AudioCircle

Industry Circles => Empirical Audio => Topic started by: audioengr on 23 Jun 2019, 05:12 pm

Title: SOTAPRAT DAC updates
Post by: audioengr on 23 Jun 2019, 05:12 pm
I'm designing an affordable DAC, but with the great SQ that Empirical Audio is known for.  I can do this because I have discovered some new parts that allow me to finally design one without using multiple expensive discrete Hynes-type regulators that must be configured and tuned.  The DAC will contain the new Crystek low-jitter master clocks.

Features that I have designed in so far:

1) USB or Ethernet input interface (Roon compatible) - purchaser chooses one
2) SPDIF input (75 ohm BNC) with my world-class Synchro-Mesh reclocker in series internally
3) RCA analog outputs only, no XLR balanced
4) Front panel power button
5) Front panel input select button
6) LEDs for power, data error and DSD on front panel
7) DSD capability for both USB and Ethernet
8] Output muting when no signal
9) IEC inlet - automatic international power compatible
10) Ground-lift switch on back-panel
11) Uses Analog Devices AD1955 D/A with customized digital filter programming
11) Pricepoint - $3K for USB version, $3.5K for Ethernet version
12) Compact silver aluminum chassis with milled aluminum front panel
13) US-type AC power cord included?

All one needs is a computer or a server and a USB or Ethernet cable.

Did I miss anything?
Title: Re: Features for my new DAC?
Post by: mresseguie on 24 Jun 2019, 06:10 am
Question:

Why did you choose the AD1955 chip?

Michael
Title: Re: Features for my new DAC?
Post by: rollo on 24 Jun 2019, 02:22 pm
  Well feature wise sounds like a winner. The only way to tell is try one.


charles
Title: Re: Features for my new DAC?
Post by: audioengr on 24 Jun 2019, 04:26 pm
Question:

Why did you choose the AD1955 chip?

Michael

Because I use a predecessor in my current DAC and I know how to deliver power to it and tune the digital filter to make it sound great.  Uses the same digital filter.  These even beat NOS DACs. I used to make a NOS DAC.

I've auditioned AKM D/A chips and Sabre D/A chips.  I prefer the liveness of the Analog D/A chips.

Steve N.
Title: Re: Features for my new DAC?
Post by: audioengr on 24 Jun 2019, 04:28 pm
  Well feature wise sounds like a winner. The only way to tell is try one.


charles

I may send one around on a trial to those that sign-up.  I'm a couple of months away from having the first one.

Is the price okay for the feature-set?  I have priced this one so I can sell through dealers to hit a wider audience and get higher volume.

Steve N.
Title: Re: Features for my new DAC?
Post by: rollo on 24 Jun 2019, 04:41 pm
  Price point is just fine for dealers. Keep up the good work.

charles
Title: Re: Features for my new DAC?
Post by: ketcham on 24 Jun 2019, 09:43 pm
$3500 is retail or wholesale?
Title: Re: Features for my new DAC?
Post by: richidoo on 25 Jun 2019, 03:18 am
Please add me to the audition tour.

For $3500 I would expect remote volume control/mute for connecting direct to amp, unless the SQ punches much higher than current popular ~$3k DACs (DS Sr)

Familiar with Burson regulators?
Title: Re: Features for my new DAC?
Post by: audioengr on 25 Jun 2019, 04:18 am
Please add me to the audition tour.

For $3500 I would expect remote volume control/mute for connecting direct to amp, unless the SQ punches much higher than current popular ~$3k DACs (DS Sr)

Familiar with Burson regulators?

I hear you.  This would be nice, but it would push the price much higher.  Most of my customers are using their app to control muting and even volume control, but most are using an active preamp.

I expect this DAC to crush everything up to the $15K range at least, so I don't think this is necessary.  I think it will be a giant-killer in this price-range.  The DAC should probably be used with an active preamp to get the best slam from it anyway.  If it is driving a tube amp, maybe a transformer passive would work well enough.

I'm familiar with Burson and Hynes regs.   I have a license from Hynes to design my own versions, which I do.   Based on the specs, the regulators I'm using will actually be better.  Lower noise, better input noise rejection and faster response with smaller overshoot.

Steve N.
Title: Re: Features for my new DAC?
Post by: audioengr on 25 Jun 2019, 04:19 am
$3500 is retail or wholesale?

Retail.

Steve N.
Title: Re: Features for my new DAC?
Post by: richidoo on 26 Jun 2019, 01:55 am
Yeah, Roon/JRiver have decent software volume controls, but preamp preferable to me too.


The DAC should probably be used with an active preamp to get the best slam from it anyway.  If it is driving a tube amp, maybe a transformer passive would work well enough.

Is 50kOhm high enough load for optimum performance?  It has a discreet SS output stage I assume?


I expect this DAC to crush everything up to the $15K range at least,

Coming from you, that's quite a statement. I'm excited to hear it!
Rich
Title: Re: Features for my new DAC?
Post by: MarkR7 on 26 Jun 2019, 02:43 am
Would love to see an AES/EBU input as well! I’d like to get on the list to hear it too.
Title: Re: Features for my new DAC?
Post by: Delta77 on 26 Jun 2019, 03:30 pm
Just purchased the innuOS ZEN (should be coming soon), and am now looking for a DAC that would pair nicely with it..
Currently using a Oppo 205 as DAC / Volume control..
I may want to be on the list for a Trial..?? 
Title: Re: Features for my new DAC?
Post by: audioengr on 26 Jun 2019, 05:34 pm
Yeah, Roon/JRiver have decent software volume controls, but preamp preferable to me too.


Is 50kOhm high enough load for optimum performance?  It has a discreet SS output stage I assume?

Should be fine down to ~2K.  The output impedance will be around 20 ohms.  Op-amp output, not discrete.

Steve N.
Title: Re: Features for my new DAC?
Post by: audioengr on 26 Jun 2019, 05:36 pm
Just purchased the innuOS ZEN (should be coming soon), and am now looking for a DAC that would pair nicely with it..
Currently using a Oppo 205 as DAC / Volume control..
I may want to be on the list for a Trial..??

Another customer of mine has an InnuOS and he is deciding on an Off-Ramp 6 or 5 USB converter because his DAC's USB interface is disappointing at best.  This is the case with most DACs.

Steve N.
Title: Re: Features for my new DAC?
Post by: A_shah on 28 Jun 2019, 09:10 am
 @ Delta 77
Congratulations ! let us know how InnOus  Sound , have been using the Blue node 2I for a month but will send it back to Amazon and try out the the Cambridge audio CXN V2 which I have ordered today , Also ordered  a Focal Stelia headphones !  Since you mentioned Innous have been looking at  the possibility of getting one and trying it out ! , to be honest i am satisfied with the SQ & the options available with BS node 2i I have used it as a DAC as well as a transport with the PS audio DirectStream DAC  :popcorn: :thumb:

Asghar
Title: Re: Features for my new DAC?
Post by: andrewd01 on 18 Jul 2019, 05:56 pm
Hi Steve,

Sounds like an interesting product.
I would prefer the SPDIF input to be an optional extra.  I would prefer to only pay for the inputs needed.  I like the idea of one input only as it eliminates ugly switches on the casework (and also simplifies the circuit, which cant be a bad thing).

Instead of IEC, would it be possible to have an option where you can order it configured to run off a Dynamo (12V DC)? 
Title: Re: Features for my new DAC?
Post by: audioengr on 18 Jul 2019, 08:54 pm
Hi Steve,

Sounds like an interesting product.
I would prefer the SPDIF input to be an optional extra.  I would prefer to only pay for the inputs needed.  I like the idea of one input only as it eliminates ugly switches on the casework (and also simplifies the circuit, which cant be a bad thing).

I can only do 2 versions, not three.  The versions are 2 different input modules.  The S/PDIF input must be on-board, so no module.  These are the constraints for making an affordable DAC that I can sell through dealers. One circuit board, one chassis, one set of panels. 

All of the options on the Overdrive DAC prevent it from being something I can sell through dealers. It would have to be $50K and that is a non-starter.

If I eliminated the modules, I would have to make custom front panels with no input select pushbutton hole and custom back-panels with no module hole.  It would be less expensive, but recouping my costs for the different panels would be difficult.  I cannot just buy 10 of each.  They would be too expensive, like $100 each.  Then I need to rework the baseboard so that the S/PDIF is always selected.  Manual rework adds a lot of cost.  Cannot have it on this product.

Quote
Instead of IEC, would it be possible to have an option where you can order it configured to run off a Dynamo (12V DC)?

It will have one configuration and that is AC input.  It needs multiple power supply voltages, so a single external DC supply would not work.  The Overdrive uses 3 external DC supplies.

Steve N.
Title: Re: Features for my new DAC?
Post by: andrewd01 on 19 Jul 2019, 06:47 am
Ok, thanks Steve
Title: Re: Features for my new DAC?
Post by: audioengr on 25 Aug 2019, 12:15 am
Some photos of the SOTAPRAT DAC:


(https://www.audiocircle.com/image.php?id=197866)


(https://www.audiocircle.com/image.php?id=197867)

Photo of the inside will come later.  It's being debugged.

for those not familiar with the lingo, SOTAPRAT is State of the Art Pace Rhythm and Timing. 8)

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: I.Greyhound Fan on 25 Aug 2019, 12:57 am
I am not big on the bling factor of audio gear but I think at that price you may want to consider a nicer face plate and buttons.  You will sell more of them.  It would also be nice if you could order one with XLR's.  My system is fully balanced, including my Luxman DAC which I would eventually like to replace with something more SOTA.  MY system just sounds better fully balanced.
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 25 Aug 2019, 01:28 am
I am not big on the bling factor of audio gear but I think at that price you may want to consider a nicer face plate and buttons.  You will sell more of them.  It would also be nice if you could order one with XLR's.  My system is fully balanced, including my Luxman DAC which I would eventually like to replace with something more SOTA.  MY system just sounds better fully balanced.

The faceplate is machined 8mm aircraft aluminum, anodized.  Costs me more than $100 each.  You want me to spend $200 or more for a faceplate?  This would add about $500 to the cost.  Most companies use 4-6X multiplier.

If you want fully balanced, my Overdrive SX is hard to beat.  Only a couple of DACs compete with it.
Title: Re: SOTAPRAT DAC updates
Post by: I.Greyhound Fan on 25 Aug 2019, 01:40 am
The faceplate is machined 8mm aircraft aluminum, anodized.  Costs me more than $100 each.  You want me to spend $200 or more for a faceplate?  This would add about $500 to the cost.  Most companies use 4-6X multiplier.

If you want fully balanced, my Overdrive SX is hard to beat.  Only a couple of DACs compete with it.

I am not complaining about the face plate but I know a lot of people take into account of how gear looks.  McIntosh sells a lot of gear just on looks alone. :D
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 25 Aug 2019, 05:30 pm
I am not complaining about the face plate but I know a lot of people take into account of how gear looks.  McIntosh sells a lot of gear just on looks alone. :D

I don't want it to be ugly, but my products are all about sound quality first.  I'm not about audio jewelry.

The pushbuttons are heavy-duty for extended use and low resistance for the AC power.  Unlike many DACs, there is no power usage until it is turned-on.  The regulators don't waste much power either, even though there are 11 of them.  Runs much cooler than my Overdrive SX.  Much Greener.  Also, the power button is on the front panel rather than on the back like many DACs.  My cost on the pushbuttons is $14 compared to $2 for other manufacturers.  The standard buttons are plastic, but there are aluminum ones that no one stocks.

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: richidoo on 25 Aug 2019, 09:08 pm
I don't want it to be ugly

Too late.  :P   j/k

Screams 70s style! Having grown up in the 70s, I love the red and gray buttons and Mattel-ish industrial-chic style. I was a little shocked when I first saw it, but it quickly grew on me and now I think it looks pretty cool. Maybe millennials are finally ready for some 70s vintage look; they sure like their vintage 60s and 80s styles.

So the SPDIF with SynchroMesh is intended to be the primary/best input in your view?

XMOS usb?

Is this internal synchromesh implementation just as effective as the external Synchromesh product?  I have Sonos with terrible jitter, I'd like to be able to use that for main transport without an additional jitter removing device between Sonos and DAC, like all my previous DACs.

Does the synchromesh filter affect the data stream coming from USB and ethernet inputs?
Thanks
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 26 Aug 2019, 04:59 pm
Too late.  :P   j/k

Screams 70s style! Having grown up in the 70s, I love the red and gray buttons and Mattel-ish industrial-chic style. I was a little shocked when I first saw it, but it quickly grew on me and now I think it looks pretty cool. Maybe millennials are finally ready for some 70s vintage look; they sure like their vintage 60s and 80s styles.

So the SPDIF with SynchroMesh is intended to be the primary/best input in your view?

Both inputs are equivalent.

Quote
XMOS usb?

Yes.

Quote
Is this internal synchromesh implementation just as effective as the external Synchromesh product?

Should be even better because there is no S/PDIF conversion or cable involved.  Just I2S output.

Quote
I have Sonos with terrible jitter, I'd like to be able to use that for main transport without an additional jitter removing device between Sonos and DAC, like all my previous DACs.

Should do the trick.

Quote
Does the synchromesh filter affect the data stream coming from USB and ethernet inputs?
Thanks

No, these are bit-perfect and low jitter. Not routed through the SM like the S/PDIF is.

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: Brucemck on 2 Sep 2019, 06:27 pm
SPDIF and USB only .... no Ethernet as per first post in this thread?
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 2 Sep 2019, 07:40 pm
SPDIF and USB only .... no Ethernet as per first post in this thread?

(USB*S/PDIF) + (Ethernet*S/PDIF)
Title: Re: SOTAPRAT DAC updates
Post by: Norman Tracy on 2 Sep 2019, 09:10 pm
Earlier in this thread some opinions were expressed to the effect that Empirical Audio's styling is lacking. I was too busy at the time to comment, now with a lazy holiday afternoon and this thread popping up here are my opinions.

I have always appreciated the clean minimalist form follows function look of Empirical Audio's products. I would even argue given their name minimalist is the logical choice. Among industrial design professionals and educators the contribution of Dieter Rams to the field is quite literally the stuff of legends. So when I say Empirical Audio's styling reminds me of Rams iconic designs for Braun that is one of the highest compliments I have in the area of product design.

(https://s3files.core77.com/blog/images/2013/04/Braun-PC5CSV60CE16-viaDasProgramm.jpg)

https://www.core77.com/posts/24768/a-history-of-braun-design-part-3-audio-products-24768 (https://www.core77.com/posts/24768/a-history-of-braun-design-part-3-audio-products-24768)

(https://sgustokdesign.com/archive/Dieter-Rams-Braun-PCS-5-CSV-60-CE-16-03.jpg)

https://youtu.be/ncw3f4jgNP4 (https://youtu.be/ncw3f4jgNP4)

It is accepted that Apple looked to Rams for many of its designs.

(http://imgs.abduzeedo.com/files/articles/post-dieter/dieter-rams_apple_design1.jpg)



Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 4 Sep 2019, 08:53 pm
I've had some feedback from a good customer and I decided to redesign the front panel per his advice.  It looks more elegant now and less bold.  I like it.  When I get the new proto panels, I will post pictures here.

On another thread I was criticized for using shipping companies and selling an unnecessary product because these create CO2 and therefore unnecessarily add to Global Warming.  I responded by saying that humans need culture to thrive and my products are small and light, so they share the shipping with a LOT of other cargo, making their footprint small.  In the future, my products will create even smaller carbon footprint as the power system transitions to renewables and transportation converts to electric.  I personally have already made this transition.

In addition, this new DAC consumes significantly less power than my Overdrive SX DAC.  This is by design.  I want it to be as green as possible and create the smallest carbon footprint.  This is the responsible thing to do.

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: andrewd01 on 12 Nov 2019, 10:05 pm
Hi Steve,

I like everything about the look of the unit, except the word PRAT in massive letters!  Could be embarrassing to explain to friends!

https://dictionary.cambridge.org/dictionary/english/prat

I would prefer understated branding, perhaps a simple Empirical Audio DAC engraved in 8 point font.

Good luck with the project.


Edit: I see you got similar feedback from another customer, looking forward to seeing the new design.

Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 13 Nov 2019, 02:20 am
New version:


(https://www.audiocircle.com/image.php?id=200797)


Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: path73 on 19 Nov 2019, 09:19 pm
Why not include the word "DAC" on the front plate?
At least the function of the unit would be explicitly stated.

"SOTAPRAT", could be just about anything (source, amp, reclocker, DAB receiver, ...) and I'm not sure PRAT is the only area where Steve's products shine.

I always tend to stay away from qualifiers like "SOTA" or "New" or "Latest", since these are time related and are a bit self-evident. No one is going to bring out a new product which is not trying to be state of the art art.

Why not something more easy on the ears, e.g.
simply "DAC" or if SOTA is really required "SOTA DAC" or more spot on would be "statement DAC" or to stay in automobile racing spirit "pace DAC" or "pacer DAC" or "carve DAC"?

Just my 2 cts. By the way, I am really interested in this new product!
/path
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 21 Nov 2019, 07:06 pm
This product is SOTA is several areas, but mostly the voltage regulators, which have only become available this year.  Without these, I would not have this product.  The D/A chip is newer than my Overdrive, but still fairly old.  Chosen because of the great SQ.  The Ethernet interface and XMOS interface are also very new in my product line and excellent performers.

I was actually reluctant to put too much on the front panel.  I have had complaints in the past about "Empirical Audio" on the front panel.  I mostly want it to look a bit sculpted.

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: ketcham on 22 Nov 2019, 12:18 am
The Faceplate is fine.  Great actually.  For the footprint, price and what it offers, it will be popular.

Title: Re: SOTAPRAT DAC updates
Post by: I.Greyhound Fan on 22 Nov 2019, 01:20 am
I like the new face plate.  Still not a fan of the red and white buttons though but that's just me.  I prefer symmetry and would prefer silver or black buttons.  Wish I could hear one as I may be replacing my Luxman DA-06 DAC sometime in the next year after I probably buy a pair of Fyne Audio 702's or 502sp's.
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 23 Nov 2019, 05:50 pm
I like the new face plate.  Still not a fan of the red and white buttons though but that's just me.  I prefer symmetry and would prefer silver or black buttons.  Wish I could hear one as I may be replacing my Luxman DA-06 DAC sometime in the next year after I probably buy a pair of Fyne Audio 702's or 502sp's.

Grey and black buttons are an option.  It's actually a grey and red button, not white.  I just wanted it to be obvious which was the power.  It is labeled on the panel though, so they could both be black if that is preferred.
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 28 Nov 2019, 12:40 am
Today I had a breakthrough on a vexing problem I have been fighting for a month.  The source code for my state machine to program the D/A chip had a filename that was too long so the simulator was rejecting it.  Simulating well now.  Should be able to test all sample-rates in about 2-3 weeks when I get the new programming socket and put the new state machine chip on the board.  Then on to testing DSD functionality.  The plan is to support only 64X DSD mode. I would have to add a manual switch to select 128X mode and I don't want any more switches.
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 24 Apr 2020, 09:26 pm
Update - I gave the SOTAPRAT a rest for a while because my brain was not giving me the solutions I need.  I have been tweaking the decoupling to get the best bass and it's getting there.

The problem that has had me stumped for months is that I need to offer DSD as well as 192 PCM in the SOTAPRAT and getting both seemed impossible with my XMOS USB module.  Because it is galvanically isolated, there are only so many signals through the isolating interface and this was limiting my options.  I could either send 192 mode or DSD mode indicators, but not both.  It is not a problem with the Ethernet module because it does not need galvanic isolation.  Ethernet does this by definition.  Either module can be used in the DAC.

I finally solved this today.  I can use an encoding of the sample-rate bits to get a DSD encoding to go through the isolation interface.  It's a simple thing to try this on the USB module, but requires a bit of rework unfortunately on a board that I already have a bunch in stock.  I'll report back on this when I try it.  Once this works, and I can do all PCM sample-rates, I will try DSD.

Unfortunately, with only one encoding of DSD I can do only DSD64, not DSD128.  Doing both is possible, but a LOT more work and major changes to the DAC board.  My hope is that DSD64 will be sufficient for most audiophiles.

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: richidoo on 24 Apr 2020, 10:21 pm
Thanks for the update!

I have no use for DSD. I would use Ethernet and SPDIF.

I'm still looking forward to hearing this DAC.
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 25 Apr 2020, 09:30 pm
Thanks for the update!

I have no use for DSD. I would use Ethernet and SPDIF.

I'm still looking forward to hearing this DAC.

Listened last night to 44.1 and 96 tracks.  My wife and I both agree that it beats the Overdrive for vocal liveness using my Music First passive line stage.  For bass and slam, the jury is still out, but may be limited by the line stage transformers.  Really smooth natural vocals.

Still a lot of work to do and money to spend to get it in final form, ready for sale.  I should have a proto to send around before that though.

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 2 May 2020, 09:00 pm
Tried native DSD64 yesterday with the Ethernet interface.  Amazing sound quality using Linn Kinsky.  I have the same track 24/96 and DSD64 and the DSD beats the PCM hands-down.  More clear, less echo noise, superb bass.  No overhang.  Great attack and decay.  I've never been a fan of SACD, but this is something else.  Very exciting!!

I plan to download some HDtracks DSF files today and try some tracks that I'm more familiar with.

USB license for DoP is another problem.  At least with Audirvana, it is not showing DSD capable.....
Title: Re: SOTAPRAT DAC updates
Post by: richidoo on 3 May 2020, 12:26 am
You mentioned Roon compatible. Also DLNA? Are there any other ethernet streaming protocols?
thanks
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 4 May 2020, 07:10 pm
You mentioned Roon compatible. Also DLNA? Are there any other ethernet streaming protocols?
thanks

Yes, it does DLNA, UPnP and Open Home. I don't know of any other protocols.

I determined that the USB interface can only do DoP, but I have not tested this yet.

The Ethernet can do both DSD64 and DSD128 now.  Cannot do DSD256 because the D/A chip does not support it.  I decided it needed DSD128 because many of the downloaded tracks are only available in 128 and 256.

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: richidoo on 26 Jun 2020, 02:50 pm
(https://www.audiocircle.com/image.php?id=200797)

Still 70 style, but less GI Joe.  :thumb:

Glad you kept the red button.
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 27 Jun 2020, 05:10 pm
Richidoo - thanks.  I have had a lot of feedback and made some changes as a result.  I try to listen to what customers prefer.

I made some progress on the DSD and now it should support both 64 and 128 natively using the Ethernet interface.  Still getting the signal timing ironed-out to make the D/A chip happy.

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: beowulf on 16 Aug 2020, 06:10 am
This is exciting and very well may be my next DAC.  If I may ask or suggest ... why not just use the same font style and size style of the more classy looking Overdrive on the SOTAPRAT as well as the same toggle switches?  Also, why not use the same amount of slots or are the extra bottom slots needed?

In other words, make the face plate look like the power supply chassis of the Overdrive.

Thanks and looking forward to reading more when you have some updates!
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 18 Aug 2020, 01:01 am
This is exciting and very well may be my next DAC.  If I may ask or suggest ... why not just use the same font style and size style of the more classy looking Overdrive on the SOTAPRAT as well as the same toggle switches?  Also, why not use the same amount of slots or are the extra bottom slots needed?

The cooling holes in the top and bottom are not needed, so this reduces cost.  This is a much more efficient DAC that does not get as hot as the Overdrive.

The font from the Substation is much too small to be used on the front panel of the Sotaprat IMO.

Steve N.
Title: Re: SOTAPRAT DAC updates
Post by: audioengr on 4 Aug 2022, 05:27 pm
The SOTAPRAT with XMOS USB is complete but needs to have baseboard rework imbedded in the new fab.
 
This DAC is sounding more dynamic than even my reference Overdrive SE.  In fact, I think it is the most dynamic DAC I have ever heard.  I'm using it with a passive transformer line-stage.  Very enjoyable to listen to.  The main difference compared to my Overdrive is a less extended bass end.  I have replaced and upgraded many of the electrolytic caps to make this better and it has helped, but I think the voltage regulators are limiting it.  Compared to most DAC's, it has great bass however.  The Overdrive is exceptional in this regard, so it is a hard thing to compete with.  For instance, I have auditioned many of the Chord DAC's and their bass response is not as good as the SOTAPRAT.

The problem is going to market with it.  It is a $100K investment to do a 100 build of the complete DAC.  I am reluctant to put that kind of money into it when I'm frankly retiring soon.  I think I may just do a new fab imbedding the rework and do a 100 build of the fab only for now.  Then, I may look for another audio company to productize it. I have one more of the original FABs with the regulators soldered on it (must be machine-soldered), so I may build another prototype.

Steve N.