X-Can cooling

[rickcr42]

Hey Mikamundo dude,just looking at your X-Can mod/cooling page and realised you forgot to add bottom slots to the casing

Those top holes aren't doing a whole lot without the convection cooling from cooler air being sucked in from the bottom then 'exhausted" out the top as hot air

not picking man but trying to be helpful.

also.I understand there is a resistor scorching problem area that is doing damge to the boards and unless you go to TO-220 type power resistors and heat sinks which take up a whole lot of real estate the only other "option" i see mentioned is raising these problem resistors off the board a bit.

This may fix the "pcb scorch" but maybe a better bandaid would be to get those suckers off the pcb entirely by using metal case power resistors then bolting those suckers directly to the back panel then running some #20 solid wire back to the original holes.

This is all "thinking out loud" type suggestions from what i have read in these forums as a problem area.I do not actually have or own an X-can or I would have already beat it into submission and made it as cool runing as myself

[PinkFloyd]

Hi Rick,

Good observation and totally correct. Ideally there wouldn't "be" an enclosure and the entire shebang would sit naked in all its glory but, unfortunately, to satisfy domestic concerns and keep the RFI god at bay the guts have to be enclosed.

Obviously your solution is the most sensible and would ensure a clean supply of fresh "cool" air blows over the components. It would also be a potential fire hazard "if" anything untoward went down inside the unit what with all that extra oxygen on tap to fuel things.

We only hear about the few X-cans that have burnt out, my personal stash has (touchwood) not so much as a scorch on the PCB's. The actual enclosure itself acts as a huge heatsink and the board venting and heatsinks seems to be enough in "normal" climates.

Sid (another X-Can owner) tried the standard venting and I believe he measured the core temperature of the transistors and found they were running cooler with just the top of the unit (and a small hole in the rear panel) vented (more here imageevent.com/sidandcoke/musicalfidelityxcanv1mods;jsessionid=uapv9u20a1.tiger_s)

I did this with my first ever "vented" V2 but wasn't as economical as Sid with the rear vents!





Total overkill IMO and the ruination of a completely "nice" looking rear panel.... the bastard certainly ran a lot cooler though but flies "were" a problem, they were attracted to the glow of the valves and entered via the vents........ "mesh" would have been a good idea as in Sid's "take two" example.

Man, I am so tired I forgot what I was writing about here...... oh yes, "vents".... umm where was I........

Yes, drilling the bottom "and" the top is the best solution but will detract from the aesthetics..... as Sid says, the unit is "not" airtight and fresh air will get in from the front and rear of the unit whether it's vented or not so maybe the holes in the top are enough but "only" if you live somewhere with an extremely hot climate, in normal domestic temperatures it shouldn't be be necessary to "vent" As I say, I have a V2 here that's been on for about 6 years and it runs as cool as a cucumber (enclosure lukewarm to the touch) with no indication of scorching on the board.

To vent or not........ this is the question.


Standard venting


Full monty "take it out into the garden naked" vent ;D

[rickcr42]

Good observation and totally correct. Ideally there wouldn't "be" an enclosure and the entire shebang would sit naked in all its glory but, unfortunately, to satisfy domestic concerns and keep the RFI god at bay the guts have to be enclosed.

more the "prying fingers" thingy.some people just can't help but stick their fingers in places they do not belong.some kind of mental imperative that says "DO IT ! GO AHEAD ! IT WON"T HURT !"

Obviously your solution is the most sensible and would ensure a clean supply of fresh "cool" air blows over the components. It would also be a potential fire hazard "if" anything untoward went down inside the unit what with all that extra oxygen on tap to fuel things.

dude you must be tired ! Anything "untoward" goes down and in no amount or lack of oxygen is gonna help !

BZZZZZZZZZZT ! sssssssssssss BZZZZZZZzzzzzZZZZZZZT

See ya ;D ;D ;D

I did this with my first ever "vented" V2 but wasn't as economical as Sid with the rear vents!

horizontal venting is usally best when 'assisted" and by that i mean having a fan.
Again this means having an air entry and an air exhaust point so that the fan PULLS hot air out rather than BLOWS cool air in.that is provided by the lower or front air entry points.

Top an bottom venting allow for natural convection because as we all know heat rises,cold air sinks being heavier

Parts :

A part with a specific wattage/power rating will only be capable of reaching that potential if either open air mounted (not enclosed in a sealed "room" without windows) or if it has additional heat radiators attached to the points on the package provided for such so to see TO-220 transistors or resistors without heat sinks is a waste and a smaller/cheaper "non heat sink attachable part" would accomplish the same exact level of performance.the reaso for the "tab" is to get heat away from the silicon and not because it looks cool,even though it does

The absolute WORST is when I see DIYers using those pretty metal finned power resistors rated for 10W duty mounted to a pcb.What they are doing is no better than having a typical/generic 1W power resistor but spending extra to get a "look".
Reading the data sheets of all such parts it is clear the "metal" is meant as the means of transmitting heat to an external heat sink and it in itself is not an actual heat sink so just "pretty gold armor".
bolt that same part to the bottom of a metal chassis or to a metal front or rear panel and the heat is handed off and dissapated over the attached surface and only then is the part able to reach its "rated" potential.

To vent or not........ this is the question.

always a good question that can only be answered on the specifics but be aware that heat can actually change the value of parts,resistors especially,can deform dielectrics making them a potential problem area down the road (any capacitive device which includes actual capacitors but also jacks and plugs) and WILL shortent the lifespan of active devices (and why high bias Class-a comes at a price not just in additional heat sinking but device lifespan)

I like to build small but the real world of electronics says this is bad so what to do ? Always a tough choice between what i WANT to do and what I SHOULD do and is just another example of comprimise entering into audio electronics which is nothing but comprimses or even a simple single stage opamp gain stage would end up costing $500.

I run my triode gain stage "hot" and that means yearly tube replacement but it sounds great.i could back off on the bias and damn near never replace the tubes yet would have a lesser sounding piece of equipment for the duration so it comes down to

A-Great sonics,more hassle higher/expense
B-Good enough sonics,no hassle,no expense,play it and forget it.

Model "B" is where a piece of commercial audio gear MUST live.Option "A" is where we usually take the "B" gear when we modify it

Rickasuarus Rex