Tube Rolling w/Crack

[Maynard]

That's great something to explore!

[MrPotatoSalad]

I got a 12AU7 Bugle Boy and there was a deep hum in the right earpiece with stock Crack. I was going to return it since neither my stock RCA or cleartop RCA 12AU7s made this noise. Is the Bugle Boy a bad tube or is it on my end, most likely?

Secondly, anyone have issues with the RCA 6AS7G background noise? Mine sounds like a quiet power line. Does it go away with burn in usually? Not a big issue but it is noticeable when I first put the headphone on.

[hwaitung]

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fgd1.alicdn.com%2Fimgextra%2Fi1%2F585846110%2FT2z.B6XzRXXXXXXXXX_%21%21585846110.jpg&hash=0e73311e790685504319b05a9f31219ce9d0cc9c)

Saw this on a China website. It converts two 2C22 to 6SN7, I wonder if it can be done on Crack (since people are using 6SN7 on Crack already) Regardless of the sound, it does have an intimidating look.

[mcandmar]

I have  questions about tube but it's not for the CRACK so pardon me.
Do i need a match pair of  tube for the S.E.X.?
Is it important to match the  tubes for S.E.X.?
 
THANK YOU!

You dont "need" matched pairs but it is preferable.   Its also very difficult to do as there are two sections per tube so finding a pair that measure the same for each section is rare.  Even with half a dozen tubes you will end up making compromises to try and get a fairly even pair so i wouldn't worry about it personally.

Saw this on a China website. It converts two 2C22 to 6SN7, I wonder if it can be done on Crack (since people are using 6SN7 on Crack already) Regardless of the sound, it does have an intimidating look.

Thats a bit fugly looking.  Go buy a 6F8G and converter instead, its pretty much an identical tube to a 6SN7, but in a far prettier package.

[i luvmusic 2]

THANK YOU!

[FairDinkum]

Crack with Speedball and HD650 here. I've purchased some Conn 12AU7 clear top. Any suggestions for power tubes? I mainly listen to soundtracks, classical and vocals. In the mean time I'll be going through all 61 pages of this thread lol.

[i luvmusic 2]

Chatham 6AS7G,TUNG-SOL 6080(not those graphite plates i can't afford it:) and 6H13C these are my fav.......

[Colin]

Well, I just couldn't resist any longer.
I replaced the Toshiba 5963 that was included in my kit with a mid 50's CBS Hytron 5814a BP, 2mica with the tilted square getter.  I still have the supplied RCA 6080 installed but I replaced the stock signal wire with Cardas 24awg shielded between the RCA's and the pot and 21awg solid silver (from M Percy) for the rest.
It's just been a couple of hours but I'm lovin' it! Great imaging, deep soundstage, fantastic bass, very nice snap, and the highs aren't nearly as forward as with the Toshiba. Very musical!
I almost don't have the heart to try the rest of my stash,.. I said almost.
I'll live with this set up for a while though,.. of course there's that new TKD pot staring me in the face too.
I just have no self control anymore!

I'm a newbie in diy. Just finished build my first diy, crack. After reading this topic, i impress & want to try make some upgrade/changed with yours. So what do you mean by 'stock signal wire'? Is that the red wire? Changed it from rca terminal to potentiometer pot(only)? And 'the rest' is mean the white wire from rca terminal to poteniometer pot? Please help. Thank you

[Colin]

I've so voided my warranty:  All of the signal path wire is multiple-strand silver-plated Teflon mil-spec, the RCA jacks feed the pot via Canare shielded quad, the pot's from DIY-HiFi (their Alps clone), the headphone jack is a Neutrik locking jack, the caps are those huge Axon films, and I've rolled in a RCA 6AS7.

What an amazing amp!  Dead quiet, the bass has incredible slam and definition.  Brushes against a drumhead are stunning. It does a better job with my HD-650's than my K-702's but not by much. Right now I'm feeding it Apple Lossless via a RWA modified iPod. Blows away my DarkVoice 336 and my Woo Wa3. In fact I just gave the DV to my son-in-law.

Dead simple to build and incredible sound. Doc, you guys rock!

So impresive to hear your modification and its results. Want to try changed the headphone jack, but miss understanding the way you're done. Could you please to help me post a picture. Thank you very much

[tjessen]

I'm running my Crack with a Tung sol 5998 but the stock driver tube. Has anyone have any good suggestions? I'm looking at the 12au7 clear top but was curious about other sound signatures.

Thanks 

[JamieMcC]

I'm running my Crack with a Tung sol 5998 but the stock driver tube. Has anyone have any good suggestions? I'm looking at the 12au7 clear top but was curious about other sound signatures.

Thanks 

The RCA clear top will work well if your using the HD650 but might not suit if your listening with cans that already have a bright signature or a trebly top tend.

What cans are you using?  Perhaps we can suggest a few 12au7 options for you to look into further. 

[tjessen]

HD650 Jamie, however I'm looking for a brighter and not so bright tube

[JamieMcC]

HD650 Jamie, however I'm looking for a brighter and not so bright tube

So RCA clear top, easy to find and cheap if you go for the CONN branded ones.

For a not so bright tube with the 650's look for a Tung-sol JTL 12au7 the earlier the better, one from the 1950's is ideal these are very similar to the Tung-sol 12au7 black glass but less expensive and are nice sounding tubes but still have a slightly brighter presentation which the helps the 650's.

If your running the speedball then the a E80cc is a must try.

[nate craig]

Hi guys, I just noticed that my tube has crack on it, don't know how it came, so I'm looking to replace it with another tube.
Currently I'm running 6080 stock with 12AU7A clear top, Senn 650 and mostly listening to Jazz & Acoustic.
Any recommendation?

Sorry, I'm a dummy, but what does "Test Result" (on eBay) mean?

[Maynard]

Hey.
Anyone have experience with the rca 6as7g black plate clear tops with a mazda 12au7?? Also looking forward to trying my svetlana 6h13c with the rca 12au7 clear top after a recommendation from a previous post!!