Millett "Starving Student" hybrid amp - Page 50

Hey Joe! Welcome!
I haven't seen any official "order of build" for this amp, but you might search the thread to see if anyone has tried a 9 volt battery prior to pluggint it in. I would imagine that nobody has done this because the cost is pretty low for the amp.

Rat's nest: try not to. If you stay organized while building, your amp will be that much easier to troubleshoot if you have problems later. There is a small chance that you could minimize some induced noise, but let's just get the basic build working for you first.

Have fun.

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PTP doesn't really lend itself to a build order simply because how you go about it is completely layout dependent. I'd suggest figuring out where you want the major components to go first and then do a rough wiring diagram.

It's a Bud Industries case. The only reason I chose it over the Hammond was because it's cheaper.

Oh man, had I seen that, I wouldn't have spent the hours polishing that nasty Bud case!

/golf claps

Nice. Good answer! Yes, I think getting item locations set up first is a great start.

As I may have mentioned before (heh), the many high-resolution photos on this and related threads are an enormous help to a beginner, when trying to steal^h^h^h design a layout.

This makes me feel good since I spent a good bit of time just doing it. I don't know how a beginner like me could approach this without doing a diagram.

I'd concur with this. I know I spent a good deal of time thinking about alternative positions for the heatsinks, tubes, connectors, etc. and then once I settled on a layout, I drew a picture of it as it would be seen from inside the case. This meant the left channel was on the right, right on the left, and the pinouts for the tube socket's and MOSFET's reversed. Having a picture helped from getting this confused in my mind.

With that in hand, then it was a matter of transferring the schematic to the physical layout of the sketch. Again, I just drew a new diagram with the resistors and capacitors (with their values) in the actual locations within the chassis. By the time I was ready to start assembling this thing, it was a piece of cake because I could just follow the diagram and concentrate on soldering instead of the schematic. All of the thinking was done ahead of time.

One other tip is once I got the layout drawn on the masking tape prior to drilling the case, I set all of the large components on top to make sure that the terminal strips would fit comfortably in terms of soldering. I was cramming mine into a small space, so this helped choose the optimum locations before drilling the holes for the terminal strips.

Maybe this will help somebody starting out. I know this was my first experience with a 'free-form' point-to-point assembly, and I was glad I put so much effort into the planning before plugging in the soldering iron. It paid off because the amp fired up first try.

BTW, it is a great sounding amp. I am blown away at how good it really sounds. I'll be building another one soon for my brother.

Finished!

And it works









Sounds great too. Absolutely NO audible hum or hiss even with the volume turned right up and the sound quality is fine - well balanced tonally and nice lively dynamics.

It's a bit messier inside than I'd hoped, but not too bad considering I'm so new to this.



Took my time - guess I spent 12+ hours on it. Getting the case done was the hardest bit as I was hampered by a severe lack of tools and facilities (one old power drill and the kitchen table). I had to make all the large holes by drilling small ones and then making them bigger with a file. Have since bought a step bit and a Dremmel-type tool - so the next build should be a lot easier.

I've got nearly enough parts left over to build a second one (partly because I ordered extra in case of me messing up and partly due to Farnell's order multiples for some components) which I'll use on my work desk. I'll need some way of protecting the valves for that one. Also I might include an iPod dock and multiple input switching.

Thanks Pete for coming up with such a great design and thanks to all posters in this thread without whom I wouldn't have had a prayer of tackling this.

^ very nice build. I really like that case.

Wait... it doesn't go up to eleven?

Nice build, very classy.

Hello Keiths, at what point in the diagram did you take off the wires for your LED?

I was also wondering if mounting the heatsinks inside the case is a bad idea. I am not even sure if I can fit mine but I thought it could be a good idea if travelling. Would just have to unplug the tubes and put the box in a bag.

It would not be a problem, so long as the case has proper ventilation. Hestsinks rely on air to dissipate heat, so about the worst thing you could do is close them off from the outside.

Do the mosfets get particularly hot?
I have some smaller heatsinks lying around and maybe I could recycle those.

I would only have some ventilation at the back. But I suppose I could drill some holes at the top too. It will be very cramped inside if I do this but I like the idea if I can pull it off. The dimensions of my case inside will only be around 12x10x4.5cm so it may be a stretch.