The Adcom GDA 600 modification thread

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Comments

  • heiney9heiney9 Posts: 24,108
    edited May 2010
    Well the guy says 50% off my initial 59.90--so I'm waiting to see what really happens--at this point I am really confused--but not complaining

    I'm still waiting for my email order confirmation. That would be something if you get 50% off the sale price - lol :p
    "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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • Poee7RPoee7R Posts: 902
    edited May 2010
    The website has been changed to reflect the 50% off of the regular price of $39.95.

    Just waiting on my order confirmation now.


    Dave
    Once again we meet at last.
  • heiney9heiney9 Posts: 24,108
    edited May 2010
    I guess my question to Fred is, is there anything else parts wise we need for this mod? If I'm going to order the regulators I'd like to order everything at once to save on shipping if other parts are needed.

    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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • heiney9heiney9 Posts: 24,108
    edited May 2010
    I'm a little disappointed no one has gotten back to me from Parts ConneXion. The first time I bought something from them they were on top of it and got me a confirmation within hours and it shipped very quickly. The second time they never confirmed my shipping and it took a little longer. This time I just need them to send me the total so I can pay them.

    Hopefully by tomorrow. I'm sure they are a little behind because if the Canadian holiday yesterday, but I expected a confirmation of my order today.

    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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • george danielgeorge daniel Posts: 11,989
    edited May 2010
    heiney9 wrote: »
    I'm still waiting for my email order confirmation. That would be something if you get 50% off the sale price - lol :p

    Brock and company,,I spoke with someone from PCX this morning,and he did tell me that it would be 50% off the advertised sale price,,however it seems that I'm in the same boat as ya'll,, waiting for my invoice to reflect that,,we'll see what happens.
    JC approves....he told me so. (F-1 nut)
  • heiney9heiney9 Posts: 24,108
    edited May 2010
    Brock and company,,I spoke with someone from PCX this morning,and he did tell me that it would be 50% off the advertised sale price,,however it seems that I'm in the same boat as ya'll,, waiting for my invoice to reflect that,,we'll see what happens.

    I'm not in a hurry to do the mod, but I want to make sure they don't exhaust their stock before I get a pair :D.
    "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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • george danielgeorge daniel Posts: 11,989
    edited May 2010
    heiney9 wrote: »
    I'm not in a hurry to do the mod, but I want to make sure they don't exhaust their stock before I get a pair :D.

    he,he,,I am.;)
    JC approves....he told me so. (F-1 nut)
  • FTGVFTGV Posts: 3,644
    edited May 2010
    heiney9 wrote: »
    ... is there anything else parts wise we need for this mod?
    Unless the app. note included with the regs suggest a local bypass cap be used ,then no parts should be required.
    (The same .1uf Panny stacked film's used near the opamp's would work if needed).The parts I listed previously will need to be removed and just in case I would suggest that they be kept and labeled until your certain the new regs are working correctly.

    Also as I mentioned to Goerge in a previous post you should have a DMM handy to do basic voltage measurements.The reg's have a pot that will likely require some tweaking to set them to the correct voltage.
  • george danielgeorge daniel Posts: 11,989
    edited May 2010
    Just got my invoice--48.27 shipped.
    JC approves....he told me so. (F-1 nut)
  • FTGVFTGV Posts: 3,644
    edited May 2010
    Just got my invoice--48.27 shipped.

    Awesome.:)
  • dacboydacboy Posts: 23
    edited May 2010
    FYI

    Just order Sonic Craft Gen II's for the project. SC is having 15% sale till May 31st. Picked up some solder too which ended up basically free after the sale pricing. :)
  • george danielgeorge daniel Posts: 11,989
    edited May 2010
    If anyone opts for the GenII's please post your impressions,,I used the Gen I's in mine,,IIRC H9 used multicaps.
    JC approves....he told me so. (F-1 nut)
  • heiney9heiney9 Posts: 24,108
    edited May 2010
    I think Gen II's are a good choice. That was my 2nd choice based simply on $$$ and shipping. At PCX I could combine shipping of the Multicaps w/the other PS caps I needed.

    I doubt in the position they are used in anyone would be able to hear a difference between Gen I or II. But good choice to both on Sonicaps.

    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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • FTGVFTGV Posts: 3,644
    edited May 2010
    he,he,,I am.;)
    Getting addicted to solder fumes are we?:D
  • george danielgeorge daniel Posts: 11,989
    edited May 2010
    Yeah,,cannot decide between the WBT or the Cardas:)

    BTW-- just paid for my Bursons
    JC approves....he told me so. (F-1 nut)
  • heiney9heiney9 Posts: 24,108
    edited May 2010
    I sent PCX an email asking when I could expect my final invoice. Stephanie said they are extremely busy because of the sale and they were invoicing as quickly as possible.

    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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • heiney9heiney9 Posts: 24,108
    edited May 2010
    Still no confirmation e-mail about them being in stock and the final sales price. Really starting to get annoyed. I sent them an order on Monday!!! This is starting to get ridiculous, I don;t care how much you have on sale they can't have that many orders to respond to.

    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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • Poee7RPoee7R Posts: 902
    edited May 2010
    Sorry to hear that H9.

    Ive gotten my confirmation with total for shipping, received it yesterday. I would email them again and see whats going on.

    That being said, I got my order in yesterday from Sonicraft, and it was a bit wrong, thats life eh.

    Good Luck.


    Dave
    Once again we meet at last.
  • heiney9heiney9 Posts: 24,108
    edited May 2010
    That was fast. I just emailed her and she got back to me with a total in less than 2 minutes. :D
    "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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • george danielgeorge daniel Posts: 11,989
    edited May 2010
    I'm somewhat reluctant to post this,,but mine have shipped.:p
    JC approves....he told me so. (F-1 nut)
  • heiney9heiney9 Posts: 24,108
    edited May 2010
    I'm somewhat reluctant to post this,,but mine have shipped.:p

    No problem George, you are the guinea pig :D. I just wanted to make sure I secured my parts before they sold out of them.

    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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • FTGVFTGV Posts: 3,644
    edited May 2010
    ..but mine have shipped.:p
    If it's via Canada Post you might see them before July.:eek:
  • george danielgeorge daniel Posts: 11,989
    edited May 2010
    heiney9 wrote: »
    No problem George, you are the guinea pig :D. I just wanted to make sure I secured my parts before they sold out of them.

    H9

    I'll walk point if Fred is behind me;)
    JC approves....he told me so. (F-1 nut)
  • heiney9heiney9 Posts: 24,108
    edited May 2010
    George or anyone else who had done the full mod, have you noticed a lot more bass? It's almost as if in my rig there is too much bass as in it tends to be a little more colored.

    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 Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • dacboydacboy Posts: 23
    edited May 2010
    Sonicaps Gen II's arrived:D
  • FTGVFTGV Posts: 3,644
    edited May 2010
    Well get them and the rest of the mods installed already.
  • davide256davide256 Posts: 50
    edited May 2010
    With both channels operating and about 10 hours of play so far here are my observations
    1) detail isn't that different than the CD source direct output so far... detail equaling do you know the instrument is there or not... makes me feel better about the $1700 price tag 10 years ago
    2) whats greatly better is color and weight. Best simile I can give is take 2 copys of a pencil sketch, have a master color 1 in with watercolor and the other with oils... the oil will always be richer and more engaging. What was passive or even iritating before now pops out and is engaging. Sounds have a weight when they are percussive, that thump in your chest
    3) low (below 45hz) base shows signs of base doubling but with MG1B's I can't really tell if its the speaker pushing base beyond its limit up an octave in harmonics or if its actually the DAC... hopefully the MG 1.7's due this week will show its not.

    Wondering if perhaps the filter capacitor/inductor should have stayed in to cut out sub 30 hz/over 22khz harmonics...
  • FTGVFTGV Posts: 3,644
    edited May 2010
    davide256 wrote: »

    Wondering if perhaps the filter capacitor/inductor should have stayed in to cut out sub 30 hz/over 22khz harmonics...
    I'm not sure which cap you are refering to but the inductor would be working above the audio band not in the low bass.IMO It being in series with the output has the potential to affect SQ in a negative way and it really doesn't need to be there.In fact in the dozens of schematics I have seen of DAC's and CD players ,I have never seen any other design with them in the analog signal path.


    btw.Did you get your 600 hum free and working with the OPA627's?
  • george danielgeorge daniel Posts: 11,989
    edited May 2010
    heiney9 wrote: »
    George or anyone else who had done the full mod, have you noticed a lot more bass? It's almost as if in my rig there is too much bass as in it tends to be a little more colored.

    H9

    I wanna' say nope-- but I'll give it a listen in a few a report back.

    A question for all that have performed this tweak-- how many hours do you have on your units? (Post Mods)
    JC approves....he told me so. (F-1 nut)
  • davide256davide256 Posts: 50
    edited May 2010
    FTGV wrote: »
    I'm not sure which cap you are refering to but the inductor would be working above the audio band not in the low bass.IMO It being in series with the output has the potential to affect SQ in a negative way and it really doesn't need to be there.In fact in the dozens of schematics I have seen of DAC's and CD players ,I have never seen any other design with them in the analog signal path.


    btw.Did you get your 600 hum free and working with the OPA627's?

    DAC's working fine now that the factory cap error is fixed. I also did an A/B comparison without/with the caps across OPAMP pins 4&8... Norah Jones CD's seem to be recorded at high gain and without the caps sounded distorted.

    on the original analog output for the GDA 600 there was a cap and inductor filter before the RCA outputs. The cap value is documented in the schematic but the inductor doesn't show a value.
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