[tdogzthmn]

Quote:

Hmm, I got a pair of Sextetts coming in but didn't realize they were 600 ohm, so this kit looks like just the thing I'd need (argh, this hobby feeds itself!)
 
Has anyone tried this with Orthos? I've been thinking of getting the Fostex T50RP from my local music shop, which are only 50 ohm.

No orthos but I have the K240 M which is also 600 ohms.  Sounds very detailed and neutral.

 

[gopack87]

I'm thinking about getting some NOS 1958 RCA 6AS7G tubes off ebay to try some tuberolling.  6080 and 6AS7G are interchangeable, right?  My Crack with speedball upgrade was assembled by the Bottlehead team and I don't know if any mods or anything need to be done to try different variants

 

[Doc B.]

6080 and 6AS7 are interchangeable, and you can also plug in a 5998 without making any other change even though it has somewhat different specs.

 

[gopack87]

Quote:

6080 and 6AS7 are interchangeable, and you can also plug in a 5998 without making any other change even though it has somewhat different specs.

Awesome, thanks!  Let the tube rolling began

 

[druelle]

I'm currently building my Crack and have done a bit of research on 12AU7 tubes, but haven't come across any recommendations for 12AU7 replacements for the Crack.  Does anybody have any experience rolling 12AU7s in the Crack?

 

[maverickronin]

I've already got a small collection of 12AU7s for my Indeed G2 Hybrid, that I'll be able to try out eventually.  I just ordered my crack last week, so It will be a bit before I receive it and get a chance to build it.

 

[Doc B.]

So far I have found that the same 12AU7s I like in other gear work for me in the Crack. Mullards, Teles, Amperex, the usual suspects.

 

[ironbut]

Yeah, that Mullard that Doc supplied with the "Demo" Crack/Speedball for CanJam was real nice! IIRC, it was mated with an RCA 6080 (or GE?)
I certainly don't have the level of experience that Doc has with 12au7 types but I tried a few of the common subs. As usual, what tube you're using in the 6080 position and any component mods makes a difference in the 'tuning'.
Subs I've tried;
Tungsram E80cc
CBS/Hytron 5814a
Brimar 13D5
RCA 5963 bp d getter
 
and a few other 12au7's that just happened to laying around that really weren't memorable.
 
6080 types
 
Sylvania 6080
RCA 6080 (supplied w/kit)
Tung-sol 6080 graphite plate
Tung-sol/Heintz and Kaufman 5998
 
My fav's depended on whether the Crack had the Speedball upgrade or not.
 
Stock, I like the Tungsram E80cc with the Sylvania or the graphite plate Tung-sol. Pretty subtle differences so your cans and ears will make all the difference.
BTW, I didn't have a 5998 before I upgraded so that could be total hogwash if you have this tube.
 
After the upgrade, I really like the CBS/Hytron 5814a with the Tung-sol 5998. I think the CBS is in the same ballpark as the Mullard I mentioned above so I'd say that Doc's recommendations with the 5998 are all bound to be over the center field wall as well.
 
Some particulars;
 
The Tungsram E80cc is slightly higher gain and very clear/transparent. For many of the 6080's,it was too much of a good thing IMHO. Very impressive sounding and great for demo type listening but not something that I'd enjoy day in and day out. IOW audiophile sounding.
 
I really found the Sylvania 6080 to be something of a sleeper. It went well with a large majority of 12au7 types including the E80cc. Great bass, fluid mids and highs and just didn't do anything wrong.
 
The TS graphite plate had a quicker sound and with something like the CBS/Mullard it was a great match. With others, it seemed a little bass shy.
 
The Tung-sol 5998 with the CBS, Mullard is heaven IMHO. Bear in mind that I have made a couple of mods to my Speedballed Crack such as film output caps, slightly upgraded pot and silver signal wire but those pale in comparison with the improvements that the Speedball and the 5998 made. They were done before the Speedball since it would be tougher to get in there after the extra boards were installed.
 
As usual, YMMV. These listening impressions were done with my AD2000.

 

[HiGHFLYiN9]

Coming along slowly but surely, just waiting on a part at the moment
 

 

[tdogzthmn]

^ impressive looking build.

 

[ironbut]

Looks good Highflyin9!
Damn, your picture reminds me of some subs I meant to try before installing the Speedball. Oh well.
Those Kiwame's sound pretty nice but I don't like the smell when they get warm.

 

[HiGHFLYiN9]

Thanks! I found out later on that the larger wirewounds end up getting tossed to the curb when the speedball is installed... doh.
 
If I'm able to swing the space, the third 220uf is going to get pulled in favor of a solen film cap. The 100uf caps are going to be Solens, perhaps bypassed with some Russian PIOs.
 
Tube sockets are the teflon type with Woo boards. I punched the chassis and dropped in a Neutrik locking as you can see. Stepper is a DACT I had in the parts bin, I probably would have went with a TKD or Noble otherwise.
 
I'm beginning to use the Kiwames for everything now, not only do they sound really nice, but I really like the unusual flat green look. I haven't noticed the smell yet, lol, an added bonus I suppose. Here's a bonus photo of a kiwame stepper I just put together tonight:
 

 

[tdogzthmn]

I forgot how good the K240 M sounded with this amp,  I have been too busy with the K340 and K400.  I would really like to hear a K240 sextett, whos got one?

 

[Armaegis]

I've got a sextett. Just need to get off my duff and actually build this thing...

 

[HiGHFLYiN9]

I finally got the 9 pin PCB I was waiting on, so I finished the initial build last night (minus wiring in the speedball, that will have to wait until after testing and initial listening). Also I've gotta touch up the paint on the top-plate a little bit before it's photo-worthy.
 
I'd love to see some photos of some other peoples builds, even if they're still in progress like mine