Setting up SDA speakers with Yamaha AX-700u integrated amp

I have a new amplifier i want to connect up my SDA speakers to. I recently serviced this Yamaha AX-700u integrated amp and want to test it. Not sure if this a common ground and wanted some advice. I did use a meter and have continuity between both the r/l black(-) speaker terminals to the ground connector on the back. Does this sound like a common ground amp? thanks in advance.
SDA 1C (wood)- Vr3 crossovers/ Gimpod board's, Larry's rings, RDO194 tweeters, Dynamat. Updated terminal cup and binding posts. Custom IC by Vr3 with Neutrik connectors. SDA 2B(studio)- SonicCraft crossovers(TL mod), RD0-198 tweeters. Hurricane nuts, DynaMat and JB Weld.

Comments

  • pitdogg2
    pitdogg2 Posts: 19,884
    It's common ground.
    Nice integrated amp. I had both the AX500 and 900. Loved them both.
  • F1nut
    F1nut Posts: 46,483
    vulcan wrote: »
    I have a new amplifier i want to connect up my SDA speakers to. I recently serviced this Yamaha AX-700u integrated amp and want to test it. Not sure if this a common ground and wanted some advice. I did use a meter and have continuity between both the r/l black(-) speaker terminals to the ground connector on the back. Does this sound like a common ground amp? thanks in advance.

    I know Ivan already answered your question, just wanted to tell you that to test for common ground you do so between the r/l black(-) speaker terminals only.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • mhardy6647
    mhardy6647 Posts: 28,600
    edited December 2021
    Not sure there's anything particularly "inflated" about the AX-700U power claim.
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    https://www.hifiengine.com/manual_library/yamaha/ax-700.shtml

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    https://www.canuckaudiomart.com/details/649371245-refurbished-1989-yamaha-ax700u-integrated-amplifier-135wpc-japn-price-includes-shipping/

    Looks OK for its era.

    That said, probably not a very viable choice for any traditional SDAs given common ground amplifiers and the relatively limited apparent current delivery capability.

  • Gardenstater
    Gardenstater Posts: 2,151
    edited December 2021
    I looked it up a couple days ago. Couldn't find any independent testing reviews. I like that they give the dynamic power and headroom at both 8 and 4 ohms, BUT it always bugs the heck out of me when they *verbally* brag about its low impedance driving qualities in a non-quantitative manner but do not even RATE IT at 4 ohms, as far as a continuous RMS wattage rating.
    George / NJ

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  • pitdogg2
    pitdogg2 Posts: 19,884
    As I sated I had two the AX500 and the AX900 both played above their rated wpc IMHO. In those days Yamaha under rated their gear, as for 4ohm I never tried it at 4ohm. I can state for a fact the AX900 and my Cerwin Vega D7's got me in hot water more than once :smiley: I opened my door to Johnny Law
  • pitdogg2
    pitdogg2 Posts: 19,884
    edited December 2021
    As I stated I had two the AX500 and the AX900 both played above their rated wpc IMHO. In those days Yamaha under rated their gear, as for 4ohm I never tried it at 4ohm. I can state for a fact the AX900 and my Cerwin Vega D7's got me in hot water more than once :smiley: I opened my door to Johnny Law. As for SDA's I wouldn't try it on the big boys or something like the SDA2a. It's not going to be the best but if you have some of the SDA2b or SDA1c it would work if you don't try and drive them like race cars.
  • F1nut
    F1nut Posts: 46,483
    edited December 2021
    If each pair is rated at 70 watts max and there's 2 pair pair channel....well, do the math.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • F1nut
    F1nut Posts: 46,483
    Are you on medication?
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • invalid
    invalid Posts: 738
    The nakamichi pa5 and pa7 are not common ground amps.
  • invalid
    invalid Posts: 738
    The threshold stasis that these are based on are not common ground, maybe nakamichi tweaked the design.
  • pitdogg2
    pitdogg2 Posts: 19,884
    invalid wrote: »
    The threshold stasis that these are based on are not common ground, maybe nakamichi tweaked the design.

    They did
  • Schurkey
    Schurkey Posts: 1,996
    vulcan wrote: »
    I did use a meter and have continuity between both the r/l black(-) speaker terminals to the ground connector on the back. Does this sound like a common ground amp?
    pitdogg2 wrote: »
    It's common ground.
    "Continuity" is meaningless for determining compatibility with SDA speakers.
    .000000001 ohm is "continuity". 20 ohms is "continuity"

    20 ohms will not work with SDAs.

    You need to determine the resistance in ohms, and "less than one ohm" would be compatible with SDAs. Lower is better.
    pitdogg2 wrote: »
    I had two the AX500 and the AX900 both played above their rated wpc
    Pretty-much all amplifiers will "play above their rated WPC". It's not difficult...if you're willing to also "play above the rated THD + noise"




    Not having an FTC rating for 4-ohm use (or, like newer Yammie amps, having FTC rating for 4 ohm use but only if the Strangulation Switch on the back panel is engaged) would make me VERY suspicious. Either there's not enough power supply, not enough heat sink, or not enough output devices--or some combination.