But I'd like to avoid paying a 15% fee on that Philips. Hopefully, someone knowledgeable can explain the sonic differences and advantages. I am open to other options, but when it comes to the deal at The Tube Store, these are the only in stock options. Thanks in advance for the help, I'm looking forward to going even further in the DIY audio world!

I don't recommend expensive power tubes (GEC 6as7g, 421A etc.) for the crack. If you have the $$, I hope you will upgrade the caps first.

There are a lot of choice for driver tubes which can be obtained at very reasonable price (i.e. the one Paul suggested). 

[vafan13]

I have it on good authority that Santa is bringing me a pair of Beyer T1s to go along with my crack w/speedball.  Currently using stock tubes, considering trying something else.  Are there any in particular that work well with the T1?