Bottlehead Crack

voltz

I got a message from Bottlehead about my "Speedball upgrade" had some bad/counterfeit parts and they ask me to check it and see if it was shiny and said Korea on top, well it did and they shipped out a new part.. got it today but it will be long time before I go "Speed Balling"

Oh and I not gonna show ya my Crack up close

ALL212

14u is a bit tight....

wait...what...it works too!?? It's not supposed to work - just supposed to be fun to build. You didn't really think that tube stuff is for real??!!

Nice job!

voltz

Need some advise on 12AU7's...I have a Lindal & some china tubes, been looking at some Telefunken Black diamond or Genalex gold lion's maybe.

ALL212

voltz wrote: »

Need some advise on 12AU7's...I have a Lindal & some china tubes, been looking at some Telefunken Black diamond or Genalex gold lion's maybe.

Now you went and done it...advice on tubes - might as well ask a politician to make a definitive budget decision.

Here's what I wrote up a few months ago over on the Odyssey forum based on the tubes that I've kept (and I've been through some 12AU7's and variants) and how they sounded in the Candela.

Tesla ECC802S yellow label - I left these in to replace the 7316's. Well balanced.
RCA 5963's long black plates - Very nice - highs and bass both very good.
CBS Hytron 12AU7 long grey plates - Good
Amperex 7316's (ECC186) - could be getting worn out but lacking bass, every other aspect is wonderful
E80CC - Very quiet, good but not great
CBS Hytron 5814 short black plates - Highs are a bit brittle, bass boomy. Vocals are good.
RCA 12AU7 clear tops - Flat sounding - no joy.

Currently on the big crack are a RCA 5963 long black plate with a 5998 in the 6080 slot and that combo is amazing.

In the new crack is an Amperex orange globe 12AU7 with a stock 6080 and I'm a smilin'!!

Over in the BH forum is an 80 page thread on tube rolling in the Crack - I'm sure there will be some opinions there that may guide you.

If you want some decent quality tubes from a good vendor look up Brent Jesse's web site. He stands behind what he sells. Most of what I have is from the crazybay.

mhardy6647

voltz wrote: »

The most exciting phrase to hear in science, the one that heralds new discoveries, is not “Eureka!” (I found it!) but “That’s funny …”

That is what I was saying when I found out my Crack actually works

Not bad for a 1st timer. still I hate soldering especially around 14U after the cap is sitting on top of every $#%^ wire

Heh -- I know what you mean. My one quibble with Doc B's product designs -- I find their "three-dimensional" point-to-point layout (which, at least in early days, they touted as a feature) to be tedious to assemble and to work around. I've had to resolder joints, melted stuff, and occasionally just plain screwed up with Bottlehead kits (and I rarely have/had any problems with Heathkits or DIY). The layout of the Bottlhead kits ('specially in the neighborhood of the power supply components) to me is a bit cantankerous.

voltz wrote: »

Need some advise on 12AU7's...I have a Lindal & some china tubes, been looking at some Telefunken Black diamond or Genalex gold lion's maybe.

I gots a box full (well, relatively full!) of used RCA cleartops; I can check and use-test a couple and send 'em to you if'n you want; just shoot me a PM (as they say).

EDIT: Well, heck, if they sound flat (as in lifeless, not as in "no deviation from theoretical response", I presume)... well, the offer stands if you'd like to see for yourself ;- ) I think I've got some other 12AU7s "in stock"; nothing too exotic but I can see what's downstairs and at least offer two (or however many you need?!) at least to try out. The clearops would be freebies, though, if you're interested.

voltz

Thanks Doc I will, I could learn a lot from Aaron works. He's super neat & tidy and makes me want to go back and unsolder and clean it up a bit LOL, but I'd lose what little I have left of my hair!

Thanks for the tube list I' have to check on a few and do some reading.

ALL212

The "flat" could be just the way the Candela handled them. The stock tube I got from BH on this kit is a clear top. Now, I prefer the sound of the 5963 but there is nothing wrong with that clear top.

Only way you'll know if you like a tube in a particular system is to get 'em and listen to 'em. And then keep in mind that it's in that particular system you get that sound. Another system may be better or worse - just based on synergy.

ALL212

While we're bouncing this topic around I'm switching tubes between the two Cracks and took the 5998 and 5963 and put them in the new Crack. I wasn't real thrilled with what I was hearing in the new crack and it's not near as modded as the other so maybe that's the magic. New crack...heck, I can't put a finger on it - a bit of "fuzz" in the sound is about as close as I'm going to get. I put a couple 6080's (nothing fancy) and a couple of odd 12Au7's in the new one and I'm not getting much of a difference...just not as thrilled listening to it as the old Crack.

5998 and 5963 in the new Crack and...

Tubes make a difference. (that there would be a period!)

ALL212

Definitely have some "fuzzy" tubes. Found a Siemens 5814a military I forgot I had and combined it with a 6080WC and no fuzz. Not sure if I have the patience to figure out which is what in the fuzzy department.

Overall - copper rods appear to help in the 6080's whether it's the ST (6AS7G) variant or the fireplug stock 6080. I've always like the heavy graphite (indirectly heated?) 6080WC or WB's but copper rod there as well. And if you want a treat go steal someone's 5998 (ST bottle). Should you win the lottery pick up a 421(ST bottle) - but there's supposed to be a bunch of fakes of these.

I'd be willing to send a sample pack around of some of what I have for you guys to have fun with and pass on. No sense letting them get moldy especially now that I've narrowed the premium stock down to about three tubes.

ALL212

voltz wrote: »

Thanks Doc I will, I could learn a lot from Aaron works. He's super neat & tidy and makes me want to go back and unsolder and clean it up a bit LOL, but I'd lose what little I have left of my hair!

Thanks for the tube list I' have to check on a few and do some reading.

My first build ain't near as Purdy as this one and until you turn over the plate - no one knows!!

ALL212

HEY!!! Soapbox time! Looks like I'm owning this thread biatches...

Doc B's 3d design is a bit interesting and it took me until the last two builds to get a grip on it. I agree that in some places he packs some serious schtick into seriously small places and it becomes almost too much of a challenge but...

I was thinking 2d on all the other builds except the last two. I would solder a wire in and then bend it down to the plate to route it. This Crack I tried to make sure that if it was a "U" solder spot to leave the wire in the air and route it. Anything I could keep off the plate I kept off the plate. Long runs don't work well unless you have standoffs but a bunch of those short ones (especially with solid core wire) will hang very nicely an inch off the plate. This gives you room to squeeze wire under and around those high lines.

Wait 10 more minutes and I'll have another thought to share...especially if I can cram another cup or two of coffee into that time frame...

10..
9..
8..
7..

voltz

I been doing morning chores and just now eating breakfast before I start in again. I found a 6080 WC says GE Jan 6080WC USA 88-17 and it has the copper rods

I haven't even listen to it as it came with my WOO WA3 and I put in the 7236 from the start and just now dug it back out. ( I am stupid that way)

You know I have like some of the Mullard & Tung-sol new production I have heard in the 12AT7 variety. (used with my MC100B)

mrbiron

Breath Arron....Breath. In with the good, out with the bad. Rinse and repeat!

I really need to get going on this thing so i can ask up-to-date questions instead of waiting until the thread has run dry. OK....YARD WORK TIME!

mhardy6647

[yes - yard work. After goofing off all morning, sitting on the porch (with a sweatshirt on; chilly this AM up here in the frozen north), then lunch... now out to putter in the yard.

Freaking gorgeous here today; hope it is in MA as well!



Hey, mrbiron, I can set aside a few 12AU7 volunteers for you to try, too, if'n you wish..

mrbiron

It is yard work I swear!...although I severely under estimated the amount of stone I needed to complete my project. Now I have to wait till the wife gets home with her "larger" vehicle.

mrbiron

Just because of the yard work comment Mr. H. I ran out to the garage to glue the last corner. Full steam ahead!!

Yes I will borrow some tubes when complete...as long as the tubes don't deteriorate between now and my impending completion. This may take a while!

voltz

Cheater, Real men use Duck Tape

every time I try to do something outside it starts raining again

mrbiron

I told you I had a frame clamp. That crap shoot is I can only glue one side at a time

mhardy6647

A workshop simply cannot have too many clamps.

mrbiron, I know what you mean when it comes to projects like yours. I calculate the amount I need, round up, buy triple that amount... and have to go back once or twice to buy more.

voltz

that is a nice clamp!

ALL212

something about clamping your crack....I just can't put it together right now but it's there....wait for it...

mhardy6647

sort of like binding feet...?

voltz

Snow helped me with some 12AU7 tubes so I think I'm going to be good in that area for now.
I stained my Box but I'm can't clear coat it today too low of temp and high humidity says I should wait.
Been working on my "SpeedBall" doing the PC boards so they are ready for the change-up but I want to get more ear time on the stock version...plus I think those caps like my crossovers are going to need some burnin time before they sing better!

voltz

Aaron have you seen this mod?



an easy modification for your Crack amp that will keep the startup voltage at the output down to 0v with no headphones plugged in.

Was curious if you have tried this.

ALL212

Yes- please do that mod. It's not mission critical but it makes sense. Once this is done your voltage measurements are going to go to 0v...but I don't remember where. Put in one of those 1/4 to 1/8 inch adapter headphone jack things to separate the contacts and you'll read normal voltages when you do your final checks.

If you're still wiring make the wire coming in from the volume control about an inch longer and just use it to ground 'em up.

ALL212

I did have my new Crack sold. Did have and decent price also. I'd say some "kid" under 35 or so - probably mid 20's ish. We were doing fine but I don't think he had a paypal account and audiogon wouldn't let him purchase so we went straight paypal. That worked out fine also - he payed with an e-check and then things got "interesting". I don't think he understood the e-check has to clear. He wanted it shipped now (he has every other weekend off and the upcoming one is an off for him) and I told him that wasn't going to happen until the check cleared. He got huffy and a bit rude so....I cancelled his e-check. Amazing how nice he suddenly got.

I was going to throw in an extra set of tubes, pay for two boxes for shipping so the tubes wouldn't have to ride with the amp and he was close to getting some free RCA's also.

Kinda sucks but my spidey sense was tingling...

mrbiron

Voltz, please post the link to the mod here so we can all see it

mrbiron

I "accidentally" bought another piece of gear to compete against the Crack. I never wanted to really get into headphones but lifestyle changes are leaning this way.

My mystery piece will stay just that for a bit. Need to finish thebcrack first.

ALL212

Here's the thread on the mod to the jack.

bottlehead.com/smf/index.php?topic=2946.0

Here's one on the grounding path - in case you've painted both sides of your plate!

bottlehead.com/smf/index.php?topic=4812.0

mrbiron

ALL212 wrote: »

Here's one on the grounding path - in case you've painted both sides of your plate!

bottlehead.com/smf/index.php?topic=4812.0

I feel like this is directed at someone(s)..................VOLTZ!