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Crack;Bottlehead OTL - Page 104

post #1546 of 6029

Hello everyone,  I'm new here, and new to 'head phone hi-fi.'

 

Saturday I 'won' someone's Bottlehead Crack project on ebay.  It's in transit at the moment.   I have in my possession Sennheiser HD 650 headphones as well as Beyerdynamic DT990 Pro (250 ohm version.)

 

My random question is that I just noticed the transformer in the crack is hanging low.  The person who built it mounted it underneath the aluminum plate.  Is this an issue?  All of the photos I've seen have it sitting on top of the plate.   I'm planning on cleaning it up when I get it but I wanted to know if this is definitely incorrect.  

 

Here's a photo.  I don't know how to embed photos on this message board yet since I'm new and it doesn't appear to take BB code or HTML.

 

http://farm9.staticflickr.com/8378/8533534049_26365b3014_c.jpg

 

Here's the underneath shot:

 

http://farm9.staticflickr.com/8377/8534642286_26dd8b5673_c.jpg

 

 

Thanks for any info!


Edited by silverhead - 3/6/13 at 8:21am
post #1547 of 6029
Quote:
Originally Posted by silverhead View Post

Hello everyone,  I'm new here, and new to 'head phone hi-fi.'

 

Saturday I 'won' someone's Bottlehead Crack project on ebay.  It's in transit at the moment.   I have in my possession Sennheiser HD 650 headphones as well as Beyerdynamic DT990 Pro (250 ohm version.)

 

My random question is that I just noticed the transformer in the crack is hanging low.  The person who built it mounted it underneath the aluminum plate.  Is this an issue?  All of the photos I've seen have it sitting on top of the plate.   I'm planning on cleaning it up when I get it but I wanted to know if this is definitely incorrect.  

 

Here's a photo.  I don't know how to embed photos on this message board yet since I'm new and it doesn't appear to take BB code or HTML.

 

http://farm9.staticflickr.com/8378/8533534049_26365b3014_c.jpg

 

Here's the underneath shot:

 

http://farm9.staticflickr.com/8377/8534642286_26dd8b5673_c.jpg

 

 

Thanks for any info!

Great price - I saw that for sale on Audiokarma.  Already have one otherwise I would have bought it!

 

I think you're fine, but I'm sure Doc will be here to comment.

post #1548 of 6029
Quote:
Originally Posted by silverhead View Post

Hello everyone,  I'm new here, and new to 'head phone hi-fi.'

 

Saturday I 'won' someone's Bottlehead Crack project on ebay.  It's in transit at the moment.   I have in my possession Sennheiser HD 650 headphones as well as Beyerdynamic DT990 Pro (250 ohm version.)

 

My random question is that I just noticed the transformer in the crack is hanging low.  The person who built it mounted it underneath the aluminum plate.  Is this an issue?  All of the photos I've seen have it sitting on top of the plate.   I'm planning on cleaning it up when I get it but I wanted to know if this is definitely incorrect.  

 

Here's a photo.  I don't know how to embed photos on this message board yet since I'm new and it doesn't appear to take BB code or HTML.

 

http://farm9.staticflickr.com/8378/8533534049_26365b3014_c.jpg

 

Here's the underneath shot:

 

http://farm9.staticflickr.com/8377/8534642286_26dd8b5673_c.jpg

 

 

Thanks for any info!

Lol, so you are who outbid me :)

 

I wanted to build one myself anyways, just tried to see if I could snag it for cheap.

post #1549 of 6029

I don't think there would be any issues. Looks interesting that way. 

post #1550 of 6029

The only thing I can think of is that there might be a bit of hum by putting the transformer underneath the plate, but I don't know for certain.

post #1551 of 6029
Quote:
Originally Posted by Armaegis View Post

The only thing I can think of is that there might be a bit of hum by putting the transformer underneath the plate, but I don't know for certain.

 

I was thinking having it further away from the power tube, might actually reduce hum. :/

 

Hopefully Doc can chime in. 

post #1552 of 6029

I dunno... further away from the tube, but closer to all the other guts.  blink.gif

post #1553 of 6029

Anyone know off hand what gauge wire comes with the kit?  I'm assuming it is solid core.  

post #1554 of 6029
Quote:
Originally Posted by FraGGleR View Post

Anyone know off hand what gauge wire comes with the kit?  I'm assuming it is solid core.  


Solid core 20AWG.

post #1555 of 6029
Quote:
Originally Posted by ben_r_ View Post


Solid core 20AWG.

Thanks! 

post #1556 of 6029
Quote:
Originally Posted by silverhead View Post

Hello everyone,  I'm new here, and new to 'head phone hi-fi.'

 

Saturday I 'won' someone's Bottlehead Crack project on ebay.  It's in transit at the moment.   I have in my possession Sennheiser HD 650 headphones as well as Beyerdynamic DT990 Pro (250 ohm version.)

 

My random question is that I just noticed the transformer in the crack is hanging low.  The person who built it mounted it underneath the aluminum plate.  Is this an issue?  All of the photos I've seen have it sitting on top of the plate.   I'm planning on cleaning it up when I get it but I wanted to know if this is definitely incorrect.  

 

Here's a photo.  I don't know how to embed photos on this message board yet since I'm new and it doesn't appear to take BB code or HTML.

 

http://farm9.staticflickr.com/8378/8533534049_26365b3014_c.jpg

 

Here's the underneath shot:

 

http://farm9.staticflickr.com/8377/8534642286_26dd8b5673_c.jpg

 

 

Thanks for any info!

 

Quote:
Originally Posted by FraGGleR View Post

Lol, so you are who outbid me :)

 

I wanted to build one myself anyways, just tried to see if I could snag it for cheap.


congrats, bid on that myself, also wanted one on the cheap just to try with my hd650's

post #1557 of 6029
Quote:
Originally Posted by dave1109 View Post

 


congrats, bid on that myself, also wanted one on the cheap just to try with my hd650's

 

Seeing how imperfect that one was on ebay and how it went for around 200, it makes me more willing to try one! I could always sell my first imperfect, but working, attempt. 

 

Does anyone know when the last time there was a group buy on headfi for the Crack? 

 

Are there any pre-fabricated OTL tube amps that come close to the Crack in the price range? I'm scared of DIY...though I'm getting tempted! 


Edited by imackler - 3/7/13 at 7:50am
post #1558 of 6029
Quote:
Originally Posted by imackler View Post

 

Seeing how ugly that one was on ebay and how it went for nearly 200, it makes me more willing to try one! I could always sell my first ugly attempt. 

 

Does anyone know when the last time there was a group buy on headfi for the Crack? 

 

Are there any pre-fabricated OTL tube amps that come close to the Crack in the price range? I'm scared of DIY...though I'm getting tempted! 

 

I was hoping that since it was so ugly, I'd get it closer to $125-150.  I was wrong.

 

From what I understand, this kit is as paint by numbers as you can get.  Maybe not as simple as stuffing a PCB, but a lot of people have done this as their first DIY project and completed it an evening or two.

 

No idea about the group buy, but I regret not going in with another Headfier on Black Friday.  Not only was there a discount, but by going in with another person, there was a discount for buying more than one.  

 

Reading a bit about this kit on the forum and speaking to several experienced Headfiers, there isn't really anything in its price range that can compare quality wise.  Someone who's opinion I very much respect has tried his HD800 with a number of amps, including a couple Woo Audio amps that approach $2000 and he still says the Crack with Speedball is the better sounding match.

post #1559 of 6029

The Crack comes with an excellent manual. I would say it's doable in two nights, but don't rush it. I've done it in a single day before, but that wasn't my first time and I spent a separate day prepping and pre-cutting/stripping all the wires beforehand. 

 

Actually, I'd highly recommend spending time to prep all the wires beforehand anyways, and maybe tinning some of the strips if you've got a lousy iron. For first time builders, also take a careful look at the placement of those capacitors near the transformer. It can be a bugger getting them into place and finding room to sneak the iron in. 

post #1560 of 6029
Quote:
Originally Posted by FraGGleR View Post

 

I was hoping that since it was so ugly, I'd get it closer to $125-150.  I was wrong.

 

From what I understand, this kit is as paint by numbers as you can get.  Maybe not as simple as stuffing a PCB, but a lot of people have done this as their first DIY project and completed it an evening or two.

 

 

 

They made a very weird choice to not glue the base and bracket/brace it (badly w/gaps) instead.  Easy fix to remove the brackets, wood glue it to look nice, optionally stain and poly it.  It'd be harder to finish the top plate since it's built out, but the aluminum with nicely stained bottom would look nice.

 

Build wasn't the cleanest, but if it didn't hum, no big deal since the innards are hidden.  And that transformer placement was unconventional, but again, as long as it doesn't cause problems or degrade SQ, it's actually lower profile.  :)

 

It is a pretty straightforward kit to build.  I did it with little previous soldering experience and my only issue as a hum it took me awhile to track down (cold solder joint).  There are some points in the assembly where you have to get into tighter spaces (soldering wires and LEDs near the tube sockets) that require steadier hands and decent hand/eye coordination, but I consider myself pretty much a hacker and I did it without issues.

 

I'd do it in multiple evenings as well.  It is enjoyable if you don't rush through it, and spending time prepping (measuring and stripping wires in advance) can minimize interruptions.  I found it a little annoying to measure/strip each wire as I needed it.  Would have been nicer to have the all ready to go in case you're feeling in a "soldering groove".

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