[uzziah]

Quote:

Originally Posted by amb Yes. The idea is to make the price of the custom sized cases reasonable with the group buy. Since only ten is enough to get the price down, I guess it's possible to have a couple of (size/color/finish) combinations if we could get enough quantity together for each one. By the way, the 2" high case has an available internal height of 1.85" after subtracting the thickness of the top and bottom panels. It will fit a board with the 1.5" heat sinks, but just barely. See diagram: You'd have to use short (0.125") spacers to mount the board and put an insulating plastic sheet below the board to safeguard the heat sink screws and parts pins from touching the bottom, and that gives only 0.145" clearance above the heatsink to the top cover. Also, the volume/bassboost pots will have their centers below the centerline of the front panel by 0.205". There isn't enough pin length on the Alps blue velvet to raise them to the center. But then my home-built case also has the pots below the centerline and it looks fine...

ok, i'll have at the groupbuy. i have the time right now, so i can arrange it. i've not organized one before however, so i could use input from others who have. i understand the basic premise. assuming we cannot get a larger-discount by buying over 10 cases (has this been verified?), we could probably do with different size/color/finish combos as amb states. but if we can get an increased discount for buying over 10 cases; and certainly if there is not enough interest (less than 10 cases) for a specific size/color/finish combo, perhaps we should consider one design only. either way, but i'd like to know if $30 per case (was that it?) is the lowest price we can get. i'll get on the phone and try to negotiate the lowest price possible once we have a definite idea of what we want. i'll post a seperate thread shortly.

 

[Magsy]

Woohoo! Order placed, cant wait

 

[amb]

Quote:

Originally Posted by Nisbeth AMB: Could you perhaps update the documentation on your website with the max. physical dimensions of the capacitors (especially for C6 and Cbb)?

Hi nisbeth, download and print this M³ pcb silkscreen layer pdf. It should print in actual size, and you could see how much space there is for everything. The hole spacings are listed under the "Parts list" section of my M³ web site.

 

[morsel]

Sawing off 1/8" from the 1.5" heat sinks would allow for 1/4" standoffs for the pcb, eliminating the need for the plastic sheet under the board, and resulting in centered alignment of the pot, without significantly reducing the effectiveness of the heat sinks. An orbital sander with coarse grit could remove 1/8". Thoughts?

 

[n_maher]

Any reason someone doesn't design a standoff for the pot? It would seem to me that one of the more gifted folks on this site would have no problem designing a Brown-Dog like adapter to lift the pot(s) 1/4", rather than mess with grinding all the heat sinks.

Just a thought.

Nate

 

[morsel]

such a pot standoff would be more trouble than shortening the heat sinks, and would not solve the problem of the pcb standoffs being too short, thus requiring a plastic sheet to insulate the case bottom from the standoff screw heads.

 

[doobooloo]

Quote:

Originally Posted by morsel Sawing off 1/8" from the 1.5" heat sinks would allow for 1/4" standoffs for the pcb, eliminating the need for the plastic sheet under the board, and resulting in centered alignment of the pot, without significantly reducing the effectiveness of the heat sinks. An orbital sander with coarse grit could remove 1/8". Thoughts?

But then the heatsinks would be ugglllyy...

 

[morsel]

The sanded side could face the pcb if it was not uniform. Alternatively, go to a shop and cut them down with a table saw. The cuts should be cheap.

 

[doobooloo]

What about having the heatsinks just stick out a bit (a la tube amps) from the top? The top panel can be cut out like amb's amps, if the top is made of clear acrylic there is no danger of shorting so the heatsink holes can even be made tighter (but then heat dissipation would be worse)...?

I think it'll look quite cool. I may even install 2"~2.5" heatsinks and make them extrude out more. If I can't have tubes, gotta have my second best alternative, right?

Then jack up the bias...

 

[Nisbeth]

Quote:

Originally Posted by morsel The sanded side could face the pcb if it was not uniform.

Doesn't these heat sinks have solder pins?


/U.

 

[morsel]

They have screw holes: Aavid Thermalloy 531102b00000

 

[amb]

Quote:

Originally Posted by morsel Sawing off 1/8" from the 1.5" heat sinks would allow for 1/4" standoffs for the pcb, eliminating the need for the plastic sheet under the board, and resulting in centered alignment of the pot, without significantly reducing the effectiveness of the heat sinks. An orbital sander with coarse grit could remove 1/8". Thoughts?

The board side and the top side of the heat sinks are not the same... There is a cutout towards the board side and the screw hole for the TO-220 mount is not exactly in the vertical center. I suppose there is a little bit of tolerance for you to grind off on the bottom side but not much. Grind off too much and the MOSFET's pins won't insert far enough into the board to allow the screw hole in the TO-220 tab to line up with the hole in the heat sink.

 

[morsel]

An internal bar could be bolted across the tops of 1" heat sinks, adding mass without requiring unsightly holes through the case top. If the bar were of the right thickness and had recessed bolt head cavities, it could maintain contact with the case top over a wide surface area, thus conducting heat into the case top, eliminating the need for ventilation and allowing even higher bias currents than would be possible with the standard 1.5" heat sinks. Since this would be a simple rectangular aluminum bar with a few holes, it should not cost much to have it made at a machine shop.

 

[BradJudy]

Quote:

Originally Posted by morsel without requiring unsightly holes through the case top.

I think an MMM with extra tall heatsinks poking up through the top of the case would look pretty nice.

 

[uzziah]

Quote:

Originally Posted by BradJudy I think an MMM with extra tall heatsinks poking up through the top of the case would look pretty nice.

only issue being the same with the issue of slits on the top of par-metal case: dust