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mogwai
Account closed
Registered: Mar 2005
Posts: 5 |
SID burn protection
I am planning to build a SID protection card in order to prevent more SIDs for travelling to silicon heaven.
goto80 and I was discussing the problem and he asked me to build something for him since he was burning so many SIDs during his performances.
Anyway, the reason for posting this topic in this forum is that I need as much information as possible regarding what is causing the problem. So I was wondering if you could give your stories about when you toasted your SIDs.
My guess is that it is caused by ESD. Since the C64 design is using a serial resistor connected to a transistor follower design on the audio output it is probably not caused by excessive current so my only theory right now is ESD when connecting the audio. However it is only a theory and I need as much input as possible.
If you have any nighttime horror stories about the time when your SID passed away, then please tell me. I need as much detailed info as possible regarding what you did, which cables were connected, to what, in what order or if you didn't do anything and it was just dead one morning etc.
Looking forward to your stories.
P.S. Sorry, accidentally placed the question on the coding forum. Don't know how to remove it. Reposting under general discussions.
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Conrad
Registered: Nov 2006
Posts: 849 |
Good thing you asked actually, because I've been worrying about the SID chip in my own c64. For quite a few weeks now it is producing unpleasant spitting noises every time a low filter cutoff frequency is executed, this being an 8580r5 model so it produces much deeper filters than the 6581. The distortion also reduces the volume of sound output slightly and increases back to normal state after a few seconds of silence.
I still can't remember why it's become like this though. It's either for two reasons. Firstly, my computer is a 1991 C64C with no modifications at all (apart from a spray paint :) so the SID chip itself is about 17 years old - thus it may be due to aging, even though it's been cleaned recently.
Or secondly (which I'm thinking THIS is the reason.) I accidentally plugged in a QuickShot QS-137F joystick into port 1, forgetting that the joystick mode was in MSX mode (it has a mode switch for the joystick to be compatible with other platforms using the DE-9 gameport as well as C64). I pressed fire and the whole RAM and screen completely scrambled like hell, looking like a form of power surge. This could well be as you mentioned, ESD, and I'll completely regret what I did if THIS is the reason why the chip is producing those glitches. |
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Tim
Account closed
Registered: Mar 2002
Posts: 467 |
I once fried a sid simply by trying to use a printer on my c64. I have no clue what i did wrong (i actually was carefull and read the manuals), but as a result i never ever hooked up a printer to the c64 just scared shit it would happen again.
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A Life in Hell
Account closed
Registered: May 2002
Posts: 204 |
The biggest killer of SID's for me has been connecting/turning on/turning off amplifiers connected to the audio out. 1 opto coupler later, and that problem went away.
EDIT: i had one friend suggest that this can happen inside the c64 too, and actually hook it between the phyiscal audio-out ping and the chip socket. |
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JackAsser
Registered: Jun 2002
Posts: 2014 |
The SID-chip in my C128 got fried when I accidentally used an Amiga PSU. |
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ready.
Registered: Feb 2003
Posts: 441 |
to \^_^/: what kind of optocoupler did you use? How did you connect it? Could you please provide a scheme?
thanx,
Ready. |
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Frantic
Registered: Mar 2003
Posts: 1648 |
In my case fried SIDs was always an effect of fiddling with the audio out/video port. There have been no instances of fried SIDs while simply using a machine.
Perhaps no news really, but still..
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ready.
Registered: Feb 2003
Posts: 441 |
Googling I found this:
http://www.goldmine-elec-products.com/prodinfo.asp?number=G15396
I ordered some pcs. As soon as I test them I'll post the results here.
Also it would be interesting to read what GOTO80 did to kill all those SIDs. Other big SID killers around?
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Frantic
Registered: Mar 2003
Posts: 1648 |
Well, mr Goto played live a lot and thus connected/disconnected the video port cable a zillion times, connecting it to all kinds of soundsystems. |
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linde
Registered: Jul 2006
Posts: 47 |
alih, how exactly did you do it? I've been too paranoid about breaking the SID to connect my 64 to anything else than the TV so far, but this seems like a good solution. |
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Oswald
Registered: Apr 2002
Posts: 5094 |
back in the days been connecting my c64 to our amplifier with a pair if wires, plugging their plain metal ends into the pins through the din connectors at both ends for ~3 years. (so I could rock turbo outroun, and etc. on the big speakers:) it did no harm. oh, btw that also includes the times until I figured out & learned mostly by trial and error that which wire goes where :) |
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Mindcooler
Registered: Nov 2006
Posts: 28 |
I fried the sid chip in my C128D by shorting the wires from the AV port. |
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goto80
Registered: Jan 2002
Posts: 138 |
Mogwaiii! I wish I could remember what I did all those times I broke the SIDs. Here are some ideas:
* unplugging the a/v-cable while C64 on (doh!)
* plugging it into powerful soundsystems, but through mixers
* uncareful packaging for flights (cold temperature in the airplane luggage room, airport handling in general)
* too much magnetic fields in the air (when the c64 is accompanied by shitloads of electronic devices, big soundsystems, etc)
* humanoid magnetic storms in me resulting from stun guns (!?)
* foreign voltage issues (should be ok in europe, right? but i dont know shit about electricity)
* humidity in the air?
Funny thing is that the machine I have used for the most amount of gigs, never broke down. The SX-64! I haven't been very nice to it either, but also never took it on a flight.. It seems to be the choice for us hardcore executives, after all! |
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Devia
Registered: Oct 2004
Posts: 401 |
Goto80: You most likely had the SX grounded with the rest of the stuff you connected it to. - if not, this is something you should do in the future!! ;-)
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mogwai
Account closed
Registered: Mar 2005
Posts: 5 |
Thank you for all the input. |
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ready.
Registered: Feb 2003
Posts: 441 |
Here is my sort of technical explanation why a SID chip might fail due to plugging/unplugging with C64 and audio input device ON.
When you plug in/unplug the jack the positive wire (channel A) might touch the ground of the audio input device and this might be seen as a short at the C64 audio output.
P.S.: I switched the Channels A/B on the amplifier side, but it does not affcet the explanation.
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ready.
Registered: Feb 2003
Posts: 441 |
Since the thread is about SID protection, I wonder if a better cooling could make the SID's life longer (provided no other killing factor comes in). In fact the SID gets quite hot, especially 6581, 8580 runs cooler.
Does anybody use any cooling system? Some C64s have a metal shield which serves two purposes:
1) Electromagnetic shielding
2) Cooling (in fact there are "metal fingers" touching the hottest chips like SID, VIC, PLA)
But other C64s just have a metal coated thick paper, useful only for Electromagnetic shielding and even blocking the heat exchange.
So I though I might put a piece of metal on top of hot chips to make their life longer. |
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Frantic
Registered: Mar 2003
Posts: 1648 |
Let's put fans in our C64 so they start sounding awful!!!
...but, yes, I think that is pretty much the recieved view on why they added the "cooling stuff" in later models.
@Mogwai: What are your plans? Will it result in a product which people could by, assembled and ready-yo-use?
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taper
Registered: Dec 2001
Posts: 119 |
Okay, since I posted in the duplicate thread and it doesn't seem like any admin merged the threads, I'll repost my message here:
Well, every time I've killed a SID, I have been fiddling with the AV-cable one way or another. Last time was at the last LCP in Linköping. Someone had fiddled with my monitor and removed my AV-cable so I had to re-hook my c128 up to it again. Either I was so static that I blew it when I was touching the AV contacts, or I inserted the wrong contact into the wrong place on the monitor (audio where video should be or something). I can't remember, but the SID died anyway...
Then again, we have blown quite a few compo machine SID's at FLOPPY, when the computer has been connected to an amplifier. Not all of them were blown during hook-up, I think we had accidents while turning on/off the amplifier and shit like that too...
Sorry for not being to specific here... but This is a great initiative Mogwai! We really need to protect our precious SID's, they're getting scarce by the minute! |
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taper
Registered: Dec 2001
Posts: 119 |
..about the heat-issue, too much heat is ofcourse never good, and cooling your chips is probably a good idea, but I don't think I ever blew a SID due to overheating... The SID get quite hot, but it seem natural. |
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ready.
Registered: Feb 2003
Posts: 441 |
Sure, self generated heat does not blow up the SID, but let's assume a SID without cooling lives for 15 years, a SID with cooling might last 30 years.
Back to the protection device:
1) I am interested to know how ALIH managed to protect it using optocouplers, these toys are known to be not linear at all, so I think he might get sound distorsion. Please ALIH, let us know what you use!!!!
2) The SID Station by Elektron uses a SID--> I assume SID Station is not affected by burned SIDs as the stock C64 is--> what is protecting the SID inside the SID Station? |
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Exin64
Account closed
Registered: Jan 2004
Posts: 24 |
Hmm, i wonder why this didnt came up yet.
I have read about a "sid protector" in a few magazines.
Mainly it disconnects the Input line and had some resistor all over the socket.
Also, if you connect something strange that gives some feedback signal to the SID output and input, that could fry the Filter. If the filter is fried, then you wont have much to hear.
Long long time ago, when i had my first C64, i think it already had some filter methods only partially responding. I wonder how that happened. But here are the details:
In Matehmatica, it plays only half of the channels at all, sometimes the only left channel produced garbage.
In most older games the sound was okay nsomewhat.
In the mood preview crack screen by Dytec or Acraise (The one with the light grey background and colorful oldskool logo above), only the melody was there. Without filters. Bass drum and other stuff was missing.
And so on.
Its the only sid that ever was totally broken at all.
Exin |
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ready.
Registered: Feb 2003
Posts: 441 |
Dear all,
maybe I have come up with something interesting. Lately I had some discussions with different audio and electronic technicians. Combining feedbacks from car audio and radio amateur applications, I think a solution could be a ground loop isolator. Read this article:
http://mysite.verizon.net/vze20h45/radio/radio_pc/radio_pc.html..
This one is also interesting:
http://www.bcae1.com/glisoltr.htm
A commercial product:
http://www.elektronikashop-vdsluis.nl/product_info.php?products..
As you can see there are products commercially available, I ordered one. As soon as it comes, I'll let you know how it works.
So basically a separator transformer (1:1 transfer ratio) between SID output and amplifier/mixer input would do the job. But since an isolator transformer is reversable, it could happen that if a high voltage transient comes from amplifier/mixer side, this is transferred to the SID. So I think that 2 clamping dioes could be put on the coil that goes to the amp/mixer. I will test this also, as I am building an isolator myself.
Commercially available products I think don't have clamping diodes.
More to come...... |
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null
Account closed
Registered: Jun 2006
Posts: 645 |
Quote: Let's put fans in our C64 so they start sounding awful!!!
...but, yes, I think that is pretty much the recieved view on why they added the "cooling stuff" in later models.
@Mogwai: What are your plans? Will it result in a product which people could by, assembled and ready-yo-use?
I've got 2 fans in my C64: one for the VIC-II, and one for the chassis. you barely hear them, only if you really pay attention to it.
these are 2 CPU fans, 12V, but hooked up to 9VAC on the c64 userport.
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http://zomgwtfbbq.info |
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SIDWAVE
Account closed
Registered: Apr 2002
Posts: 2238 |
put heatsinks on all chips in the c64, that will prolong its life. use metallic heat conducting double sided tape to glue the heatsink to the chips |
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ready.
Registered: Feb 2003
Posts: 441 |
good suggestion by Rambones! Never thought about the double sided tape.
I tested the ground loop isolator (see links of my previous post) and I am really satisfied with it. Some advantages:
1)With all the equipment ON, when (dis)connecting the plug on the audio amplifier side no glitch is heard and the SID is well protected.
2)Also the two grounds are isolated from each other, thus avoiding the problem of different potentials between them and avoiding the circulation of any current between them.
3)I have alsways had the problem of hearing the 50Hz component from the PSU on my C128DCR. The ground isoloop filters out this components.
I did some reaserch and found a second possibility to protect the SID. This device is an isolation amplifier: hcpl7800, Google for it. It might provide even more protection to the SID, since the previous device is reversable (power may flow from outside to the SID), the hcpl7800 is not reversable, but it requires more components (an operational amplifier and an external power supply).
Ready.
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