adcom gda 700 mod ?

soundfreak1
soundfreak1 Posts: 3,414
edited May 2012 in Electronics
Will be doing a mod on my 700 . Is there any particular brand of opamps and the other parts needed in the mod that would be recomended?
Main Rig:
Krell KAV 250a biamped to mid/highs
Parasound HCA1500A biamped to lows
Nakamichi EC100 Active xover
MIT exp 1 ic's
Perreaux SA33 class A preamp
AQ kingcobra ic's
OPPO 83 CDP
Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
Denon DP-1200 TT. AToc9ML MC cart.
Monster HTS 3600 power conditioner
ADS L1590/2 Biamped
MIT exps2 speaker cable
Post edited by soundfreak1 on
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  • george daniel
    george daniel Posts: 12,096
    edited May 2012
    Fred?
    JC approves....he told me so. (F-1 nut)
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  • heiney9
    heiney9 Posts: 25,171
    edited May 2012
    soundfreak1 wrote: »
    Will be doing a mod on my 700 . Is there any particular brand of opamps and the other parts needed in the mod that would be recomended?

    Do you have any interior shots? I will go out on a limb and say you can use the wonderful opa 627 from Brown Dog. As far as the rest, since it will most likely be different than the 600 a schematic will be necessary to be sure the values are correct and/or the parts are all in the same place, etc.

    If you wanted a straight mod, you should have gotten the 600, but once the schematic is posted then we will see how different they are. Since they use a completely different digital section I'm betting the analog section is very different.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    I do have the schematic. Just have to figure out how to post.it in my phone and cant send from there. Will figure it out.
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
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  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    No freds here george.
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
    · Share on FacebookShare on Twitter
  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    My tech is doing the mod to a 600 for a friend of mine and said he can do the same upgrades to 700 (diff
    specs of course.) just looking for the best ( within reason) parts as far as brands go. When i did my 5jr+ speakers i used clarity SA caps not the very top or bottom,but looking for simular quility.
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
    · Share on FacebookShare on Twitter
  • george daniel
    george daniel Posts: 12,096
    edited May 2012
    soundfreak1 wrote: »
    No freds here george.

    he,he,, he'll chime in. :wink:
    JC approves....he told me so. (F-1 nut)
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  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    Ia that a good thing? George?
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
    · Share on FacebookShare on Twitter
  • george daniel
    george daniel Posts: 12,096
    edited May 2012
    soundfreak1 wrote: »
    Ia that a good thing? George?

    I don't think he will bite,, I'm sure he's had all of his shots though.
    Fred (FGTV) has helped me immensley the first time around with this mod,,,pop a schematic up in this thread,,and we'll see if that will entice him. :wink:
    JC approves....he told me so. (F-1 nut)
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  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    Trying.
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
    · Share on FacebookShare on Twitter
  • FTGV
    FTGV Posts: 3,649
    edited May 2012
    george daniel wrote: »
    Fred?
    You called?:cheesygrin:

    SF as I mentioned in a previous thread the 600 and 700 are similar enough that the same basic mods can be done to the 700 as was done to the 600.The key areas to look at upgrading are the opamp in the I-V convertor,and the one in the output buffer/low pass filter section.A third opamp thats configured as an invertor driving half the bal output could be upgraded if you use the bal outputs.The 600 used dual opamp packages whereas the 700 uses single packages which opens up lots of options depending upon budget.Other improvements can be done in the areas of voltage regulation (especially for the analog section)as well of local decoupling and bypassing caps,replacing the main filter caps etc.There are certainly other tweaks but IMO these are the main things to look at.Once I get a schem I would be glad to give specific recommendations if you want them.
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  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    Ftgv i would take all the sugustions i can get. Trying to get the sch. So i can post tonight. Thanks very much.
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
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  • FTGV
    FTGV Posts: 3,649
    edited May 2012
    I have done some digging for a schem but no luck yet either.
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  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    Ive got it . Its just in a download in my ph. Need to get ot to my computer to post it here. Will have it here asap.
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
    · Share on FacebookShare on Twitter
  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    hope this goes thoughAdcom_GDA-700_service_manual_1_-1.pdf
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
    · Share on FacebookShare on Twitter
  • FTGV
    FTGV Posts: 3,649
    edited May 2012
    Perfect,I will take a good look as soon as I get the chance,then throw some ideas at you.
    btw.your PM box is full.
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  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    Thanks! Cleaned up my inbox
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
    · Share on FacebookShare on Twitter
  • FTGV
    FTGV Posts: 3,649
    edited May 2012
    I 'll have more to add later but for starters I assume the stock opamps are soldered in place so I would remove them and install some high quality DIP sockets such as these. http://www.digikey.ca/product-detail/en/110-43-308-41-001000/ED90032-ND/947040

    For the opamps(U402,403,404,405 and U500,501 if using balanced output) I can recommend the excellent National(now Ti) LME49710.Don't let the price fool you these are high performance devices and are my current fave IC opamp .They are low distortion, low noise and very neutral sounding and should provide a nice performance upgrade from the stock AD711's. For details see links http://www.ti.com/lit/ds/snas376b/snas376b.pdf
    http://www.digikey.ca/product-detail/en/LME49710NA%2FNOPB/LME49710NA-ND/1302099
    Ofcourse dependant upon your budget there are many other options such as the Burson discrete opamps or the Ti/BurrBrown OPA627 that everyone liked in their GDA600 mods.

    I would also recommend installing a paralelled pair of Panasonic stacked film and FC series electrolytics for local bypssing and decoupling at the opamps power pins.(see links) http://www.digikey.ca/product-detail/en/EEU-FC1E101S/P10269-ND/266278
    http://www.digikey.ca/product-detail/en/ECQ-V1H124JL3/P4526TB-ND/43911 This .12uf/100uf cap pairing would replace C404,405,406,407,418,419,420,421
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  • soundfreak1
    soundfreak1 Posts: 3,414
    edited May 2012
    Ftgv i really appreate that info.
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
    · Share on FacebookShare on Twitter