Author Topic: DDDAC 1794-NOS 24-192  (Read 174846 times)

Offline rhlauranna

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Re: DDDAC 1794-NOS 24-192
« Reply #220 on: April 08, 2014, 11:22:50 PM »
yes, here it is, for all those who wanted to have a closer look onto Bernd's monster controlled power supply, now "finished" in a cabinet, weighing more than 20 kilograms:



but please, for any further inquiries, go ahead and do not ask me, but Bernd directly:

thanks
« Last Edit: April 14, 2014, 04:28:55 AM by rhlauranna »

Offline ozmillsy

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Re: DDDAC 1794-NOS 24-192
« Reply #221 on: April 08, 2014, 11:48:02 PM »
Lift the skirt,   we want to peak inside.   8)
It's all about the music,, not the equipment.

Offline rhlauranna

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Re: DDDAC 1794-NOS 24-192
« Reply #222 on: April 08, 2014, 11:52:14 PM »
I have already posted some pictures from the inside under No. 205 of this thread, I hope that helps?

Offline ozmillsy

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Re: DDDAC 1794-NOS 24-192
« Reply #223 on: April 09, 2014, 06:49:41 AM »
Yep, I see them.  In post 205, it looks like a temporary wooden case was used.

Was the content simply moved into the new case 'As-Is' ?
It's all about the music,, not the equipment.

Offline rhlauranna

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Re: DDDAC 1794-NOS 24-192
« Reply #224 on: April 09, 2014, 08:31:08 PM »
Yep, I see them.  In post 205, it looks like a temporary wooden case was used.

Was the content simply moved into the new case 'As-Is' ?


the temporary wooden case is my actual version, and yes, the content of it was rebuilt 'As-Is', the only thing that Bernd has changed is an even more forceful power supply, so that it is able to handle as well and completely without problems the DDDAC1543 with 256 chips, so that the users, if they use both DACs - like me, will be in need of only "one" controlled power supply, just switching from one to the other DDDAC...

« Last Edit: April 09, 2014, 08:34:55 PM by rhlauranna »

Offline rhlauranna

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Re: DDDAC 1794-NOS 24-192
« Reply #225 on: May 12, 2014, 07:58:58 PM »
... I think that the development and especially the results of regulated power supplies (not only for this DAC) are of common interest, so let me link to Stefan's result here:

http://www.diyaudio.com/forums/digital-line-level/224108-nos-192-24-dac-pcm1794-waveio-usb-input-177.html

No. 1766, or read it here:

"Hi,

So here are the pictures of my new power supply. It's quite elaborate so I needed to rearrange the complete layout. I put the wave IO on top of the Pi, I still use two streamers, the Alix and the Pi; Alix through Wave IO and Pi I2S connected. I like the Pi more. Just waiting for Russ White to release the cape for the BBB.

On to the supply: on the left side there is a big 200VA transformer (sec. 2x12V), a friend of mine had ordered these specially manufactured to order for use with other Dacs and CD players. This is a really awesome transformer!

It is a simple CLCLC supply using two Silmic 2200uf caps parallel and Lundahl filament chokes.

This supply surpasses all supplies I have used up to date, including the one from Bernd during the visit at Klaus!

It's been a long time since I had so much goose bumps listening to music

Advantages: dynamics, openness, forcefull, detailed, more space, did I mention dynamics?

This one will stay for sure!
The Salas supply is for the Pi and Wave IO.


Regards"

and here are his corresponding pixes so that you may have a look:







« Last Edit: May 12, 2014, 08:04:04 PM by rhlauranna »

Offline Tuyen

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Re: DDDAC 1794-NOS 24-192
« Reply #226 on: May 14, 2014, 06:01:56 PM »
That power supply seems easy enough to build. 4 schottky diodes, a few elna silmics, 2 chokes and a big 200VA tranny.    Simple CLCLC design.   I should be able to build something similar. I have a pair of chokes and some caps. Just need a big tranny and the shcottky diodes.       It will be done...  sometime this year.    ;D

Offline Tuyen

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Re: DDDAC 1794-NOS 24-192
« Reply #227 on: May 26, 2014, 06:24:47 PM »
Interesting comparison between a tweaked DDDAC1794 to a stockish DDDAC1794 and a tweaked AudioNote KIT DAC 4.1 at a recent mini gtg.

The following taken directly from a link on diyaudio forum - http://www.diyaudio.com/forums/digital-line-level/224108-nos-192-24-dac-pcm1794-waveio-usb-input-192.html#post3939495

I always enjoy reading about other people’s get-to-gathers, so thought some might enjoy reading about ours.

Last night myself Mark (I) Verhoeven (idem forum name), Mark II (friend of Mark I) and Cees Pel had the privilege to be invited around to Stefan (Supersurfer) his place for a DAC comparison/listening session.

The equipment line-up for the test/comperisaon, we had in mind. was:

· Mark verhoeven’s,Audio Note Kit DAC 4.1 pretty tricked out NOS DAC, see picture below.
· Stefan’s DDDAC, 4x board DAC, balanced to single-ended “cap”less out , with Tentlabs shunts and own "hi-end" PSU.
· Cees Pel brought along a PSU he’s build for his own DDDAC implementation which unfortunately wasn’t ready yet, but Is promising to be something special as well.
· & my DDDAC, with 4x standard DAC boards, balanced to single-ended “cap”less out and a slightly modified standard 12Vdc supply.

The reference system used was Stefan’s superb sounding home grown DIY system, consisting of very special (looking and sounding) set of tube amps, which worked something like this (I’m personally not a tube-head, so please excuse any ignorant mistakes) :silver rock input transformer -> emissionlabs EML 20A mesh triod’s -> tamura interstage -> western electric VT-25 triode -> tamura interstages parallel -> EML AD1 triode parallel -> tamura output transformers and these were hooked up to Manger driver augmented with some Vifa kevlarwoofers, again in a home build enclosure.

So plenty of quality there to bring out the good and the bads in our respective DAC builds.

To boot, it also turned out Stefan had an extensive collection of well recorded reference tracks to listen too.

First off was my DDDAC build which meant I could get a feel for what Stefan’s system sounded like. We started off with a Pink Floyd DVD-A track, which we all know to death. Needless to say it sounded pretty great, dynamic and good soundstage, however it revealed a light bit of harshness to my ears and was lacking a bit of body in the midtones. We mainly attributed this to my use of Caddock IV resistors and thinking about it afterwards might also be due my choice of signal path cabling (skin effect?). (I suspect some of the quibbles where in the recording too..) I learned a lot in those first 5 minutes, right there and then.




Next up was Stefans DDDAC. It was quite a remarkable difference. The same track sounded even more dynamic and became more spacious, the tonal quality was better too. Some tracks later (I think it was: Miles Davis - Complete Live At Plugged Nickel 1965 (1995)) the soundstage was simply amazing. The occasional Goosebumps moment of being teleported back to being “there”.., if you know what I mean. Simply superb. I think Stefan is definitely evolving the DDAC in the right direction and the good news is there is still plenty of scope/ideas for further improvements..

Last up was Mark’s Audio Note DAC (4.1), another highly regarded DAC design but a totally different proposition based around a single AD1865N NOS chip and a tube/transformer output stage. In my ears the tonal quality of this DAC was superb, very relaxed and natural. However, especially compared to Stefans’s DDDAC the dynamics and presence was not the same, also the soundstage was not as open/wide/deep with the AN DAC. None of which should come as a complete surprise considering the inherent differences of the designs.




Especially when Stefan switched back to his DDDAC we were all quite convinced this was a step up. However there seems to still be scope to get the tonal balance dialled in further by playing around with the type of capacitors in the design.

Cees his PSU had some interesting features too, like a little hand wound HF filtering coil in the place of the fuse holder, Mills resistors some Ebony encapsulated caps, check out the picture below.. , years of experience shows, should be very intresting to see what he makes of the DDDAC.




Thanks again to Stefan for inviting us and for a very enjoyable evening.

Hopefully we can do it again, maybe next time to compare Field coil PSU’s :)

Offline rhlauranna

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Re: DDDAC 1794-NOS 24-192
« Reply #228 on: June 29, 2014, 09:57:45 PM »
...there is some interesting "excursion" by "eduard" from The Netherlands regarding transformers which I think might perhaps be of use here (and not only within this context):

#2164 and #2166

you will find them as well as corresponding links here:

http://www.diyaudio.com/forums/digital-line-level/224108-nos-192-24-dac-pcm1794-waveio-usb-input-217.html
« Last Edit: June 29, 2014, 10:01:15 PM by rhlauranna »

Offline rhlauranna

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Re: DDDAC 1794-NOS 24-192
« Reply #229 on: August 18, 2014, 07:28:21 PM »
...well, here are some new test reports especially regarding the implementation of Tent shunts and more by Doede himself:

http://www.diyaudio.com/forums/digital-line-level/224108-nos-192-24-dac-pcm1794-waveio-usb-input-250.html

no: 2941
« Last Edit: August 18, 2014, 07:40:00 PM by rhlauranna »

Offline Chanh

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Re: DDDAC 1794-NOS 24-192
« Reply #230 on: August 21, 2014, 10:18:09 PM »
In all fairness, Doede did not install the 3.3V TentShunt in the optimal position. What's the point having Shunt when it must go through a couple of 47uf electrolytic in order to get to chip Vcc?
I will be in the position to provide honest feedback when my 11-Stacks are finalised with 47 Tents Shunts. Still waiting for the remain Sanyo OSCon, should not be too long now.



Offline dddac

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Re: DDDAC 1794-NOS 24-192
« Reply #231 on: August 24, 2014, 06:48:37 AM »
Hi Chanh,

just to make sure, I installed the 3,3 volt shunts directly at the chip. There were no couple of 47 uF in the way....  Are you still planning to do listening tests with and without the 3,3 Volt shunts as only changed parameter? That would be the real honest feedback. Changing several things at the same time will never make 100% clear what really made the difference.

I am really looking forward to more people doing this test with only one change at a time. Last week I had independent feedback from Marcel for Switzerland, who removed the 3,3 volts ten shunts and replaced them with LDOs again. He is using the 8 volts at the analog side of the dac and is also pleased with this. I think there is no discussion about this improvement anymore...

don't get me wrong, this is not a discussion who is wrong or who is right. I just reported back what I heard and what some else has done. I know you spent a lot of money on the dac and specially on the tent shunts. for that reason it would make most sense to this in two steps, wouldn't you agree? if you install all in one step, you for sure will have a hell of a dac, but knowing what made the true difference is something I am sure also you are interested to know, not only me ;-)

look forward to your reports !


Offline zenelectro

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Re: DDDAC 1794-NOS 24-192
« Reply #232 on: August 24, 2014, 03:56:38 PM »
Hi Chanh,

just to make sure, I installed the 3,3 volt shunts directly at the chip. There were no couple of 47 uF in the way....  Are you still planning to do listening tests with and without the 3,3 Volt shunts as only changed parameter? That would be the real honest feedback. Changing several things at the same time will never make 100% clear what really made the difference.

I am really looking forward to more people doing this test with only one change at a time. Last week I had independent feedback from Marcel for Switzerland, who removed the 3,3 volts ten shunts and replaced them with LDOs again. He is using the 8 volts at the analog side of the dac and is also pleased with this. I think there is no discussion about this improvement anymore...

don't get me wrong, this is not a discussion who is wrong or who is right. I just reported back what I heard and what some else has done. I know you spent a lot of money on the dac and specially on the tent shunts. for that reason it would make most sense to this in two steps, wouldn't you agree? if you install all in one step, you for sure will have a hell of a dac, but knowing what made the true difference is something I am sure also you are interested to know, not only me ;-)

look forward to your reports !

Yes, finally a post with some measured sanity.

We have had endless long posts here of various DDDAC changes and mods with no real logical approach or explanation.
To me they just read like a DDDAC sales brochure but offer virtually zero real information WRT mods that might work in
another application. 

As the DAC's designer you well know that there are many details that must be addressed, separately to fully and fairly evaluate any
design change such as this case, a shunt reg.

For evaluation of a shunt reg here's an example of things I would be testing in isolation:

a/ is the shunt reg super low impedance but low bandwidth?
b/ is the shunt reg a higher impedance but very wide bandwidth
c/ what bypass caps were used
d/ were there combinations of bypass caps, IOW say a film cap in parallel with an elecro. This can have a big effect
e/ where is the shunt reg located? Is it right on the DAC or further away?
f/ what sort of grounding is the shunt reg tied to? For a DAC like 1794 there is lots of HF content so is there a ground plane, how good is it?
g/ Does the bypassing cap location make a difference?

Most tinkerers don't have a really good understanding of these finer points and just proceed into having fun modding their DAC's - which is
great in the spirit of DIY  But as such the results often don't often translate reliably to something else.

Another example is the multiple paralleling of 1794 DAC's. This technique is very well known and has been used for many years to, for
example get lower noise from transistors etc.

However for me again there has been no real scientific evaluation of the advantages - a lot of effort and cost goes into stacking boards up.
Looking at the distortion results of DDDAC, they are very poor and don't come close to getting what the chip is capable of. So in the
case of designing a current output DAC with a passive OP stage we have compromised the DAC's linearity by a huge margin. You can use
one DAC and get 20 x lower distortion without having to use opamps. Maybe the DAC sounds good -because- of this higher distortion,
it would not be the first time.

Maybe the multiple parallel DACs sound better because of higher OP current drive - but then we can get huge current drive with one
DAC and a simple OP circuit.

For me, the first thing I would do is evaluate what the change in sound is with 1794 OP voltage swing. The 1794 does not like to have
OP voltage swing, it causes a lot of distortion. So I would make a test jig up and vary the OP resistance and see how this affects sound.
I can almost guarantee that the more voltage swing on the DAC OP will translate to a richer and more musical sound, because of the added
distortion.

Once I had done this I would then evaluate the optimum driving impedance for the OP transformer. Transformers work best with a certain
drive impedance and also they usually need a snubber on the OP. Looking at the square wave performance of yours, it has overshoot so
needs to have a snubber installed. You should be able to get "perfect squares" from a transformer with no overshoot.

You might well find that a single well optimised 1794 driving a transformer that is also optimised will sound better than a stack
of 16 that are not optimized.

Food for thought.

cheers

Terry

Offline vitavoxdude

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Re: DDDAC 1794-NOS 24-192
« Reply #233 on: August 25, 2014, 04:09:44 AM »
 ;D  The DIY effect, if one is good then 10 must be great! errrrrrrr hmmm, well put Z, fine if you have all the measuring equipment but enthusiasm usually makes up the bulk of the design decisions for enthusiasts!
V
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline Chanh

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Re: DDDAC 1794-NOS 24-192
« Reply #234 on: August 25, 2014, 02:00:45 PM »
......
You might well find that a single well optimised 1794 driving a transformer that is also optimised will sound better than a stack of 16 that are not optimized.
Hi Terry,

Lots of useful technical infor there!  ;)
Btw, unsure if the design is optimal per individual standard, but I do use Sowters Transformer as output and could never go back without them.

Hi Chanh,
.......
look forward to your reports !
Hi Doede,

Perhaps my wording w.r.t the word "honest" was misleading? I think the word "unbiased" is more appropriate here. It was never intended to critic your facts/findings. I think I must have read your post in a hurry where my interpretation was you installed the 3.3V Shunt at the stock regulator.
Hopefully your weren't offended?
I will post my findings on a single DAC with and without Tent Shunts.

;D  The DIY effect, if one is good then 10 must be great! errrrrrrr hmmm, well put Z, fine if you have all the measuring equipment but enthusiasm usually makes up the bulk of the design decisions for enthusiasts!
V
I think you are contradicting yourself here Steve! You have heard my setup with 4-stacks and again with 8. According to you, there were noticeable improvement(s) "time, phase, and imaging". "A more of analog sounding" with 8 stacks. If I recalled correctly, you have also mentioned "use your ears not measurement". After-all, this whole audio hobby is so subjectively biased. What's a good/excellent sounding DAC? Will that excellent DAC be universal perceive as excellent to all audience/system setup(s)...., and engineering measurement? If so the ESS Sabre chip should be outstanding chip of all since on paper its measurement are absolutely second to none but yet some found it too clinical.  :D

Offline vitavoxdude

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Re: DDDAC 1794-NOS 24-192
« Reply #235 on: August 25, 2014, 03:27:30 PM »
No contradiction here Chanh, merely echoing the thoughts of Zen and saying it is up to the individual if he/she wants to continue down a path of replacing parts in a new design and experimenting.  Engineers take a different slant as they are usually constrained more by costs.   I applaud people who take a design to its logical conclusion for them not criticise.
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline ozmillsy

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Re: DDDAC 1794-NOS 24-192
« Reply #236 on: August 25, 2014, 06:51:56 PM »
If so the ESS Sabre chip should be outstanding chip of all since on paper its measurement are absolutely second to none but yet some found it too clinical.  :D
Hey Chanh, good post.  I have never heard a dddac, and hope to one day.   Do you have the super power supply?

WRT to ESS, I honestly feel that no one has completely unlocked the potential of the Sabre chip. There are a zillion configurable parameters.

Interestingly, ESS use a combination of design and listening tests to validate their theories.  They openly admit to using people with "educated ears" and that their designers generally cant hear the differences that some audiophiles can.  :)

Personally,  I reckon peal everything back to the basics, and get genuine unaltered single bit performance to where it needs to be.   That means a different path to both the dddac and kdac choices.
« Last Edit: August 25, 2014, 06:55:25 PM by ozmillsy »
It's all about the music,, not the equipment.

Offline Chanh

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Re: DDDAC 1794-NOS 24-192
« Reply #237 on: August 25, 2014, 09:55:50 PM »
.......
I agreed with you here! Doede in his design allows room for parts/components improvement . This does not mean his design wasn't optimal, to my ears it sound great hence much love and funding were investmented.  ;)
Hey Chanh, good post. ......
Thanks Ozmillsy!
I think DAC chip is only a third of the equation, implementation and quality parts are the rest of that magic formula!  :)
My tweaked DDDAC surely will be powering by raw unregulated chokes input. The EI transformer(s) were from Vitavox! This Man has ears, trained/experience ears those are!  :-*
Nonetheless, if the negotiation falls, I will replace the power transformer to 300VA R-Core.



DAC at 11-Decks prior dissembled for the Tent Shunts mod.
 






Offline rhlauranna

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Re: DDDAC 1794-NOS 24-192
« Reply #238 on: August 25, 2014, 10:12:05 PM »
Chanh,

congratulations on your achievements...

bravo !!!

Offline zenelectro

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Re: DDDAC 1794-NOS 24-192
« Reply #239 on: August 25, 2014, 10:20:48 PM »
Hi Terry,

Lots of useful technical infor there!  ;)
Btw, unsure if the design is optimal per individual standard, but I do use Sowters Transformer as output and could never go back without them.


Yes I am also a fan of transformers - done right.

Quote

 After-all, this whole audio hobby is so subjectively biased. What's a good/excellent sounding DAC? Will that excellent DAC be universal perceive as excellent to all audience/system setup(s)...., and engineering measurement? If so the ESS Sabre chip should be outstanding chip of all since on paper its measurement are absolutely second to none but yet some found it too clinical.  :D

Hence my comment WRT the 1974, as used in the DDDAC allows it to swing considerable OP voltage swing which creates a significant amount of added distortion.
So the question is - does the DDDAC sound better because of this added distortion or in spite of it? How is this added disortion affecting the sound? Personally I
would want to know this and the answer is easily revealed by, as I suggested, using a simple Opamp OP stage and varying the resistance feeding it. Yes we know
people don't like opamps but here we are just using it as a constant to evaluate a certain property of the DAC. Knowing the outcome of this is a very handy 'tuning'
tool. There is often indeed a certain OP swing that is the right balance between musicality and detail or accuracy. Maybe it will just sound better with no OP swing.

But invariably, hi end designers don't do these simple tests because they are maybe a boring deviation from the usual, regardless of their usefulness.

This brings us to Sabre - it is certainly one of the best measuring DACs but there are many things lurking inside the Sabre more than a simple resistor weighted DAC
that affect it's sound such as various digital filters, a sample rate converter, etc etc. There are people who feel that Sabre with all that extra Tom Foolery disabled and a
good valve OP stage is one of the best DACs out there.

So my general advice is hold the audiophile hyperbole descriptions of mods and their sonic effects and post more details that will help us to better understand how the
mods were specifically applied. As such we can have a better idea if they will translate to other designs that we are doing.


cheers

Terry