Build Your Own Arcade Controls Forum
Main => Audio/Jukebox/MP3 Forum => Topic started by: MrD on July 13, 2005, 11:30:22 am
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I think I'm going to go the car amp route in my jukebox.
Does anyone have any experience with a Chiefmax power supply?
They have a 650 watt model with 12v 34A. That should be enough to run a main amp, and possibly a sub amp as well. I'm concerned about "noise". I know all power supplies are not created equally.
http://www.chiefmax.com/psu/cm650.php
Anyone ever use one of these?
Thanks
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I'm going to be using these...
http://www.newegg.com/Product/Product.asp?Item=N82E16817182002
Same output as the Chiefmax, +12V@34A.
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I ended up buying one of the chiefmax ones just to test with my amp. I had to "fake it" to believe the power was ok. I put an automotive stop/turn light bulb and socket on the +5 and +12 sides. (The bulb has two filaments inside). When I hooked the power supply to the amp it would start, and then after a couple of seconds later it would shut down. After some research I found out the power supply needs some load on the +5 and +12 side to feel like it's ok. After I installed that, the PSU and amp works great. Neither the amp or the power supply get warm at all, even for extended time periods. (If I can find the article a saw about using the light bulb, I'll post it). I had tested it first on a 2amp regulated power supply. It would run fine until there was some bass and then it couldn't supply enough power. It confirmed what I had thought, that even though amps are higher rated, they hardly ever draw the max.
As an aside, I was at Lowes last night for a totally unrelated reason. As an alternative to this kind of supply, you can get a transformer that is used for outdoor landscape lighting and pond pumps. They are 12v. Some are up to 500 watts. Which would be about 40+ amps. You can get those on ebay cheap. And for an added bonus you could have it turn on and off for you. LOL.
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Those transformers are AC output however, you will need to add a rectifier and capacitor to get DC, and if I recall correctly, 12 volt AC will give you more then 12 volt when rectified so it may not work quite right.
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I just want to drop in here and mention that this article is great and shows how to wire everything up with a single resistor. I'm actually hooking this up tonight on a ChiefMax 650. Cross your fingers :)
http://web2.murraystate.edu/andy.batts/ps/POWERSUPPLY.HTM
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Ok, just an update. I followed the directions on that site I listed in my last post and they worked perfectly on my first try. The only issue is that you will need to dissapate heat quickly on the resistor as it gets HOT fast on a 650 watt PS. I'll be getting several more of them tomorrow so I can run them in parallel to reduce some heat.
I do question how much of a speaker setup you can run off a 650 watt power supply. I don't think Im getting enough juice at 35 amps to run my 12" subwoofer along with my 6"x9"s properly. I might be mistaken but the subwoofer was much quieter then I expected and it started distorting a bit at significantly less then full volume.
Have fun!
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That seems like quite a load even for a 650W power supply. My set up has a 30W/channel car amp, a powered Bazooka sub, and two 5x7 car speakers. I assumed from the start that the PS would not handle this type of load, so I went to Radio Shack and picked up a a 15A 13.8V power supply/converter:
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=22-508
I'm not planning on making ears bleed with my sound set-up, so I think the 15A should handle the load (they also have a 25A model). Not a cheap solution, but it should do the job.
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Doh! I meant to come back in here and update the thread after last night. My 650 watt computer power supply puts out 34 amps at 12 volts. The bass problems I were experiencing had to do with me being a moron. I hadn't mounted the subwoofer in the bandpass yet and was expecting too much from running it free-air.
Now that it's mounted properly, it pounds like crazy with no distortion. In the end, I'll be running two 6x9s, two 5 1/2" components and the 12" sub. Even with all that, it sounds great and still gets ear-bleeding loud with no problems. The bass can have a pretty low gain as you are very close to it when standing at the cab. I'm pretty sure almost all the amp draw comes from the bass.
Have fun!