Raak dac is not overpriced
Sorry, but every product compared to strictly DIY will appear "way overpriced ".I consider Rakk Dac - cheap for what it does (even though myself can't afford Lundahl trans right now; ;0). The cheapest Erno Borbely's J-fet stage (board +Psu board) would be ~$500 and ultimate way over $1000. No tubes ,no transformers .The finished phono stage based on K&k design (also available as a DIY) run over $4K retail
and some still consider it a great value. You may have a look at ANUK transformer prices and still AN Kit 1 amp was called what "a bargain of the centaury"??? You know ,DIY is fine and great when you exactly know what you're doing and have some Electronic lab with test equipment at home or at least exposure to the best out there .So many times(almost always) DIY stuff sounds just pathetic ,but the owner/designer is so proud and happy that there is nothing to say.
Sorry, but every product compared to strictly DIY will appear "way overpriced ".I consider Rakk Dac - cheap for what it does (even though myself can't afford Lundahl trans right now; ;0). The cheapest Erno Borbely's J-fet stage (board +Psu board) would be ~$500 and ultimate way over $1000. No tubes ,no transformers .The finished phono stage based on K&k design (also available as a DIY) run over $4K retail
and some still consider it a great value. You may have a look at ANUK transformer prices and still AN Kit 1 amp was called what "a bargain of the centaury"??? You know ,DIY is fine and great when you exactly know what you're doing and have some Electronic lab with test equipment at home or at least exposure to the best out there .So many times(almost always) DIY stuff sounds just pathetic ,but the owner/designer is so proud and happy that there is nothing to say.
Trade-offs in an active versus passive output?
It really has a lot to do with the whole system. Your observation of “…using passive output was giving us less power to work with but with higher quality ( untouched ) signal” is a good one. There will always be electronics down stream from the DAC and depending on the drive capability of the DAC and what the down stream electronics is and how it handles the signal will determine if you need an active output or can use a passive output. You can think of the active output as effective and appropriate electronics for the DAC to drive. The electronics can be designed to have greater drive capability than is available from the DAC chip. If the electronics is well done and coordinated with the DAC then it won’t hurt the sound and can enhance it.
So the benefit of the passive solution is fewer parts and lower cost. A passive output can be an excellent solution if it works well in your system.
The benefit of the active solution is potentially better sound. The active output is generally less system dependant.
With the RAKK dac Passive Output versus RAKK dac Active Output, the Active Output provides a little better life and sparkle to the music as will as a better presentation of the sound stage in every dimension.
The question of transformers is a separate issue. If you were to look at many of my designs, you might not believe it but I tend to be a minimalist – less is better. I will only add something if it provides a benefit. I have found (many times) that a transformer on the input or output of a circuit will help rather than hinder the performance of the circuit. I suspect that galvanic isolation is more important than we realize.
I don’t want to get into a religious war on which circuit topology is best and I’ll just say that I have had good results with transformer outputs.
Dave
P.S. I’m leaving for a long weekend at the beach so this will be my last post till Monday or maybe late Sunday.
It really has a lot to do with the whole system. Your observation of “…using passive output was giving us less power to work with but with higher quality ( untouched ) signal” is a good one. There will always be electronics down stream from the DAC and depending on the drive capability of the DAC and what the down stream electronics is and how it handles the signal will determine if you need an active output or can use a passive output. You can think of the active output as effective and appropriate electronics for the DAC to drive. The electronics can be designed to have greater drive capability than is available from the DAC chip. If the electronics is well done and coordinated with the DAC then it won’t hurt the sound and can enhance it.
So the benefit of the passive solution is fewer parts and lower cost. A passive output can be an excellent solution if it works well in your system.
The benefit of the active solution is potentially better sound. The active output is generally less system dependant.
With the RAKK dac Passive Output versus RAKK dac Active Output, the Active Output provides a little better life and sparkle to the music as will as a better presentation of the sound stage in every dimension.
The question of transformers is a separate issue. If you were to look at many of my designs, you might not believe it but I tend to be a minimalist – less is better. I will only add something if it provides a benefit. I have found (many times) that a transformer on the input or output of a circuit will help rather than hinder the performance of the circuit. I suspect that galvanic isolation is more important than we realize.
I don’t want to get into a religious war on which circuit topology is best and I’ll just say that I have had good results with transformer outputs.
Dave
P.S. I’m leaving for a long weekend at the beach so this will be my last post till Monday or maybe late Sunday.
I built a RAKK DAC Mark1 Right after the Mark 2 was announced.
I am currently running:
The RAKK DAC,
The RAKK DAC PS,
EDCOR 10k:600 interstage transformers.
As it sits, it is the best DAC I have ever heard. I had never heard a passive output, and wanted to try it without spending a lot of money. $25 seemed to be a lot less risky for something that seemed a bit different.
I will upgrade the transformers to the RAKK DAC passive output.
I'm just not in a hurry. I am really curious to hear the difference.
I will also upgrade to the Mark2 at some point. Kevin and Dave are excellent engineers and make a quality product.
Just My two cents.
Doug
I am currently running:
The RAKK DAC,
The RAKK DAC PS,
EDCOR 10k:600 interstage transformers.
As it sits, it is the best DAC I have ever heard. I had never heard a passive output, and wanted to try it without spending a lot of money. $25 seemed to be a lot less risky for something that seemed a bit different.
I will upgrade the transformers to the RAKK DAC passive output.
I'm just not in a hurry. I am really curious to hear the difference.
I will also upgrade to the Mark2 at some point. Kevin and Dave are excellent engineers and make a quality product.
Just My two cents.
Doug
JinMTVT said:hi ezkcdude!!
i think i had overlooked your kit!
i hadn't notice that you'r using the 1794 chip!
Have you measured your DAC's performance?
compared with others?
how do you think it compares to Rakk unit?
( measurable things...i don't care about how sweet it sounds on a sunny afternoon)
What is the cost of your pcb board,
and tota cost for the best version ( 131$ is for all parts except the pcb ?? )
what exactly is used for output stage here, only direct active ops?
nice kit neway, i like how simple it looks!
and i always like to buy stuff from member of this community when possible
I just looked at the K&K website again. I didn't realize there was a new version of the Rakk DAC with ASRC. Now they use the exact same chipset that I do. Interestingly, they don't mention anything about AD1896, but it is pin-compatible with SRC4192, so you could use either. It's still more expensive than my board (by quite a bit), but I can't argue with the design anymore, since it's pretty much exactly like mine. I do have a pet peeve though, in that it's not really much of a "kit". They pre-mount all the smt components. DIY should involve some major pain, right?
As for measurements, some others have done some measurements on my dac:
http://www2.kumc.edu/students/ezamir/DIY/builders/haowu/1794.htm
http://www2.kumc.edu/students/ezamir/rss/2007-04-06-1.html
I bought a sound card (EMU-1212M) to do the same, but I haven't quite figured out how to do it yet.
As for the Rakk DAC, I've never seen any measurements, but I sure would like to compare!
EZ: no prob i'll email you latter..
i'd start by 1 unit to compare it to my current RAKK dac just for fun of it ..
but thinking of it, i'll probably need more than 10 units
( building new house and i'll have to supply alot of sound to alot of different places in the house so;
but only the home theather won't be stereo ..everything else should be stereo thus requiring only 1 unit each)
Could you elaborate on your output stage ?
why have you choose this particular design
( minimum with op ?? )
have you tried with different options ? why no transfos?
i'd start by 1 unit to compare it to my current RAKK dac just for fun of it ..
but thinking of it, i'll probably need more than 10 units
( building new house and i'll have to supply alot of sound to alot of different places in the house so;
but only the home theather won't be stereo ..everything else should be stereo thus requiring only 1 unit each)
Could you elaborate on your output stage ?
why have you choose this particular design
( minimum with op ?? )
have you tried with different options ? why no transfos?
You hit the nail on the head. It's the minimum that needed to be done for my "ez" design. I needed something with single-ended output, and the simple balanced-to-single-ended op amp converter is the simplest active design out there. Remember the I/V is actually done passively with the resistor, so the op amp is not doing I/V - just gain. Anyway, there is at least one person who has taken my board and simply populated the chips - and then used a different output stage. I certainly have no problem with that, and am not offended in the least. The way I see it - my board does a few things and does them well - and not too expensively. If you want to use different power regulation or output - those things are possible to.
As for using transformers - I have no plans to. They are a little too "boutique" for my taste. I can only compare my design to other DAC's I have had (Derek Shek, Theta Pro Prime IIa, and the SqueezeBox analog output) - I like mine.
The only thing I will warn you about is that if you are inexperienced with soldering (as I was when I started the project) - this dac can be tough to build. It really helps if you've had plenty of experience with smt debugging.
i have confidence, and some experience with smd stuff..no problem for soldering ( well equipped with Hakko 936 and a myriad of small tools and tips )
What would you suggest could be improved without investing another 100$ on your output stage?
i'll send you an email for price and stuff..
thanks
)What would you suggest could be improved without investing another 100$ on your output stage?
i'll send you an email for price and stuff..
thanks
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