[Tom-s]

Thanks! So my description should be:

Mullard 12AU7 (Blackburn factory, Great Britain, code Gf1 B4DX), Catham 6080

???

I can't place the X on the end, Philips tube code is as follows:

Gf1 B4DX
TTC FYMW

TT = Tube Type = Gf = ECC82/12au7
C= Change code? = Old code, in my collection only Gf1 and Gf2's are present.
F= Factory = B = Blackburn
Y= Year = 4 = 1964, 1974 etc
M= Month = D = April
W= Week = 1, 2, 3 etc.

I've searched my collection (+-25 Blackburn ECC82's) for the X, but can't find any.
They do use different coding for some ECC82's code like k61, B61 for the dual getter tall plates.

 

[Paladin79]

I will have to watch for a Chatham 6080, is that not a division of Tung Sol? I know I have seen some while searching that say Sylvania and Tung Sol as well.

 

[Aradea]

Ah this new head-fi is giving me headaches.. I cannot seem to quote.

@deserat: yeah I own a standard crack. I'm loving it with my HD 650 and DT880..
But with my HD 800.. as you said, it does not push the 800s to the maximum. It just sounded fine..
Will modding the crack helps? I am relunctant to part with it

 

[Timoteo80]

Well...finally installed the Speedball upgrade to my Crack after sitting on it for about 4 months. I've been enjoying the standard Crack & wanted to get used to its signature first.

Yesterday I got an itch to install it & finished in about 4hrs. I really took my time & enjoyed the build making sure each solder looked nice & followed every step to a T. It fired right up last night on first attempt. It was late tho & I wanted a fresh approach to first hearing it so I went to bed BEFORE giving it a listen. Woke up about 30min earlier than normal before work & got a small listening session in this morning.

First thing I noticed was the darker background everyone talks about. Details had more "air" to them & just like Bottlehead describes, everything "tightened up". I'll post more of my thoughts later after I get a hold on it's new signature. Just wanted to post my initial thoughts.

 

[Allanmarcus]

I will have to watch for a Chatham 6080, is that not a division of Tung Sol? I know I have seen some while searching that say Sylvania and Tung Sol as well.

Yes, catham or tung-sol 6080 or 6080WA. From reviews I read, only the tung-sol/Catham's are worth getting.

 

[Paladin79]

I have been on the lookout for some but have yet to catch a deal. I used to know some people who dealt in tubes from the 60's and such, eventually I will lay my hands on some since people speak so highly of them.

 

[deserat]

@deserat: I'm loving it with my HD 650 and DT880..
But with my HD 800.. as you said, it does not push the 800s to the maximum. It just sounded fine..
Will modding the crack helps? I am relunctant to part with it[/QUOTE]

There are alot of mods you can make to the Crack that improve SQ. Some of the more popular are:

Speedball
Roll Tubes.
Choke the power supply.
Better Pot or a Stepped attenuator.
Upgrade Capacitors.

From reading alot of posts on the subject, it seems you can increase the SQ quite a bit. But you're likely to end up spending more money over time than buying or building a crackatwoa or mainline. Granted it's not always about the money, it's often about having built something totally custom. I choked mine, run better tubes, and put a pkd pot in it, the choke was the least expensive upgrade, and it does yield noticeable results, the only tough part is where to put the choke.

There are alot of Crack build posts out there, this thread has serveral, https://www.head-fi.org/f/threads/b...-comparison-thread-crack-sex-mainline.683012/ does as well. The Bottlehead forums have alot of god discussion as well.

 

[Paladin79]

I am not familiar with PKD pots but I have tried TKD I am a bit of a sci-fi buff so the only PKD I know of wrote the book the Bladerunner is based on: Philip K. Dick....Do Androids Dream of Electric Sheep. Your advice is sound.

Personally I do not mind upgrading the Crack and I am doing electronic as well as aesthetic upgrades. I am building two Cracks and the upgrades I do to either should pay dividends towards the one I keep. It may not be the best approach, but I am happy with my approach. Down the road I may add a Mainline and mod it to match the Crack, and the headphone rack, and headphones I am modding for my build.

 

[deserat]

I am not familiar with PKD pots but I have tried TKD I am a bit of a sci-fi buff so the only PKD I know of wrote the book the Bladerunner is based on: Philip K. Dick....Do Androids Dream of Electric Sheep. Your advice is sound.

Personally I do not mind upgrading the Crack and I am doing electronic as well as aesthetic upgrades. I am building two Cracks and the upgrades I do to either should pay dividends towards the one I keep. It may not be the best approach, but I am happy with my approach. Down the road I may add a Mainline and mod it to match the Crack, and the headphone rack, and headphones I am modding for my build.

LOL you'll have to forgive me I must've been hallucinating a world in which my volume pot controlled my resistance to reality! Am a PKD fan... yes I meant TKD.

 

[Paladin79]

No harm intended and your advice was most solid! I found some NOS Alps single ganged pots that are obviously segmented but just a bit large for my application. I may use them in another upgrade. It's been years since I studied tube theory so I wanted to start small with the Crack. I am trying to impress some sci-fi friends with my steampunk build... all sorts of clockwork gears, blade switches, copper and brass, pressure gauges etc.

 

[HiddenFatKid]

So I've pretty much decided to get the crack, and later add the speedball upgrade, with hopefully either a tung sol 5998 or a chatham 2399 tube and gold lion tubes. Before building the crack, is there any parts that i should upgrade before building (like better caps, a stepped attenuator, pots, stuff like that?) the crack so i dont have to take it apart later to do it? Links would be awesome!

Also would it be possible to add a decibel guage on the crack (like the ones used on the front of McIntosh Amps? I feel like that'd be looking pretty snazzy.

I'm planning on using the crack with my HD600's, and hopefully eventually HD800's. What are some good closed back cans that work with the crack, besides Beyerdynamic Cans, or the ZMF Eikon, are there any other options?

 

[Tom-s]

The Bottlehead team always suggest to build the amp completely standard first. This to make troubleshooting more easy.

If you'd want to upgrade one thing from the start (because it's a pain later on), then this would be silver(plated) wiring for the signal pathway.

 

[Paladin79]

You have to build the amp completely even if you plan on doing the speedball upgrade. I guess it is good to know if you like the difference. I really do not think it too bad to install a different pot or capacitors. You will be changing a lot of things if you do the speedball though. The VU meter or meters are just add on devices. Personally I am having bigger cabinets made so I will have room for more and more upgrades if I so desire.

 

[larcenasb]

I envy all of you who've stocked up on 5998s, the struggle is real-ly annoying right now lol. Feelin' like a dinosaur hunter out here...

 

[Jimmy24]

Do 6DJ8 tubes work with Crack or do I need to modify it?