Bottlehead Crack

Nice. It's amazing how a few simple details can improve the looks!

 

Of course the Crack/650 is peanut butter and jelly. I expected that. What I didn't expect is how nice the hd800 sounds on Crack.

 

Speedball that shit.

Don't trust me. Trust all of the other people saying that you should Speedball that shit. I am in agreement with them, however.

 

As always to each their own but I don't really like my 800s with it, seems like they lose 2 much of that fine detail i love so much. Could just be me though.

Edit- but my stock old 600s are always plugged in.

 

It's been a few months, but I've finally been able to add the C-7X Triad choke to my Crack. The damn thing was sold out everywhere for weeks and came back in stock sometime in the last 2 months (don't know the exact date). But anyway, mounting it wasn't as bad as I had thought. Drilling through the metal plate was easy, the metal is surprisingly soft. Taking it slow and starting with a small hole like @AllanMarcus suggested, then stepping up, it was straight forward without a lot of effort. I ended up mounting it behind the transformer, like @Jeb has on page 7. I would also agree with his assessment of what it adds to the amp, things are just a little more crisp with it installed.

I'm still running the Winged C and RCA 5814A for tubes, they've been very nice and provide a good balance for my tastes. I haven't had much urge to upgrade or swap out my gear since getting the Crack to where it is today... but one day I will have to try out the HD800, and if I ever want more from my amp I think I will go with the Crackatowa rather than attempt more upgrades on the Crack.

 

@Steakface did you find any guidance on how to wire the choke up? I cannot find a succinct guide on how to wire the choke up and have been wanting to try this mod.

 

There are two large white resistors (5W 270ohm) near the transformer. You remove one of the resistors and connect the two wires from the choke to where one of those resistors was connected. It’s very easy.



If you want to add a second choke, you can remove the other 270 ohm resistor that is horizontal across the transformer and install it in it's place.

 

Yep, doesn't get much easier than that. Just a snip and a solder, you're replacing one of those white ceramic block resistors with the choke, doesn't matter which one. Polarity doesn't matter either. I forget exactly where I read about this, but it was somewhere on the bottlehead forums.

 

Interesting, it is as simple as I thought. For some reason I was thinking it would be more complicated and I was missing something.

If it doesn't matter which resistor why does there seem to be a preference to replace the one that's harder to get to? Seems like the one laying across the transformer is easier to remove.

 

I'm sure others can chime in and correct me. If you are placing a single filter in the power supply section of the amp, you put it closer to the end of the circuit

 

Makes sense. Thanks! Mouser order was placed.

 

A Bottlehead S.E.X underway:



I don't like the everything-on-the-top-plate look, so I'm building a case somewhat like a Zana Deux or Moth Audio, but with a copper top and bottom.

 

Thanks @Melvillian and @Steakface. I got my choke last night, got it installed and it was simple.

 

How does one ground the choke?

 

Put a solder-tab on one of the bolts, and run a wire from there to the central chassis grounding solder-tab. Here's a picture of one from a S.E.X.:

 

Thanks for showing us that blob of stuff on you SEX. Very, erm, helpful! I alway enjoy seeing pics of people's SEX and how they have maintained and modded them and kept them working in peak condition with as few complaints as possible for as long as possible

 

I got the transformer snubbers in, the filament supply done (I've converted the 10,000uF RC filter to a 15,000/15,000 CRC filter), and much of the right channel in. (I haven't started the left yet because I broke the tab strip and am waiting on a replacement.)

 

@JeffYoung that's some pretty point to point work my friend! How much longer do you have till your finished?

 

I'm currently stalled out waiting for parts to arrive. I figure I've got about 3 days to do once the stuff comes in.

 

It's a crappy picture, but here's the chassis: