[bigfatpaulie]

When you added the first board of the speedball, did the crack work fine? That would help for you figure out if the issue is with the first board or the second board. Also, post lots of pictures of the boards and the wiring, including under the boards.

It tested fine, but I didn't listen to it in that state...

Here are some photos. Pardon the mess but everything has been either re-flowed or re-soldered 3 times now so, you know.

Please let me know if there something specific you want to see.

 

[drtechno]

So I've got an itch to build another DIY amp (I've built a Project Solstice before) and the one I want to build is rather complicated. I thought I might start with a Crack and mess around with mods and stuff to build up a little more knowledge before tackling something more complex.

Some questions for you fine folks: I haven't actually heard one before, I only know them by reputation. The only high impedance cans I have at the moment are my trusty HD800. How do they fare with the Crack? By comparison, I'm currently driving them with a Liquid Carbon.

How often do they go on sale? I've seen the $200 price mentioned in the last few pages, but it's nowhere near that right now. Am I going to be waiting until Black Friday or is it more of a regular thing?

Can I use my tubes from the Solstice in the Crack?

Just build it. These are simple common tube circuits located in the RCA tube manuals. The only real expensive part would be the $35 transformer. Otherwise, you could build it under $100 with the cheap parts I saw on the bottlehead site.

 

[kevlar51]

Looks like you have an opportunity to buy or build an RCA switch box!

Alternative, you can try simple RCA Y splitters and run the DAC output to both the Jot and the Crack.

I have some info on RCA switch boxes here:
https://sites.google.com/marcusfamily.info/diynotes/home/rca-switchbox

I've got one already, but it's not hooked up yet. I've known for a while that I was going to need to put a switch between the Jot (preamp) and the Crack so that I could also have my PC hooked up to an old Onkyo receiver hooked to passive speakers.

So if I dump the Jot, I'll need to get another switch. And a phono preamp.

 

[Jimmy24]

Thanks. I just double checked both tube sockets, all clear.

I reflowed all the joints in the right audio channel path as well.

No dice.

Make sure you post pics on the BH forum. They usually can pinpoint exactly what's wrong with your amp. The owners are quick to respond and can usually figure it out.

 

[drtechno]

redo these solder joints. wires should go around at least 1 1/2 times on eyelet terminals...

 

[drtechno]

redo these solder joints. wires should go around at least 1 1/2 times on eyelet terminals...

 

[Stillhart]

Just build it. These are simple common tube circuits located in the RCA tube manuals. The only real expensive part would be the $35 transformer. Otherwise, you could build it under $100 with the cheap parts I saw on the bottlehead site.

Interesting. You're not the first to suggest hat the parts can be obtained for a lot less than the kit price. At that price, it's a bit of a no-brainer.

 

[Allanmarcus]

Please let me know if there something specific you want to see.

So far what I see looks good, but since all the LED are lighting, I would check the jack, and make sure it's soldered well, and the wires that connect to it.

I never did the 1.5 wrap around wiring in the eyelets that @drtechno mentioned, but I did do a little curl, and then pliers to crimp the wires to the eyelet, then solder to hold in place.you can check continuity with power disconnected to verify the joints.

Also, walk through the manual again and verify each step. When I made my Mainline, I missed a step. I didn't catch it until I actually printed the manual, went through each step, and physically checked off the step in the printed manual.

But for now, I would world backwards from the jack.

 

[Allanmarcus]

Interesting. You're not the first to suggest hat the parts can be obtained for a lot less than the kit price. At that price, it's a bit of a no-brainer.

some of the magic of the crack is the transformer. It's a good transformer.

The larger magic of the crack is the instructions and support community. if you try to replicate the crack and build it yourself, you will need to seek support from other DIY communities. Many are absolutely fantastic.

 

[drtechno]

Interesting. You're not the first to suggest hat the parts can be obtained for a lot less than the kit price. At that price, it's a bit of a no-brainer.

Well about 30 years ago, I used to teach people how to construct point to point, and those all look like the ones in the tube manuals. The only issue I see is he initially uses the wrong grid stops, that will cause problems, until you put a ccs on them (the magic speedball upgrade).

 

[drtechno]

some of the magic of the crack is the transformer. It's a good transformer.

The larger magic of the crack is the instructions and support community. if you try to replicate the crack and build it yourself, you will need to seek support from other DIY communities. Many are absolutely fantastic.

you always use a good transformer. Like the Hammond he is using.

btw, why would someone (like me) who repaired/restore antique radios for a couple of decades would need help with the simple designs that apparently, he put the wrong parts in the kit?

btw he doesn't have the simplest version of css, like using a preamp tube per channel, and use the heater of the preamp tube as the 6080/6as7 cathode resistor.

 

[Allanmarcus]

you always use a good transformer. Like the Hammond he is using.

I always use the transformer that comes with the Bottlehead kits, so yes, I used a good transformer.

I'm pretty sure the Crack does not use any transformer from hammond. From the BH forum and posted by a BH employee:

There isn't any drop-in power transformer from Hammond that would work in the Crack. The Crack power transformer is labelled with a rating for DC current from a voltage doubler, which is not how it's configured in the Crack.

 

[bigfatpaulie]

Thanks, @drtechno. Done. I've reflowed them all. No change.

 

[bigfatpaulie]

So far what I see looks good, but since all the LED are lighting, I would check the jack, and make sure it's soldered well, and the wires that connect to it.

I never did the 1.5 wrap around wiring in the eyelets that @drtechno mentioned, but I did do a little curl, and then pliers to crimp the wires to the eyelet, then solder to hold in place.you can check continuity with power disconnected to verify the joints.

Also, walk through the manual again and verify each step. When I made my Mainline, I missed a step. I didn't catch it until I actually printed the manual, went through each step, and physically checked off the step in the printed manual.

But for now, I would world backwards from the jack.

Thanks. Yeah, I did what you described - curled it around and soldered. I've tested the continuity from one solder point to the other without touching the multimeter to the wire, just the tab to ensure that there is current flow from the tab, to the wire, through the wire, to the next tab. I can't find a gap anywhere.

I also jumped from the back of the RCA jacks past the volume pot straight into the input tube (IE Very loud) and I am still having the same issue.

 

[drtechno]

I always use the transformer that comes with the Bottlehead kits, so yes, I used a good transformer.

I'm pretty sure the Crack does not use any transformer from hammond. From the BH forum and posted by a BH employee:

looking at the closeup, it looks like a triad transformer. Still doesn't matter, I bet I could get Edcor to build one for $40, and with end bells