[Edwii]

I'm a pretty adaptive DIY kinda person, but not overly well off money wise.  I really want a Bottlehead crack to go with my HD650, but they are a lot more money than they used to be, and our Canadian dollar has taken a big hit as of late. 
 
The kit looks so simple for the most part.  Plus I didn't really want to build it in the standard Chassis, as I want to make a rack mount variant
TLDR
My question:
 
Would it be very hard to order my own parts, get the assembly manual, and fabricate the rest from scratch? Has any one done this before? 
*note I'm pretty handy, but don't overly know technical specifics, if that makes a difference.

 

[00940]

http://headwize.com/?page_id=427
 
This is very, very close in topology to the Crack. The Crack is one of the most basic designs around. 

 

[harlw]

Wondering about this myself

 

[tomb]

  I'm a pretty adaptive DIY kinda person, but not overly well off money wise.  I really want a Bottlehead crack to go with my HD650, but they are a lot more money than they used to be, and our Canadian dollar has taken a big hit as of late. 
 
The kit looks so simple for the most part.  Plus I didn't really want to build it in the standard Chassis, as I want to make a rack mount variant
TLDR
My question:
 
Would it be very hard to order my own parts, get the assembly manual, and fabricate the rest from scratch? Has any one done this before? 
*note I'm pretty handy, but don't overly know technical specifics, if that makes a difference.

 
I think it's safe to say the same thing that most DIY-ers say around here: You are not going to save money in building a DIY amp compared to a commercially-available built amp.  I think the same can be said for a fully-loaded amp kit, especially if it comes with a ready-machined case.
 
Casework can easily end up being 50% of the cost of the amp ... or more.  Looking at the Crack, that top plate has enough punches in it to cost someone a pretty penny when it was first designed and fabricated.  If you build a rack version, chances are it will be even more expensive.  You can't drill square holes, chances are you'll need a Greenlee punch for the tubes and/or sockets ($$), and rack-mounting hardware is often not cheap.  A lot of people go the FrontPanelExpress route, but that can run you $50-$75 just for an endplate.
 
Ordering parts is one of the most difficult things about DIY, if not the hardest.  It's very seldom that you will find parts in the same place.  With a tube-based amp using a transformer, you can almost guarantee that you'll have to source from three places, at least - possibly more.  Of course the wood is an entire story all by itself, I'm sure.  That's part of the casework, though, and perhaps shouldn't be considered if you're going a different direction.  Still, coming up with the BOM, paying shipping for multiple locations, and then re-ordering when you forget that single item or piece of hardware that you need (this always happens) can be both frustrating and expensive.
 
I wouldn't dare talk someone out of contemplating a DIY effort, it's just that doing it to save money compared to a commercial offering - kit or built - is probably the wrong reason.

 

[EniGmA1987]

You could definitely make it up yourself, but the rackmount chassis will have to be at least 2U just to fit the main power tube in a horizontal mount. 4U if you want to mount the tubes vertically. I would also buy some small fans to mount at the back of the chassis sucking air out to help cool the thing because it gets very hot normally and a rackmount design will be even more constrictive. Going 4U will help you with the fans to get some very quiet models. Another thing I would recommend is buying the Speedball kit at least because that is harder to make with the PCBs and stuff, and it has a pretty big improvement in clarity for the amp.

 

[Edwii]

Originally Posted by tomb /img/forum/go_quote.gif

 You are not going to save money in building a DIY amp compared to a commercially-available built amp.  I think the same can be said for a fully-loaded amp kit, especially if it comes with a ready-machined case.
 
Casework can easily end up being 50% of the cost of the amp ... or more.  Looking at the Crack, that top plate has enough punches in it to cost someone a pretty penny when it was first designed and fabricated.  If you build a rack version, chances are it will be even more expensive.  You can't drill square holes, chances are you'll need a Greenlee punch for the tubes and/or sockets ($$), and rack-mounting hardware is often not cheap.  A lot of people go the FrontPanelExpress route, but that can run you $50-$75 just for an endplate.
 
Ordering parts is one of the most difficult things about DIY, if not the hardest.  It's very seldom that you will find parts in the same place.  With a tube-based amp using a transformer, you can almost guarantee that you'll have to source from three places, at least - possibly more.  Of course the wood is an entire story all by itself, I'm sure.  That's part of the casework, though, and perhaps shouldn't be considered if you're going a different direction.  Still, coming up with the BOM, paying shipping for multiple locations, and then re-ordering when you forget that single item or piece of hardware that you need (this always happens) can be both frustrating and expensive.
 
I wouldn't dare talk someone out of contemplating a DIY effort, it's just that doing it to save money compared to a commercial offering - kit or built - is probably the wrong reason.

I appreciate the caution.  
As I hinted, I've never done anything like this, I'm just good at fabricating things in general.  
 
I was going to make my own "chassis" and mounting solutions from scratch more or less. Which does eat up a lot of time, but being handy-caped/unemployed I have time to spare.   
 
For the fancier finishing touches, I have accesses to a friends CNC mill, which should be able to help the project.  
 
As for ordering my own parts,  yes I imagine that would be the biggest chore,  and I realize the shipping expense could also be a problem.  
 
The factor I am trying to avoid, is buying USA components, being that I live in Canada and our dollar is terrible right now. If I had known about the bottlehead when are our dollar was strong I would of snapped one up, but now it costs 20% on the dollar + 14% tax to get one across the border.  
So to get a Speedball Crack would cost me around $570CAD :/  
In addition, I am hearing a lot of people lately that have been waiting literally months for their bottlehead orders to arrive, and still waiting.  
So between trying to avoid heavy USA premiums + attempting to fabricate my own custom chassis, I feel there is a strong chance I can save a respectable amount, or at least I hope.  
 
My biggest problem, is knowing where to start accumulating a parts list. I have the Crack manual, but I am unsure if it lists all the needed information.
 

You could definitely make it up yourself, but the rackmount chassis will have to be at least 2U just to fit the main power tube in a horizontal mount. 4U if you want to mount the tubes vertically. I would also buy some small fans to mount at the back of the chassis sucking air out to help cool the thing because it gets very hot normally and a rackmount design will be even more constrictive. Going 4U will help you with the fans to get some very quiet models. Another thing I would recommend is buying the Speedball kit at least because that is harder to make with the PCBs and stuff, and it has a pretty big improvement in clarity for the amp.

I have a 48u Middle Atlantic Rack. And at least 16-20u not being used for anything 30u or more if i take out the storage drawers. And yes plenty of fans and venting already. 
I could see myself buying the speedball kit directly, as it does not contain any hardware that would be unused (ie more chassis).

 

[hennezzy]

i will try build one, will post photos when done. would like the speedball upgrade too, but wouldnt know where to start

 

[00940]

There isn't anything magical about the speedball upgrade. Those are simple CCS, which could very easily be wired on perfboard. Schematics for similar ccs can be found here:
 
http://www.pastisch.se/faktiskt/diyAudio-CCS-beta3.pdf

 

[JacobAguilera]

I’m interested too

But I see a weak point here: Power supply usually makes a huge impact on amp performance.
Anyone knows if it’s possible to “copy” or “get” same Power transformer as supplied with original kit?

Kind regards guys!

 

[tomb]

Edcor can supply you with pretty much anything you need. If they don't already have it in stock, they can custom wire it. Hammond Mfg is another source that has ready-made power transformers in stock for tube amplifiers.

Don't let a bunch of comments about transformers being expensive scare you - they're not if bought through the right source and PTs are usually not that expensive anyway. The Bottlehead doesn't use output transformers. That's where you can get into some esoteric material construction and things can get expensive, fast.

 

[DutchGFX]

I'm a big fan of Antek transformers. They are toroidal not EI, so you might want to get a transformer cover ($10 or so on eBay) to help with appearance (and maybe hum).

They are very good for the money, and I use them in a lot of my diy testing projects.

You can actually probably make a very good regulated supply for only a few bucks by adding a zener diode and a BJT, which would further reduce the effects of the transformer.

 

[JacobAguilera]

Wow! Thanks a lot for all that info.
I wrote down your suggestion "DutchGFX".

"Tomb", I'd checked Edcor and Hammond Mfg webpage, and both are from America.
I'm from Europe (Spain); do you know any reliable supplier here?

Thanks again for both suggestions

 

[Tom-s]

In my experience with Bottlehead kits with the supplied power transformers are of good quality. The powersupplies are adequately overbuild as far as i can see. Yes, you can improve them by replacing some caps here and adding chokes there. I think Bottleheads parts are chosen carefully to get a very good sound, based on that circuit design, to start with. They do leave some room in the amps for improvement on some parts. See the Bottlehead Forum for all that is done with these kits.

For my DIY SE tube amp builds I'm a happy customer at Don Audio in Germany for Edcor and Hammond transformers here in Europe (reasonable EU shipping prices). They also sell Lundahl output transformers for headphones (have them on stock).
I've also used Jukebox-revival with good succes for Hammond parts.
For a custom transformer it's worth it to mail AE Europe transformers in The Netherlands (contact them via email with your custom wishes), this is the company that makes the transformer sets for Triode Dick tube amp builds.

Edit: From personal experience with BH kits and all DIY tube amps. It's about as expensive to buy it as a kit compared to DIY. Only difference is a DIY build will give you more headaches for everything you have to do over, or redesign, for sure.

 

[Doc B.]

That subject line is pretty bold. If you make it, it sure as hell isn't a Bottlehead kit.

 

[DutchGFX]

Edit: From personal experience with BH kits and all DIY tube amps. It's about as expensive to buy it as a kit compared to DIY. Only difference is a DIY build will give you more headaches for everything you have to do over, or redesign, for sure.

This is a good way to put it. The beauty of the Bottlehead kits is that they have been perfected over the years and the design has been refined by literally thousands of builds. When I design my amps, I usually have to design them 2-3 times to get them to work as I would like, and that means a decent number of wasted parts. Maybe I suck, but it's definitely easy to forget little things, even in Spice.

You could have a go at building another simple design, but you would likely end up spending as much or even more than the Bottlehead kit.

One design you might want to look at is
"Another Completed OTL"
Google that and you will find the thread...