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TioFrancotirador  
#21 Posted : Thursday, November 24, 2016 9:38:09 PM(UTC)
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Seems like accuphase has already implemented dual es9038pro in dc-950 and dp-950.

http://www.accuphase.com/cat/dp-950_dc-950_e.pdf

Just the price scares away :)
Russ White  
#22 Posted : Sunday, November 27, 2016 2:55:04 AM(UTC)
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ES9038 is essentially 4 ES9018/28 output stages in parallel. So each of the 8 channels is equivalent to 4 channels in parallel (one stereo mode channel) of the ES9018/9028.

I am working on a very special output stage that will work for both new DACs. :)
thomaspf  
#23 Posted : Sunday, November 27, 2016 3:41:13 AM(UTC)
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Hi Russ,

that is great to hear. I can't wait but take your time to get it right...

Cheers

Thomas

P.S.: So the ES9028Pro is more of an incremental upgrade to the ES9018 and the ES9038pro requires a more complete redesign of the I/V stage?
Russ White  
#24 Posted : Sunday, November 27, 2016 5:50:29 PM(UTC)
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That is correct. The 9028 is essentially a 9018 with an improved core and digital stage. The analog stage is basically the same. There is big downside to the ESS chips (old and new) that makes dual mono less than desirable. I will talk more about that later.

ES9038 absolutely needs a special output stage - it's output current and current consumption is huge - it needs very special care to be sure. This is because the analog output is directly referenced to the AVCC input - there is no PSRR. So with the huge currents involved you need very special care indeed.

Cheers!
Russ
TioFrancotirador  
#25 Posted : Sunday, November 27, 2016 7:19:26 PM(UTC)
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Originally Posted by: Russ White Go to Quoted Post
That is correct. The 9028 is essentially a 9018 with an improved core and digital stage. The analog stage is basically the same. There is big downside to the ESS chips (old and new) that makes dual mono less than desirable. I will talk more about that later.

ES9038 absolutely needs a special output stage - it's output current and current consumption is huge - it needs very special care to be sure. This is because the analog output is directly referenced to the AVCC input - there is no PSRR. So with the huge currents involved you need very special care indeed.

Cheers!
Russ


Russ,

What does it mean: "This is because the analog output is directly referenced to the AVCC input - there is no PSRR." technically and how it impact overall performance?

Russ White  
#26 Posted : Sunday, November 27, 2016 10:46:10 PM(UTC)
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It means that the analog output is really just raw FETs with Drains and Sources connected to the analog rails. It's actually just like a switch.

That means any noise/ripple present on the analog supply will definitely be present in the output signal. This is compounded by the fact that the DAC itself (as a significant load) is causing ripple all the time - so the AVCC supply has to have excellent load regulation and PSRR itself.
dahlberg  
#27 Posted : Monday, November 28, 2016 4:37:57 PM(UTC)
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I own three BuffaloIIIse's using them in a 3-way dsp xo and has used John Broskies "Unballancer" for output stages. I like them a lot regardless of them being somewhat in the voltage region. I'm hoping for them to be a good fit for the BuffaloIV as well. I'm planning for one 8-channel dac using 4-channels for l/r-hp and the remaining 4 for l-r subs and l-r midbass. As I read this the avcc inputs will draw 4 times as much current as the ess9018 did, is this correct ?
TioFrancotirador  
#28 Posted : Monday, November 28, 2016 5:41:35 PM(UTC)
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Thanks Russ for explanation.

I am just wonder how close to R2R dacs es9028pro is ... especially to R2R Vout types.
Russ White  
#29 Posted : Monday, November 28, 2016 11:00:45 PM(UTC)
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Not at all - it is a completely different kind of analog stage.
Russ White  
#30 Posted : Monday, November 28, 2016 11:01:28 PM(UTC)
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Originally Posted by: dahlberg Go to Quoted Post
I own three BuffaloIIIse's using them in a 3-way dsp xo and has used John Broskies "Unballancer" for output stages. I like them a lot regardless of them being somewhat in the voltage region. I'm hoping for them to be a good fit for the BuffaloIV as well. I'm planning for one 8-channel dac using 4-channels for l/r-hp and the remaining 4 for l-r subs and l-r midbass. As I read this the avcc inputs will draw 4 times as much current as the ess9018 did, is this correct ?


Yes - the whole chip uses much more current.
dahlberg  
#31 Posted : Monday, November 28, 2016 11:19:30 PM(UTC)
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Originally Posted by: Russ White Go to Quoted Post
Originally Posted by: dahlberg Go to Quoted Post
I own three BuffaloIIIse's using them in a 3-way dsp xo and has used John Broskies "Unballancer" for output stages. I like them a lot regardless of them being somewhat in the voltage region. I'm hoping for them to be a good fit for the BuffaloIV as well. I'm planning for one 8-channel dac using 4-channels for l/r-hp and the remaining 4 for l-r subs and l-r midbass. As I read this the avcc inputs will draw 4 times as much current as the ess9018 did, is this correct ?


Yes - the whole chip uses much more current.


I imagine this is mostly for the avcc section and the digital side is similar (for current draw) to the BuffaloIII, right ? How about pcb size, will it fit in 100x125mm ?

Edited by user Monday, November 28, 2016 11:21:02 PM(UTC)  | Reason: Not specified

Russ White  
#32 Posted : Tuesday, November 29, 2016 11:41:44 PM(UTC)
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It uses more current from all supplies - but mostly from AVCC.

The I/V stage is still being worked on - it will be the largest board - probably a bit larger than the current IVY-III

I will finalize dimensions when I am able.
thanks 1 user thanked Russ White for this useful post.
dahlberg on 11/30/2016(UTC)
AndriyOL  
#33 Posted : Wednesday, November 30, 2016 9:38:45 PM(UTC)
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Russ, will the dac board comes with U.FL sockets?
akras  
#34 Posted : Tuesday, December 13, 2016 9:20:23 PM(UTC)
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I am planning to use I2S outputs of the miniSHARC board to feed an 8-channel DAC feeding 8xUcD180 amplifiers. Buffalo III is known to work well in this configuration.

Are there any reasons to expect that the miniSHARC+Buffalo IV will not be as happy a marriage as miniSHARC+Buffalo III? I'm planning a basic decoupling plus RC filter for the output stages, at least for now. I'm trying to decide between getting a Buffalo III now and Buffalo IV later...

Thank you for your advice and suggestions.

Edited by user Tuesday, December 13, 2016 9:21:54 PM(UTC)  | Reason: Not specified

Russ White  
#35 Posted : Wednesday, December 14, 2016 2:22:02 PM(UTC)
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It will indeed work for that application as well or better.
thanks 1 user thanked Russ White for this useful post.
akras on 12/14/2016(UTC)
markk02474  
#36 Posted : Monday, December 19, 2016 5:30:02 AM(UTC)
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Originally Posted by: Russ White Go to Quoted Post
That is correct. The 9028 is essentially a 9018 with an improved core and digital stage. The analog stage is basically the same. There is big downside to the ESS chips (old and new) that makes dual mono less than desirable. I will talk more about that later...

Are you talking about chip to chip variations making a chip for each channel a problem? Resonessence seems to parallel half the channels from each of two DAC chips to make an output channel.

That's mentioned here: http://www.resonessencelabs.com/service-support/faqs/ under the question of "What's the difference between the Invictus and Invictus Mira?"

Quote:
"Doubling the number of channels reduces the noise by 3db. However, Resonessence does a little more. Firstly, we use a circuit level implementation that distributes the left and right channels equally between the Sabre chips, this ensures perfect channel to channel matching. And secondly, we actually also parallel the AD797 output amplifiers so that they also have their noise reduced by 3db at the same time. This second level of connectivity in parallel extends to the regulators as well: their noise goes down too."
Gbatokai  
#37 Posted : Monday, December 19, 2016 1:47:11 PM(UTC)
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Originally Posted by: Russ White Go to Quoted Post
It uses more current from all supplies - but mostly from AVCC.

The I/V stage is still being worked on - it will be the largest board - probably a bit larger than the current IVY-III

I will finalize dimensions when I am able.


Sounds good! :) I don't know if this is decided yet, but will it be a discrete stage such as the Legato, or integrated like the IVY?
Russ White  
#38 Posted : Monday, December 19, 2016 2:22:13 PM(UTC)
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Originally Posted by: markk02474 Go to Quoted Post
Originally Posted by: Russ White Go to Quoted Post
That is correct. The 9028 is essentially a 9018 with an improved core and digital stage. The analog stage is basically the same. There is big downside to the ESS chips (old and new) that makes dual mono less than desirable. I will talk more about that later...

Are you talking about chip to chip variations making a chip for each channel a problem? Resonessence seems to parallel half the channels from each of two DAC chips to make an output channel.

That's mentioned here: http://www.resonessencelabs.com/service-support/faqs/ under the question of "What's the difference between the Invictus and Invictus Mira?"

Quote:
"Doubling the number of channels reduces the noise by 3db. However, Resonessence does a little more. Firstly, we use a circuit level implementation that distributes the left and right channels equally between the Sabre chips, this ensures perfect channel to channel matching. And secondly, we actually also parallel the AD797 output amplifiers so that they also have their noise reduced by 3db at the same time. This second level of connectivity in parallel extends to the regulators as well: their noise goes down too."


That really does not solve the chip to chip matching issue. Which is not about output level - but output impedance. There is no way to make two DAC chips perform identically. :) Even if their output is the same.

What you "could do" but would be foolish in my opinion - is parallel multiple chips - but with the ES9038 you would really see no net gain - because you would hit the limits of the analog stage.
thanks 1 user thanked Russ White for this useful post.
markk02474 on 12/23/2016(UTC)
Russ White  
#39 Posted : Monday, December 19, 2016 2:23:40 PM(UTC)
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Originally Posted by: Gbatokai Go to Quoted Post
Originally Posted by: Russ White Go to Quoted Post
It uses more current from all supplies - but mostly from AVCC.

The I/V stage is still being worked on - it will be the largest board - probably a bit larger than the current IVY-III

I will finalize dimensions when I am able.


Sounds good! :) I don't know if this is decided yet, but will it be a discrete stage such as the Legato, or integrated like the IVY?


It is completely new- but most like the IVY. Later I may do a more legato like stage - but it is not really practical with the ES9038 without some major re-factoring. :)
akras  
#40 Posted : Tuesday, January 3, 2017 10:43:39 PM(UTC)
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Russ,

Is it correct to assume that you will recommend powering the new Buffalo (just the DAC, not including the I/V stage) with Placid HD v2.1 or there will be a new power supply released?

Thank you,

Andrey

Edited by user Wednesday, January 4, 2017 4:50:26 AM(UTC)  | Reason: Not specified

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