Author Topic: The mackie DL1608 white noise saga continued..  (Read 76764 times)

WK154

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Re: The mackie DL1608 white noise saga continued..
« Reply #30 on: September 30, 2014, 10:56:09 PM »
For iPad internal info I found the iFixit guys to be very thorough and have torn apart every iPad since V1.
https://www.ifixit.com/Teardown/iPad+3+4G+Teardown/8277
Too bad they're not interested in the DL1608. :)
My DL won't sing to me but I can consistently loose sync albeit with a 1M cable extension and battery charge at 80% or below.
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iBloke

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Re: The mackie DL1608 white noise saga continued..
« Reply #31 on: October 01, 2014, 08:05:51 AM »
Thankfully I rarely see the loss of sync issue from both docked or wireless iPads.

In fact even using my otherwise shitty dlink router (2.4ghz only in mostly crowded venues) I rarely see a drop out of sync.

I don't give a shit about the white noise issue anymore. Apple? Mackie? Both? Don't care.
Its obviously an issue that ain't gunna be fixed so I've moved on...

After quite a few gigs with the DL I couldn't stand going back to a static mixing position on an analogue mixer that requires a ton of outboard gear for both FOH and monitors, which for past few years has been side stage, and at the last gig to be able to stand next to the relatively fussy bassist/vocalist and tune out the "honk or whatever" in real time is worth the price of DL1608 entry alone.


Kev tyler

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Re: The mackie DL1608 white noise saga continued..
« Reply #32 on: October 01, 2014, 09:28:05 AM »
My mate has a pacemaker, it is affected by proximity to LCD monitors and other things, he has collapsed a few times and the people who make the implant deny that outside interference can possibly be taken serious.

I saw on the news that we will be charging all our  batteries by rf soon,

Progress?

gerenm63

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Re: The mackie DL1608 white noise saga continued..
« Reply #33 on: October 01, 2014, 10:05:09 AM »
My mate has a pacemaker, it is affected by proximity to LCD monitors and other things, he has collapsed a few times and the people who make the implant deny that outside interference can possibly be taken serious.

Thanks for this little nugget, Kev. My dad has occasional problems with his pacemaker that no one seems to be able to figure out. He spends a lot of time on the computer -- particularly his laptop.
Geren W. Mortensen, Jr.
Westminster, Maryland, USA

Kev tyler

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Re: The mackie DL1608 white noise saga continued..
« Reply #34 on: October 01, 2014, 05:44:31 PM »
He said its all manner of leccy stuff, if it's too close, he gets a timing problem

Tell your dad to be careful testing this theory out

 :)

Kevin

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Re: The mackie DL1608 white noise saga continued..
« Reply #35 on: October 01, 2014, 05:48:32 PM »
Here are some measurements of the charge cycle for an 18 mo old Gen 3 iPad, with the DL1608, and Apple 10W and 12W chargers

To measure current from the DL, I popped the plastic housing off my old Patazon 3ft 30 pin cable, cut back about an inch of the jacket in order to separate out the red usb power wire (pin 23) and measured it with a current clamp meter (accurate to 1% and calibrated a few months ago).  Voltage readings were from Pin 23 to 15.

http://imgur.com/DQ6fL70

Under no load, the DL puts out 5.01v

With the iPad battery completely discharged, so that the iPad is unable to boot, the DL puts out 0.48A (dumb USB mode) and voltage drops a bit to 4.94v. Interestingly both the 10W and 12W apple chargers put out about 1A in this mode, and have a lot more of a voltage drop (~4.2v)

When the battery gets to 2 percent charge (so that the iPad is just barely able to boot), the current from the DL goes to 2.01A and the voltage drops to 4.69v. I put a scope on pin 23, expecting to see a sawtooth waveform on top of the rail, with a spike on the rising edge, but it actually looked pretty clean, with a solid 4.7v rail (I'm still not sure I believe this though, and might try to borrow a better scope for further testing).

At this point, the apple 10W charger was putting out 1.03A @4.21v and the 12W was putting out 1.05A at 4.24v. This is the most current that they put out during the whole charge cycle, and is only about half of what they should be able to produce. In order to measure these, I had to plug them through the 3 ft Patazon cable, so the total charge cable length was about 6 feet. That could have caused them to cut their current back, although the iPad did display "charging". If I can find an extra iPad charging cable, I might open one up like I did the Patazon and see how these two chargers work when there is only 3 feet of cable

The DL continued to put out about 2 amps until the battery was somewhere between 50 and 65 percent (I wasnt watching it closely enough to see exactly where it went into CV mode). By 65 percent, the current had cut back to 1.85A and it slowly dropped until it got to 1.50A at 95 percent - which is where things started to get a little strange.

At 95 percent, I was still seeing dropouts with MF, which was unusual. Then, while playing with MF, the SOC went straight from 95 to 100 percent in a blink. Next, when unplugging and re-plugging the cable to get my synch back, the current from the DL dropped from 1.50A to 0.89A, at which point I had a solid connection.  Unplugging and re-plugging the 30 pin cable, sometimes I would get ~1.5A, in which case MF could not keep the synch and sometimes I would get ~0.90A and have a solid connection.

What is probably going on here is that when the iPad first displays 100%, it is not really at 100%. This has been documented elsewhere. In reality, the battery is still halfway down the CV curve. It turns out that 0.89A is the current draw for my iPad running MF when the battery is completely charged. So at this point, the iPad's charger is having trouble deciding what to do. Plug the cable in once and the iPad thinks it still should be charging and pulls 1.5A. Plug it in again and it thinks the charging is done and just pulls what it needs to run the iPad. All the time, the battery display is 100%.

By this point it was getting late, so I disconnected the iPad from the charging cable and left it sitting overnight. The next morning it was at 97 percent and when I ran MF, it almost immediately dropped to 93 percent. That was not too surprising since it didnt really charge to a full 100 percent the night before (even though the display said it did). What was very strange though is that now when I plugged the iPad into the DL, it was only drawing 16mA, which is much less than the current needed to power the unit. The 10W and 12W apple chargers were only supplying 7mA and 8mA respectively, so this appeared to be an iPad issue, not a DL issue.  During this time MF would not synch at all, even though I would normally have no problems at 93 percent. Then, to make matters more confusing, the battery indicator ticked up to 94 percent. It was impossible that the battery could actually be charging because the iPad needs ~0.8A just to stay on and the DL was only putting out 16mA.  I then played some music through the iPad speakers, just to use more power and let it go for about an hour. During this time, the battery level crept up to 100 percent again, even though the most the iPad ever pulled was 17mA. Over the course of an hour with the iPad's display on and music playing, the actual battery charge would have dropped by about 3-4Whr - even though the indicator said it was charging! So clearly the iPad charging logic has some issues. At the end of the hour, I checked the iPad draw from the Apple chargers again, and they were still only putting out 7-8mA. I powered the iPad down and back up again and same thing. Unit displays 100 percent, and only draws a few mA from the DL or either Apple charger. This looks to me like some sort of bug in the iPad's charging circuit, which happens right around the time that the battery display goes to the false 100 percent charge (but battery is still in the middle of the CV curve). In retrospect, I should have tried docking the iPad to see if it had any effect. I might try this again to see if I can replicate it. I suspect that when the iPad gets into this mode - right at the onset of the "false 100 percent" charge, the iPad can lock up in a state where it wont synch to the DL and wont take a charge. This appears to be the iPad's issue, not the DLs. Running into this at a gig would really, really suck.

Next, I powered down the iPad and left it for an hour. When I powered it back on, the battery display was still at 100 percent, but the DL was putting out 1.5A again, so at least the iPad realized that it was supposed to be in CV mode and was drawing a reasonable current. I let the iPad go to sleep mode, at which point the charge current went to 0.87A and tapered down to 0.22A over 90 minutes. After 3hrs, it reached what seems to be a steady 0.11A.

At this point, the DL and iPad went back to being their old normal selves again. Power draw from the DL was about 0.8A to 1A while MF was running and MF had no problems keeping synch with other programs running. However playing around with the setup some more, I realized that "normal" is not quite what I thought it was.

It turns out that keeping MF from dropping out is not really so much of having the battery fully charged, but keeping the current draw from the DL below about 1.2A (for which a full battery is needed). If I increased the brightness of the iPad display to about 3/4, I would get periodic drop outs, and at full bright (about 1.5A), it wont hold synch at all. No problems at default and lower brightness settings.  Even my 6 ft Cable Jive cable (normally rock solid at full charge) drops out after about 15 min at full brightness on a fully charged battery. The 2ft Cable Jive has no problems at full bright (or any other condition that I've run into so far).

That's about all I have time for this week and still a lot of open questions, but I figured I'd throw these results up to see if anyone else has some insight as to what might be going on.

TLDR: Looks to me like the problem(s) might be with power distribution on the iPad, but further testing is needed. In the meantime, if you are having disconnect problems, make sure that the iPad battery is fully charged (not just displaying 100 percent - give it a good 2 hours of charge time after it gets to 100 percent). If you are still having problems and dont want to hack a 30 pin cable, try reducing your display brightness and see if that helps






stevegarris

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Re: The mackie DL1608 white noise saga continued..
« Reply #36 on: October 01, 2014, 06:23:54 PM »
Thankfully I rarely see the loss of sync issue from both docked or wireless iPads.

In fact even using my otherwise shitty dlink router (2.4ghz only in mostly crowded venues) I rarely see a drop out of sync.

I don't give a shit about the white noise issue anymore. Apple? Mackie? Both? Don't care.
Its obviously an issue that ain't gunna be fixed so I've moved on...

After quite a few gigs with the DL I couldn't stand going back to a static mixing position on an analogue mixer that requires a ton of outboard gear for both FOH and monitors, which for past few years has been side stage, and at the last gig to be able to stand next to the relatively fussy bassist/vocalist and tune out the "honk or whatever" in real time is worth the price of DL1608 entry alone.

Yep. I've never heard white noise and my DL rocks!

WK154

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Re: The mackie DL1608 white noise saga continued..
« Reply #37 on: October 01, 2014, 11:24:10 PM »
Kevin great job. :thu: I have yet to start with the cable test, waiting for a USB meter. I'm glad we both have the same iPad 3 and probably the same vintage DL which should make comparisons simple. Since I started at the "100%" battery charge point because I needed to be connected to see where it would drop sync my results are only centered around that issue.  From what I've read so far the results are similar in those areas. I tried to find a spec sheet on the power management chip that Apple uses but apparently that spec has been carefully purged from the Internet. The part is Qualcomm's PM8028correction Apple 343S0561. This is the mystery IC causing the strange results we observed. We can only speculate what happens to the battery beyond the 5V source unless you're up to taking your iPad apart. I will get to some of it by weekend. A separate load test on the DL should give indications as to who is dropping the current. The data lines need to be monitored for control status as well.
« Last Edit: October 03, 2014, 05:21:59 AM by WK154 »
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Kevin

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Re: The mackie DL1608 white noise saga continued..
« Reply #38 on: October 02, 2014, 04:10:28 PM »
WK154 - Thanks for the link to the ifixit teardown of the iPad 3

The Qualcomm PM8028 looks like the power management chip for the cell radio subsystem, not the main power management chip.

The main power management looks like the Apple 343S0561, which you can see in step 19.  According to a teardown done by tech insight, this contains a Dialog D1974 power management unit. No datasheet for that either, but Dialog does make some similar stock parts that perform this function

http://www.techinsights.com/teardowns/new-apple-ipad-gen3-teardown-analysis/
http://www.dialog-semiconductor.com/products/power-management

It looks like the DL1608's iPad charging circuit may be just a current source which responds to the controller on the iPad. Power comes into the iPad's main logic board through the ribbon connector on the bottom left hand side of step 19, and into the power management section immediately adjacent. Power to/from the battery appears to travel along the edges of the PCB and around the micro and BT/WiFi sections, to the five gold pins that make contact with the battery pack, that you see on the bottom left of the step 15 image. Not sure why the battery contacts werent located closer to the main power management section.

WK154

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Re: The mackie DL1608 white noise saga continued..
« Reply #39 on: October 02, 2014, 09:25:30 PM »
Hummm missed that one but unfortunately the same problem, no specs. All in all we can't do anything about that anyways so we need to focus on what matters. I need to find out what kind of signalling exists between the DL and iPad via the D+- lines. This could be simple voltage levels or it could be messages as per USB spec. Of course who's paying attention to the spec? There is no point to focusing on LiPo charging since it has no real bearing on the problem. I'll make the assumption that Apple has that well under control from their track record via the power management chip. It's the actions of the DL and MF that determine sync status. Quite frankly the charging circuit should have nothing to do with the communications path. Mandolin is the protocol that send messages and data between the DL and iPad via 3 other lines TX,RX,Gnd. These along with iPad information apparently are used to determine sync status. Some of this will be cleared up when the D+- lines are monitored. Shutting down the communication link without serious transmission errors is lunacy, especially if it's based on charging status. The TX/RX lines need to be monitored and that requires a lot of work (reverse engineering Mandolin). If the decision is based on internal iPad indicators alone then code knowledge is required to determine that. Good luck getting your hands on that. Too bad my rig from DOS 5 days is gone, I designed and wrote a monitor for RS232C duplex communication. It payed for itself in no time. You can buy communications monitors but they are pricey and usually specific to protocols although most will give you raw data. The best we can hope for is to characterize the actions and avoid clear problems, Mackie is the one that can fix it. :(
« Last Edit: October 02, 2014, 11:13:22 PM by WK154 »
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iBloke

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Re: The mackie DL1608 white noise saga continued..
« Reply #40 on: October 05, 2014, 04:58:55 AM »
I bought an iPhone 6 today. While I was at the apple store I also bought an apple 30 pin to lightning adapter lead which measures 200mm long.

I've used it to plug my iPad mini into the DL.

I've been playing music directly from the "docked" iPad mini for a cuppa hours now and have not had one incident of the dreaded "white noise".

This is a first for me!

Prior to this I used 3 full sized iPads, all with 30 pin dock connectors.

2 x iPad 2's, and my iPad 3.

These 3 iPads ALL produced the white noise blast with both the DL1608's I've had. (I sent the first DL back coz it was so bad. The current replacement is much better, but still has random white noise blasts)

The iPad 3 is on ios 7.1.2, and the iPad 2's are on iOS 7

I've got all my fingers and toes crossed the combination of iPad mini/iOS 8.0.2/30 pin - lightning adapter will remain white noise free.
Coz if it does I've just gained an extra 2 channels on the DL.

Wish me luck  ;D


robbocurry

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Re: The mackie DL1608 white noise saga continued..
« Reply #41 on: October 05, 2014, 07:45:05 AM »
That's the exact combo I use iBloke and never have problems. Hope it's the same for you  :)
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iBloke

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Re: The mackie DL1608 white noise saga continued..
« Reply #42 on: October 05, 2014, 09:03:40 AM »
That's the exact combo I use iBloke and never have problems. Hope it's the same for you  :)

G'day Robbo.

Reeeeeeeally good news....so far.

It's currently 7:40pm and my iPad mini has been running non stop for hours, (sorry I'm too drunk to work out the exact amount of time right now) but I've never been able to play music from the docked iPad uninterrupted for so long.
I've even tried to make the white noise happen by opening, and using as many apps, and mucking around with as many settings in master fader as I can.
I haven't been able to induce the white noise no matter how hard I've tried.

Now, I don't wanna jump the gun, and maybe Jinx myself, but this is the most stable behaviour I've seen from a DL1608, and I've had 2 so far.

As far as the technical issues behind this issue are concerned, I wouldn't have a clue.
WK154 has been incredibly helpful since I bought my first DL and quickly discovered its white noise thing.
As I've already said, I tried 3 different iPads (30 pin dock connector) and had the same white noise from each, to varying degrees.
 
And I've been told to "shut the f*** up", and to "f*** off" by one particularly ignorant cacophony forum member who blamed my white noise problem on both me, and the iPads I've used

Anyway it's nearly 8pm now and the music is still playing with zero incidents of white noise.

I'm quietly confident I now have a 16 usable channel DL :)

And after last nights incredibly successful gig I'm feeling pretty chuffed right now
« Last Edit: October 05, 2014, 09:08:48 AM by iBloke »

Kev tyler

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Re: The mackie DL1608 white noise saga continued..
« Reply #43 on: October 05, 2014, 09:22:06 AM »
So what is different in your set up, is it the new lead, sorry just got up.
Cheers

Kev

robbocurry

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Re: The mackie DL1608 white noise saga continued..
« Reply #44 on: October 05, 2014, 09:24:21 AM »
Happy daze iBloke👍😉
The older I get, the better I was!