Pics of the GDA-600 board.

fbm211

I got a digital camera! Now Im gonna try to post some pics with it.The quality might be bad as I never had a dig camera before.Its a sony DSC-P51 and only 2mp so I may need to get a better one. http://s301.photobucket.com/albums/nn56/fbm211/?action=view&current=Picture004.jpg http://i301.photobucket.com/albums/nn56/fbm211/Picture002.jpg

fbm211

Seems I have some ghosting, hmm..

ben62670

I find its the flash not the megapixels that kills photos.

fbm211

Ben.That was at normal flash.Do you use low,norm,or high.Here are some at 640 res.

ben62670

I like 1 mega pixel for posting. Good outdoor lighting and a stable camera do wonders for pics. I shoot most of mine in my dungeon after the sun goes down:(

Systems

This looks like a dream to work on,and I like that the power supply is on its own separate PC board.Parts quality looks good atleast in the low pass filter section were they used some nice film caps ,and the PCM63's are great dac chips.Most of the better sounding DAC units back then used PCM'63's.

heiney9

GV#27 wrote: »

This looks like a dream to work on,and I like that the power supply is on its own separate PC board.Parts quality looks good atleast in the low pass filter section were they used some nice film caps ,and the PCM63's are great dac chips.Most of the better sounding DAC units back then used PCM'63's.

This is a real stellar sounding DAC, and then factor in a used price of $250 or less and it's a real steal.

I used to e-mail a former Adcom designer in NJ and he says the 600 is even a nicer sounding DAC than the 700. The 600 was actually a departure from the Adcom "house" sound, a very smooth sounding open DAC.

Not to say the 700 was a slouch but they sort of paved the way with the 600 and actually made a lot of great design decison's witht he 600. The Burr Brown PCM-63K is a stellar chip set even still today.

H9

ben62670

I have been debating selling my GDA-700, and getting the 600. That would put some coin in my pocket, and I don't think I would be taken a performance hit:)

600/700
input decoder

---

Crystal CS8412/Ultra Analog AES21
DAC

---

R-2R BB PCM-63/BB PCM-1702P

What I would lose is HDCD(who cares), balanced outs, and the class A biased direct coupled output stage. The later I care about.

Adcom info is found here
http://www.adcom.com/manuals.aspx

fbm211

Its gonna sound even better once I get those IC adapters installed.Then I can compare as many opamps as I like.Just waiting on the 60Watt iron.

heiney9

ben62670 wrote: »

I have been debating selling my GDA-700, and getting the 600. That would put some coin in my pocket, and I don't think I would be taken a performance hit:)

600/700
input decoder

---

Crystal CS8412/Ultra Analog AES21
DAC

---

R-2R BB PCM-63/BB PCM-1702P

What I would lose is HDCD(who cares), balanced outs, and the class A biased direct coupled output stage. The later I care about.

Adcom info is found here
http://www.adcom.com/manuals.aspx

Ben I might be mistaken but I thought the 600 was also Class A biased dc output. That seems to be a common thread among Adcom's.

My brother has both a 600 and 700 and they both sound great. I think the 600 has a tad more musicality to it, but the HDCD decoding is hard to beat.

ben62670

heiney9 wrote: »

Ben I might be mistaken but I thought the 600 was also Class A biased dc output.

The one thing about the 700 if you look at both the 600, and 700 boards the 700 has no signal caps. I think this is what Adcom meant by direct coupled?
http://www.polkaudio.com/forums/showpost.php?p=905347&postcount=15
Well C430-434 may be used for an LF filter.

Systems

heiney9 wrote: »

Ben I might be mistaken but I thought the 600 was also Class A biased dc output. That seems to be a common thread among Adcom's.

Correct there are no output coupling caps so its direct coupled and if you look in the schem of the 600 (and likely the 700) you will see that the op amps have Fets attached to their outputs so they will be biased heavily into Class A.

Systems

ben62670 wrote: »

I have been debating selling my GDA-700, and getting the 600. That would put some coin in my pocket, and I don't think I would be taken a performance hit:)

600/700
input decoder

---

Crystal CS8412/Ultra Analog AES21
DAC

---

R-2R BB PCM-63/BB PCM-1702P

The AES21 contains an CS8412 with a special PLL circuit for reduced jitter,the 1702 IIRC is the replacement for the PCM 63.Same specs but the smaller DIP packaging.

Systems

ben62670 wrote: »

t=15[/url]
Well C430-434 may be used for an LF filter.

Yes C430-C435 are part of the low pass filter.

heiney9

Thanks for the clarification GV . I'm kind of sad because at one time Adcom really made some great gear for the money. They worked hard at making great sounding, long lasting products that were still affordable. I remember talking to a lot of Adcom brass at CES when I was a dealer in the mid 80's. They were so passionate about the brand and where they were going with it.

It's sad to see a company like this a shell of it's former self. Luckliy they didn;t fall by the wayside as rapidly as Nakamichi.

A little trip down memory lane

H9

mmadden28

fbm211 wrote: »

Seems I have some ghosting, hmm..

Damn that hurts the eyes.

Not familiar with your camera, but it almost seems like you have the shutter speed way too slow, even with a flash. Set it to auto until you can master manual settings (if they are even an option).

If you have a point and shoot, check the "easy mode" settings whatever they may be called. You might be in some kind of Portrait, low light, night or fireworks mode.

mmadden28

Check out the 6th paragraph down. Seems to describe what you're pics look like.
http://www.steves-digicams.com/2002_reviews/P51.html

Scene Mode - Twilight Portrait ??

Systems

heiney9 wrote: »

It's sad to see a company like this a shell of it's former self.

Yes it sure is as they had some great products for comparitively reasonable prices.I have had no personal expeirience with any of their products but was very aware of them from reviews and advertising and such.Strangely they didn't seem to have much market presence up here unlike NAD which was very well represented.

Luckliy they didn't fall by the wayside as rapidly as Nakamichi.

Boy did they ever disappear from the radar,are they still in buisness?

A little trip down memory lane

H9

Back in 85-88 I was also in Audio retail,or atleast pretended to be a salesman so I could listen to the equipment.