Next project: Adcom GDA-700

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So, here it is in its final form.

Completely recapped. Nichicon on the power board. Elna Silmic II everywhere else except a few Oscons as digital decoupling caps. Vishay Roderstein MKP 1837 as 0.1uF bypasses. Many of the new caps are hiding underneath the board.

PMD100 replaced with DF1704 (big improvement). Opamps are BB OPA827 - I liked these better than the 627s! Digital input stage has been removed up to the transformer coupling and now we just switch between Toslink and Coax1 with the final relay.

Output inductors and caps also removed.

Gave my wife a blind test between this and my GDA-600 and she chose the GDA-700 as clearer. I agreed with her assessment. The 700 now has more detail and a wider sound stage. The 600 has a little more bottom end oomph. Some of this is due to the OPA 627 in the 600 and the OPA 827 in the 700.

But, ultimately, I succeeded. My previous best DAC (Lampizator) was beat by the GDA600, which is now beat by the GDA700! (after a month of on and off work)

I suspect I may have to break down and buy a Yggdrasil to beat this one. :)
 

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Yep....and many reading this thread in the future will want an answer: GDA-600 or GDA-700?

Get the 600. In its stock form, I suspect it's a lot better, and the GDA-700 will take a lot more expense and effort to get up to shape. It became an obsession to me to make the 700 beat the 600, but it really wasn't worth the time and effort given the amount of work needed. In my brutally honest opinion, the PMD100 digital filter in the GDA-700 is crap.

The Adcom GDA-600 is the best bargain out there.
 
Glad it finally worked out for you.
I'm listening to FLAC's and WAV's from my NAS through my Sonos on my stock GDA-700 through my speakers (Snell E-3's) and it's so much clearer than my Adcom GCD-750 CDP. Both Adcom units are HDCD capable and I therefore assumed used the same internal circuits and components. Apparently not.

I can't speak for the GDA-600, but through my speakers, I really like the stock GDA-700. It's non fatiguing and clear as all hell. Good system synergy with my tube pre and power amps I guess.
 
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Heyraz, it is all good gear, no question.

From what I have heard, properly tweaked, it has the potential to rival new gear in the $3,000+ category.

If you have the means, grab a GDA-600 for $200 to compare. I suspect you won't regret it.
 
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I recently purchased a cronus magnum 2 tube amp from rogue audio. Until now, I had stopped playing cd's and my 500 or so disc's went into storage. I bought a Clearaudio performance DC turntable earlier this year as I have a much larger vinyl collection......I am currently taking advantage of "Tidal" music streaming service.
After gettg the tube ampI decided to throw in a few cd's and I was pleasantly surprised as the sound did not sound so digital anymore.....so now I have been using my android phone to play quasi-hi rez music from "Tidal" streaming service.
The sounds pretty good because tidal uses less compressed files but I'm certain the dac in my cell phone is not an audiophile level dac.
Since I spent a lot this year on gear, I have decided to buy a vintage dac with a great reputation. My research has led me to two choices....one is a new product, the Audioquest "dragonfly red" & an Adcom Gda-700 ( or 600 after reading this thread).
I always like getting opinions or thoughts before making a purchase. So, do you think the Adcom is a good choice for what I want to do? The other option was to upgrade my android to an "LG V20" which has a phone dad designed for music as opposed to typical low performance dac's that typically come with a phone.....However, this would limit me in the event I wanted to connect a laptop or other streaming device which would have inferior dac's. I was interested in a tube driven dac too but wasn't sure if that would be cost effective.....if like to keep budget under 300...
 
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