Functional or aesthetics?

[radiowires]

Hi all,

I'm about 80% through building my Crack (with no apparent problems so far), and while doing this, I've been wondering how much leeway there is in arranging the components. I've seen photos online of Crack builds that differ in how neat the wires are (e.g., whether they're laid out in right angles or not), so this doesn't seem to be functionally important. However, I've gathered that, for example, the twisting and braiding of wires is functional.

This made me wonder about other components. Is orienting the two adjacent 220 uF capacitors at right angles to each other critical, and if so, why? What about the third 220 uF capacitor -- must it be flat (if so, why)? Does it matter if a wire is routed under/over, or around one or another side of a terminal strip?

While I'm at it, a more general question is whether it would be possible for BH to perhaps include a supplemental document explaining the functions of different parts of the amp. What do the LEDs, capacitors, rectifiers do, etc? What clever design choices were made? I understand if this is intellectual property that BH doesn't want to reveal, but as a builder I'd be much more satisfied if after building my Crack, I gained some understanding of audio circuitry, instead of just following a recipe. Even a general schematic -- this part generates a DC current, this part amplifies the input signal, etc would be informative!

Thanks very much for any feedback.

[Paul Birkeland]

This made me wonder about other components. Is orienting the two adjacent 220 uF capacitors at right angles to each other critical, and if so, why?

The one that pokes up can't lay down because it would hit the power switch.  This could become really nasty if it got pushed into the switch really hard and the wrapper was punctured (by really nasty I mean that it would just blow fuses endlessly).  Whenever possible I will tend to lay a capacitor down if doing so doesn't obstruct anything.  Having them oriented this way makes it much, much easier for the builder to inspect the solder joints.  If you end up needing help later, it's much easier for me to see where there might be an issue in any photos you post if these parts are out of the way.

Does it matter if a wire is routed under/over, or around one or another side of a terminal strip?

Sometimes yes, sometimes not so much.  This really depends a lot on exactly which wire.  We try our best to keep the heater wiring right against the chassis, then layer the ground wires on top of that, then everything else.  YMMV if you do it differently. 

While I'm at it, a more general question is whether it would be possible for BH to perhaps include a supplemental document explaining the functions of different parts of the amp. What do the LEDs, capacitors, rectifiers do, etc?

That supplemental document would be hundreds of pages long.  We can point you toward resources to learn this stuff and we can definitely answer specific questions along the way.

Even a general schematic -- this part generates a DC current, this part amplifies the input signal, etc would be informative!

The Schematic is on page 6, though it doesn't have the information you're looking for.  The 12AU7 is the voltage amplifier and the 6080 is the current amplifier.  We can address any specific questions you have about the design.

[radiowires]

Thanks very much for the quick and informative reply!

I'll check my wiring layout, especially the heater wires.

If you can suggest a couple of resources for the basics, I'd love to check them out. My main experience with electronics is Arduino type stuff, rather than analog, and certainly not audio, but I'd love to learn more. (side note: I have much less experience with woodworking, so finishing that has been quite a bit more stressful than the soldering). I'd forgotten about the schematic on page 6, it'd be a fun exercise to map that onto the physical layout of the build.

Thank you again!

[Deluk]

Before I started my Crack build I spent some time browsing the Gallery and was going to suggest you do the same but it has been "temporarily dropped". It's been a couple of years now so perhaps it's time to have it back again. I downloaded a few build pictures that I liked, the really neat ones that builders were pleased to upload. The striking thing is that the really neat ones appear to have far less wiring than the untidy ones so there's a sort of moral there. If you follow the book and use the preferred wiring methods you end up with a layout that you are proud to show off. Using a small hook of wire that's squeezed shut on the terminal giving an initial mechanical connection is the way to go, and then, as Paul says, you only need a small amount of solder to make a neat and secure joint. Good solder and a small point on your iron helps a lot.

So, can we have the Gallery back, please?

[Paul Birkeland]

If you're comfortable with what an Arduino does, then starting with Ohm's Law seems unnecessary. 

You might find this article helpful.  The Morgan Jones books are also popular.

-PB

[Deke609]

That is great article. Thanks for posting the link.

[radiowires]

A gallery would be really nice. I did find several build photos on Reddit and elsewhere that have been useful to compare against, so the info is out there anyway, but it does take a bit more searching. I found a couple of comprehensive build guides online that I've kept open while I've been building that I found useful, especially for the wood aspects. There's of course lots of good info in this forum from Doc, Paul, and others, which I've tried to glean as well. After I'm done building, I may make a little post on Reddit summarizing some of the most useful resources that I found online for those who were a bit overwhelmed at the start like I was.

Paul, that article is the perfect starting point for me personally, so thanks a lot for that. I majored in physics (a while ago now, and have since morphed into a biologist), so I've got a few of the theoretical basics, but relatively little practical know-how (everything is a spherical cow). You're right that everyone has a different starting point, so it'd be hard, if not impossible, to design an explanatory document that would work for everyone without it being overly long.

I do hope the gallery comes back up someday! I'd love to post mine, I've been growing quite proud of it as it slowly shows signs of its final form...

[Doc B.]

The problem with the gallery forum was that people were linking images from other websites that were, for some reason, bringing the site down constantly. You can certainly post a picture of your work here using the attachment feature, just like when you post a picture of the circuit for tech support. I don't know that a separate gallery board is the most efficient way to house the images. It probably makes more sense to post images in the board for the given product.