Inside the latest Benchmark DAC1
Jul 14, 2004 at 11:56 PM Thread Starter Post #1 of 181

dip16dac

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I had a chance to look inside the latest Benchmark DAC1 and this is what I saw.

It has a single circuit board for everything including the power supply, receiver, ASRC, DAC, and headphone amp.

The headphone amp has two BUF634F buffers, two 5532A opamps, and a really small alpha pot.

The receiver is the AK4114, the async sample rate convertor is the AD1896A, the DAC is the AD1853 followed by four 5532A opamps.
A LC02A and RX176 is in there also. Four more 5532A opamps are by the output connectors.

The power supply has a three inch torroid, two TL401 rectifiers, a 7818 pos reg, a 7918 neg reg, a 7805 reg, and a LM1085.

Looks like there is plenty to modify in this thing.
 
Jul 15, 2004 at 12:07 AM Post #2 of 181
Quote:

Originally Posted by dip16dac
Looks like there is plenty to modify in this thing.


[licks chops] and there will be one on my doorstep by this weekend
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Boy I though I'd buy this babe, and no modding would be necessary. I guess we'll have to see about that. I guess new opamps would be the first place to start. Are there any decoupling capacitors for the voltage rails on the opamps?
 
Jul 15, 2004 at 12:41 AM Post #3 of 181
There are four 100 uF caps near the Buf634 buffers and two 22 uF caps next to the last two DAC opamps. Nothing next to the headphone opamps. There are two 100 and two 10 next to the DAC, two 10 for the ASRC, and two 10 for the receiver. The four regulators have a total of five 330 caps. The rectifiers have two 1000 and one 1500. Thats about it for the electrolytics which are all surface mount.
 
Jul 15, 2004 at 6:08 AM Post #4 of 181
after reading the components list I couldn't resist but ask: how on the earth can this sound good??
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Jul 15, 2004 at 6:19 AM Post #5 of 181
Quote:

Originally Posted by Glassman
after reading the components list I couldn't resist but ask: how on the earth can this sound good??
confused.gif



Because it's $1000, it must sound good!
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<I'm seem to be using this anti-flame suit a lot lately>
 
Jul 15, 2004 at 11:59 AM Post #7 of 181
Quote:

Originally Posted by Glassman
after reading the components list I couldn't resist but ask: how on the earth can this sound good??
confused.gif



the ra-1 curse strikes again!
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Jul 15, 2004 at 12:08 PM Post #8 of 181
So how does the latest benchmark differ from older models?
 
Jul 15, 2004 at 2:41 PM Post #9 of 181
Quote:

Originally Posted by Glassman
after reading the components list I couldn't resist but ask: how on the earth can this sound good??
confused.gif



The sum of it's parts is greater?
 
Jul 15, 2004 at 3:43 PM Post #10 of 181
Quote:

Originally Posted by Glassman
after reading the components list I couldn't resist but ask: how on the earth can this sound good??
confused.gif



I guess I will find out tomorrow or the next day.

It is a bit of a paradox, if it does sound good, as I'd wonder if it could sound better through mods, but perhaps it is optimized with what it has already, and mods would be of no help? Of course there is the famed Stereophile review, where Atkinson compares it very favorable with a $17K Levinson DAC. I guess the question is, when does the point of diminishing returns kick in, even for mods. It is tempting, and will probably be even more tempting once it gets here to rip out those terrible slow opamps for some LT1364's
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Jul 15, 2004 at 3:59 PM Post #11 of 181
Quote:

<sigh> i miss my dac1!


Me too
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Quote:

the ra-1 curse strikes again!


Yeah, perpetuated by those who have never heard it (as usual)
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Jul 15, 2004 at 5:22 PM Post #13 of 181
Quote:

Gee, you guys are getting me even more excited now.


Actually ID, imo the Benchmark is not a good match for the CD3k's. Slightly forward sounding DAC/amp + bright(imo) headphones = fatigue. That's just me though. YMMV
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Jul 15, 2004 at 5:30 PM Post #14 of 181
Quote:

Originally Posted by jpelg
Actually ID, imo the Benchmark is not a good match for the CD3k's. Slightly forward sounding DAC/amp + bright(imo) headphones = fatigue. That's just me though. YMMV
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Well, they're bright, no doubt about it, but I like that. I know that you don't like the CD3K in general, so perhaps the DAC1 just made a bad situation for you worse. Most of the comments that I have read put the DAC1 as being slightly bright, not overly so, which was enough for me to dive in and give it a try, especially at a significant discount from retail. Remember of course that the modded CD3K's I have are not as bright as stock, and are smoother up top, so again it might not be much of a problem. I am familiar with the 5532 opamps from the M-Audio cards, all of which have a bit of a bright sound. It might just come down to swapping them out, then bam, a more natural sound appears. We will just have to wait and see.
 

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