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Are all DACs the same - an investigation

IMF+TDL

Active member
{MODERATOR'S COMMENT: This thread is a fork from the original thread on CD players, here.}
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So following on from Hifidave, perhaps the answer is to look for a decent DAC that will last you a good number of years and provide a range of other services, and a cheap as chips CD with a digital out to use as a transport. It may cost a bit more up front, but you won't be replacing electronics due to mechanical failure.
The proportional cost of the electronic parts required to implement the DAC function is remarkably small compared to the total price of a CD player. The $300 players mentioned use a DAC chip which costs about $1, along with an op-amp, or two, for the output amplifier/filter costing about $0.25.

The price of the DAC and amplifier parts found in a $1,000 player is seldom more than $5. Buy a stand-alone DAC and you're paying double for an enclosure, power supply, circuit board, etc.

Thus, you may not realize much savings, if any, by opting for a stand-alone DAC unit.
 

Kumar Kane

New member
Cost reality

Cost reality

The price of the DAC and amplifier parts found in a $1,000 player is seldom more than $5.
Buy a stand-alone DAC and you're paying double for an enclosure, power supply, circuit board, etc.
Thus, you may not realize much savings, if any, by opting for a stand-alone DAC unit.
I knew it was low, but not that low - good to know. And the saving of the extra costs of another enclosure and other stuff is an excellent point, at a time when the DAC problem has been solved from an audible sound quality perspective. Other than wanting another box in the set up for appearances, there doesn't now seem to be a point in buying a standalone external DAC for any reason.

That doesn't stop the marketing of USD 10K standalone external DACs though! Along with expensive interconnects.
 

ssfas

Well-known member
DACs and costs

DACs and costs

I knew it was low, but not that low - good to know. And the saving of the extra costs of another enclosure and other stuff is an excellent point, at a time when the DAC problem has been solved from an audible sound quality perspective. Other than wanting another box in the set up for appearances, there doesn't now seem to be a point in buying a standalone external DAC for any reason.

That doesn't stop the marketing of USD 10K standalone external DACs though! Along with expensive interconnects.
You can get standalone external DACs for £50 (possibly less) on Amazon.

IMF+TDL likes cheap audio and that's fine.

However, I find that I use my DAC as a digital hub.
(1) Physical connections: Typically, a DAC with USB, optical and coaxial inputs would be used for computer/hard drive, airplay and CD sources respectively.
(2) Network connections: Bluetooth, wifi and CAT5 connections will allow streaming from external NAS drives, iPhones etc
(3) Built-in streaming services: Many DACs now had spotify and other services built in.

You may want some or all of these facilities, or none at all. There are DACs around with most or all of these facilities starting at around £500 or £600.

Not all DACs sound the same. AS used a DAC at Bristol that costs £7,000 and had a single USB input. I tried a similar £4,000 valve DAC and the sound had breathtaking transparency. I tried the DAC in my $300 Tascam CD200 player and it is hugely inferior. (I only use the CD200 as a transport.)

So if you think about whether or not you want to use other digital sources, you may find a DAC a sensible option. Given you want to future-proof, that may be a route to go.
 

HUG-1

Moderator
DACs at Bristol, etc.

DACs at Bristol, etc.

You can get standalone external DACs for £50 (possibly less) on Amazon.

IMF+TDL likes cheap audio and that's fine. ... You may want some or all of these facilities, or none at all. There are DACs around with most or all of these facilities starting at around £500 or £600. Not all DACs sound the same. AS used a DAC at Bristol that costs £7,000 and had a single USB input.....
Not so. The entire Bristol performance was from physical CD direct or from a $150 Tascam DAC as reported in the Bristol show write up here. Amps were Trigon or Creek.

DACs most definitely do not sound the same or measure the same. (Unexpected shock at HUG HQ)
 

SChat

New member
Minimal investment now?

Minimal investment now?

... So if you think about whether or not you want to use other digital sources, you may find a DAC a sensible option. Given you want to future-proof, that may be a route to go.
On the other hand, given that technology for DACs are most likely to evolve rapidly (relative to more matured technologies for Amps, Speakers, Transport) does it make better sense to buy the cheapest so that replacing them with new ones is easier as newer technologies and services (like streaming that did not exist until only a few years ago) are developed?
 

willem

Well-known member
Sonic differences between DAC's

Sonic differences between DAC's

That last line ('DAC's do not sound or measure the same') deserves some elaboration and probing.

I know there are inferior DAC's, but does one have to spend serious money, or are inferior DAC's just bad implementations?

{Moderator's comment: Or the inverse?}
 

Kumar Kane

New member
Filter bypassing

Filter bypassing

DACs most definitely do not sound the same or measure the same. (Unexpected shock at HUG HQ)
They may not measure the same. I have however still to see a published well controlled level matched DBT of modern DACs, with sound shaping filters defeated, that have shown audible differences between them.
 

HUG-1

Moderator
Explanation please?

Explanation please?

They may not measure the same. I have however still to see a published well controlled level matched DBT of modern DACs, with sound shaping filters defeated, that have shown audible differences between them.
Please explain this point in simple language for us as we are not DAC experts here. Thanks.
 

SChat

New member
Why dispense with filters?

Why dispense with filters?

They may not measure the same. I have however still to see a published well controlled level matched DBT of modern DACs, with sound shaping filters defeated, that have shown audible differences between them.
not challenging it ....just curious, why would one want to have the "sound shaping filters defeated"?

In the process of converting binary to analog information aren't filters a necessity so that the resulting frequency curves are smoother? Aren't the filters part of DAC design?
 

acroyear

Active member
Better informed purchase decisions for DACs?

Better informed purchase decisions for DACs?

Please explain this point in simple language for us as we are not DAC experts here. Thanks.
Kumar Kane's point seems pretty well stated already. If DAC's can be objectively distinguished from listening (they must also measure differently in that case) then it would be valuable information to know, at least a punter could go into a purchase armed with this and hopefully find a relationship between cost and performance (or preference perhaps!)

I know Alan had hinted at differences a while back, hopefully more light will be shed.
 

willem

Well-known member
Filter options?

Filter options?

From what I understand the performance of a DAC is limited by the chipset used. It provides a ceiling to that performance. If the chipset is implemented properly, all or almost all of the potential performance is realized. If not, results can be rather worse. So the question is whether well designed DAC's using common chipsets are sonically different, or not. How do they measure, and how do they compare in a proper abx test?

I think Kumar Kane is referring to some DACs like the DACmagic that also have some adjustable filter options. In that case, the comparison should be done with the filter set to neutral/flat or whatever it is called. That is what he meant, I think.
 

Kumar Kane

New member
Sound changing filters

Sound changing filters

Please explain this point in simple language for us as we are not DAC experts here. Thanks.
Nothing complicated about this, it actually simpler than the amplifier thing because with DACs there isn't the speaker load/interaction issue to muddy the waters as it can with two amps.

Modern hifi amps that measure different on the test bench will still not have audible differences in level matched DBTs when working within designed limits. Precise level matching remains important with DACs too because their output signal voltages vary.

My experience with DACs I have used in the last five years suggests this no audible difference conclusion. That does not make me a DAC expert of course, but I haven't found a single well controlled DBT published anywhere, where two DACs have been audibly distinguished.

Many DACs now come with sound shaping filters that are similar conceptually to tone controls, and as tone controls have to be bypassed in an amp DBT, these filters have to be left out of the loop for an apples to apples comparison of two DACs where the post conversion sound signature is to be compared.
 

willem

Well-known member
Cheap DAC measuring well

Cheap DAC measuring well

See here for a test of an excellent implementation of a USB DAC with very cheap components: http://nwavguy.blogspot.nl/2011/02/behringer-uca202-review.html

The question is, quite simply of a more expensive DAC like the ODAC or even more so the Benchmark DAC2 will not only measure better, but will also sound audibly better? I am already very pleased with the Behringer DAC. As for bad implementations, see: http://nwavguy.blogspot.nl/2011/02/nuforce-udac-2-drama.html
 

HUG-1

Moderator
Explain 'filters'

Explain 'filters'

....... My experience with DACs I have used in the last five years suggests this no audible difference conclusion. That does not make me a DAC expert of course, but I haven't found a single well controlled DBT published anywhere, where two DACs have been audibly distinguished.

Many DACs now come with sound shaping filters that are similar conceptually to tone controls, and as tone controls have to be bypassed in an amp DBT, these filters have to be left out of the loop for an apples to apples comparison of two DACs where the post conversion sound signature is to be compared.
I'm confused. Are there more than one type of "filters" in a DAC? Didn't even first generation CD player's DACs have "output filters"?
 

Kumar Kane

New member
Anti-aliasing filters and sound shaping filters

Anti-aliasing filters and sound shaping filters

Those are filters that are needed for accurate rendering of the converted source signal - anti aliasing filters for example. There is no provision in DACs to defeat these, and aren't the ones I was referring to.

The ones I referred to are DACs that have further filters to change the sound to suit the room or the music genre. Similar to the ones in AVRs. I was referring to the defeating of these for a valid apples to apples comparison of the conversion quality of two DACs.
 

willem

Well-known member
Testing methodology

Testing methodology

I am not so sure the stereomojo test qualifies as a proper DBT. What is needed is a statistical analysis to see if the result is more than the product of random error.

With this setup, I have my doubts. In a shootout there is always a winner, but would the same DAC win again next time?
 

pkwba

New member
DACs being produced at present - what is peculiar with them?

DACs being produced at present - what is peculiar with them?

Not so. The entire Bristol performance was from physical CD direct or from a $150 Tascam DAC as reported in the Bristol show write up here. Amps were Trigon or Creek.

DACs most definitely do not sound the same or measure the same. (Unexpected shock at HUG HQ)
You signalized this problem with contemporary DACs in more than one post. Where is the rub? Maybe some more thorough general explanation what engineers at Harbeth have found in this matter? Very, very interesting topic.

ATB
 

Kumar Kane

New member

Kumar Kane

New member
User-adjustable filters?

User-adjustable filters?

I think Kumar Kane is referring to some DACs like the DACmagic that also have some adjustable filter options. In that case, the comparison should be done with the filter set to neutral/flat or whatever it is called. That is what he meant, I think.
Yes, thank you, these are the filters I was referring to.
 
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