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Astrosim Cabinet Simulator / Portable Headphone Amp

Here's a fun little project I finished this weekend. A two-in-one cabinet simulator and headphone amp from "Deadastronaut", you can see their information here.

As the name implies this pedal simulates the effects of a guitar cabinet, providing the same EQ and sound, this avoids that unprocessed DI sound that you get when not using a microphone and amp. 

This particular cabsim has another trick up it's sleeve, a headphone out, which makes it the perfect candidate for a portable headphone amp. Think the Vox Amplug but cooler. This is very useful for silent practice when I don't want to be using my 40W Fender amp. 

I've created my own veroboard layout which is a cut back version of the layout created by dylan159. It excludes any XLR out and indeed the line out. It doesn't save a whole lot of space on the board but you do save an op amp and have the ability to fit it in a smaller box. 

After I had built and verified the circuit it was time to box it up, I immediately thought of the old Walkman and having a hip/belt mounted unit. I found some Walkman models online but it would have been a lot of work to make them functional for this, for that reason I went with a more basic Hammond enclosure.

With that decided I opened up Solidworks and got to designing, luckily for me Hammond have the CAD files for their enclosures freely available on their website, and in a format that can be easily edited. No need to reinvent the wheel for this.

I initially thought of using the 1590G2 but after some quick measurements this would have been too small so I went with the old reliable 1590B, a little thicker and not quite as round but still very functional and not overly large.

I mounted all the controls on the side rather than the face and put the headphone out and power switch on the top so they're easy to access when it's on my left hip.

As I want this to be portable it's battery only, no DC input here. I also added a nice belt clip to keep it in place, wouldn't be much good without that.

Below you can see some in-progress images of my build. I used the "Octagram Spiral" infill pattern in PrusaSlicer to make the top and back look more interesting. As you can see everything fit perfectly and is secured well without the need for any glues/tapes/standoffs.




I had my printer going the whole afternoon making all the parts. It's all printed in PLA, two new rolls I got in an Amazon "flash sale", the blue is "Eryone" brand who I'd never heard of before but it works well and looks great. The yellow is "eSun" who I've used before and know it's reliable. I didn't intend to pair these two colours together when I bought them but I think they go really well.  

To generate the knobs I used this script, it's one of my go-tos for custom knobs. 

Time will tell how well the belt clip holds up, it's only 2mm thick so it's probably going to end up snapping. Luckily I based it on some metal clips I've seen on eBay so if worst comes to worst I can just buy one of those.

Conclusion

Now this brings us to the thrilling conclusion. I have to say this might be one of my favourite projects so far, both in terms of functionality but also in terms of looks, I can't get over how well the aesthetics came out.

It does sound fantastic and will be perfect for silent playing, there's such a range of sound options in the small number of controls. I've been pairing it with my TC Electronic "Dark Matter" distortion pedal which acts as a pseudo amp head and can provide a nice amount of grit. 

A slight modification to make in future will be replacing the LED, I'm currently using a 5mm red LED which, even with a 2k2 CLR, is very dim. I'd like to replace it with a 2/3mm bright yellow LED both to match the look and to be a bit more noticeable. 

If you'd like to make your own exactly like mine then you can head over here and get the CAD files.

Below you can see the final result in all it's glory. 


 

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