ono group buy

[Bakmeel]

I'll put up the latest version online tomorrow. It's late now and i've gotta get up early tomorrow to make the top lids of my ono case

[Bakmeel]

Ok... here goes...

These are not the final pcb's but the designs that I made working a few days ago. My pcb designs were shaped in such a way, that everything, including connectors and transformers can fit in a single standard audio-size enclosure.

The Power supply displayed below can hold up to 44.000 uF capacitance which should be far more than suficcient. Modifications pending are: 1) removal of one or two caps to make place for a two small heatsinks, since the fets turned out a bit hot. 2) my name put somewhere and 3) finish off the silkscreen layer.

[Merijn]

NIJS!!!

[Bakmeel]

Second, there is the main board.

The baby took me more than a month total to design, spread out over an entire year. I still deeply feel sorry to all those people I had to dissapoint in the bulk order I was supposed to organise that time. It was a perfect example of selling the skin before shooting the bear. In fact, I sold that skin without even knowing what a bear is

The second layout is a lot better, and indeed, it works It features plenty of space for those big 10 uF caps needed for decoupling. A wima MKS cap fits perfectly. Q1 and Q2 can be thermally coupled. Maybe it reduces noise even further. I don't know. If desired, Q21 and Q21 can be coupled as well. The main board can hold up to 10.000 uF of additional high-speed caps in the power supply line. And for my own special feature: I have placed jumpers in the supply rails to the MC stage and the unity gain inverter. If not used, you can cut the power to these stages, and reduce noise levels on the rails even more.

Modifications pending: 1) add holes for the fets to secure them on the board (I forgot the holes!) 2) Fix errors in the silkscreen layer 3) put m name on it 4) enlage the solder pads for the fets, to make soldering easier.

[Bakmeel]

A small not I forgot on the board pics:

The PSU board is in inverted view. The traces are practically massive.

In the main board view, I have omitted the ground plane. It makes the picture a bit clearer....

Bouke

[xsnailx]

Bakmeel,
great but i have a few questions: are you able to provide gerber files for this group buy. what is the board size and when the final wersion will be ready (estimate )

[Bakmeel]

Originally posted by xsnailx
Bakmeel,
great but i have a few questions: are you able to provide gerber files for this group buy.

Yes. Or perhaps if someone else can convert ultiboard into gerber, I have no objection to that either.

what is the board size

The PSU: 85mm x 140mm (3.35" x 5.51")
Main Board: 80 mm x 270 mm (3.15" x 10.63")

note: you need at least 2 main boards. The layout is mono. 2 PSU boards is optional, but 1 will work too.

and when the final wersion will be ready (estimate )

Hopefully next week, but give me 2 weeks to be sure

[dvorak]

I would also be interested in joining your group buy.

I am in Malaysia and pcb fabrication would be much cheaper in Malaysia than in Europe. Perhaps I may assist in enquiring as to the costs for fabricating the pcb's if the pcb layout can be provided.

I would suggest that we go with the single sided pcb layout as it would be easier to fabricate.

[axelcs]

Hi,

i have seen the design from Kostas (?). The boards looks very good. It´s great to have so much power supply capacity.
Furthermore it seems to be a good solution, to use BC550 and BC560 instead of the 2SC1844 and 2SA991, especially the 2SC1844 are really difficult to get (here in europe). Unfortunately there is no balanced operation available – but i think, this is not a very big problem.
Bakmeel, is it possible, to use the BC´s in your boards too? Is it possible, to have single sided boards? You have the balanced operation included...
I don´t think that production in Malaysia could be much cheaper than Boleslav´s source (at least if we take into account the delivery to europe). The boards from his last group buy were very good and very cheap too.

Cheers Axel

[xsnailx]

double sided boards will proably double the cost. Boards will be made in the same fab that i cooperated with in my last group buy so quality will be nice. i will contact the fab today and ask for a quote on both layouts and we will se how it looks like