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Tag and karaoke player.

Discussion in 'TAG McLaren Audio Owners' Forum' started by CYRUStheVIRUS, Jan 21, 2005.

  1. CYRUStheVIRUS

    CYRUStheVIRUS
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    Don't laugh, but after setting up my av32r, when i plug the cables from my girlfriends RSQ karaoke player into the TAG, it comes up with a INPUT DC OFFSET error.

    Never had any problems with Lexicon and the player works fine through digital coaxial.
    Help she is saying it has to go. :nono:
     
  2. babaroga

    babaroga
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    There is option in the TAGMc Menu to adjust input voltages, do RTFM to find where....
     
  3. Dr Udo Zucker

    Dr Udo Zucker
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    Hi, the INPUT DC OFFSET error describes an error with the analog input signal, connected to the AV32R.

    The input signal expected is an AC signal, i.e. a voltage changing around zero. Many products offset this "zero base line" a little by a static (=DC) voltage. If that DC voltage would be amplified it could cause a permanent current through your speakers, which could harm them over time. Tiny amounts of DC are normal (the better a product the less you expect), hence the AV32R is trying to remove this incorrect DC level. It can do this up to a certain level, then it has to give up, warning the user with the error message you have seen.

    It is very simple to remove cost effectively DC by adding a capacitor into the output signal path. However, such method affects the ability to produce low frequencies correctly, hence high-end products use more sophisticated solutions. In the case of the AV32R it's the so called straight line technology. Here -in simple words- the DC level is measured and then removed using a servo.

    A high DC level is either a very poorly designed product or most likely a product with a defect in its output stage.
     
  4. CYRUStheVIRUS

    CYRUStheVIRUS
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    Thanks for the reply,
    The karaoke player is supposed to be a professional one, is there something i can buy off the shelf that will regulate the D.C. current before going into the TAG.
    Also as i never had any problems with the Lexicon MC1, does this use another way of controlling dc?

    Does anybody use a karaoke player with their TAG?
     
  5. WillyP

    WillyP
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    Hi Udo,

    So why does this sometimes happen when using my T32R tuner? I wouldn't even dare calling this a "a very poorly designed product" neither would you I suppose :laugh:

    Willy
     
  6. Dr Udo Zucker

    Dr Udo Zucker
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    Hi Willy, please read my contribution more carefully :lesson: . It says, that either a product is poorly designed or defect. So if your T32R leads to this error, it must have a defect (or the AV32R).

    However, double check that you don't mix the error messages "input DC Offset" with "input overrange". This (the second error) can be adjusted up to a certain degree, but note that older T32R's can have an analog output voltage which is higher than the AV32R can accept. This is diofferent to DC Offset and in that case a simple resistor inside the T32R's output stage change can cure the problem. IAG's helpdesk can advise on this problem in more depth.
     
  7. WillyP

    WillyP
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    Hello Udo,

    I have read your post very carefully but I didn't even want to think about the possibility that either my T32R or my AV32R (or both?) would be faulty. That would be more than I could accept at the moment after my DVD32R stopped working.

    Next time it happens I will check what the message is although I am quite certain that it was "input DC offset". I have matched the output level of my T32R to the AV32R so this shouldn't be a problem. The last time it happened when I was tuning manually and muting was off so some distorted noise could be heard.
     
  8. Dr Udo Zucker

    Dr Udo Zucker
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    Hi Willy, this seems a sensible approach. Let me know what you find. I am curious.
     
  9. canavan

    canavan
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    I do get that as well with my T32R, but it's definitively "input overrange". Maybe I'll have to ask the helpdesk how expensive the resistor change will be...
     
  10. GrahamMG

    GrahamMG
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    The resistor change fixes the "input overrange" and also has the advantage that the analogue and digital outputs are the same level afterwards, I mentioned this ages ago as it was very irritating and recieved a bag of very expensive resistors (reletively speaking) to swap with the installed items, worked perfectly ever since (one of the first T32RDAB's sold). If your tuner is out of warrenty and your skilled in electronic re-work then maybe getting the resistors from IAG helpdesk may be a cheap way of sorting it out, if your not better than good at this type of thing then I'd be curious to the cost of getting IAG service to do this task.. Finesse is needed to get the tuner knob off I seem to remember so if your unit is under warrenty you must let IAG do it.... I also seem to remember Udo being quite "vocal" at the chap who sent me the resistors so don't expect udo to approve of any DIY fixes here..... I just mention it as it is very very striaghtforward with a modicum of knowledge. I'm just amased that no-one else until now has mentioned it as an issue as it drove me nuts at the time.....
     
  11. WillyP

    WillyP
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    Hi Udo,

    This afternoon I tested what was going on. Here are the results: when tuning manually with the knob I get BOTH messages. It doesn't matter if muting is on or off, but the message shows up when the tuning isn't right and I can hear the radio station already but the sound is very distorted. Until now it doesn't happen when I use the presets or the previous/next buttons. From time to time the AV32R mutes the incoming signal.
     
  12. canavan

    canavan
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    The level difference is just short of driving me nuts. If I had known that there was a fix, I'd have had it repaired ages ago. I'm not even good at soldering, but maybe Herr Bayer can do this for me, that's probably much quicker than IAG, he just took 1 (one) day to fix the volume knob of my DP.
     
  13. Miron

    Miron
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    nightmare it is, same as on AV32R
     
  14. GrahamMG

    GrahamMG
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    Tolerance rings make a neat invisible grip though which I still prefer to a nasty grub screw, but I know how to get the knob off.......Others might prefer the grub screw....
    I am sure Hermut could do the resistor thing amost blindfold, took me 20 minutes including working out how to get the tuning knob off.....
     

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