SDA-SRS 1.2tl Amp Suggestion

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  • xoaphexox
    xoaphexox Posts: 246
    edited April 2012
    FTGV wrote: »
    Yes the biwire binding posts are paralleled with the main outputs.

    Fantastic, I have it playing now this way and it sounds great indeed. I was going to bi-wire but I think I will leave well enough alone for now. Maybe I'll try it after a while of having things set up this way.

    This was a good amp suggestion, and a very helpful thread overall. Thanks to everyone.

    Burson HA-160D > Adcom GFA-5802 > Polk SDA-SRS 1.2tl w/ Mye Sound Spikes, Mills/Sonicap XO, Larry's Rings, Dynamat Extreme, Cardas CCGR Binding Posts and Jumpers, Custom 10ga interconnect, Custom Gaskets, RDO-198
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  • transmaster
    transmaster Posts: 428
    edited April 2012
    This sure sounds like one of my early 1950's HF transmitters. The Johnson Viking 1, and 2 both require at least and hour to get to operating temperature. A couple of hours for the matching Johnson 144 VFO to get its operating temperature and to stabilize. These hollow state rigs are sure fun to operate.
    Radio Station W7ITC
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  • FTGV
    FTGV Posts: 3,649
    edited April 2012
    xoaphexox wrote: »
    Fantastic, I have it playing now this way and it sounds great indeed.
    Great,enjoy.
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  • xoaphexox
    xoaphexox Posts: 246
    edited April 2012
    Does anyone have the biasing procedure for the GFA-5802? I know the location of the pots and have the tools - I would to know what value to bias this amp at and where the best place to take the reading is.

    Still loving the sound of this amp - it was a great suggestion!

    Thanks!

    Burson HA-160D > Adcom GFA-5802 > Polk SDA-SRS 1.2tl w/ Mye Sound Spikes, Mills/Sonicap XO, Larry's Rings, Dynamat Extreme, Cardas CCGR Binding Posts and Jumpers, Custom 10ga interconnect, Custom Gaskets, RDO-198
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  • FTGV
    FTGV Posts: 3,649
    edited April 2012
    I' can't help with bias levels or recommended warm up procedure but the reaading's (in milivolts)will likely be across the big source resistors if there isn't dedicated test points.
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  • xoaphexox
    xoaphexox Posts: 246
    edited April 2012
    Thanks, this is a quote from Nelson Pass on this topic but I am not knowledgeable enough to fully comprehend it. I am used to being told point blank by a service manual - so the "see where it goes" is what throws me off.

    "Assuming that the output devices are matched - which they
    are supposed to be, you can sense the current through each
    by the voltage across the power resistor attached to its source.

    I would start out with values about 100 mA or so and watch
    where it goes."

    This corroborates what you said, but NP talks about sensing "voltage" but then gives a current reading - further confusing me :)

    Burson HA-160D > Adcom GFA-5802 > Polk SDA-SRS 1.2tl w/ Mye Sound Spikes, Mills/Sonicap XO, Larry's Rings, Dynamat Extreme, Cardas CCGR Binding Posts and Jumpers, Custom 10ga interconnect, Custom Gaskets, RDO-198
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  • FTGV
    FTGV Posts: 3,649
    edited April 2012
    I assume by "watch where it goes" means to monitor changes with temperature during the recommended warm up/adjustment period.The 100ma is likely arrived at with a little math( ie. ohms law) after determining the voltage across the source resistor and the value of that resistor.
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  • xoaphexox
    xoaphexox Posts: 246
    edited April 2012
    Thanks, so if the power resistors are .33 ohms and I want 100mA, I should dial in the bias at 33mV...

    .100 (I) = .033 (V) / .33 (R)

    Burson HA-160D > Adcom GFA-5802 > Polk SDA-SRS 1.2tl w/ Mye Sound Spikes, Mills/Sonicap XO, Larry's Rings, Dynamat Extreme, Cardas CCGR Binding Posts and Jumpers, Custom 10ga interconnect, Custom Gaskets, RDO-198
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