[nikongod]

that pcb dosnt look very far at all from most vintage amps. hand drawn lines offer some BIG advantages, with weird angles very easy to accomidate vs all the "right angle" boards out there... im sure that the "right turn" is wonderfull for board inductance, it goes way up.

building double sided pcb's for this should not be too dificult. i jsut wish i could read the schematic.

 

[AtomBoy]

Is there a better scan of the schematic? I can't make out lots of the component lables and it looks like some of it is cut off.

 

[00940]

what is lacking seems to be just one capacitor, at the end of the HV regulator.

Can someone make sense of the LM317-337 regulation section for b+ and b- ? It's wired in a very strange way...

 

[erix]

Heh, those are my scans! - I used to have 2 boards that I was going to build into one uber melos but I sold them to Carlo and then he fell off the face of the earth.

I still have all those pieces of paper - and more. Not much better quality but if someone wants them, give me an address and their yours. I even traced a schem out from the board that is a little better.

This is a whacky piece of equipment and its a wonder it works at all. Lots of heat being thrown around on this board....

What I do know:
This is a SHA-1, a preamp with a headphone out. As far as I know there was no dedicated headphone amp.
Pars is right, they hacked a SHA-1 board to make a gold. They also had higher mods with more hacks.

Bottom line - you can clone one but why bother when there are better things available?

ok,
erix

 

[Jahn]

i remember the fall NYC meet when i opened up the SHA-Gold to tuberoll and the folks who know their business took a look inside and had a look on their faces that screamed "WHAT THE HELL?"

but i closed that baby up and pure tone came out. but yeah it throws heat like mad, so i have a laptop fan pumping away whenever it's on.

 

[Jazper]

I looked inside the Melos SHA-1 that was at the sydney meet. Couldn't believe what I saw. No one in their right mind would make a board like that (long sweeping tracks? - where's the ground plane? - hello anyone home?)

It sounded very tubey and would not be surprised if it does not measure well on a scope.

The first thing I'd do if I were even remotely interested is take the original schematic and make a decent board for it and a proper power supply (think low ripple). But I am almost positive that it would sound different.

This is before I'd even START looking at different components.

 

[00940]

There's absolutly no need for a groundplane at the frequencies involved. The power supply is quite decent : lm317-337 with proper bypassing, the HV line is regulated. This being said, a new layout using vertical heatsinks for the headphones section and the LM317-337 could be useful to better manage the heat. It could also be a good idea to separate the heaters supply from the supply to the SS section.

 

[robzy]

If i were to build this i personally wouldn't touch a thing, possibly just rearrange the PCB to make it DIY-friendly. Melos are famous for sounding exactly the way they do with Grado's, and i would love to experience that.

Rob.

 

[a1rocketpilot]

Quote:

Originally Posted by robzy If i were to build this i personally wouldn't touch a thing, possibly just rearrange the PCB to make it DIY-friendly. Melos are famous for sounding exactly the way they do with Grado's, and i would love to experience that. Rob.

That is exactly what I was looking for! The current PCB is quite scary looking, so it would make building one a lot easier if there actually was a clean (and good looking) PCB for it.

Aditya

 

[Teerawit]

Hey sorry for OT but a1rocketpilot, are/have you built an M3 or are you gonna do this Melos instead?

 

[a1rocketpilot]

Nah, this was just an idea I had in my head and think would be cool to do, if it can be done. I am going to be building either an M3 or a Dynamid (bridged) soon, been teetering between those two.

Aditya

 

[nikongod]

it should be noted that ptp amps are said to sound diferent with diferent layouts.

i am curious if it is the same with a pcb amp. if the adjustment from a "round lined" layout to a squared off one makes as big of a diference in a pcb amp as it does in a ptp one.

 

[doobooloo]

Quote:

Originally Posted by nikongod it should be noted that ptp amps are said to sound diferent with diferent layouts. i am curious if it is the same with a pcb amp. if the adjustment from a "round lined" layout to a squared off one makes as big of a diference in a pcb amp as it does in a ptp one.

Well hopefully there are going to be a few more changes to the layout than just squaring off and evening out all the traces... Although I know close to nothing about tube electronics this is really exciting to follow.

 

[LFF]

So, after all this time - did anyone manage to clone it?

 

[laxx]

I'd have to say no. =[ I'm sure if someone did, there'd definitely be pics for others to see.