SDA 2b and DENON PMA-2000R

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Hi guys.

Looking for a piece of advice here.

What do you think about coupling SDA 2b with Denon PMA-2000R?

Right now I'm having Denon PMA-880R and am pretty much happy with it, but I got an opportunity to get a bigger brother. I don't know whether the dual mono nature of 2000R will couple with SDAs..
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Comments

  • F1nut
    F1nut Posts: 49,802
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    If it is a true dual mono, that is no common ground between the negative outputs, then you cannot use it with your speakers without the AI-1 or Dreadnought isolation transformer.
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  • alexanikin
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    Don’t know for sure if there is a connection or not. That the purpose of this post.

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  • Gardenstater
    Gardenstater Posts: 4,186
    edited October 2022
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    Looks like common ground from the schematic but I'm not an electrical technician

    https://www.hifiengine.com/hfe_downloads/index.php?denon/denon_pma-2000r_service.pdf

    Best to check with an ohmeter to back that up, I'd say.

    0i789n6ozn0y.jpg
    George / NJ

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  • F1nut
    F1nut Posts: 49,802
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    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

  • Gardenstater
    Gardenstater Posts: 4,186
    edited October 2022
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    The other part of the schematic that shows the L and R speaker terminals. I would like someone who is more electronics oriented than I am to explain to me why it isn't common ground when the schematic shows the L and R negative terminals going to the same node labeled GND. Seems like a killer amp.

    61hjyobzebtd.jpg
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • Emlyn
    Emlyn Posts: 4,372
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    I had my eye on buying a 2000IVR for many years but went in a number of different directions and never got one.

    Denon’s $4K A110 integrated appears to use a very similar if not identical high current amp design all these years later. It produces way more power than it’s rated for.

    Other than the forum thread above I haven’t seen any evidence the design is not common ground. It’s not mentioned in manuals or on the back of the amps. Only way to find out for certain is for someone who has one doing the usual test. The design has always had the dual transformers.
  • skipshot12
    skipshot12 Posts: 1,002
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    I did what others suggested here and ohmed between my negative speaker output terminals, on my Phase Linear amp, and was confident with the reading.
    Put it in the system to drive the SDA’s and all was well.

    Maybe this helps?
  • pitdogg2
    pitdogg2 Posts: 24,579
    edited October 2022
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    If Eric @Conradicles says it doesn't work with SDA's without a AI-1 or dreadnought you can bank that he knows.
  • F1nut
    F1nut Posts: 49,802
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    The other part of the schematic that shows the L and R speaker terminals. I would like someone who is more electronics oriented than I am to explain to me why it isn't common ground when the schematic shows the L and R negative terminals going to the same node labeled GND. Seems like a killer amp.

    61hjyobzebtd.jpg

    The two sets of binding posts on the right channel share a ground as do the left channel, but the right and left channels do not.
    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

  • Gardenstater
    Gardenstater Posts: 4,186
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    If you follow it through as indicated to the other section P5 and P7 are tied together at GND. It says "to IU-2917-3". The first schematic section I showed.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • pitdogg2
    pitdogg2 Posts: 24,579
    edited October 2022
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  • F1nut
    F1nut Posts: 49,802
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    As always, the only true way to know is test the outputs.
    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: 1,278
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    I believe the two transformers are wired in parallel, it looks like it only has one bridge rectifier, so it may indeed be common ground, but test to be sure.
  • alexanikin
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    Guys, thank you for all your thoughts. The amp is on its way, so my only option now is to test it.
  • F1nut
    F1nut Posts: 49,802
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    You should buy and build a Dreadnought regardless as it makes SDA's sound better even if the amp is common ground.
    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

  • xschop
    xschop Posts: 4,702
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    You should foam the inner frames on the MW's and phase-plug them, then see what the Dreadnought can add.
    Don't take experimental gene therapies from known eugenicists.
  • skrol
    skrol Posts: 3,339
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    As far as telling from the schematic posted, there isn't there to see where the grounds are connected. Need more over to the left.
    Stan

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  • alexanikin
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    I feel my next question is stupid, but I have to ask.

    Let's assume it is NOT common ground. Can I just add a wire between negative posts? Would it work or kill the amp?
  • pitdogg2
    pitdogg2 Posts: 24,579
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    alexanikin wrote: »
    I feel my next question is stupid, but I have to ask.

    Let's assume it is NOT common ground. Can I just add a wire between negative posts? Would it work or kill the amp?

    Sometimes you can, I cannot say for certain on this particular amp.
  • alexanikin
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    pitdogg2 wrote: »
    Sometimes you can, I cannot say for certain on this particular amp.

    Interesting something to explore.
  • F1nut
    F1nut Posts: 49,802
    edited October 2022
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    Do not strap the negative outputs without confirmation from the manufacturer.

    If you don't have a VOM borrow one.
    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

  • alexanikin
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    F1nut wrote: »
    Do not strap the negative outputs without confirmation from the manufacturer.

    Sure. I don’t have another amp and set of speakers for empirical tests..
  • Schurkey
    Schurkey Posts: 2,100
    edited October 2022
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    "Dual mono" usually refers to the "power" side, not the speaker ground side. A moment with an ohmmeter would tell the tale for certain. If the two schematics posted are accurate, this amp is SDA-compatible.

    Aside from balanced/bridged amplifiers which cannot be common-ground, virtually all the "dual-mono" amps I know of are either just-plain-common-ground, or common-ground through a resistor pair, making them suitable for a jumper-wire between the negative speaker terminals.

    Seems to me there's at least one Carver amplifier that has one channel inverted, and then the + and - terminals for that channel are inverted to compensate. Makes the power supply seem "bigger" since bass notes which tend to be monophonic, would then pull from both the + and the - supply rails. Amps like that might or might not be labeled "dual-mono", but they'd be trouble with SDA speakers.
  • F1nut
    F1nut Posts: 49,802
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    alexanikin wrote: »
    F1nut wrote: »
    Do not strap the negative outputs without confirmation from the manufacturer.

    Sure. I don’t have another amp and set of speakers for empirical tests..

    Not sure what point you're attempting to make, but it has nothing to do with what I posted. Bottom line get yourself a VOM.
    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

  • alexanikin
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    F1nut wrote: »

    Not sure what point you're attempting to make, but it has nothing to do with what I posted. Bottom line get yourself a VOM.

    This is exactly what I’ve done before my previous comment - ordered a VOM.
  • F1nut
    F1nut Posts: 49,802
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    Good man. Be sure to let us know the result.
    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

  • skipshot12
    skipshot12 Posts: 1,002
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    F1nut wrote: »
    You should buy and build a Dreadnought regardless as it makes SDA's sound better even if the amp is common ground.

    F1,
    Why does a dreadnought do this?
    Is this just for the 1.2’s & 1.2tl’s?
  • pitdogg2
    pitdogg2 Posts: 24,579
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    Cannot be used on blade/Blade models, only pin/blade.
  • F1nut
    F1nut Posts: 49,802
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    skipshot12 wrote: »
    F1nut wrote: »
    You should buy and build a Dreadnought regardless as it makes SDA's sound better even if the amp is common ground.

    F1,
    Why does a dreadnought do this?
    Is this just for the 1.2’s & 1.2tl’s?

    I have no technical answer to that.

    It applies to any SDA model capable of using the original AI-1.
    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

  • skipshot12
    skipshot12 Posts: 1,002
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    F1nut wrote: »
    skipshot12 wrote: »
    F1nut wrote: »
    You should buy and build a Dreadnought regardless as it makes SDA's sound better even if the amp is common ground.

    F1,
    Why does a dreadnought do this?
    Is this just for the 1.2’s & 1.2tl’s?

    I have no technical answer to that.

    It applies to any SDA model capable of using the original AI-1.

    From reading I can assume my blade/blade are not compatible?