Bottlehead Crack

The input wiring braiding should be tighter, it runs right across the power supply so it can easily pick up hum. You will probably pick up hum with the volume higher from the looks of it.

How to braid.

 

I was going to comment on the same thing. In my case, I eventually replaced the wire between the RCA jacks and the Pot with shielded wire. I did that when I upgraded the Pot this the blue velvet, which was not expensive at all, and was a significant upgrade (I don't say that lightly). I did have to enlarge the Pot hole for the blue velvet.

Here's my 2 minute "making crack" movie:

 

Edit: Disregard previous comment. I was a little disoriented after doing all that soldering and braiding. I have managed to get the assembly together and it looks great. Pictures soon to come of the completed project.

 

Use Scotch tape - do not use duct, will leave nasty residue and screw up finish.

Spead wood glue on all mitred ends evenly. Prop up and tape the base so it hold together. You can put some books at the end to help hold up the ends. Make sure the ends meet at a point and hold the joint together tight while applying tape to hold in place. The tape is just holding the base in place until the glue dries. Wait a couple of hours, take tape off and finish base.

 

Excellent. Two last questions! Does the glue actually hold the entire assembly together or should I get some form of fastener to put on the corners to hold the entire kit together after I have finished?

 

Glue will hold as long as tape held tight. No need for additional fasteners. If for some reason glue doesn't hold, you could use fasteners

 

About to glue the base together. How should I apply pressure to it to make sure it's a good connection?

 

First, align the top part upside down. You care if the top is aligned, not the bottom (both should be). I happen to have some large clamps I got at harbor freight, but you should be able to just tape it with painters tape if you don't have clamps.

 

I put 47uf obbligato gold film caps in. It sounds amazing. Sounds like the veil is gone and resolution has gone up - I can hear plankton.

 

I put one of these together some time back, unfortunately just before a business trip and now a vacation; between that and an aggravating and ultimately embarrassing trouble shooting session*, I've only spent a few hours listening to it. What I'm finding so far is that it's losing some detail compared with my Valhalla 2 - not a great deal, but enough to let me know that it's holding back the Gungnir Multibit when playing lossless. I plan on keeping it though, as I like it for my extensive collection of MP3s of dubious quality picked up over the years. They still sound shitty, but the Crack makes them sound shitty in a good, live-performance-under-suboptimal-conditions kind of way, if that makes any sense.

* Voltage and resistance checks went well and the initial power up verified that my wiring job held smoke, so I plugged in and...no left channel. Reflowed half the damned connections in there, then the other half, cooking the power switch in the process. Replaced switch and attempted to replace output tube, which grenaded spectacularly in my hand. (Never seen that before. Sneaky f'ing Russians.). Removed glass fragments from my hand and replaced tube; by now, I'd have both channels for a few minutes and then the left would fade out into a loud hum. Replaced the input tube and the problem was solved.

tl;dr version: the toob elves are out to get me.

 

Wow. Hope you are okay. Did you have trouble putting the tubes in the first time? I struggled putting mine in the first few times. I thought I was going to break the tubes as well. I spent like 10 minutes jimmying the tube into the socket.

 

I just wiggle them a bit when inserting or removing them. It seems to work, except when it doesn't.

Seriously, that was a weird thing. It actually blew up after it was free of the socket, so it wasn't like I was reefing on the thing when it let go. Never seen nor heard of that happening before. I blame the toob elves, and maybe Russia. According to Fox News, Hillary Clinton probably had something to do with it as well.

 

So the big international meet is happening in November and I wanted to know if my tubes are safe to bring on an airplane. I plan on carefully packing my setup into a single carry on bag with some clothes for the weekend. Is there anything wrong with this idea or am I safe to put the tubes into the packaging it came with then bubble wrapping the whole thing? Also, any tips on flying with gear in general would be great. I plan on picking up some form of hardcase for my headphones specifically. Any recommendations on that?

 

http://imgur.com/a/jE9SK

All I have to say is that this has been a wonderful journey and it isn't even over yet! Building this was such a fun and wild experience and I would recommend it to anyone with an itch for something new and exciting to do. I replaced the stock tubes with a Tung Sol 6080 and a GE 5 star 12au7 (Thanks @Jun ). I stained the wood a dark cherry color and applied some matte finish over it to prevent any damage and what not to it all thanks to the power of the Home Depot. I spent 3 hours comparing the headphones that I had immediately available to me (HD650M, SoundMagic HP150, HD428M, and AKG K7XX) with my current chain of Bottlehead Crack + Bifrost Multibit to the Magni 2 and the Modi 2. I have to say that the difference is just night and day. My HD650M is just absolutely perfect with this chain. All the other headphones are just to low of an impedance to get properly driven with the Bottlehead. The best way to explain this upgrade is via visualization. Imagine squinting at an object. The edges are fuzzy. Then you apply the Bottlehead and Bifrost Multibit. This puts the glasses and the edges become crisp and clear. I think that you define this as resolving or "fast". The bass is just wonderful. So full and rich. It doesn't bleed into the mids at all. I can't wait to install the Speedball after a month or so listening to the stock sound. I hope it enhances the upper range a bit more so I get a nice full sound. If anyone has been on the fence about getting this, don't hesitate! Let this post inspire you to build it yourself. I had 0 experience and it worked out great!

 

@Ryu , Way to go!!

 

I was planning to bring mine to the big meet but it died shortly after adding the speedball and I've been too busy to fix it. Not sure about the logistics of flying with a DIY tube amp without being detained by TSA, but i would probably not wrap it up too well in case they want to inspect it.

 

Send help! After listening for about 20 hours now I noticed there is a slight channel imbalance(?). The right earcup doesn't sound as loud and fruitful as the left earcup. What would be the best way to diagnose this?

Edit: I need to stop prematurely posting. In the manual
"Muffled sound - this usually means something is not getting all the voltage it is supposed to get, and
that you need to get inside the equipment and start taking voltage measurements."

 

@Ryu

Is this happening only at low settings of the volume control? (I am assuming that you have the stock potentiometer.) If so, this is normal.

 

Yes. I have the volume knob at 6 oclock to represent 0 and i am at about 7:30. Will the speedball upgrade fix this?