Can H/K handle high capacitance loads?

Discussion in 'AV Receivers' started by TonyWright, Aug 20, 2004.

  1. TonyWright

    TonyWright Second Unit

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    I am using an HK AVR630. I am also working on a DIY speaker cable project that is known to create fairly high capacitance loads. I am just curious as to whether my amps can handle higher loads so they won't oscilate.

    Thanks in advance for your help.

    Tony
     
  2. Kincade

    Kincade Second Unit

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    What is high? I'm running my AVR7200 w/ 4ohm mains, 6ohm center, and (4) 6 ohm surrounds, and it never even gets hot.
     
  3. Wayne A. Pflughaupt

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    Hmmm - I didn't know high capacitance was an issue of note with amplifiers...
     
  4. Michael R Price

    Michael R Price Screenwriter

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    Tony,

    It is no problem of oscillations, but you may find regular cables to sound better if it is not a real good quality amp. If it's the Cat5 cables you're talking about... use actual teflon insulated wires. I made big long ones with regular Cat5 and with my cheap amp, 16 gauge copper seemed to sound cleaner though less impact. Please consider whether all the time you put into the project would be worth it... after all, the speaker cables are not going to make your system sound that much better. It is nice to have them in the long run, but not a good idea... there are better ways to improve sound quality cheaply and easily.
     
  5. TonyWright

    TonyWright Second Unit

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    Thanks for the reply's everyone.

    Michael,

    What other ways could I use to improve sound quality?
     
  6. LanceJ

    LanceJ Producer

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    Tony: I am not an expert on this but from what I have read over the years, usually better built amps that can deal with lower impedances can also deal with higher capacitance loads......usually. But such loads, which most electrostatic speakers are known for, can make amps act weird (like I said, I'm no expert [​IMG] ) and/or shut down in more serious cases.

    Why are you planning on using a speaker cable that has high capacitance?
     
  7. Kincade

    Kincade Second Unit

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    LOL; I guess I shouldn't answer posts when I'm so tired; apparently, when you're on 3 hours of sleep, impedance=capacitance. Disregard my last post; I'll retrain myself to read posts before I answer.:b
     
  8. TonyWright

    TonyWright Second Unit

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    No worries Kincade. I know how that goes. [​IMG]


    Lance,

    The reason I ask this question is because I am using a DIY cable recipe that I found on the web. The person who posted information on how to make this cable stated that this type of Cat5 DIY speaker cable can create high capacitance loads. I have to trust that he has seen this in practice. Basically, I just want to be sure I won't damage my amp.


    Tony
     
  9. LanceJ

    LanceJ Producer

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    IMO any cable exhibiting high capacitance should be avoided. I seen no good reason for such a strange design--a speaker cable should be as "transparent" as possible to allow the amp's current to pass through unaffected.

    Be aware that a speaker's crossover uses capacitors to provide the correct frequency cut-offs for all the drivers--adding an "inline capacitor" as it were could possibly cause problems here too.

    * For more specialized info on speaker wire, here's a thorough cable test done by Gordon Gow, who worked for McIntosh Labs:

    Zip cord VS. the exotics
     
  10. Chu Gai

    Chu Gai Lead Actor

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    Personally, I've no idea if the receiver would have a problem with it and perhaps the answer lies in just how much capacitance we're talking about. The approach you're likely considering, involves something like taking Cat5 wiring and braiding the individually insulated pieces of wire. The net effect is that the cable inductance is reduced at the expense of an increase in capacitance. Braiding also has the net effect of shortening the linear distance of the wire so you'll need a bit more than 10 feet of cable to get a 10 foot run. That will raise the resistance just a tad.

    In the end, you might have something like 0.1 to 0.2 dB less loss at 20kHz if you're lucky. Regretfully I must say, that such a difference is completely inaudible. This begets the question. If you know that the potential improvement is inaudbile, and you know it's going to take hours if not a couple of days to finish the job, and you know that your fingers are going to be sore as hell, and you know that as a general guideline adding additional capacitance is not such a great idea, and you know that the wire is going to very inflexible like a coat hanger, then you will have to justify to yourself the sanity of such an approach. Just because a 300 lb woman can figure skate does not mean that is a desireable weight in which to compete at the Olympics.
     
  11. JamesDB

    JamesDB Stunt Coordinator

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    Chu,

    Your clarity and sound mind always cuts to the heart of the matter. Great reasoning.

    James
     
  12. TonyWright

    TonyWright Second Unit

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    Thanks for all the replies!


    I am just trying this to see how well it works. It's more of a curiosity than anything else.

    There was a poster above that mentioned other improvements that could be made cheaply and easily. Does anyone have any suggestions or any upgrades they have made to their systems?

    Thanks.

    Tony
     
  13. Michael R Price

    Michael R Price Screenwriter

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    Oh, Tony, I meant in terms of speaker placement and crossover setup which can work wonders for your systems balance even if you think it's set up alright. The difference from the Cat5 wires might not even exist as Chu pointed out, and if you believe it does, it's so small that it has a similar effect as moving a speaker, maybe an inch.
     

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