[HiGHFLYiN9]

A couple more photos:
 
I have a friend in the promotional products business. I created a vector file with a nice vintage font and sent it over to him to have made into a metal badge for the amp. I picked "Bottlehead" rather than "Crack" as it sounds a little classier It's a weathered copper finish, about 3" wide. He passed a sample along to Doc, just in case he wants to have a few made for customers.
 

 
 
 
Here's a progress pic with the big'ol Solens. It should be ready for testing, then I can drop the Speedball and the bypass caps in.
 

 
 
EDIT: I've had countless people ask about how to get a badge made like the one above. Unfortunately my contact is no longer in the promotional products business so I do not have any referral information. 

 

[TheWuss]

that's one sweet lookin' badge.
very well done, highflying. 

 

[mrarroyo]

Bryan, that "Crack Amp" is coming along sweeeet! I wish I could listen to it or have the building abilities you have. Enjoy it.

 

[tdogzthmn]

Did you use a custom wood with your amp? It looks too good to be stain.

 

[Armaegis]

Hmm, solder looks ok, resistance checks look good, powers up, tubes glow... but I'm getting negative voltages... Help?
 
 

Spoiler

1      -1
2      0
3      0  
4      -1
5      0

6    0
7    0
8    0
9    0
10    0

11    0
12    0
13    -1
14    -232
15    -1
16    0

17    0
18    -90
19    -86
20    -232
21    -1
22    0
    
a1    0
a2    0
a3    1
a4    -232
a5    -232
a6    -1
a7    0    
a8    0
a9    -232

b1    -1
b2    -1
b3    0
b4    -1
b5    -1
b6    0
b7    -232
b8    -233


 

 

[HiGHFLYiN9]

Thanks gents. Miguel, I'm still a little green at the whole amp making thing, trying to learn what I can here and there. Doc includes some pretty detailed instructions if you want to give a "crack" at it
 
TDogz, that's the stain from the hardware store; MinWax stain and seal and four coats of Minwax satin polyurethane. It's on the base that came with the kit. I'm not super satisfied with the way the stain laid on the wood, but it's a nice color. You're seeing the best side in the photo
 
Armaegis, are you sure you don't have the leads on the multimeter reversed?
 

 

[Armaegis]

Quote:

Armaegis, are you sure you don't have the leads on the multimeter reversed?
 

Positive (pun intended). Triple checked all my solder points and component orientations. I wonder if I just have a bad component somewhere.

 

[ironbut]

You've got either got your diodes reversed or the wiring and resistor out of the bridge is reversed,.. almost certainly the diodes.
If you think of the band on the diodes just like the line on a schematic with the arrow pointing into the line from the opposite end. That means the current is traveling in from the end of the diode without a band. Two of the four junctions are the + and - terminals. The + junction is the one where the two diodes are pointed together and the negative junction is the one where the two diodes are pointed away from each other. The positive junction is where the resistor leading to the power supply caps is and the negative is connected to the wire that leads to the negative end of the caps.
If you do have these reversed, don't bother taking the diodes out, just switch the resistor and wire connections.
There's a good picture of what's going on in this wiki page;
 
http://en.wikipedia.org/wiki/Diode_bridge
 
That capacitor off to the right is the same as the filter caps in the Crack.

 

[Armaegis]

Grr, nope. Diode and cap orientation was the first thing I checked. Too tired to check it over for a fifth time right now. Will need to take a crack (oi, another pun) at it tomorrow or the day next with some fresh eyes.

 

[Todd R]

Armaegis,
Don't forget to post this problem at the Bottlehead site too. Someone there can help also.

 

[andrew3199]

Beautiful looking amp. Has anyone tried the Bottlehead with Ety's?

 

[WyldRage]

Etymotic IEMs? Real bad idea: they have far too low impedance for this amp. The Crack has an output impedance of 120 ohm in stock form, so you should try to match it using 120 ohm or higher input impedance. That means Beyers Premium line 250 or 600 ohm, old AKGs and the K601, or top-of-the-line Sennheisers. I may be missing a few, but I believe that's pretty much it for high impedance, in-production headphones.

 

[Armaegis]

I made myself some resistance adapters so I could use my low impedance cans. Now if only I could get the crack to work...

 

[ironbut]

This thread (and well as the Crack forum on the Bottlehead forum) has gotten big enough that some of the stuff that was discovered by the "early adopters club" is pretty well buried now. Some of that "stuff" were typos in the manual that was shipped with the first run of kits. Doc did a great job of posting the corrections on the Bottlehead site and rewriting those items in the manuals that went out with the subsequent runs.
If you bought your kit from an original owner who never assembled it, you would be advised to check the early threads on the Bottlehead site for any threads with titles like "Crack Manual -corrections".
Here's the one that Doc posted with the first manuals;
 
http://www.bottlehead.com/smf/index.php/topic,657.0.html

 

[Armaegis]

Much to my dismay, my crack doesn't have enough juice to suitably push my vintage Fostex T40 (orthos). I wonder if the speedball will fix this? I'm comparing to my G&W T2.6f tube amp which does seem to adequately power them.