Interesting that chassis construction is such a critical issue for RF isolation.
Can you explain why this level of isolation is so important going through the DETOX and up to where the signal enters the DAC but less so/not at all once it crosses the input USB of the DAC itself?
I understand that the cable between the source and DETOX may not matter(?) but after DETOXing the signal so thoroughly, will the construction, e.g., shielding, of the umbilical to the DAC matter?
Thanks for the comprehensive anser John getting a seal on a complex flat surface like that is difficult I worked for most of my career in Automotive design so have some experience, could a compressible ridge be added to the board or maybe machined into the base.
The Detox budget sets limits to how far I can go - but I'd like to believe its already many orders better then any other competing design in this regards.
If you see the internal Lid and Base renderings then you can see how the PCB has its own isolated sections,
........
The Base and Top cover will be machined post anodising to expose a conductive Grounding path to the PCB on the "walled" sections.
John, I'm a chemist, not an engineer, and perhaps this is splitting hairs, but what will this machining do? Flat gold or copper (on the PCB) on to flat aluminium doesn't sound like much of a contact to me, given the insulating oxide film which grows on aluminium within milliseconds of machining. The conductive wire gaskets you mention would I guess break through the film, but it didn't sound as if you intended to use these here.
However I'm quite sure that every one of those screws will be making good electrical contact between top and bottom of the case as they are tightened, and so long as the PCB ground strip is separately tied to the case, this lack of direct contact may be unimportant.
John,
I would definitely want the deluxe fully milled chassis for the FDAC if it becomes an option
We had discussed plans to copper plate the concerned chassis areas .
John, I'm a chemist, not an engineer, and perhaps this is splitting hairs, but what will this machining do? Flat gold or copper (on the PCB) on to flat aluminium doesn't sound like much of a contact to me, given the insulating oxide film which grows on aluminium within milliseconds of machining. The conductive wire gaskets you mention would I guess break through the film, but it didn't sound as if you intended to use these here.
However I'm quite sure that every one of those screws will be making good electrical contact between top and bottom of the case as they are tightened, and so long as the PCB ground strip is separately tied to the case, this lack of direct contact may be unimportant.
Not sure what you mean by copper plate, but if the copper has direct contact to the aluminium, you'll get a battery reaction and the copper will 'eat' the aluminium. contact corrosion.
unless you put an isolating layer inbetween
Not sure what you mean by copper plate, but if the copper has direct contact to the aluminium, you'll get a battery reaction and the copper will 'eat' the aluminium. contact corrosion.
unless you put an isolating layer inbetween
I'd agree the mech engineer should know what he's doing..
There is no "Detox" inside the FDAC - the RF needs to be attenuated before entering the DAC chassis.
BTW - Did the replacement OLED panel arrive for your MDAC? (or am I confusing you)?
We had discussed plans to copper plate the concerned chassis areas - the mechanical engineer is in discussion with the vendors as to the exact processing.
We might end up having to punch a custom gasket, but tooling costs are a prime concern (and the limited Qtys).
Looks like I will be hitting the buy button for two Detox'es soon
Yes, the replacement OLED part arrived and I successfully installed it. My MDAC Premium Fusion is looking great now and sounding great (as always). Sorry, I have been terribly busy lately and delayed emailing Renata (and you) on the receipt and successful install of the OLED part.
~Leon
Thanks John- that clears it up; sorry to have stirred up so much else at the same time.
Timola- pm on the way; this thread is already too cluttered!