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The Centrance HiFi M8 thread - Page 129

post #1921 of 5166

Ah, that's fair.

 

I should add that I did in fact smack my friend upside the head when he told me it was his job to program the spam bots. rolleyes.gif

post #1922 of 5166
Quote:
Originally Posted by mgoodman View Post

Just a friendly request - spam bots crawl these sites regularly and collect stray email addresses.

Please remove the email you had in your original post and convert it to hifi-m8 [at] centrance [dot] com.

Reason: We would like to minimize the amount of spam coming in, so that your emails receive the highest priority. Thanks!

That was dumb of me. It has been removed. Hopefully in time to avoid getting picked up.
post #1923 of 5166
Thank you kindly!
post #1924 of 5166

I'm not getting replies back from Centrance at the above email. Anyone getting responses? btw, when exactly the preorder window closes? If I order now, what is the tentative date of shipment?

post #1925 of 5166
Quote:
Originally Posted by Radiohead99 View Post

I'm not getting replies back from Centrance at the above email. Anyone getting responses? btw, when exactly the preorder window closes? If I order now, what is the tentative date of shipment?

I think it closes today......you want one, don't stand on ceremony .......call them!

post #1926 of 5166
Quote:
Originally Posted by Saraguie View Post

I think it closes today......you want one, don't stand on ceremony .......call them!

No think about it........it closes today.

post #1927 of 5166
Quote:
Originally Posted by Saraguie View Post

I think it closes today......you want one, don't stand on ceremony .......call them!

 

Quote:
Originally Posted by Saraguie View Post

No think about it........it closes today.

Don't think! Don't think!

post #1928 of 5166
Quote:
Originally Posted by Saraguie View Post

I think it closes today......you want one, don't stand on ceremony .......call them!

 

Quote:
Originally Posted by Saraguie View Post

No think about it........it closes today.

 

Quote:
Originally Posted by thegrobe View Post

 

Don't think! Don't think!

I'm bought and paid for 6+ months already!  Anyone on the fence "Just Do It"

post #1929 of 5166
Quote:
Originally Posted by AndreYew View Post

The mil-spec connector (the blue rectangle in that blog post) is used for the M8 all the time.  The M8 appears to be a two-board design with one board sitting on top of the other.  The two boards communicate through that mil-spec connector.  One consequence of this sandwich design is that the two boards are very close together, so you may not be able to physically access the parts of the boards that are facing each other.  You may want to do this to make measurements or adjustments during production.

 

What Michael is making is a breakout board that lets the two boards be apart and not in a sandwich configuration:  think of an open-face sandwich where the two pieces of bread are lying side by side instead of on top of each other.  This production rig (which is used only when assembling the M8s on the assembly line) translates the tiny blue mil-spec connector into a standard ribbon cable connector so that the two boards can be connected through a ribbon cable and still function as a complete M8 without being on top of each other.  

 

See the text on the board where it says "Plug under Digital PCB" (and the analogous Analog on the left side)?  That describes what the board does.  The analog PCB would plug onto the blue connector on the left.  You'd run a ribbon cable from the two rows of yellow connectors on the left (board 1) to the two rows of yellow connectors on the right (board 2), and then you'd plug the digital PCB into the blue connector on the right.

 

Here is an annotated picture that may help.  There are two boards in that picture, too.  FYI, I don't have inside info on Centrance, but I do make electronics (in a completely unrelated industry), and a lot of what Michael's going through is familiar to me, and fairly standard practice.

 

I think I did not understand what was happening and really appreciate your explanation.  So am I right in now thinking that the ribbon is something that will be used during final measuring phases and that the Mil-Spec plug will be used in the production units?  So the ribbon is like a small bridge between the boards?

 

I think that I understood from M Goodman's response that there were only digital signals going through the connector and no analog at all.  So it sounds like a very clear path was designed for the analog signal to go through.  I knew I should have listened more in engineering classes before asking these kind of questions and showing everyone how dim I am when it comes to these things.   

 

Thanks again for the explanation.  I'll stop going to JiffyLube too.  


Edited by pspivak - 5/2/13 at 12:44pm
post #1930 of 5166
Quote:
Originally Posted by pspivak View Post

I think I did not understand what was happening and really appreciate your explanation.  So am I right in now thinking that the ribbon is something that will be used during final measuring phases and that the Mil-Spec plug will be used in the production units?  So the ribbon is like a small bridge between the boards?

 

Yes.  Another way to think of the ribbon cable and those two boards is as an extension cable for the mil-spec connector.  The normal M8 that we'll all be getting is mil-spec-to-mil-spec connector with no ribbon cable or adapter boards in between.

 

I don't know how much Michael wants to tell us about that mil-spec connector, but it looks like one that's designed to carry pretty high-speed digital signals (like 10s or 100s of megahertz).  We use one that has a similar footprint (Samtec ERF8 and ERM8 series) to carry multi-gigahertz signals.

 

The ribbon cable is also probably not usable for M8s that have to work out in the real world.  Depending on what Michael's transferring over that connector, he picked that connector balancing a variety of design constraints:  

 

- packaging: the M8 has to be small, so the connector has to be dense and short.  The ribbon cable is entirely too big and clunky.

 

- emissions: fast digital signals can radiate a lot of noise, and connectors that have shields (this one doesn't appear to have one, but this is not necessarily important), enough pins to use every other line as ground (this connector can be used in this way), and defined electrical characteristics like having a characteristic impedance can all help reduce radiated noise.  When you reduce emissions you usually also help with susceptibility:  the situation where an external source of electrical noise (like cellphones) can screw up your device.  When you do the FCC and CE testing for electronic devices, you are expected to test both emissions and susceptibility.

 

bandwidth: the ability to pass fast digital signals without distortion which could cause things like jitter if you're driving the clock through that connector, or unreliable communications between the boards.  Many of the things that help with emissions also help here.

 

- durability: you don't want anything breaking or coming loose when it's handled roughly (UPS and FedEx in my experience as most users are pretty careful).  Things that are plugged and unplugged also have a cycle rating that says how many times they can be plugged and unplugged before they become unreliable (not important here, but applicable to things like headphone jacks).

 

- cost: you don't want to use a more expensive part than is necessary to achieve your design and quality goals.  There are some very expensive connectors out there for no other reason than that they are produced in very small quantities.  Some connectors require handwork to assemble onto a board, and that can cost more money (for the extra human time for putting the board together) and decrease reliability.  As much as possible, you want the assembly of the board to be automated: with little exception, it will be cheaper and more reliable.

 

- availability: available from different vendors is good so you don't run out of parts, or in case one vendor goes out of business

 

So you can see that picking a connector is a mix of design and manufacturability, and it's not uncommon to have to compromise on one or more of these things because there isn't a connector that fits your needs perfectly.  

 

And that's just for one connector!  There are lots of other things that go into the board along with the board itself that can affect the quality, cost, and reliability of the device.

post #1931 of 5166
Quote:
Originally Posted by Saraguie View Post

I'm bought and paid for 6+ months already!  Anyone on the fence "Just Do It"

 

6 months 2 weeks, actually, but who's counting?  wink.gif

post #1932 of 5166
Quote:
Originally Posted by AndreYew View Post

The ribbon cable is also probably not usable for M8s that have to work out in the real world.  Depending on what Michael's transferring over that connector, he picked that connector balancing a variety of design constraints:  

AndreYew,
Thank you for the information. This was a very interesting read.
post #1933 of 5166
Quote:
Originally Posted by jacal01 View Post

 

6 months 2 weeks, actually, but who's counting?  wink.gif

 

You're ahead of me by 12 days! Really looking forward to getting this gem.

post #1934 of 5166
You guys beat me. November 4th for me. 6 months on Saturday. But as was said, who's counting.
Edited by aamefford - 5/2/13 at 7:12pm
post #1935 of 5166

Pre-order will end within 24 hours.

 

popcorn.gif

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