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LVjetboy
05-07-2004, 10:49 PM
Sony controller says 0.3 amps max. So what's the current draw for amp turn-on?
"Professional" installer says no more than two components w/o relay. Crutchfield says no more than four w/o relay. Sony tech say he's got no clue...take it to a professional installer. Idiots! Don't Sony technicians know what the specs are on current drain for amp switching? Nope. Can't look it up in his instant knowledge by computer system. Where's the specs on current draw for xyz amp turn-on?? Not in their lame ass installation guide either. Missing in action. I don't want word-of-mouth, folklore or opinions ranging from two to four components...just hard facts. Is that so hard?
jer

Havasu Hangin'
05-08-2004, 04:31 AM
I've installed quite a few systems...and I've learned two things:
1. Not all amp-remote drains are the same
2. It is a pain to fix once the head unit remote goes.
I've had them give out on as little as two amps. On my last system, I had 5 JBL amps w/no relay (Kenwood head unit). However, I installed one after one season (just to be safe).
A Bosch relay is around $7 and 5 minutes to wire...cheap insurance, IMIO (in my ignorant opinion).

Mr. Naudio
05-08-2004, 04:49 AM
A Bosch relay is around $7 and 5 minutes to wire...cheap insurance, IMIO (in my ignorant opinion).
Get the relay if you are concerned at all witch it would seem you are.
remote turn on from head unit to post 86
ground to post 85
batt positive to 87
post 30 is out to amp turn ons
post 87a can be left empty

1stepcloser
05-08-2004, 08:24 AM
I have always used relays to turn on the amps.
Like HH said, good relays are about $7.00 and a snap to wire in.
Cheap insurance to protect a head unit.

riverbound
05-08-2004, 08:48 AM
When we use more than 2 amplifiers on any system we run a relay just for safe measure.

ROZ
05-08-2004, 10:37 AM
you should fuse the 12v constant, the remote turn on, and fuse the leads to all the amps. ;)
Atleast throw a small fuse on your remote and 12 constant wires... 86 and 87 pins on the bosch relay.
The moment I go to multiple amps, I install a relay...
EDIT: Most decks have 200-500 millivolts on the remote turn on.

LVjetboy
05-08-2004, 11:11 AM
Thanks for the replies. A relay's not expensive, just didn't wanna wire one unless I had too. Then it hit me...duh...why not just measure the current? So I did...
http://members.cox.net/lvjetboy/RemoteAmps.jpg
A miserly 0.54 mA draw for this amp. So then I measured every amp I had...
Bazooka EL6A 11.75 mA
Sony Xplod 580W XM1002HX 1.10 mA
Sony Xplod 600W XM4060GTX 0.54 mA
Sony Xplod 760W XM2150GSX 0.55 mA
And from the internet...
C-7 TRU 1100+ W 33.0 mA
A bit of a range but none even close to my controllers remote maximum output current rating...
Sony Controller XR-C450 0.3 A (300 mA)
I could hookup a sh*t load before coming close to even half that. Looks like my newer amps draw less. But that expensive amp from the net ($2,500) draws a lot more. In the test review of the C-7 they mention a relay for more than one unit but go on to say, "Some decks in the past have had difficulty providing more than about 2mA. If using more than one amplifier, you will likely have to use a relay to turn the amplifiers on."
Some decks only supply 2 mA?? Jeez. If so you'd need a relay for only one of those bad boy amps draining 33 mA. Apparantly there's a wide range in controller remote capabilities too. At least with my deck, they were kind enough to print the spec. I don't understand why amp mfgs don't print remote current draw specs. Seems easy enough...and necessary to figuring out if you really need a relay. One less thing to go wrong.
Measuring current draw is simple and assuming no transient spike at turn-on, I'll be at 2.2 mA with the three amps I'm planning on running. Well below 300 mA.
jer

LVjetboy
05-08-2004, 11:26 AM
ROZ, did you mean most decks have a 200-500 milliamp rating on the remote turn on?
My deck says 0.3 amp (300 mA) max on the amp remote and 0.1 amp (100 mA) max on the antenna remote...so that jives with what you posted if you're talking mA. BTW, I've driven the Bazooka, XM1002 and XM2150 on just the amp remote from my Sony controller with no problems (13.4 mA). But when I bought the XM4060 I thought maybe I'd overload the controller amp remote based on "X number of amps," so I posted the question. Apparently, "X number of amps" is not a valid measure of either capability or limitation...which seems obvious now given the wide range in output to input specs.
I'm wondering if newer controllers may be rated less because newer amps require less?
jer