[ultrachrome]

My initial plan was to have the heatsink sticking out the front of my enclsoure with the transformers in the back.  For my enclosure this provides the easiest access to the internals.

However, I am concerned about the signaling wires running around or over the power supply components.

If I reverse my plan with the power supply in front and the heatsink in back, there isn't alot of room on the back panel for ins and outs.

What are some definite things I should avoid?  BTW, the internal dimensions of my enclosure are 4.25" * 14.25" * 9.25".

[AKSA]

Ultrachrome,

If you put the heatsink and 55W amp modules on the back, one to the left and one to the right, then the hum susceptible input wires are VERY short since the RCAs can be mounted on the rear panel right alongside each module.  While you are correct that there is scant room (a 350mm width will only leave 25mm (1") each side of the installed heatsink), with care there is sufficient space, since if you choose a height of 4", and you have only two binding posts and a single RCA per side, there is just sufficient room under the heatsink and in the center of the enclosure to mount the IEC power input module.  It's wires are best routed up the spine of the enclosure to the transformers at the front anyway, so this is no hardship and in fact quite an advantage.

This approach is very sensible since it places the bottom of the sink fins a little off the ground, giving a flueing effect for better cooling.

Alternatively, if you want a slimline, say 3" and no more (the height of the heatsink, and the minimum height), then you need only make the enclosure a little wider.  If you choose a width of 380mm, this gives 40mm, almost 1 1/2", each side;  plenty of room.  380mm width is 15".

Cheers,

Hugh

[ultrachrome]

That's what I was afraid of.  I was hoping to decorate the front panel with the heatsink.  Despite the crowded rear panel, it does make the most sense from an assembly point of view as well as sonic.

My design (not fully realized) consists of a removable front face plate, originally coutout to accomodate the heatsink, and a frame with the heatsink, powersupply components, and rear plate mounted to it that would slide out the back.

  If I attach the heatsink to the rear panel, will it get very hot?  My front/rear panels are 5mm aluminium (as you guys say).

My enclosure is a walnut veneer cabinet made by Compass Techincal in the 60's.  They are nice and cheap although after being in storage for nearly forty years, the top has sagged a couple of millimeters.  http://www.surplussales.com/Enclosures/encl_2.html[/img][/url]

[EchiDna]

That's what I was afraid of.  I was hoping to decorate the front panel with the heatsink.  Despite the crowded rear panel, it does make the most sense from an assembly point of view as well as sonic.

My design (not fully realized) consists of a removable front face plate, originally coutout to accomodate the heatsink, and a frame with the heatsink, powersupply components, and rear plate mounted to it that would slide out the back.

  If I attach the heatsink to the rear panel, will it get very hot?  My front/rear panels are 5mm aluminium (as you guys say).

My enclosure is a walnut veneer cabinet made by Compass Techincal in the 60's.  They are nice and cheap although after being in storage for nearly forty years, the top has sagged a couple of millimeters.  http://www.surplussales.com/Enclosures/encl_2.html[/img][/url]

after seeing that case, how about turning it sideways and mounting 100w heatsinks on the original front and back sections?? that could work very nicely! you would need to drill a few small holes in the 'ends' for plugs, switches etc but it should be quite possible. GL with the project!

[Propstuff]

UltraC,
Put the heatsink on the front! It's a good look! (you can see my Aksa on the Aspen gallery)
Keep the power supply things at the back and bring the signal in at the front. Then you can show off your hideously expensive audiophile "trinket" connectors and signal leads! ;-)

If you're not ashamed of the visual appeal of your speaker wires and connectors, you can bring them out the front too! :-)

Seriously; I'd do it! (although I'd probably take the speakers out the back)

Don't follow the herd: put it of the front! :-D

N.

[ultrachrome]

You know, I kind of like that idea.  Kind of like the Dynaco ST-70.  Being that the cabinet gives it a vintage look, it might just work.  However, I believe I would want the speaker terminals in back but then I risk picking up noise from the power supply, don't I?

I can't do the sideways thing for two reasons, 1) I have the 55W amp with one heatsink and don't feel link chopping it in two and 2) the front edges are venered while the back edges are not.

  In general, should I be prepping my tranny wires in any particular way?  Twisting?  Should I make them as short as possible?

[Pleb Plebian]

IMO, reducing interference comes down to routing and wire length.
Power (AC - both incoming and supply to the recifiers) wires should be kept as far away from anything 'audio' as possible - if you need to cross any audio wiring, make it at 90 degrees.
Audio wiring-being input and speaker outs (to a lesser degree), should be be kept as short as possible.

I've used this 'system' in all my kits with great success - minimal hum even on my original GK prototype with 3-dimensional point-point wiring :-))

I'll just make one more plug for my favourite alyout: remote-mounted transformers, local rectifiers. It _is_ controversial (its one of those things Hugh and I agree to disagree on) - but it works for me, giving the quietest noise floor  I've ever had the pleasure of (not) hearing.
Worth considering, anyhow.

HTH
-Darl

[Grumpy_Git]

I've finally decided to mount the Amp of my dreams to a nice case and am going to get a rackmount one from Maplin as suggested by Hugh.

I just want to ask for any advice or suggestions on mounting the heatsink of my 55 to the inside of the case so it doesnt rattle around.

Cheers people.

Nick

[ultrachrome]

Assuming your enclosure has vents on top and bottom I would think the most efficient mounting method would obviously be positioning the heatsink above an below those openings and mounting the heatsink so that it was equidistant from the top and bottom, in other words, elevating the heatsink above the floor of the enclosure.

You could do this using aluminum bar (I use .5" square bar) drilled and tapped on both ends with a screw coming through the bottom of the enclosure and a then drilling the "shelf" of the heatsink as close to the fins as possible to attach to the top of the aluminum bar.  The length of the bar should position the height of the heatsink appropriately.

You could use one bar per side and maybe a third in the middle.

Of course this assumes you have access to aluminum bar and a drill press.

You could simply use threaded rod, washers and nuts positioned at the base of the fins.  You could use a capped nut on the bottom, enclosure foor, nut, washer, heatsink, washer, and nut.  To give it some stability you could position the threaded rode at base of the fins on the outsides and position a third rod closer to the end of the fins in the middle.

I could send you an illustration of both methods if you'd like.