[GreenNeedle]

Started wanting to emulate another member's dark stained rounded corner with polished top crack and my desires changed too many times. lol.

Here is the finished (still stock) crack. Exclusive to head-fi as despite buying the crack and trying to register on the BH forum several times with 3 different e-mail addresses it was to no avail. They don't want me I went with the stock base in the end, veneered in Santos Rosewood. Danish Oil finish, Cream enamelled top, black hammered bell and 12AU7 clamp.

It has a TKD 2cp-2511 volume pot which is the smoothest I have ever experienced, both in actual feel and audibly. The volume knob was from ebay and a little taller than I wanted but I have grown to like it. The feet are spikes with little disks for them to sit in. Yes they are for speakers but I like them.

Tubes are Tung-Sol 5998 and Mazda 12AU7. The Tung Sol needs no introduction but the Mazda is cheap (£20) and readily available. Both the British and "foreign" version sounds really good and thus I have bought a few of these. I have quite a lot of 12AU7 variants at this point but the Mazda (IMO) is one of those that people will learn about and prices will rise.

I will try other tubes with adaptors in the 12AU7 spot but only once I have done the speedball........which at this point I am in no rush to do.

Anyway pictures. Forgive the mess behind, I am in the midst of several projects:

 

[JTori]

Started wanting to emulate another member's dark stained rounded corner with polished top crack and my desires changed too many times. lol.

Here is the finished (still stock) crack. Exclusive to head-fi as despite buying the crack and trying to register on the BH forum several times with 3 different e-mail addresses it was to no avail. They don't want me I went with the stock base in the end, veneered in Santos Rosewood. Danish Oil finish, Cream enamelled top, black hammered bell and 12AU7 clamp.

It has a TKD 2cp-2511 volume pot which is the smoothest I have ever experienced, both in actual feel and audibly. The volume knob was from ebay and a little taller than I wanted but I have grown to like it. The feet are spikes with little disks for them to sit in. Yes they are for speakers but I like them.

Tubes are Tung-Sol 5998 and Mazda 12AU7. The Tung Sol needs no introduction but the Mazda is cheap (£20) and readily available. Both the British and "foreign" version sounds really good and thus I have bought a few of these. I have quite a lot of 12AU7 variants at this point but the Mazda (IMO) is one of those that people will learn about and prices will rise.

I will try other tubes with adaptors in the 12AU7 spot but only once I have done the speedball........which at this point I am in no rush to do.

Anyway pictures. Forgive the mess behind, I am in the midst of several projects:

Absolutely beautiful! Love the oiled rosewood base and cream top. Having built three BH amps (Crack/Speedball, Mainline and Crack-a-two-a), I would say that once you're ready, the Speedball is a meaningful upgrade. Then, having had a taste of that, I wondered what's the platform capable of and weighed modifying my Crack vs. building the C2A. I opted for the C2A and haven't looked back! It's my favorite of the three. Enjoy your amp. You've done an exceptional job on it!

Joe.

 

[cddc]

Started wanting to emulate another member's dark stained rounded corner with polished top crack and my desires changed too many times. lol.

Here is the finished (still stock) crack. Exclusive to head-fi as despite buying the crack and trying to register on the BH forum several times with 3 different e-mail addresses it was to no avail. They don't want me I went with the stock base in the end, veneered in Santos Rosewood. Danish Oil finish, Cream enamelled top, black hammered bell and 12AU7 clamp.

It has a TKD 2cp-2511 volume pot which is the smoothest I have ever experienced, both in actual feel and audibly. The volume knob was from ebay and a little taller than I wanted but I have grown to like it. The feet are spikes with little disks for them to sit in. Yes they are for speakers but I like them.

Tubes are Tung-Sol 5998 and Mazda 12AU7. The Tung Sol needs no introduction but the Mazda is cheap (£20) and readily available. Both the British and "foreign" version sounds really good and thus I have bought a few of these. I have quite a lot of 12AU7 variants at this point but the Mazda (IMO) is one of those that people will learn about and prices will rise.

I will try other tubes with adaptors in the 12AU7 spot but only once I have done the speedball........which at this point I am in no rush to do.

Anyway pictures. Forgive the mess behind, I am in the midst of several projects:

Looks gorgeous!

How did you paint the top as smooth as a mirror? I can't believe the finish is even better than those from appliance factories. Fantastic job!

 

[PsilocybinCube]

Hey fellow BHC owners. Quick question - has anyone here rolled in a 12bh7 tube into their Crack? Speedball is a must I believe, I'm eager to try the tube but wanted to verify the usability first.

 

[GreenNeedle]

Looks gorgeous!

How did you paint the top as smooth as a mirror? I can't believe the finish is even better than those from appliance factories. Fantastic job!

It isn't as smooth as it looks. I intentionally wanted that enamelled look so it isn't "piano finish." It isn't like the Orange peel effect from car paints though. I guess enamel spray does have a smoother finish than your standard acrylic paint though.

If I had wanted a smooth finish, then I would have sprayed an acrylic paint. Then sprayed clearcoat, then run through the wet and dry grades, culminating with some Brasso because I hate paying loads for a rubbing compound when Brasso works very well.

I'll take a few pictures at some point closer up to the finish so you can see.

The spray I used was "Rustoleum Mode" which is an ultra glossy finish. Spray loads of coats thinly every 20 mins hour until you are there. Spray it too thick and it won't go hard. I learned that early. It also does not like baking The Hammerite on the bell was fine with me baking it hard. The "Mode" bubbled so was scraped off and second attempt made sprayed thinly and no baking this time. About 10 thin coats on this. Could still see mismatched colours of the metal showing through until the 3rd/4th coat.

 

[GreenNeedle]

OK, I took a few pictures. I hate close-ups. They show too much dust, lol.

I took some pictures of my turntable which I have finished too so they match. They are in temporary places at the moment because I am re-doing the area they will eventually reside.

So firstly the turntable (please ignore the dust. lol) First pic gives an idea of the finish on the front edge of the chassis:

From just a little bit away it looks much smoother:

And from a distance it looks really smooth. Notice also the rim of the platter, which I have polished up. In the extreme close up you can see tiny scratches, In the second you can barely see them. In the photo below it looks like I spent hours polishing it. I could have and may well do in the future but for now it is just a basic fine wet and dry with a quick rub with Brasso:

Similarly with the Crack, the earlier post it looks smooth and does so in its current position:

But get up close and you see that enamelled finish (and all the dust ):

 

[GreenNeedle]

Hey fellow BHC owners. Quick question - has anyone here rolled in a 12bh7 tube into their Crack? Speedball is a must I believe, I'm eager to try the tube but wanted to verify the usability first.

Pretty sure from reading the whole 140+ pages of the Crack tube rolling thread on the BH forum that to use the 12bh7 without risking damage to the unit requires some rewiring at a minimum.

 

[Little Bear]

trying to register on the BH forum several times with 3 different e-mail addresses it was to no avail. They don't want me

I had the same problem. If you email Dan Schmalle (Doc Bottlehead), he'll activate your account manually. They're having problems with their email notifications.

 

[Bullpride]

Hey fellow BHC owners. Quick question - has anyone here rolled in a 12bh7 tube into their Crack? Speedball is a must I believe, I'm eager to try the tube but wanted to verify the usability first.

https://forum.bottlehead.com/index.php?topic=663.0

Tube Rolling Crack thread suggests this tube requires the Speedball upgrade to use.

Apologies, I didn't see the login issues. Here is the meat of the original post.

\
DROP-IN EQUIVALENTS

Input Tubes (Original: 12AU7)

12AU7(A)(WA)
ECC186
ECC82
ECC802(S)
E8025
E82CC
CV4003
CV4122
CV491
5814(A)
6189(W)(WA)
6680 (WL6680)
6067
7489
7316
5963 (computer version of 12AU7)

Sort-of-Drop-In (but not equivalent - for best results, replace plate resistors with Speedball boards)

E80CC
12BH7

Power/Output (Original: 6080)

6AS7G
6080
6H13C
5998
7236
6N13
NOT THE 6SN7!!!!!

 

[PsilocybinCube]

Pretty sure from reading the whole 140+ pages of the Crack tube rolling thread on the BH forum that to use the 12bh7 without risking damage to the unit requires some rewiring at a minimum.

Yes, I have the Speedball upgrade. I suppose I'm wondering it requires more than that. I can't find anything staying more is needed...but it makes me nervous.

 

[GreenNeedle]

Yes, I have the Speedball upgrade. I suppose I'm wondering it requires more than that. I can't find anything staying more is needed...but it makes me nervous.

It may well be just the speedball needed. I think it is quite early on in the tube rolling thread on the BH forum but it wasn't something I was really looking at so didn't pay too much attention. My focus has been more on 12AU7 variants as well as after speedball 6NS7 variants in that position. The BH thread is well worth the read though if for nothing more than knowing what you can and can't use and what others you can use with slight adaptations/adaptors.

 

[Tom-s]

Look at the E80CC/12BH7 modifications thread on the BH forum and all info's there.
https://forum.bottlehead.com/index.php?topic=5989.225

As you'll learn from that thread; the 12BH7 wants 7-10mA current to optimize it in Crack. This is done by lowering the R1 resistance on the CCS (see post 226).
If you ask this much current from the Speedball small boards it's best to change the MJE-350 transistor to MJE 5731A to accommodate the extra heat dissipation.

Edit: I've enjoyed +-10 different 12BH7's and liked all of them! Very engaging sound. Great mid range. Spacious. Nice tube for Crack. I mostly prefer it over the more steroid like sound of E80CC and over ECC82's.

 

[cddc]

It isn't as smooth as it looks. I intentionally wanted that enamelled look so it isn't "piano finish." It isn't like the Orange peel effect from car paints though. I guess enamel spray does have a smoother finish than your standard acrylic paint though.

If I had wanted a smooth finish, then I would have sprayed an acrylic paint. Then sprayed clearcoat, then run through the wet and dry grades, culminating with some Brasso because I hate paying loads for a rubbing compound when Brasso works very well.

I'll take a few pictures at some point closer up to the finish so you can see.

The spray I used was "Rustoleum Mode" which is an ultra glossy finish. Spray loads of coats thinly every 20 mins hour until you are there. Spray it too thick and it won't go hard. I learned that early. It also does not like baking The Hammerite on the bell was fine with me baking it hard. The "Mode" bubbled so was scraped off and second attempt made sprayed thinly and no baking this time. About 10 thin coats on this. Could still see mismatched colours of the metal showing through until the 3rd/4th coat.

OK, I took a few pictures. I hate close-ups. They show too much dust, lol.

I took some pictures of my turntable which I have finished too so they match. They are in temporary places at the moment because I am re-doing the area they will eventually reside.

So firstly the turntable (please ignore the dust. lol) First pic gives an idea of the finish on the front edge of the chassis:


From just a little bit away it looks much smoother:


And from a distance it looks really smooth. Notice also the rim of the platter, which I have polished up. In the extreme close up you can see tiny scratches, In the second you can barely see them. In the photo below it looks like I spent hours polishing it. I could have and may well do in the future but for now it is just a basic fine wet and dry with a quick rub with Brasso:


Similarly with the Crack, the earlier post it looks smooth and does so in its current position:


But get up close and you see that enamelled finish (and all the dust ):

Your work on painting the plate and case is definitely artistic / professional. I wish I had your level of skills on painting.

My Crack to date is still sitting on naked wood, because of my innocence in woodworking and painting. ...somehow I like the natural color of wood, so it didn't bother me too much.

With my clumsy hands, my painting skill is really bad. I had to use up the whole can of paint to just get one finished top plate, so here is my story: it all started with some Youtube video watching, I watched some spray painting tutorials and thought it's a piece of cake. So I started working on it.... Gee, why the finish was uneven after I sprayed 4 or 5 layers...no problem, I thought to myself, just remove the paint and paint the plate again. So I found myself some kitchen towel and tried to wipe off the paint....What...the paint was so sticky, it couldn't be wiped off completely, there was always some paint residual holding on to the plate like it's born there . I was so desperate, I thought it's impossible to remove the residual paint unless I can find some solvent, but I didn't know what is a good solvent for the paint. What's worse, my hands got painted too when I tried to wipe off the paint...and the paint couldn't be washed away by soap or dish detergent (only days later it seemed to disappear by itself). So I had to re-paint the plate with bumpy residuals, hoping that the new layers would cover them up, but no luck, the finish was still uneven. Sprayed and wiped off, sprayed and wiped off, so it went. I lost count on how many cycles I repeated...until finally I got some good even finish, by which time the can of paint was nearly depleted. Some people said you can paint 10 plates or more with one can of spray paint, but I got only one . And here it is:

My soldering skill sucks too. I hoped to add some bypassing caps or Crees to my Crack, but never dared to do it...what if my perfectly working Crack is ruined during the mod...

 

[PsilocybinCube]

Look at the E80CC/12BH7 modifications thread on the BH forum and all info's there.
https://forum.bottlehead.com/index.php?topic=5989.225

As you'll learn from that thread; the 12BH7 wants 7-10mA current to optimize it in Crack. This is done by lowering the R1 resistance on the CCS (see post 226).
If you ask this much current from the Speedball small boards it's best to change the MJE-350 transistor to MJE 5731A to accommodate the extra heat dissipation.

Edit: I've enjoyed +-10 different 12BH7's and liked all of them! Very engaging sound. Great mid range. Spacious. Nice tube for Crack. I mostly prefer it over the more steroid like sound of E80CC and over ECC82's.

Hey, thanks for the detailed reply. I read the posts you referenced and may give this a whirl. The change doesn't seem too difficult.

 

[GreenNeedle]

Your work on painting the plate and case is definitely artistic / professional. I wish I had your level of skills on painting.

My Crack to date is still sitting on naked wood, because of my innocence in woodworking and painting. ...somehow I like the natural color of wood, so it didn't bother me too much.

With my clumsy hands, my painting skill is really bad. I had to use up the whole can of paint to just get one finished top plate, so here is my story: it all started with some Youtube video watching, I watched some spray painting tutorials and thought it's a piece of cake. So I started working on it.... Gee, why the finish was uneven after I sprayed 4 or 5 layers...no problem, I thought to myself, just remove the paint and paint the plate again. So I found myself some kitchen towel and tried to wipe off the paint....What...the paint was so sticky, it couldn't be wiped off completely, there was always some paint residual holding on to the plate like it's born there . I was so desperate, I thought it's impossible to remove the residual paint unless I can find some solvent, but I didn't know what is a good solvent for the paint. What's worse, my hands got painted too when I tried to wipe off the paint...and the paint couldn't be washed away by soap or dish detergent (only days later it seemed to disappear by itself). So I had to re-paint the plate with bumpy residuals, hoping that the new layers would cover them up, but no luck, the finish was still uneven. Sprayed and wiped off, sprayed and wiped off, so it went. I lost count on how many cycles I repeated...until finally I got some good even finish, by which time the can of paint was nearly depleted. Some people said you can paint 10 plates or more with one can of spray paint, but I got only one . And here it is:


My soldering skill sucks too. I hoped to add some bypassing caps or Crees to my Crack, but never dared to do it...what if my perfectly working Crack is ruined during the mod...

Your finish looks fine to me but then I don't know what you were after A lot of people try to spray too much in one go. Takes a lot of skill (that I don't have) to put a wet coat on without runs or lumps, so I will do 10+ "flash coats" with 20 mins or so in between. If there are any bumps then 2 hours and a gentle wet sand, waft a tacky rag over the top to pick up dust without leaving an impression and then flash further.

As a guide your avatar is a guitar with a "piano gloss" finish. A Pro can wet spray that to perfection. I would spray clear as above maybe 20x. Then get to the wet and dry and rubbing compounds.

Don't worry about how far a can goes. I did the turntable and the Crack from 1 can but not much left in them. I've had quite a bit of practice with spraying as I have done all sorts over the past decade. I just restored an old Raleigh steel frame which took many less cans than I used a decade ago. Like everything it takes practice and then you find a way you are happy with. Maybe not perfect, not quite as good as the pros but it works for you to achieve a finish you are happy with.



Same with finishing your crack. If you like natural get a natural oil finish. doesn't have to be Danish Oil. For that low lustre finish you could use pure linseed Oil. Best way for a newbie I would suggest is to paint it on with a brush quite quickly, then get a t-shirt and immediately wipe it in/off. Repeat a few times, then leave a week for it to harden. Instructions will tell you to wipe off after half an hour but I find it can already be curing on the surface by that time and make a mess. After quite a few oiling project I tend to wipe it on now and leave it.

Linseed Oil will darken and yellow it a little but not as much as a glossier finish. Like an aged Cricket bat colour with Linseed Oil.