[a1rocketpilot]

Since the Melos company went under a while back, no new Melos SHA's have been built for a while, making it much more difficult to find one. However, would it be possible (and ethical) to create a PCB for DIYing a Melos SHA? It would make the build process much simpler than having to protoboard or P2P it. It is a shame to let this great amp go down, but at the same time, would it be ethical to do so, seeing as the design is Melos' after all. At the same time, the amps wouldn't be sold for profit and kept for personal use. So what say the Head-Fi'ers about it?

Aditya

 

[ATAT]

You have the melos SHA schem?

personally, since the company went down under, the schem is open game.. consider the two scenarios -

No one clones the melos - a great amp goes bye bye, prices of old melos inflate and it becomes useless

People clone the melos for DIY - a great amp is sold DIY for no profit, everyone's happy.

It would be possible, and I'd be willing to make a Melos pcb given a melos schematic or a melos (broken or not)

 

[a1rocketpilot]

I have a schematic for the Melos SHA-Gold. However, I am not sure if it is for the preamp or the headphone board. As I am mainly after the headphone amp in the Melos, it may be wiser to open up a SHA-1 or a SHA-Gold to see what the headphone section is like. The schematic is posted on my website here:

http://www.prism.gatech.edu/~gth676f/MelosSchem.pdf

(be aware, 2MB's approx)

Aditya

 

[FallenAngel]

Holy Crap! That's the scariest PCB I've ever seen!

 

[doobooloo]

Damn, was the PCB hand-drawn or something?

Interesting to see parts and wires just kind of dabbed here and there underneath...

 

[a1rocketpilot]

True, it does look like a sort of haphazard arrangement. If we can make a PCB, it will also be easier to make it neater and provide a cleaner build though.

Aditya

 

[00940]

Bah, the PCB does it job, doesn't it ? You guys have obviously never worked inside those vintage receivers, Marantz, Pionneer or Harman Kardon.

This PCB is looking just like that.

You have all you need to build one. The headphone section is on the top left of the schematic.

 

[doobooloo]

Quote:

Originally Posted by 00940 Bah, the PCB does it job, doesn't it?

I guess it does its job mighty well indeed!

 

[Pars]

Probably some mods to the Melos SHA to turn it into the -Gold version. Just added it to the plain SHA PCB I would guess, but I'm not that familiar with Melos.

 

[a1rocketpilot]

The board layout on page 9 of that document doesn't quite cover everything. If you look at the pics of the completed board on pages 10 and 11, you will see that there are traces that are on top of the board, so it is at least a dual layer PCB.

Another thing that confuses me are the many attachment points on the side of the board, labeled 1-12. Many of these don't seem to attach to anything on either the top or the bottom of the board, which leads me to suspect that either they are air-wired or that there could be a third layer of the PCB. So basically, the PCB layout they give is incomplete, which is why I posted this thread to see if someone could use the schematic and lay out a PCB design for this. I will give it a shot myself, but I have no idea if I can lay out a good one.

Either that or we can cannibalize a broken Melos and just duplicate that PCB.

Aditya

 

[00940]

The holes 1-12 are for the switches, volume control and other hardwired stuff. See page 6 of the service manual.

It will take less time to redraw a simple PCB layout than to clone this one. I'd bet it'd be easy to make one single sided PCB with a few jumpers.

But it would take even less time to P2P the whole amp.

 

[a1rocketpilot]

Either way, it would be a shame to let this die out. To cut out some of the complexity, I think we should try and duplicate a SHA-1 board instead of the SHA-Gold. Are there any companies out there that can duplicate a PCB if it is sent in?

Aditya

 

[JahJahBinks]

There are companies that can do PCB if you send in your schematics.

 

[Iron_Dreamer]

That is one spaghetti bowl of a PCB! It would be really cool if some of you did manage to rework this legendary amp. I wasn't too fond of the one I heard, but that was a limited audition, a LONG time ago (and wasn't with HP1000's

).

 

[robzy]

Noob question: Whats the difference between the SHA1 and the SHA-Gold?

Rob.