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#4899 - 20/08/1999 16:37 My review II (#53)
jfranke
member

Registered: 09/06/1999
Posts: 124
Today was work - i put the unit in the car :-) Had to modify the slot a little since the init didn't go all in, then it was OK.

Then, cabling work. No big deal since i had a stereo in there before. After an hour all was connected and i switched the empeg on - wow, noise noise. OK, i forgot to lower the input level of the pre-amp since the stereo before had a .8V out. After doing that, it was hard to hear the noise, so that went fine. RTFM.

Then i started the car, but after it started the empeg was hung. So i pulled out the unit and back in - came back to life fine. Another try, same result. Whenever i start the car, the empeg is hung. I tried both, permanent and ignition + with the same result. When the unit was on constant +, thought that might fix the issue. No luck. + is on all the time, but the starter sucks so much power that the voltage drops so low that the empeg stops operating - at least this is my guess. So here the same result. I have to take the empeg out and back in to get it back. This is what i am doing now all the time. Before i start the car, i pull the unit, when the car is running, i stick it back in.

I don't know what will happen if a put all the amps on power. I got about .7KW RMS in the car, thats about 1KW power which will drain like 90A @ 12V out of the battery, almost the same the starter uses. Since the unit hangs up with the starter, i guess it will hang also wenn the amps will run 'full speed'. I will try that one day.

Exept that, all is working. The visuals look way batter when the unit is mounted in the dashboard. At night...Very cool.

Many features to come here, according to Hugo. Curious to see what future relases of the software will allow us to do...

I still miss the wire to mute the empeg when a call phone call comes in - but maybe one day there will be a device for the serial port which can do such things - via software!

Thanks for your time! AO


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#4900 - 23/08/1999 01:52 Re: My review II (#53) [Re: jfranke]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3452
Loc: Palo Alto, CA
As far as we can tell, the "hang" is to do with the "ohmigosh, I've lost power" interrupt, which casues the empeg to save its state to flash - basically, if it gets a false one of these, the empeg stops (ie false=voltage drops below 10v but not to the point where the CPU reboots). We're having problems replicating the situation in our own cars, but we have a couple of ideas which will hopefully make it into the next beta which may well address this problem.

Hugo



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#4901 - 23/08/1999 03:09 Re: My review II (#53) [Re: altman]
jfranke
member

Registered: 09/06/1999
Posts: 124
It may have problems with power in general. Yesterday, i found another very strange symptom: The engine was off, the empeg was playing fine, but the display was off. I reset the empeg like 5 times, with no change. It was playing fine, but blank display. I was thinking that the display is broken for some reason. Then i was starting the car and reset the empeg once more, and the display came up fine. My guess is that the display will fail if the power is too low. I could imagine my batterie is pretty used up, but it is only about a year old. Also the car starts very well, the battery doesn't 'sound' like weak - i mean the starter, not the battery :-) I will measure the voltage to find out more. Also, i will measure to which extend the voltage drops when using the starter.

Thanks, Jo


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#4902 - 23/08/1999 08:23 Re: My review II (#53) [Re: jfranke]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3452
Loc: Palo Alto, CA
No, the display being blank at low voltage is the powerfail interrupt kicking in too - this is the same software fix as the other power problem.

It's not necessarily very low voltage, but there is a dip in the (empeg's) local power when the display filament heater starts up, as this takes 250ma @ 5v and this can, in low voltage (less than about 12.2v) trigger the powerfail interrupt - which, as a matter of course, blanks the display...

You may have problems measuring the voltage drop when the starter is running as most multimeters have long sample periods - a storage scope is probably required.

Hugo



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#4903 - 23/08/1999 15:12 Re: My review II (#53) [Re: altman]
tanstaafl.
carpal tunnel

Registered: 08/07/1999
Posts: 5398
Loc: Ajijic, Mexico
Would some sort of UPS (Uninterruptible Power Supply) like I have on my home computer be feasible? Of course there aren't any 12V DC UPS's out there, but for the team that designed the empeg, this ought to be a piece of cake. Just a small rechargeable battery (Nicad? Lead/Acid gell-cell?), a re-charging circuit, and a very fast switching relay that would isolate the empeg from the vehicle's power source and supply proper voltage until the vehicle's system voltage was back up to the normal 13.6v. You would only need enough battery power in the empeg UPS to keep it running for half a minute or so, the whole thing could be as small as a pack of playing cards. Sell it as a $100 option, you could mount it on the back of the docking tray, or anywhere under the dash.

Of course, it's easy for me, wallowing in monumental ignorance of things electronic, to tell you how easy this will be....

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"
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"There Ain't No Such Thing As A Free Lunch"

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#4904 - 23/08/1999 15:43 replicating blank display [Re: altman]
Clarke
journeyman

Registered: 18/08/1999
Posts: 90
Loc: Scottsdale, AZ USA
Hugo, I found an easy way to replicate the blank display problem. As you indicated it's related to the voltage available and the amount of current the unit can pull. I bought a car lighter adaptor at the local electronics store that takes the 12V in and has switchable output 3, 4.5, 6, 9, and 12v out. I wasn't thinking when I bought it but it's current limited to about 300ma. Cost about 20 USD, I can send it to you if you want to play with it - I've got a better adapter now.

When I used it with the empeg at the 12V setting the empeg would boot and play music and if I remembered the buttons correctly I could control the unit but no display. None at all. Everything worked but the display. You should be able to replicate the problem with it.

There is a definate problem with momentary voltage drops rebooting the unit. When ever I start my car, the empeg blanks for about 7-10 seconds and then starts to reboot.

=-Clarke
#351, SN 00045

Cheers,

_______________________________
List 351, empeg 00045, 10gb, Amber
_________________________
______________________________________ Queue 351, Mk I, 30GB Mk II #60000022 80gb, Blue - docked Mk2a, 80GB, Bruface, lighted buttons and dial

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#4905 - 24/08/1999 09:43 Re: replicating blank display [Re: Clarke]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3452
Loc: Palo Alto, CA
The PSU you use probably droops like anything if it's only rated at 300ma, hence the blank display.

Monentary voltage drops will cause a reboot - well, starting your engine is generally at least 1 second of cranking, which gives a huge voltage drop (below the 8v level where the PSUs will still work). This is totally expected - every car radio I've owned has reset during cranking the engine, it's just that the empeg takes a little longer to reboot.

Hugo



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#4906 - 24/08/1999 21:56 Re: My review II (#53) [Re: tanstaafl.]
Jake
stranger

Registered: 09/06/1999
Posts: 28
Loc: MN, USA
Ask your local car audio experts to explain to you the advantages of having a second battery for your car stereo. They are usually used for a large amp setup but a second battery might do the trick. Hugo - any comments?

Jake


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#4907 - 25/08/1999 08:34 Re: My review II (#53) [Re: Jake]
NasalGoat
member

Registered: 23/08/1999
Posts: 129
Loc: Toronto, ON, Canada
A second battery is only useful if you sit in the car with the engine off listening for long periods. It's no helpwhile the car is running.

If you have problems with dropping out, I suggest an alternator upgrade.



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#4908 - 02/09/1999 06:56 More power... [Re: NasalGoat]
spoulson
new poster

Registered: 30/08/1999
Posts: 10
Nasalgoat is 100% right. The battery(ies) do nothing when the car is running. It is the alternator's job to supply power from that point on.

However, how about this thought... Would a 1/4F or 1/2F capacitor, like you see on large stereo installs, provide power long enough to keep the unit running? I'm not an electrical wizard when it comes to calculating figures, but a large capacitor would definitely dampen the voltage drop, possibly to the point that the unit will never see it. Should that work, the only other problem is locating the capacitor somewhere. 1/2F caps are kinda big and you want to protect its leads against a short.

---
Shawn Poulson
[email protected]
_________________________
---
Shawn Poulson
[email protected]

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#4909 - 02/09/1999 09:06 Re: More power... [Re: spoulson]
Jazzwire
addict

Registered: 09/06/1999
Posts: 483
Loc: Guernsey
I've got a 1.7F cap on my amp, so I wonder if I could use that...
I'd have to switch powerleads from the accessory switch to the perm +ve of course...
Worth a play I think.. =)

Jazz
(List 112, S/N 00030, 4 gig blue)
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Jazz (List 112, Mk2 42 gig #40. Mk1 4 gig #30. Mk3 1.6 16v)

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#4910 - 02/09/1999 10:00 Re: More power... [Re: spoulson]
NasalGoat
member

Registered: 23/08/1999
Posts: 129
Loc: Toronto, ON, Canada
A cap such as you describe would offer no real benefit. The reason they are used with amplifiers is because they do offer some voltage stability during the transient low bass hits, when the amp is drawing the most power. However, it is important to note that these intervals are measured in microseconds - the voltage drop described here is much too long to really be solved by a cap.

Your best bet is to get a bigger alternator, or try that Jacobs Accuvolt. I have no experience with it, so YMMV.


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#4911 - 04/09/1999 06:20 Re: More power... [Re: spoulson]
steve
stranger

Registered: 08/06/1999
Posts: 48
Loc: Cambridge, UK
How about doing the maths...
Energy in a capacitor = 0.5 * C * V^2
Energy in the cap when it's charged to 12V (12V is roughly right- a non-running car, with a 0.3V Schottky diode in series) = 72J * C
Energy left in the cap when the Empeg unit stops running (at 8V?) = 32J * C
so you've got 32Joules times the size of your capacitor to play with.
The Empeg unit takes about 8W (8 joules per second), IIRC.
If your car takes 2 seconds to start, you'll need a 0.5 farad cap. Not unreasonable. Note that there's no slack in there, and some of my assumptions may be wrong, especially the cutoff-voltage one. It's not impossible, though...

STeve


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#4912 - 05/09/1999 02:14 Re: More power... [Re: steve]
steve
stranger

Registered: 08/06/1999
Posts: 48
Loc: Cambridge, UK
Yeah, there's 40 joules in the cap (72 - 32). Doh.
While tidying the lab, I found a promising datasheet-
http://www.powerstor.com have some aerogel based capacitors, they're only good for 2.75V, so you'd have to use balancing resistors (or zeners, I guess...) stop them hogging volts, but an AA size package (14mm diameter, 50mm long) gets you 10 Farads, and a 1/2 length AAA gets you 1.3 Farads. Samples are available at $25 a shot.

Steve


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#4913 - 06/09/1999 04:28 blank display and hang at engine start [Re: altman]
danthep
enthusiast

Registered: 29/08/1999
Posts: 209
Loc: new zealand
You mention somthing about a software fix, does this mean the problem is fixed in beta6? Using beta5 i also get both these problems; often when i start the empeg it runs fine except no display, this is fixed by starting the engine while it boots, i can then stop the engine and it runs fine. When starting the engine cold, i've never had it hang, i guess cause the empeg loses power for long enough to reboot. But when warm, i.e after stopping to fill up with petrol, it only takes a quick crank and then the empeg will be hung, i have to pull it out for a minute or so, then put it back in.


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#4914 - 06/09/1999 04:31 Re: replicating blank display [Re: altman]
danthep
enthusiast

Registered: 29/08/1999
Posts: 209
Loc: new zealand
another way to replicate the hang after starting the engine, run the empeg using the empeg ac adaptor. quickly remove and then replace the power connector (with about 2 seconds).


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#4915 - 06/09/1999 07:17 Re: blank display and hang at engine start [Re: danthep]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3452
Loc: Palo Alto, CA
Hopefully the problem is fixed in 5c onwards - try beta6 and see how you get on.

Hugo



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#4916 - 09/09/1999 19:47 Re: blank display and hang at engine start [Re: altman]
danthep
enthusiast

Registered: 29/08/1999
Posts: 209
Loc: new zealand
I'm running beta six now.

When i turn the car on to accessory the display now comes on and the boot logo displays. But there it frezzes, with the boot logo on the screen, no music, no menus, no response.

Haven't tested the hang after short power loss (eg when starting engine) as commuting to work doesn't give the engine a chance to warm up. I'll be able to test that bugfix throughly this weekend while i'm away skiing at treble cone [http://www.new-zealand.com/TrebleCone/index.html] though.


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#4917 - 23/09/1999 20:36 Re: blank display and hang at engine start [Re: danthep]
danthep
enthusiast

Registered: 29/08/1999
Posts: 209
Loc: new zealand
OK, the hang after short power loss seems to be fixed for the most part.

However it is still not booting the first time unless the engine is running. It will usually boot up if the engine has been running very recently, but leave the engine turned off for more than 5 minutes and the empeg will hang as it boots up when you turn the keys into Accessory.

I checked the voltage coming out of the 2 year old battery one cold morning and it was a good 12.4Volts.




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#4918 - 24/09/1999 01:31 Re: blank display and hang at engine start [Re: danthep]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2992
Loc: Wareham, Dorset, UK
I've observed this too; why the empeg should hang at the Tux screen I really don't know. It requires an engine start, as you experienced, to get off the ground. Any ideas, Hugo?

_________________________
One of the few remaining Mk1 owners... #00015

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#4919 - 24/09/1999 07:50 Re: blank display and hang at engine start [Re: schofiel]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3452
Loc: Palo Alto, CA
The idea I currently have is that the 3.3v is staying stable but the 5v is wobbling enough to upset the hard disks - It's on the to do list to investigate. We can reset the hard drives in software, so this may be an option after a powerfail condition.

Hugo



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#4920 - 06/10/1999 17:35 Power drops/protection...Re: blank display and hang at engine start [Re: altman]
jimhogan
carpal tunnel

Registered: 06/10/1999
Posts: 2591
Loc: Seattle, WA, U.S.A.
My interest in the empeg is more for my sailboat than my car. I have having boxes of CDs sliding around on the boat. I am rewiring a lot of the DC on the boat and am looking at adding a capacitor-based unit from Newmar Marine that is supposed to keep radar, GPS, and other instruments from re-booting when you crank the diesel. Street price for this unit is ~$125 U.S. Even if software improvements make the unit more power-dip-proof, I may try wiring up the Empeg to the Newmar unit on the boat -- cranking voltage drops for the diesel (a Universal/Kubota) seem a lot deeper than the average car.

OK, I installed new speakers in the cockpit last weekend. I'm ready! I'm pumped! I'm.....#8705..... Um, sailing season's tailing off anyway.

Jim
Seattle, WA

_________________________
Jim


'Tis the exceptional fellow who lies awake at night thinking of his successes.

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#4921 - 11/10/1999 15:38 Power drops/protection...Re: blank display and hang at engine start... fixed? [Re: jimhogan]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3452
Loc: Palo Alto, CA
Just a quick note for anyone monitoring this thread who hasn't looked in the bugs section recently - we've released an upgrade patch to 7a which (in our experience) appears to totally cure the power up problems. We'd appreciate feedback from people on this before the next release - the upgrade is available at:

http://www2.empeg.com/upgrades/test/interim/

Comments about it are probably best put in the bug reports thread, though.

Hugo



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