Page 13 of 23 FirstFirst ... 345678910111213141516171819202122 ... LastLast
Results 121 to 130 of 223

Thread: All-in-one Atom330/ION project

  1. #121
    Variable Bitrate
    Join Date
    Jun 2007
    Location
    Boston MA
    Posts
    364
    Damn it. I think I just fried my amplifier! I didn't notice that one of the speaker wires wasn't connected, so there was no load on one of the channels. I put the whole computer together and hooked it up to a new power supply I got from radioshack (13.8VDC, but close enough to 12 - none of the devices really care that much about 12V vs 13V). The computer and the screen turned on OK but the amp would stay off. I took the amp out of the box, hooked it up directly to the power supply and turned it on. The fan started spinning but then something popped on the amp - probably one of the capacitors blew? Either way, it started smelling like fried electronics so I think that was it for that amp

    There's a very small chance the fan fried, but I don't think fans die with a pop. I'm pretty sure that was a capacitor pop.
    Last edited by nivanov; 04-23-2011 at 07:41 PM.

  2. #122
    Constant Bitrate tibimakai's Avatar
    Join Date
    Feb 2005
    Location
    San Pedro, USA
    Posts
    180
    sorry to hear that. mine it's still in a plastic bag, waiting for a magnifying lamp to put it together. check if do you see some domed capacitors, those are gone. that's how I fixed an lcd monitor. I have found three capacitors with domed top, replaced them and it worked as new. maybe you are lucky. usually semiconductors go out the fastest like transistors, diodes and ICs.
    the amp doesn't have some kind of protection if a speaker is not connected?

  3. #123
    Variable Bitrate
    Join Date
    Jun 2007
    Location
    Boston MA
    Posts
    364
    So I've noticed that the "new" TDA7850 amp that's going on sale soon on mp3car is available on ebay for about 30 bucks. Has anyone ever used it? I've googled around and there was a discussion on mp3car forums about it before and soundman mentioned that it's not that great. I think it might be good enough for my requirements though. I still can't figure out two things about it - is it ok with voltage fluctuations or does it need a regulated 12V line? And does it have an on/off pin to prevent thump?

    EDIT: So I've checked out ByByte's spec sheet for this unit - it has no On/Off pins - it just turns on when power is applied to it. ByByte suggests using a 12V relay to prevent thump. In my case, I want to be able to turn on the amp using one of the serial lines (DSR, for instance). I'm not sure if I can do that with the relay though. I'd buy another AMP9 in a heartbeat but the assembled version has been out of stock for quite a while, so I might have to get one of TDA7850 from ebay - they have ones with a denoiser - whatever that is. They are cheap enough to allow that kind of experimentation.
    Last edited by nivanov; 04-25-2011 at 11:19 AM.

  4. #124
    Constant Bitrate tibimakai's Avatar
    Join Date
    Feb 2005
    Location
    San Pedro, USA
    Posts
    180
    You couldn't talk to the guys at the 41hz and try to fix the amp?

  5. #125
    Variable Bitrate
    Join Date
    Jun 2007
    Location
    Boston MA
    Posts
    364
    Quote Originally Posted by tibimakai View Post
    You couldn't talk to the guys at the 41hz and try to fix the amp?
    I'm not really sure what burned, so I don't really know how to fix it. The two big capacitors (they ARE capacitors, right?) seemed to be intact - usually capacitors get deformed when they blow, as far as I know. I visually inspected the board and couldn't identify the burnt part which makes it very difficult to fix it up, especially since I have very limited electrical experience. If you have any suggestions at all, I'd really appreciate it. I can upload hi-res pictures of the board, but I doubt you'd see anything in them.

  6. #126
    Constant Bitrate tibimakai's Avatar
    Join Date
    Feb 2005
    Location
    San Pedro, USA
    Posts
    180
    you should ask in the 41hz forum that in this case what blows? maybe is the amp ic and maybe it can be purchased separately and replaced by somebody who has the right tools and experience for a small amount.
    I'm pretty sure there are others who had the same issue.

  7. #127
    Variable Bitrate
    Join Date
    Jun 2007
    Location
    Boston MA
    Posts
    364
    I think it's more trouble than it's worth - diagnosing this amp would probably be a nightmare since I couldn't see which part blew up. I'm also not sure that not having one of the speakers plugged in actually fried it.
    I'm probably going to order the TDA7850 from ebay - it's much smaller so I'll be able to make a proper breadboard with ground loop isolator transformers instead of having them dangle inline. I'm worried that it doesn't have an on-off pin, but I think I can accomplish that with a relay, as indicated on bybyte.com . The relay they are using has 1 contact for remote on - do you think I can still do the serial cable trick to trip the relay that way? I'm pretty sure serial port ground and battery ground are really different grounds, no?

  8. #128
    Constant Bitrate kolton5543's Avatar
    Join Date
    Apr 2011
    Location
    Safford Arizona
    Posts
    170
    Quote Originally Posted by nivanov View Post
    [SoundMan, I hope you are still reading this thread once in a while]

    So I hooked up everything (monitor/amp/pc) to one power supply, similar to how it's gonna be hooked up in the car. Immediately I had two problems:

    1. I have a SPST switch on the IGN line, which is a line that branches off the power supply V-IN. That way, I get a constant line (simulates battery), a line with a switch (simulates ignition) and, of course, ground. I noticed that if I hook up the amplifier to the IGN line and throw the switch, the amplifier does not turn on and the power supply shuts off as well. I wonder if the amp shorts the line if it detects a problem? But what problem is there to detect? Of course there's some momentary noise on the line due to the switch flipping, but I thought this amp is OK with variable DC voltage.

    2. I switched the amp to get power from the constant line. I throw the switch, the power supply sends Power On signal and everything turns on great. Now I get noise coming from all the speakers. It's nothing too dramatic but would definitely be noticeable, even in the car (or maybe not, it's hard to tell in a quiet room). The sound still plays fine, but there's noise - the noise changes when I move the mouse or start a program. Without turning anything off, I unplug the amp wires from the sound card and plug in my headphones - no noise. I plug in the amplifier into my phone's headphone jack - no noise either. It's only when the amp is connected to the sound card that I get the noise. I'm aware of ground loop noise, but both of these parts are connected to the same ground and powered from the same power supply - how can there be any ground loops? [EDIT] I think I misunderstood how ground loops occur. I think it is a ground loop issue - I'll add ground loop isolators into the line and see if it helps.

    If anyone has any idea what's going on, please let me know!

    Some sound cards, weather the're onboard or external, make some noise do to low end parts or just improper installation. If you use headphones these sounds may not be audible but are still there. If you use a amplifier these sounds will be amplified and therefore become audible. I believe that may be you problem here although I could be wrong.

  9. #129
    MySQL Error soundman98's Avatar
    Join Date
    Jan 2008
    Location
    on the border of northern IL/IN
    Posts
    5,820
    i have had to retract that opinion-- all of the bybyte amps use a similar amp chipset as your 41hz amp, the actuall power output is a little different, but the audio characteristics should be the same..

  10. #130
    Variable Bitrate
    Join Date
    Jun 2007
    Location
    Boston MA
    Posts
    364
    Quote Originally Posted by soundman98 View Post
    i have had to retract that opinion-- all of the bybyte amps use a similar amp chipset as your 41hz amp, the actuall power output is a little different, but the audio characteristics should be the same..
    Hey soundman! Didn't know you still check this thread - good to have you here I had a quick question if you don't mind:

    ByByte posted a pdf about installation of this amp here. They use an automotive relay that has 1 pin for tripping the relay on and off. I'm planning on using a serial port line to trip the relay, but I'm not sure just soldering a DSR wire to the sensing part of the relay would do it - aren't grounds different in that case? As I understand, when Sense and V-in are shorted, the relay gives amp the power, so I guess I could use a secondary relay that would short Sense and V-in of the automotive relay when COM DSR and Ground are shorted. Any advice on my situation?

Similar Threads

  1. Integrate Solar Energy in your CarPC Project
    By hexxamillion in forum How to Power a Laptop
    Replies: 26
    Last Post: 11-26-2009, 09:58 PM
  2. Crowdsourced Map Data Collection, Mapping and Routing: project explained.
    By Heather in forum Crowdsourced Data Collection, Open Source Mapping And Routing
    Replies: 0
    Last Post: 10-02-2009, 09:26 AM
  3. DIN compatable PC project
    By don-m in forum Worklogs
    Replies: 4
    Last Post: 10-23-2005, 11:11 AM
  4. New Project: Contrast Mediaplayer
    By pplante in forum Software & Software Development
    Replies: 26
    Last Post: 07-07-2004, 12:06 PM
  5. RLion Project Webpage
    By Reactor in forum General MP3Car Discussion
    Replies: 0
    Last Post: 02-18-2004, 06:43 AM

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •