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"No-Dac" and "No-USB"


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Just a few words of warning and some general info.

a/ This concept of low pass filtering DSD stream is indeed very old and the first people to do it were (the late) Allen Wright and Joe Rasmussen with their first

SACD player upgrades over ten years ago. They were taking DSD straight from decoder chip, pre DAC and using some active low pass filtering.

b/ The concept is attractive from a perceptual POV because you might think that you got rid of one part from the signal chain - the DAC. Well that is sort of true

but the reality is you just changed the DAC to a single bit DAC and moved it to a different place - wherever the I2S is made.

As such you now have a DAC that is basically the logic chip that generates I2S signal.

c/ With a single bit DAC like this there will be a -LOT- of RF noise to filter. For valve amp users, not too much sweat - most valve amps won't breal a sweat and

will even be part of the LPF. For SS amp users - be very careful feeding all that RF into your amp. I wouldn't recommend a single order (1 cap / 1 resistor) LPF

if you are running a SS amplifier. It really depends on the design, some will be OK others may not like it at all.

d/ One of the main reasons it sounds good is 1/ it's DSD - it's a great sounding format 2/ you are eliminating the LPF normally in DAC chip (even for DSD)

Generally the software conversions from PCM to DSD do a better job and some have multiple configurations / filters etc etc.

e/ As far as comparisons between direct I2S versus USB->I2S converter, same rules apply. The best results will come from the design that is 1/ properly isolated 2/ re clocked

with a VG clock 3/Has the right logic

cheers

Z

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Just a few words of warning and some general info.

a/ This concept of low pass filtering DSD stream is indeed very old and the first people to do it were (the late) Allen Wright and Joe Rasmussen with their first

SACD player upgrades over ten years ago. They were taking DSD straight from decoder chip, pre DAC and using some active low pass filtering.

b/ The concept is attractive from a perceptual POV because you might think that you got rid of one part from the signal chain - the DAC. Well that is sort of true

but the reality is you just changed the DAC to a single bit DAC and moved it to a different place - wherever the I2S is made.

As such you now have a DAC that is basically the logic chip that generates I2S signal.

c/ With a single bit DAC like this there will be a -LOT- of RF noise to filter. For valve amp users, not too much sweat - most valve amps won't breal a sweat and

will even be part of the LPF. For SS amp users - be very careful feeding all that RF into your amp. I wouldn't recommend a single order (1 cap / 1 resistor) LPF

if you are running a SS amplifier. It really depends on the design, some will be OK others may not like it at all.

d/ One of the main reasons it sounds good is 1/ it's DSD - it's a great sounding format 2/ you are eliminating the LPF normally in DAC chip (even for DSD)

Generally the software conversions from PCM to DSD do a better job and some have multiple configurations / filters etc etc.

e/ As far as comparisons between direct I2S versus USB->I2S converter, same rules apply. The best results will come from the design that is 1/ properly isolated 2/ re clocked

with a VG clock 3/Has the right logic

cheers

Z

Good advice. This is one way to get very good sound at a small price, but it has compromises as Z points out. I'm getting "better" sound out of another way, but its a lot more work and complexity.

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Good advice. This is one way to get very good sound at a small price, but it has compromises as Z points out. I'm getting "better" sound out of another way, but its a lot more work and complexity.

Thanks Mick.

WRT better sound, what is your current digital reference? I know you like to experiment with a number of digital replay systems.

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Just a few words of warning and some general info.

....

cheers

Z

Great infor Z! Fantastic seeing you here too.

I didnt have the gut posting such useful infor as often they might get miss-interpreted..!

I kept telling my SNAers circle in W.A of the risks this is posing, someone will/may fried their tweeters if they have no electronic background.

Great to see Ray in diyaudio forum has advanced further with this old-school idea. We (Ray, Stijn, Acko, myself, and couple others) began this idea back in the day of our venture in i2s from RPi to DAC via Acko S03. I since lost interest after my new setup with Accuphase DC-37 and idealish server.

Sent from my iPhone using Tapatalk

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Great infor Z! Fantastic seeing you here too.

I didnt have the gut posting such useful infor as often they might get miss-interpreted..!

I kept telling my SNAers circle in W.A of the risks this is posing, someone will/may fried their tweeters if they have no electronic background.

Great to see Ray in diyaudio forum has advanced further with this old-school idea. We (Ray, Stijn, Acko, myself, and couple others) began this idea back in the day of our venture in i2s from RPi to DAC via Acko S03. I since lost interest after my new setup with Accuphase DC-37 and idealish server.

Sent from my iPhone using Tapatalk

 

 

The "risk' is certainly worth considering, but its not as bad as you are making out. The low pass filter does a pretty good job of attenuating the hash, although its certainly still there. Personally I think if a solid state amp is going to have problems with whats left of the HF , then it probably isnt worth owning , as it isnt going to be a particulary nice sounding amp anyway.

 

I have a couple of high bandwith SS amps , including one weird Australian design that accentuates the <100Hz and >20Khz frequencies ( to get good phase response, I think) and have no problem with either, although I dont use mega thousand dollar tweeters. But if your the worrying anal type, or convinced there's only one way (your way) then best to stay away.

 

The no-dac is not an attempt to topple any other implementation off it's throne, its a really inexpensive, interesting concept that is easy to build, even for someone who hasn't done any diy. And it sounds bloody good for what it is, which is a fun device to play around with. I've moved on, but I'm impressed enough to want to share the fun, diy gets shrouded in secret service and kiss my arse I'm a guru , and this a finger to that.

 

Chanh Yeah I heard your early i2s ventures remember, imo you gave up too soon, maybe you didn't try all the possibilities, newer design choices, etc, but I suspect we have different taste in how music should sound anyway , so  we would probably always be on a different path, which is the way it should be, would be boring if we all thought we were gurus and guardians of the only truth. 

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but I suspect we have different taste in how music should sound anyway , so  we would probably always be on a different path, which is the way it should be, would be boring if we all thought we were gurus and guardians of the only truth. 

 

 

Now there is some wisdom. 

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Statman, looks really interesting :) Have you had a look at the implementations on diyaudio ... best dac no dac

Yeah ive been there from the start, have some of Ray's mute boards. Contributed regularly.

Ive done some more listening to the more sophisticated JLSounds boards as no-dac , set it up so I could play same track as my "best" dac with immediate switching, so uninterrupted A/B comparism.

No its not the world's best dac, but jeez for what it costs it sure has some serious arsenal, will be putting it up against a stupid price commerial dac soon, will be interesting.

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Yeah ive been there from the start, have some of Ray's mute boards. Contributed regularly.

Ive done some more listening to the more sophisticated JLSounds boards as no-dac , set it up so I could play same track as my "best" dac with immediate switching, so uninterrupted A/B comparism.

No its not the world's best dac, but jeez for what it costs it sure has some serious arsenal, will be putting it up against a stupid price commerial dac soon, will be interesting.

Very interesting :)    I look forward to reading about the result :)

 

A question... is there a board that you know of that up samples SPDIF input to 256 or 512 DSD and outputs it as I2S?

Edited by Ping
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Well the beauty of the Amanero is that it is easy for new diy'ers, with no mains power supply. The JLSounds is  better, with  better clocks etc, but it needs two independent power supplies/regulators, which means transformers and mains, and we dont want to kill anyone.  If you want to do a pcb go for it, there's usually little demand for this type of thing, but as long as it doesn't end up costing you......

I must try the Amanero with Linux, had it going with Daphile, but didn't give it a decent listen, might be worthwhile as the JLsounds is running Linux.

Gordon do you know of any other program besides JRiver, Daphile, Foobar and HQPlayer that does pcm-dsd conversion? (but no mac please) 

No Mick , still using JRIVER.

Thanks for the build guide, Saving pennies to get one of the JLsounds boards. Will let you know how it goes. :thumb:

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  • 2 weeks later...

Yeah ive been there from the start, have some of Ray's mute boards. Contributed regularly.

Ive done some more listening to the more sophisticated JLSounds boards as no-dac , set it up so I could play same track as my "best" dac with immediate switching, so uninterrupted A/B comparism.

No its not the world's best dac, but jeez for what it costs it sure has some serious arsenal, will be putting it up against a stupid price commerial dac soon, will be interesting.

Have you done the comparison?

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Yes I have, up against a very good $15K+ dac. I'm not going to say it was better, but it certainly wasn't shaded either. 

Mick,

 

Are you taking I2S OP as a voltage and adding LPF or are you using a resistor feeding I-V converter then low passing?  Any buffer?

 

Sorry I haven't had too much time to follow these threads as I am looking at my own implementation which is a bit of a departure anyway.

I think this type of 'DAC' if we can call it that has a lot of promise but implementation is really critical because of the high speeds involved.

 

PS - WRT amplifiers RF immunity comments above - yes you are right - the main exceptions are SS amps that use a lot of FB to get

very good measured / linearity. It's worth noting that there has been a bit of a resurgence in these as designers are working out how

to use FB to their advantage without so much neg sonic impact.  But that's another subject.

 

 

cheers

 

T

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  • 3 weeks later...

... any further updates?

No, I did try a buffer at output, but it didn't make much difference, with the no-dacs low gain it's ideal to use with a nice tube gain stage, preferably an accurate low impedance unit rather than a "romantic" unit that would be too lushy. The no dac doesn't need warmth as its very un-electronic sounding. 

I'm not using it, its great sound for its simplicity and cost, but i've moved on to non-usb digital solutions, anyone in Perth want to borrow the no-dac for a play?

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No, I did try a buffer at output, but it didn't make much difference, with the no-dacs low gain it's ideal to use with a nice tube gain stage, preferably an accurate low impedance unit rather than a "romantic" unit that would be too lushy. The no dac doesn't need warmth as its very un-electronic sounding. 

I'm not using it, its great sound for its simplicity and cost, but i've moved on to non-usb digital solutions, anyone in Perth want to borrow the no-dac for a play?

Wow, very generous of you. I wouldn't mind having play with this.

Won't be for a few weeks till I have time however.

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No, I did try a buffer at output, but it didn't make much difference, with the no-dacs low gain it's ideal to use with a nice tube gain stage, preferably an accurate low impedance unit rather than a "romantic" unit that would be too lushy. The no dac doesn't need warmth as its very un-electronic sounding. 

I'm not using it, its great sound for its simplicity and cost, but i've moved on to non-usb digital solutions, anyone in Perth want to borrow the no-dac for a play?

... interesting!  Do you mind describing/detailing the non-usb digital solution and why you are thinking of that solution?

Edited by Ping
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... interesting!  Do you mind describing/detailing the non-usb digital solution and why you are thinking of that solution?

Im not "thinking" about it, been using it for about 6 months now. 

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Someone was good enough to give me a harddrive with a stack of sacd files on it, so i connected the nodac back in system to listen to them, this time in JRiver I selected 4x native dsd upsampling. As far as i understand it, this takes all white noise completely out of audio spectrum.

I also used a tricked up tube line stage with E280F tubes, constant current plate and heater supplies, Peerless output trans, all the gear for state of the art tube preamplification that's possible with these late tube era triode connected pentodes.

The nodac has low gain, so it likes a bit of low noise amplification.

All this takes the nodac out of its tremendous value to money category, this sort of tube gear aint cheap, but its still got the exellent transperancy of the nodac implementation, with better everything else.

Were spoilt with digital now, so much good design has come out in the last year or so.

With a bit of enterprise anyone can have the equal of what cost $10K+ 2 years ago, for a fraction of that.

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  • 1 year later...

Dear Statman,

I have been reading your writings on No Dac, No USB with great interest.  

You seem to prefer the no USB option.  But I am not understanding that you sometimes refer to using Amanero with Raspberry Pi, could you explain how the two would work together?  I understood that you either use Raspberry Pi or Amanero (or JL Sounds).

 

Could you confirm my understanding of the device setup?

Ethernet or WiFi > Raspberry Pi > Ian Fifo S/PDIF Interface Board >Ian I2S FIFO KIT > Dac

I understand that you do not need the Dual XO if you are not changing formats.  

 

I believe you were using a TDA1541 Dac.  Is there an inexpensive Dac (less than $200 that you would recommend with the Raspberry Pi and Ian Fifo kit ?

 

Thank you for your guidance. 

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