External DAC recommendations please

[bigburner]

Analog reconstruction filter is a practical necessity in any digital system that must interface with the outside world. The output section of any CD or DVD player or an outboard DAC must have this filter. I did say that in my opinion this filter is responsible for the perceived sound of the system, because there is really nothing else that can influence the sound as much.

From a purely technical perspective in a digital system several parameters can be responsible for the sound of the system, - they are: the THD, the S/N and the frequency response. Change anyone of those appreciably to the worst and the sound will change.

The principles of DSP dictate that in order to preserve the required 16-bit resolution, the reconstruction filter must be of certain degree of complexity. In my experience I have yet to see a CD/DVD player that would adhere to the theory as needed. This reality results in an increased noise, and decreased overall signal resolution which might be audible.

Another issue, - filter alignment. Here we have a requirement for the linear phase circuit, due to the fact that the human hearing is extremely attuned to the phase linearity. The problem is that a linear phase filter of a necessary complexity is difficult to construct. In other words the phase linearity and filter complexity become kind of mutually exclusive. It is possible, but expensive, may not be as reliable and might require hand-tuning. Nobody wants to do that in a production environment.

The frequency response is another issue here, because in order to get the complexity and phase linearity the cut-off frequency of the filter may have to infringe on the audible pass-band, - with clearly audible results.

So, - here you have it, - engineering is far from simple as it is a study in multidimensional compromises, the reconstruction filter rates as a problem of an average difficulty. You can get it right, like the Benchmark did, or you can get it wrong like most companies out there even a boutique ones. It is a degree of how wrong you get it mandates the sound quality that an audiophile perceives.

If you get it right, then it is possible to built a CD player and sell it for $150US and its sound will not be different from a player costing $5000+US. I know this for a fact, as I have been there myself.

Regards,
Victor

Thanks Victor. I'm leaning towards a DAC1. It's either herd instinct or there's something genuinely worthwhile about this device. If/when I get one I'll submit an opinion.

Regards,
Nigel.

[chinets]

Yes, but Kurt how much is the improvement? especially that you are running it with Arcam and Krell equipment. Is there such a big difference?? You said it was very nice, but is it worth coughing up $1,000 when you had it very nice to begin with, and mind very expensive to begin with. Will that Benchmark Dac1 really tip the Audio part of the brain, when you had a perfect set up to begin with?? Don't think so?? Could you explain yourself better?
Regards,
Chinets

[kurtholz]

Hi Chinet's

well, first off, if you are still using a Rotel amp, i doubt it will help you anyway, hahahahha

seriously, it is a subtle difference, but one that since i have gotten used to, i wont listen to any CD without engaging it. how would i descibe the differences,

the most obvious is, everything is just clear, voices, instruments you really hear it all, it also has added a very dark soundstage, now keep this in perspective, before i had it, i would have put my set-up against anything made, i am amazed there is a difference, but there is

so, just get off your seat and pony up, you need one

:-)

regards

Kurt

[chinets]

Kurt,
I'll forgive you for the Rotel comment Ouch!!!!!!! But I have Krell too you dog! It was you who got me hooked on Krell, remember?. Ok! I also have the Rotel amp too for the HT duty!!
So I should get that Benchmark DAC1 Hmmm!!!!!!!! Well if it's good for the Kurt then it is surely good for the Chinets!!
I have the CD 1072 by Rotel and the LINN majestic CD player. So which one shall I connect it to ? Or should I get 2 !! one for each CD player.?? The LINN is fantastic and expensive and the Rotel is good and around 800 dollars. So which shall I hook this up to??
Now you hooked me on to DACs Now. Kurt,You are killing me with your Audiophile drugs man!!!!!!!!!!! I'm hooked on everything you have and more!!
Thanks for the advice friend, and hope you and the family are in the best of health?
Have a nice day,
Chinets

[whoaru99]

but is it worth coughing up $1,000 when you had it very nice to begin with, and mind very expensive to begin with.

Totally depends on how much play money one has.

If your income is $35K per year I'd guess you have a different "worth it" level for $1K outlay vs someone making $135K per year.

Notice the more this is discussed, the more "subtle" the differences seem to be described.

Don't take it the wrong way, it's still your $ and if a Benchmark DAC makes you happier, then great.

All said, my Analog Devices AD-1955 DAC evaluation board appears to be on-schedule for delivery at the end of this month. I CAN afford to play with a DAC for $166 +shipping. Well, that's a bit misleading because I could buy a DAC 1 any time if I really wanted one, so it's not really a matter of "afford", it goes back to "worth it".

They don't have documentation up for the eval board, but here's the gist of it http://www.analog.com/en/prod/0%2C28...1955%2C00.html

[kurtholz]

Hey Chinet's

your dilema is easy, throw the Krell away, or better yet, donate it to some poor 3rd world country deperatly in need of mid-fi equipment

hahahhahahha

seriously, i think you will find the Benchmark a winner, but give it a while to settle in, also it is extremely cable dependent, so spare no money there

good luck

hope all is well with you and yours as well

regards

Kurt

[whoaru99]

Oh oh Chinets, looks like you have to upgrade your whole system to make use of the Benchmark.

So, in the end, I guess it is worth it if it gives you a good reason to change everything else. :W

[bigburner]

I have the CD 1072 by Rotel and the LINN majestic CD player. So which one shall I connect it to ? Or should I get 2 !!

Not a problem chinets. The DAC1 has 3 inputs - (XLR, Coax, & Toslink) so you can connect both CDPs to it and still have room to connect your DVD!

[whoaru99]

Not a problem chinets. The DAC1 has 3 inputs - (XLR, Coax, & Toslink) so you can connect both CDPs to it and still have room to connect your DVD!

The XLR input applies only if your player has AES-EBU output. Pro gear may and high end gear may, but most players do not.

[JDH]

I've used an RCA to XLR converter without any 75/110 ohm conversion and it still works perfectly, so effectively you still have 3 inputs available for consumer equipment anyway.

The XLR input applies only if your player has AES-EBU output. Pro gear may and high end gear may, but most players do not.

[chinets]

Bigburner,
Thanks for the Info., as I had No idea you could connect 3 sources to the Benchmark DAC1........Cool!!! You saved me $1,000, just enough for the cables that Kurt was hinting.
Kurt you Audiophilic drug dealer you!! Now you say Krell is Mid Hi-Fi after I spent a bundle on my set up, because you thought Rotel was Inferior. Now I have to sell my BMW M-5 and my house to get the rest of your shopping list of Audiophilic paraphanelia, and you are still going to accuse me of being a Mid Hi-Fi Bum. Ouch that hurts!! Guess I have to throw out my whole system and start from scratch once again!
This time I'm starting with the B&W Snails and work down from there. I'll have to sell my first born child to reach and satisfy your audiophile Goals Kurt!!! Ha Ha Ha !!!!
Just kidding guys!! My heart is for that DAC1 now, and If it is good for the goose(Kurt) I am sure it will be good for the gander(Chinets)!!
Thanks for your help guys,
Cheers,
Chinets

[jim777]

And if that ain't enough inputs, a little $30 video switch can also do the trick. You won't have any problems trying pretty much anything as long as you have short cables (like 3-6').

[chinets]

I thought Kurt was the ONLY DAC freak. I guess I am living among DAC freaks here!!!!
Happy to join the DAC freak road show!! You have a winner and a believer here!!
Thanks guys for your support and help ,and Kurt get out from under that rock of yours and help the forum once in a while ,we miss ya buddy, and hope your family are well too!!!!!!
Cheers,
Chinets

[kurtholz]

Hey old buddy

I am here, always lurking, looking at the chance to bash some Rotelian, hahaha

been busy trying to get a ton of new junk up on my site, plus have a lot of projects going on building,

the little one started school, so he is early to rise, plus football, karate, and all the other activities our little ones have , so time is sparse

glad to see you going crazy buying silly stuff like i do, i feel normal

hahahhahha

warm regards

Kurt

[Bruce]

Although my opinion has not been popular, still, as someone who used to build outboard DACs I would like chime in…
. . . . . . . .
In general most DACs do not do well with jitter suppression because the SPDI/F connection relies on the signal recovery principle and it uses a special circuit to lock-on on the incoming signal. This circuit depends on the local clock. The synchronization can never be 100% and so the jitter may result. Nothing can be done about it, unless this circuit is superb and works below 1 Hz at the very least. There are some products on the market that will do that, but they are not main stream. ASRC as used by Benchmark is the most elegant solution that works very well.
. . . . . . .

Regards,
Victor

I've been on the fence and will now be exploring a slightly different route:

1) EAC ripped music to 44.1kHz files on a PC hard disk server to avoid any jitter from the dynamic conversion off a rotating CD during playback.

2) Bypass all jitter producing conversions through S/PDIF by using a usbDAC with a USB to I2S data path (no S/PDIF involved at all).

3) The anaolg outs of the usbDAC to a preamp for volume control.

I'm driving Dynaudio Contour Towers with Parasound preamp/amplication.

I'm considering a Scott Nixon NOS usbtd (non-oversampling usb tube DAC) attached to the usb port of an ethernet connected client computer. This DAC is also available as a solid-state DAC without a tube.

This DAC has it's own power supply, so it will not be influenced/polluted by the PC's power supply. The data will not be touched by any audio hw inside the computer, but is simply a buffered file from network port to usb port.

Any opinion's or user experiences of this methodology? I know there are some Emperical Audio usb- I2S ramps + P3DAC solutions in use, but I haven't heard user experience here.

[ThomasW]

Any opinion's or user experiences of this methodology?

IMO USB is the worst possible interface for audio.

Were I using a PC based system, the only DAC I'd consider is the Benchmark DAC1.

If you want the euphonics of tubes, run a tube preamp or grab someones analog tube interface.

But hey, that's just the way I'd do it... :B

[jim777]

IMO USB is the worst possible interface for audio.

Why? Bruce wants the audio to be read of his disc at the same rate that it's consumed by the DAC's clock. If a SPDIF interface is inserted, then the disc will feed the SPDIF interface but the DAC has to lock on the rate of the SPDIF interface.

I would prefer the solution where the speed that the audio is read from the disc depends only on the DAC's clock, not a digital interface clock like SPDIFs'.

[Bruce]

IMO USB is the worst possible interface for audio.

Were I using a PC based system, the only DAC I'd consider is the Benchmark DAC1.

If you want the euphonics of tubes, run a tube preamp or grab someones analog tube interface.

But hey, that's just the way I'd do it... :B

Thanks Thomas.

I don't need the tube, Nixon also has the same usbDAC as a solid state DAC. I was just interested in the I2S to DAC interface instead of S/PDIF to DAC.

It's been awhile, but I'm assuming you don't think much of NOS DACs, correct ?

Is the DAC1 avaialble with a usb > I2S > DAC > analog out interface ?

[whoaru99]

Question for those knowledgeable in this sort of thing....

Below is the description of Lavry Engineering's approach to low jitter in their DA-10 DAC. It is comparable in price to the Benchmark DAC.

This stuff is beyond me, so I'd appreciate opinions on how this compares to the approach Benchmark takes regarding jitter reduction/rejection.

Here is Lavry's CrystalLock (TM) description....

CrystalLock (TM) is a better approach
We next describe the basics of the lock circuitry found in Lavry Engineering D/A
converters (and some of our A/D converters).
Let us describe the case for an 11.2896MHz VCXO with pull range of +/- 150ppm. We
generate the 0-5V control voltage with a 12 bit D/A circuit. The D/A step size is about
1.2mV. Each step changes the clock period by .0064pS, so after 256 clocks we end up
with about 1.6pS of jitter over a 44.1KHz clock time period. Let us now run the VCXO
with a fixed D/A code for a while, say for 10 seconds, allowing it to completely disregard
any variations in input jitter. After 10 seconds have elapsed, we step the D/A up (or
down) by one code, varying the oscillator frequency by .073 ppm (300ppm pull range
divided by 4096 steps). About 10 seconds later, we may (or may not) step the D/A again
but again, only by .073ppm.
Such clock is extremely steady but can we ignore the input data rate fluctuations?
Can we "break" the tight relationship between clock rate and input data rate? If the clock
is slightly faster then the data rate, are we not going to "run out of data"? If the clock rate
is slightly slower then the data rate, do not we have "too much data" for our clock?
The answer is simple: we pre store just enough data in a temporary buffer memory,
and clock one sample at a time from the memory with our steady clock. While reading
data out of the memory (with the steady clock), new input data continues to fill the
memory from its input side. Filling the memory may be done with a lot of jitter yet the
output side is ignoring it completely.
The process can not continue indefinitely, because a difference in input and output
clock rates will eventually overflow (or underflow) the memory. To avoid the overflow (or
underflow), we utilize a processor, responsible to measure and determine if the memory
is getting too full or too empty. The processor checks for an average long term trend and
makes the small single step clock adjustment as describe above.
A single step adjustment goes a long way: Assume that the D/A is off by one step,
then we can operate with "two word deep" memory buffer without overflow for 300
seconds! In practice, the buffer memory is more then two words, because the average
input frequency is not constant. An "unrealisic" 100ppm per second input rate drift
requires pre storage of about 5 words of data for 1 second D/A stepping, or an 50 word
memory for 10 seconds of D/A update rate.
Our DA924 converter operates at an update rate of about 10 - 20 seconds. The very
small and infrequent stepping reflect only the very long average drift of incoming data,
thus in effect provide a brick wall filter with an "equivalent cutoff frequency" 1000 times
lower then the best classical PLL circuits. The control voltage D/A output is highly
filtered with a large time constant to smooth the tiny steps, and, though inherently cleaner
then CMOS gates, to reject any remaining power supply noise and other interference.

[ThomasW]

It's been awhile, but I'm assuming you don't think much of NOS DACs, correct ?

It's not an oversampling vs non-oversampling debate with me. My target is what sounds most like live music. And to date the only DAC I've used that provided a significant improvement toward that goal is the DAC1.

Another the other nice thing about the DAC1 is that is does this regardless of the source, PC (CD/DVD ROM), cheap CD/DVD player or $pendy CDP,

And the performance remains the same regardless of input. Toslink sounds the same as coax. That's not my experience with other DACs

Is the DAC1 avaialble with a usb > I2S > DAC > analog out interface ?

There's no USB connector on the DAC1

[jim777]

whoaru99, sounds nice. So being an engineer, I'll give you my opinion:

Who cares how it works, how does it sound?

The audio industry always comes up with some scientific evidence why their product is better than the competition. In the end, the sound of the equipement in your system is what counts.

This only tells us that the DA10 is worth a listen because it is about the same price as the DAC1 and it has many of the same features (like jitter reduction). All systems have some kind of jitter, even this one (from the VCXO itself), so only a listen can tell..

[whoaru99]

Who cares how it works, how does it sound?

Ultimately, this is true.

I see so, so much about the Benchmark and how its low jitter seems to be the most touted technological advantage, I would like to see some opinions on competitive technology/solution.

[ThomasW]

I'll put this in as JonMarsh's proxy. He's studied the Lavry DA-10 DAC design (it's a stripped down version of their more expen$ive DAC,) and thinks Benchmark's approach is superior. He hasn't done a head to head comparison.

[jim777]

When I searched reviews of DAC1 vs DA10, it would seam that the DA10 has a warmer sound that I would prefer.

[Victor]

whoaru99,

Lavry DA-10 DAC approach to jitter reduction is credible; - it is a well known FIFO (first in first out) approach. It works well when done right and it appears from the description you posted that Lavro Dac does keep jitter at bay.

I still think that the use of ASRC is a better approach and therefore I put my money on Benchmark. In essence, the ASRC uses of a filter bank to pick the right samples from a highly over-sampled data and it should yield the same results as a well implemented FIFO, but ASRC approach is by far more directs or if you will less convoluted in its application and therefore much less can go wrong with it.

However, if you like the Lavry DA-10 DAC, I am sure you will be very happy with it; - it looks like a fine piece of engineering.

regards
Victor

[Victor]

Bruce,

Non-oversampling DAC cannot work at all. I know that people are using it and like it, but the reality is that with no oversampling the DAC cannot reconstruct the signal to its original 16 bits. Therefore, in essence you are loosing information. To put it simply, - you do not get to hear everything that recording engineer recorded and intended for you to hear.

regards,
Victor

[AptosJeff]

Lavry jitter writeup

whoaru99,

Basically agree with Victor. What Lavry describes is a classic solution to the jitter problem; been around a long time. Is it better than other approaches? I don't know, but I respect Victor and JonMarsh's opinions. Maybe jitter performance is not the key to Lavry's DAC.

But even though I am elect eng by day, I am more interested in sound quality than theory. I've found over the years that when discerning listeners say something, they are often right; in spite of specs, in spite of theory, etc. And I like the reviews Lavry gets. You can get a 15 day trial period from the factory and that's what Im' going to do.

[Bruce]

Victor,

Thanks for your perspective. Guess I'll have to do some more investigation about how to get bit-perfect PCM and DD/DTS out of my PC on different output ports. My objective here is to always have bit-perfect 44.1kHz PCM selected for music on a specific PC output port (no switching between digital formats).

Maybe I don't have to worry about separate output ports. Does the Benchmark DAC1 passthru DD/DTS ?

My current plan was to use the usb port just for 2-channel bit perfect 44.1kHz PCM and the S/PDIF header on the motherboard for DD/DTS. Guess I can still use that methodology with a Benchmark DAC1 if I use a usb-to-S/PDIF converter.

Haven't checked specs, but does anyone know if the Benchmark can take an I2S input ?

[whoaru99]

whoaru99,

Basically agree with Victor. What Lavry describes is a classic solution to the jitter problem; been around a long time. Is it better than other approaches? I don't know, but I respect Victor and JonMarsh's opinions. Maybe jitter performance is not the key to Lavry's DAC.

But even though I am elect eng by day, I am more interested in sound quality than theory. I've found over the years that when discerning listeners say something, they are often right; in spite of specs, in spite of theory, etc. And I like the reviews Lavry gets. You can get a 15 day trial period from the factory and that's what Im' going to do.

I'm holding off on the Lavry until I get some time to play around with the evaluation board I have on order from Analog Devices. By all accounts it should be a nice piece - albeit no case. Has multiple inputs, controllable by computer interface, RCA and balanced outputs, in general, all kinds of goodies. How it sounds, well, who knows at this point. Hopefully it'll come in as scheduled toward the end of this month.

[ThomasW]

Interesting post from John Siau....

An inside look at the Benchmark DAC1 - from the designer:
All versions of the DAC1 use the following IC's:

AES Receiver:
AK4114 (AKM) - selected for its ability to accurately recover data in the presence of high-jitter, high-noise, and when signal levels are very low. The AK4114 is unsurpassed for data recovery. However, the clock recovery on this IC is very poor due to the wide bandwidth of it's PLL. The DAC1 does not use the AK4114 for clock recovery. The DAC1 only uses the AK4114 for input multiplexing, data recovery, and digital de-emphasis (for those rare CD's that actually use pre-emphasis).

Up sampler (ASRC):
AD1896 (Analog Devices) - selected for its low spurious tones, low distortion, and exceptionally low PLL corner frequency. Pin-compatible versions of this part exist, but should NEVER be substituted into a DAC1. The substitute parts have much higher PLL corner frequencies, and will destroy the DAC1's exceptional jitter attenuation.

D/A Converter:
AD1853 (Analog Devices) - selected for its exceptionally low distortion. In the DAC1, the AD1853 operates from a fixed-frequency ultra-low-jitter crystal oscillator that is well isolated from external clocks. The digital filters in the AD1853 are frequency shifted in the DAC1 to minimize passband ripple, and eliminate imaging and aliasing of near-Nyquist high-frequency audio content. The high-frequency transparency of the DAC1 is unsurpassed by anything we have measured. Most D/A converters suffer from aliasing, imaging, harmonic distortion (THD), intermodulation distortion (IMD), and jitter-induced distortion. We have gone through great pains to minimize these common defects.

While no audio device is perfect, it is possible to reduce the amplitude of error signal to inaudible levels: In the DAC1, jitter-induced sidebands never exceed -141 dBFS, spurious tones never exceed -126 dBFS, line-related hum never exceeds -126 dBFS, noise never exceeds -114 dBFS, and THD+N never exceeds -105 dBFS. This means that at a playback level of 105 dB SPL, the THD+N artifacts are at the threshold of hearing (if the room were silent), and the jitter induced sidebands are 36 dB BELOW the threshold of hearing (in a silent room). By any stretch of the imagination, jitter-induced sidebands are inaudible with the DAC1. So why do different transports sound different with the DAC1?

Transport issues: Some transports are not bit-transparent. Some DVD players have a digital volume control on the digital output. Some apply sample rate conversion to the digital outputs, and this conversion may be of a poor-quality. Also, most CD and DVD players are designed to mask or skip data when the disk cannot be read, some will attempt to re-read the data, but ultimately will skip or mask if subsequent reads fail. A dirty or scratched disk will play differently in different transports. A transport with dirty or misaligned optics will produce similar problems. Bottom line, the bits at the SPDIF or TOSLINK connector may not be identical to the bits on the recorded media. We have done some testing of transports and expect to post the results on our web site when we have more data. Some transports work very well, others do not. Unfortunately, we are finding that price is not a good indicator of transport quality.

A further word of caution when comparing digital interfaces with the Benchmark DAC1: If you connect a single transport with two different types of digital outputs to the DAC1 (SPDIF and TOSLINK for example), you WILL hear a difference between the two inputs when you flip the input selector switch on the front of the DAC1. The difference is real but the difference only persists for 500 mSec. Here is what you are hearing: When the input to the DAC1 switches, two soft-mute circuits activate to prevent pops and clicks. The mute/un-mute sequence ends in less than 100mSec (typically 60 mSec). During the mute sequence and for another 400mSec, the DAC1 UltraLock™ circuitry is disabled and the audio is pitch shifted to adjust the internal buffer lengths. The pitch shifting is completed within 500 mSec after switching inputs. The red "ERROR" LED on the front of the DAC1 is illuminated while the mute/un-mute, and pitch-shifting operations are taking place. The pitch shifting sequence is either normal-up-normal or normal-down-normal. The first half of the sequence occurs during mute, but the second half is not muted. Consequently you will hear normal audio prior to the switch, followed by a 60-100 mSec mute, followed by new input pitch shifted, followed by a 400 mS adjustment back to normal pitch. The small but abrupt change in pitch after the mute is just enough to give the impression that one input is brighter than the other. The direction of the pitch shifting sequence is determined by the relative delay between the two digital inputs. The input with the largest delay will be perceived as brighter. If the optical interface has more delay than the coaxial, it will be perceived as being brighter. After 500msec, there is no difference. Kind of interesting!

Why so many OP-Amps in the DAC1? The answer is that the DAC1 uses parallel signal paths to keep the total number of OP-Amps to a minimum in any given path. The RCA and XLR outputs have identical but separate signal paths. The front panel gain and rear panel gain are separate but identical signal paths. This topology keeps the outputs well isolated an keeps each signal path to a minimum. Cost? extra Op-Amps.

Regarding regulator layout: The regulators are positioned at the noisy side of the box, so that only clean DC is distributed to the rest of the board using a star topology.

Regarding trace lengths: Obviously signals must traverse the box from the front-panel control to the rear-panel output jacks. Such a traversal must be made with care. All long analog traces are very low impedance, and are fully shielded in 3 dimensions by surrounding the trace on 4 sides with a shield. All of the shield components are "stitched" together at regular intervals using vias. This construction is very unusual, but is very effective. Check the crosstalk specifications if you doubt the effectiveness.

Regarding grounding: The transformer secondaries, rectifiers and bulk capacitors share a single ground point and do not introduce ripple currents into the ground plane. Line-related hum is -126 dBFS or better.

John Siau
Director of Engineering
Benchmark Media Systems, Inc.

[Vince Helm]

Hello,

I have owned two Musical Fidelity DACS in the same price range as the BenchMark. Both worked very well and beat by a wide margin the internal DAC my Parasound Halo C2 PRE/PRO ($4000.00). I did try the above mentioned tube buffer with great results when used with the out board power supply. I was blown away when I replaced the power cord linking the tube buffer to power supply with a cable from revelation audio labs. At this point I can not imagine being with out an external DAC. You can also tweek the sound with different digital cables!! Have fun and good luck! Please know that I am not asking you to buy the Musical Fidelity stuff. I wanted you to know that I had great results using an external DAC.

Vince

[AptosJeff]

Analog Devices

whoaru99,
Let us know how the evaluation board works out. At $165 it sounds like a cost effective approach.

[whoaru99]

whoaru99,
Let us know how the evaluation board works out. At $165 it sounds like a cost effective approach.

Received notice today that the DAC is shipping.

FINALLY!!! It's been one day less than 5 months since I placed the order....

[ThomasW]

FINALLY!!! It's been one day less than 5 months since I placed the order....

Slow work takes time, incompetent work takes a little longer ..... :B

[whoaru99]

That's entirely possible. :lol:

The line they used on me was that they needed at least 25 orders to tool-up for a run and just looking at the website, it's not very clear how to order the eval board.

Besides, I see AD makes a lot of the "guts" (or should I say brains??) in the DAC1, so it can't be all bad.

I'll be sure to post some pics and scan in the tech details for the reading interest of those so inclined.

[jim777]

Keep us updated, I might follow your path because my dvd concert listening with the oppo could need a little boost

In the mean time, anybody knows about great dacs for dvd only (that means 48kHz audio, no 44.1) ??

[bigburner]

I might follow your path because my dvd concert listening with the oppo could need a little boost

I agree. The Oppo has great PQ but the SQ is a little edgy.

I have discovered that Benchmark has only one dealer in New Zealand - a guy who works out of his home. No Web address. I've phoned him four times but he's always out. Benchmark won't ship direct to customers living in a country that has dealers.

The trials and tribulations of hi-fi...

[whoaru99]

Keep us updated, I might follow your path because my dvd concert listening with the oppo could need a little boost

In the mean time, anybody knows about great dacs for dvd only (that means 48kHz audio, no 44.1) ??

Dunno exactly the relevance of this, but it is some of the claims of the AD1955 DAC. Perhaps it's no more than any other DAC already does.

Accepts 16-/18-/20-/24-Bit Data
Supports 24-Bit, 192 kHz Sample Rate PCM Audio Data
Supports SACD Bit Stream and External Digital Filter Interface
Accepts a Wide Range of PCM Sample Rates Including:
32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, and 192 kHz
Multibit Sigma-Delta Modulator with "Perfect Differential
Linearity Restoration" for Reduced Idle Tones and Noise Floor
Data Directed Scrambling DAC––Low Sensitivity to Jitter

But, you know those Marketing guys/gals; they can turn a sow's ear into a silk purse. :B

[Bruce]

w99,

Do you have a list of equipment you plan to use (test) this DAC with ?

I would be interested to know as you report on the results.

[whoaru99]

Bruce, I have a range of stuff, but the best I can do is

Proceed PRE pre-amp
Levinson No. 23 power amp
Paradigm Studio 100v2
Denon DCD-1560 cdp

Cables are homebrew using Belden teflon stuff (don't recall #) and some Blue Jeans made from Belden 1505F and 1694A.

I believe this eval board is supposed to have balanced outputs so I'd like to try some balanced cables between the DAC, preamp, and power amp; but I'm not going to shell out that $$ unless there is a compelling reason.

Speaker wire is some litz-type stuff I bought at a clearance store for about $5 for each 10 or 15-ft spool. I think it has Tefzel insulated conductors and is roughly 12 or 10ga equivalent using (just guessing) 20 to 24 ga individual solid strands.

I'm hoping my brother will come down and bring his Music Hall CDP and his Denon 2900. We used these various players (and a couple other REAL cheapies) when we played with the Benchmark DAC.

[Bruce]

double post

[Bruce]

Thanks for the equip list.

My equipment list:
Dynaudio Contour 2.8 towers (86dB sensitivity, 4 Ohm, 2-way with passive radiator)
Kimber Cable 4TC speaker cable
Parasound 200 wpc@4 Ohm amplification
Parasound Direct-coupled preamp.
Parasound CD player with digital and analog out.

Previously tried a Millenium II DAC ($1k) and, like you, found little difference to justify $1k.

This looks like it could be a good project, and I'm looking forward to your experience.

[Jesse111]

McIntosh MDA1000. I don't know what the others sound like. So I can't compare. But I can tell you one damn thing for sure. The MDA is incredible. Have had mine for 3 days. The improvement was very significant in every way. I suppose the size of improvement depends on what you're comparing it to. All I can say is, the MDA is my final DAC purchase.

[whoaru99]

Received notice today that the DAC is shipping.

FINALLY!!! It's been one day less than 5 months since I placed the order....

Well, seems Analog Devices has changed their date once again. It's been pushed back one more month.

It's starting to pi$$ me off. ;-x A-D

I'm starting to believe ThomasW's comment in post #79.

[jim777]

Cancel it and get another brand. What about Wolfson or Cirrus Logic. Many companies use the Wolfson, and McIntosh found the new high-end Cirrus Logic to be the best sounding one (well that's what went into the MCD201 anyway).