Amp enclosures/chasis cabinets

[magma]

Keith has rightfully pointed out that enclosures demand a seperate thread so as not to dilute the main purpose of the initial thread

so here is the enclosure thread
followed from here
http://www.hifivision.com/diy/11878-mauros-myreference-rev-c-building-queries-guide-9.html

hmmm
so many cooks!

anyway i thought i would make a standard enclosure with all hardware listed above
Chasis,Heatsinks(since i have a source after consulting linux),RCA in , speaker out,IEC power socket,Power switch,Standoffs for PCB mount maybe a volume knob (but for this i would require some pics to copy from and also would need to know what exactly fits inot the knob at the internal end)

currently no input selector since that would require 2 pairs of RCA ins which im not sure everyone wants

i will choose all components according to my preferences ( note: i am a stickler for good stuff )

then i will put that completed enclosure on sale.

from there you guys can work on suggestions for additions or subtractions and then possibly standardise a chasis

i require help in the following matters though
more pics if possible of how that PCB attatches to the heatsinks - there must be some kind of adjustment kit/packing etc
pics of how the volume pot connects to the volume knob

i request linux to send me a sample of the PCB with the chip ( or whatevever i need for that heat sink mounting)
A reject will do

Lastly what are the dimensions of the PCB and what do we need the internal dimns of the chasis
width,depth ( front to back) and height ?

 

[magma]

i was wondering

though the pic posted by quad ( the enclosure which is probably for the F5 - the one with the huge sinks) looks nice and symmetric
would it not be wiser to keep the power IEC soket and power lines a bit away from the PCBs and rcas?

i would assume that the best layout would probably be what hiten has posted in his first post here
http://www.hifivision.com/diy/11878-mauros-myreference-rev-c-building-queries-guide.html

Exception being that i would have the line IN rcas where he has shown the speaker terminals and the SPEAKER out binding posts where he has currenlty shown line IN

my mind tells me that this would put the input signal via rcas the furthest away from the power and that would be best
would it not?

This layout would also probably accomodate later upgrades with larger PCBs dont you think?

i have ofcourse not considered lenght of wiring equal or unequal ( in this layout) since i dont understand its effects or ill effects

Pls do advice

to start of pls do advice on the dimensions on THIS above suggested layout

 

[gobble]

Hi Magma

The heatsinks need to be added separately. Sometimes the chip is attached to the heatsink first then the legs of the chip are soldered onto the PCB - to protect it from heat stress. So this is a delicate process and electronics technicians will need an independent heatsink for general purposes. Since your enclosures may be used not only for the GC, there are many other projects that need a bare enclosure as the size and quantity of heatsinking will vary with each project.

For inner height I would recommend standardizing on 2U or 2.5U dimensions and slightly wider than a 1/2 rack like 16" or 17" (Wapedia - Wiki: Rack unit)

Also FYI the PCBs are mounted EXACTLY like your computer motherboard. All you need is 3mm threaded holes at the precise locations. The mounting legs are available everywhere.

HTH

 

[gobble]

i would assume that the best layout would probably be what hiten has posted in his first post here
http://www.hifivision.com/diy/11878-mauros-myreference-rev-c-building-queries-guide.html

Exception being that i would have the line IN rcas where he has shown the speaker terminals and the SPEAKER out binding posts where he has currenlty shown line IN

my mind tells me that this would put the input signal via rcas the furthest away from the power and that would be best
would it not?

This layout would also probably accomodate later upgrades with larger PCBs dont you think?

i have ofcourse not considered lenght of wiring equal or unequal ( in this layout) since i dont understand its effects or ill effects

Pls do advice

to start of pls do advice on the dimensions on THIS above suggested layout

I think trafo in center with two pcbs symmetrically on either side may also work like in the f5.

-G

 

[linuxguru]

.
i require help in the following matters though
more pics if possible of how that PCB attatches to the heatsinks - there must be some kind of adjustment kit/packing etc
pics of how the volume pot connects to the volume knob

i request linux to send me a sample of the PCB with the chip ( or whatevever i need for that heat sink mounting)
A reject will do

Lastly what are the dimensions of the PCB and what do we need the internal dimns of the chasis
width,depth ( front to back) and height ?

The PCBs have not yet been released for manufacturing, though the outline/dimensions are fixed - about 104mm x 90 mm. The location of the LM3886 and the corner mounting holes are also fixed as per the layout I posted earlier.

I will send a PCB (maybe fully-populated) as soon as I receive and assemble one.

The internal dimensions have to be large enough to comfortably allow 2 PCBs and a transformer (either toroidal or EI) to sit comfortably with additional room for wiring block, cables, connectors, etc.

The height will be governed by the height of the heatsink - the one I have from Amar Radio is approx. 2.5" in height, but maybe a 3" or 4" H heatsink is more useful.

The width between the 2 mounting faces of the heatsink has to be at least 2 x 104mm to allow the 2 PCBs to fit back-to-back. In practice, we need to leave some clearance between the PCBs for wiring, etc. Perhaps 300 mm is too large, but 240 mm may be ok. We need to ensure that the diameter of the larger toroidal (Miracle 300 VA) + adequate clearances, is less than this width.

The depth is also probably gated by the length of the standard heatsink that is chosen. We need at least 90mm + diameter of the toroidal + clearances for connectors, wiring, etc.

If some assemblers plan to use a pre-amp board in the same chassis, then additional depth may be required to accommodate it. The same applies if anybody wants to use an attenuator like the LightSpeed within the same chassis.

I'm making a sortie to S.P. Road now - I'll check if there's a suitable standard heatsink at Amar or elsewhere.

 

[linuxguru]

I think trafo in center with two pcbs symmetrically on either side may also work like in the f5.

Yes, this also works best in distributing the weight equally - the trafo tends to dominate the weight. The centre of mass will be easier to fix at the geometric centre with this arrangement.

 

[keith_correa]

IMO, I don't think we need to make the heatsinks part of the enclosure. If we do, it may be overkill for most amp. projects. I suggest we leave the heatsink implementation to individual builders.
OR
Keep the side heatsinks optional. With side heatsinks OR with plain aluminium side panels OR with wood panels OR - now I'm getting ahead of myself hyeah:

 

[linuxguru]

.
my mind tells me that this would put the input signal via rcas the furthest away from the power and that would be best
would it not?

The PCBs have a ground-plane for the small-signal section, and there has not generally been any RFI/EMI issue with them. Of course, it is advisable to keep them some distance away from the trafo to avoid picking up 50 Hz hum. The same applies to the input RCAs and the cabling to the volume control and input connector to the PCB - which will however be done with shielded wire to reduce the effect of 50 Hz pickup.

In practice, I'm using input shielded-wire at a distance of about 15 cm from an EI-core trafo in my crude prototype, and hum is completely inaudible.

 

[magma]

IMO, I don't think we need to make the heatsinks part of the enclosure. If we do, it may be overkill for most amp. projects. I suggest we leave the heatsink implementation to individual builders.
OR
Keep the side heatsinks optional. With side heatsinks OR with plain aluminium side panels OR with wood panels OR - now I'm getting ahead of myself hyeah:

im am not making the large sinks!

the sides will be like a general amp

i am talking about sinks that are required just for this ( small ones that will be IN the chasis )

 

[keith_correa]

im am not making the large sinks!

the sides will be like a general amp

i am talking about sinks that are required just for this ( small ones that will be IN the chasis )

I must have missed some posts then. I'm sorry!
So, then why are we discussing sinks at all? Is it for deciding the height / width of the chassis?

 

[saikat]

For heatsinks: Conrad Heatsinks

How difficult is it to make these? Is the material science complicated? Any local manufacturers?

 

[keith_correa]

Any local manufacturers?

Here, here and here.

 

[gobble]

I think a side panel like this pic attached can be a good idea.

Those DIY projects that do not need a major heatsink can buy the cheapest available local HS and plug it in without soldering anything to it on the inside. Or use another covering plate for a sophisticated finish. Maybe Magma can supply the covering side plate as a distinct component with the enclosure? i.e not design a single body side wall at all, but keep it as a frame (as shown in pic) + panel?

For the DIY projects that need a HeatSink - this gives plenty of room and spacing options to position the pcb and component mounting to some point on the HS internally from the chassis.

HTH

 

[gobble]

Here, here and here.

Wonderful, maybe a group buy is in order? :clapping:

Lets give the local industry a chance before importing. What with courier charges, customs, +20 days waiting for customs clearance ...

One of them even offers custom machined HS if required. hyeah:

Cheers

 

[Hiten]

Hi all,
The Pic. put up by quad is indeed of "Myreference" amp. with large heatsinks running at both sides of the panel (From components one can confirm). And in my amp layout picture quad has rightly suggested that heatsinks are small. Regarding Speaker out and line in I was trying to make all connection perpendicular to each other to reduce interference. But Linuxguru has said it would not make that much of a difference. So I would suggest first decide on Heatsink Dimension... then layout of pcbs.... then all connections.... then make enclosure in such a way that if someone wants to make any other amp they can use this enclosure with enough room in it. So we get more people in enclosure group buy. What do you guys suggest ? Here is a pic to give you rough idea...

I think I am loving this DIY more than my desire to hear High fidelity sound

 

[gobble]

Hi all,
The Pic. put up by quad is indeed of "Myreference" amp. with large heatsinks running at both sides of the panel (From components one can confirm). And in my amp layout picture quad has rightly suggested that heatsinks are small. Regarding Speaker out and line in I was trying to make all connection perpendicular to each other to reduce interference. But Linuxguru has said it would not make that much of a difference. So I would suggest first decide on Heatsink Dimension... then layout of pcbs.... then all connections.... then make enclosure in such a way that if someone wants to make any other amp they can use this enclosure with enough room in it. So we get more people in enclosure group buy. What do you guys suggest ? Here is a pic to give you rough idea...

I think I am loving this DIY more than my desire to hear High fidelity sound

I think the the L+R line-in can be on outer extremes with PCB mounted on either corner, and farthest away from the Trafo in the centre, with the speaker terminals slightly inside of them. The IEC socket + fuse and power switch can be at the center.

Just my chaar annas

 

[denom]

So with most of the major components of the my ref amp now being discussed in various threads, I would now request a rough estimate of the prices of each component be revealed for one to get a idea of what the total cost of this amp will work out to be. This will enable us to get a confirmed number of people interested in purchase of each amp & hence the final qty can be worked out for each item enabling a group discount for each component.
What say guys?

 

[stereorules]

So with most of the major components of the my ref amp now being discussed in various threads, I would now request a rough estimate of the prices of each component be revealed for one to get a idea of what the total cost of this amp will work out to be. This will enable us to get a confirmed number of people interested in purchase of each amp & hence the final qty can be worked out for each item enabling a group discount for each component.
What say guys?

I second that ..

 

[magma]

I think the the L+R line-in can be on outer extremes with PCB mounted on either corner, and farthest away from the Trafo in the centre, with the speaker terminals slightly inside of them. The IEC socket + fuse and power switch can be at the center.

Just my chaar annas

so basically the exact same thing as the pic posted by quad?

what about the volume knob and power switch
you want those at the back panel too?

if not where
if in the centre the tranny's gotta move on one side

if offset then the chasis will have to be made a bit wider

 

[gobble]

so basically the exact same thing as the pic posted by quad?

what about the volume knob and power switch
you want those at the back panel too?

if not where
if in the centre the tranny's gotta move on one side

if offset then the chasis will have to be made a bit wider

Knobs and switches at the front of course. Yes, if using an aluminum rod extender for volume pot, this layout may not work, without a rod, it might but the wires will not be the shortest. I use 7" long shielded cables in my preamp into the volume pot and there no artifacts to SQ that make me want to change it. Lets wait for Siva's opinion.

-G