GIESELER Groß DAC official release

[Gieseler Audio 2,470]

Hi everyone

I would like to present my new Groß DAC.

It is based on the AKM4497EQ DAC chip running in software mode with a onboard micro controller.There are three digital inputs, Async USB using the Amanero Combo 384 USB board plus coax & optical. I have really gone overboard this time in terms of parts quality. The USB board & DAC chip  run from four ultra low noise Analog Devices ADM7150 series regulators. The noise output level on these is only 0.9 u volts up to 100K. The critical DAC output stage is based on a zero feedback design using massive top quality Jensen line output transformers. The -3db bandwidth range is from 0.1Hz to 15MHz! No HF or LF roll off with these babies. Distortion 0.004% typ at 20 Hz and +4 dBu output level. These are the highest quality line output transformer Jensen make with PC mounting which I needed.  It is a ultra simple output stage just using the transformers. Output level is 2v RMS.

I have been in touch with AKM engineers & as a result changed a lot of the default AK4497EQ registry settings which now enables the chip to drive the transformers much better than normal. The other big bonus is the DAC output is fully variable (via remote) using the DAC chip internal 256 step attenuator. Bottom line is the DAC will drive a power amp perfectly with very smooth level control. You do throw away bits at lower levels but due to the DAC chips 32 bit architecture there does not seem to be much loss.  There is a built in memory function so the DAC always remembers all setting including output level even after a full power off.

Price -  Unfortunately I did not have enough time today to do the full parts costing which I need to do to calculate the final price.  I will definitely post that before the weekend. Build time is much quicker than the Konverter so that helps keep the final cost down too.

OK the bottom line - how does it sound?

As usual I am totally biased but this has to be the best sounding DAC only unit I have ever built by a country mile. I think the combination of ultra low noise power supplies, the AK4497EQ increased output drive & the excellent  Jensen transformers  is a match made in heaven.

 

Price

 

UPDATE!

The first five at the introductory price of $2000 have now been sold.

Current price will now go to approximately $2350 but I will confirm this shortly.

 

Edited September 3, 2017 by Gieseler Audio
Price update

[Snoopy8 3,334]

Nice looking unit.

 

My only doubt is around the name ?  Gross=very obvious and unacceptable. I can see many puns coming up e.g. It sounds gross, it looks gross etc...

 

Did you compare the sound with the Konveter? And any other dacs?

[Ancientflatulence 1,572]

Another piece of inspired genius  from the House Of Gieseler ..............

[Gieseler Audio 2,470]

All my DAC's are based on German names so compared to the Klein which means "small" in German this one is the bigger brother so "Groß" (in German means big ) was the obvious choice. However I must admit when it was first suggested to me my reaction was similar to yours. At least with a name like that you will have no problem remembering it. Also Schiit Audio has a pretty odd name but it certainly stands out.

Edited August 31, 2017 by Gieseler Audio

[joz 5,642]

Clay come to us for naming in the future.

 

My German inspired name would be after the Band.

 

 

Kraftwerk

 

But I do get the Gross as in the old Mercedes Grosser

 

Nah stick with Gross

[betocool 1,857]

When I saw it was spelled "Groß", all doubts were dissipated. But yeah... reading it in English it was a bit of a shocker in an East End kind of accent... "Tha' is gross".

 

As long as you're next product is not "Scheiße"!

[Wiffle 611]

Hey Klay (I feel I should keep with the Germanic theme),

looks beautiful and no doubt sounds better! Can you give us case dimensions? Is it essentially the same as a Konvertor minus the preamp stage?

Cheers,

Steve :-)

[matth 134]

Hi Clay,

the DAC looks nice, BUT I have a big problem with the scripture on it.

On the left side you have GIESELER, so far so good. 

On the right side you have the name of the DAC, but written in an antique font which I absolutely dislike and which IMO in no way matches the font of GIESELER.

This antique scripture on the right side is a NO GO for me. It does NOT suit this high-tech DAC. Sorry, but please have the name of the DAC in the same scripture (font) as GIESELER.

Thank you.

 

Matt

Edited August 30, 2017 by matth

[krappo 29]

46 minutes ago, matth said:

Hi Clay,

the DAC looks nice, BUT I have a big problem with the scripture on it.

On the left side you have GIESELER, so far so good. 

On the right side you have the name of the DAC, but written in an antique font which I absolutely dislike and which IMO in no way matches the font of GIESELER.

This antique scripture on the right side is a NO GO for me. It does NOT suit this high-tech DAC. Sorry, but please have the name of the DAC in the same scripture (font) as GIESELER.

Thank you.

 

Matt

Yes to this very Much  

[naggots 282]

Looks like I might be selling my trusty Klein SE. Well done Clay

Edited August 30, 2017 by naggots

[bhobba 1,059]

Hi Guys

 

Wow - nice piece of work.

 

Have recently got myself a dedicated notebook to run HQ Player.   I have found its up-sampling to be - well stunning - dead music simply comes alive with it.   My Direct Stream just goes 384 but Clays DAC to 768 - cant wait to hear how it sounds with that.   Will drop my PC fully loaded with music on its internal SSD and HQ Palayer to Clay in the next few days and see how it goes - should prove interesting.

 

I have gone through my DAC buying Days but if this thing takes out my DS - anyone want a DS?  Just kidding - mu DS has the inbuilt Bridge with MQA - but then again have this thing called an Auralic Aries - interesting listening ahead,

 

Thanks

Bill

[Jventer 1,667]

Clay

Based on the feedback - offer a custom front plate? e.g. just Gieseler, nothing, with the name Gross,Klein etc.

The model number can be a plate/sticker or something at the back or inside. I actually like the idea of a model and date number signed by the manufacturer somewhere inside or on the back. 

At the end of the day the sound is what matters, but if bespoke or tailor made or special can sell more, why not.

 

[Gieseler Audio 2,470]

Hi Guys,

yes I suppose I should have used the correct German spelling in the title but I don't know how to to that funny B on my keypad. Just worked it out.

 

Steve,

Width is 300mm x 200mm deep & 50mm high. The front panel is five mm bigger all round. The design did start out as basically the Konverter less the preamp part but I ended changing quite a few parts. In the Konverter the output transformers are driven by a active stage so there is plenty of level but the Groß DAC is using a totally passive design so the smaller transformers didn't work there. With a totally passive output stage the transformer matching is more critical & the large Jensen's ended up being a perfect match. The control menu is the same as the Konverter less the analogue inputs.

 

Matth & Krappo.

Yes guys I totally agree. The front panel in the photos was cut out about six weeks ago & at time the different font for the name  was just a impulse decision to try something diffent. The acrylic  panels take ages to do so I was being lazy with this first unit & just used the panels I had. OK I will machine a new front panel with Groß in the same font ASAP & edit the lead photo.

 

Some more info which may be of interest. 

During the R&D on the Groß DAC I spent ages looking at Galvanic isolation for the I2S lines, reclocking with a nice master clock ect.

Unfortunately there are quite a few technical issues that prevented me from doing this. All AKM DAC's operate in "slave mode" so I can't just plonk a gun clock next to the AK4497EQ & run it from that. There are ways around this though  like using a sample rate converter ahead of the dac but the sonic results aren't always they best & I feel it adds unnecessary complexity. At one stage I did have success by runing the Amanero in slave mode & then added the isolation/reclocking. Unfortunately when the Amanero is in slave mode I lose the DSD & mute flag lines which I need to operate the DAC correctly.

HOWEVER there is a solution for for those who insist on isolation & better clocks.

Singxer make a nice plug in USB board called the F1 

https://www.shenzhenaudio.com/singxer-f-1-xmos-usb-digital-interface-board-xu208-chip-high-end-u8-upgraded-version.html

Apparently it has the same pinout as the Amanero so in theory it should be a drop replacement option. I will order one & do some testing shortly. If this works out ok I can offer a choice of either Amanero or Singxer USB input when ordering. The Singxer option will cost about $165 more. 

At the moment the Groß DAC (to me anyway) sounds incredibly good & it's hard to imagine it getting much better but when I have a Singxer version I will do a side by side comparison & let you know the results.

 

Edited August 31, 2017 by Gieseler Audio

[matth 134]

33 minutes ago, Jventer said:

Clay

Based on the feedback - offer a custom front plate? e.g. just Gieseler, nothing, with the name Gross,Klein etc.

The model number can be a plate/sticker or something at the back or inside. I actually like the idea of a model and date number signed by the manufacturer somewhere inside or on the back. 

At the end of the day the sound is what matters, but if bespoke or tailor made or special can sell more, why not.

 

 

Very good idea. Two thumbs up!

GIESELER only at front left, nothing else at the front, plate or sticker at the back.

Perfect for ALL DACs, not for custom version only!!!

 

Matt

[matth 134]

27 minutes ago, Gieseler Audio said:

Hi Guys,

yes I suppose I should have used the correct German spelling in the title but I don't know how to to that funny B on my keypad.

 

Steve,

Width is 300mm x 200mm deep & 50mm high. The front panel is five mm bigger all round. The design did start out as basically the Konverter less the preamp part but I ended changing quite a few parts. In the Konverter the output transformers are driven by a active stage so there is plenty of level but the GroB DAC is using a totally passive design so the smaller transformers didn't work there. With a totally passive output stage the transformer matching is more critical & the large Jensen's ended up being a perfect match. The control menu is the same as the Konverter less the analogue inputs.

 

Matth & Krappo.

Yes guys I totally agree. The front panel in the photos was cut out about six weeks ago & at time the different font for the name  was just a impulse decision to try something diffent. The acrylic  panels take ages to do so I was being lazy with this first unit & just used the panels I had. OK I will machine a new front panel with GroB in the same font ASAP & edit the lead photo.

 

Some more info which may be of interest. 

During the R&D on the GroB DAC I spent ages looking at Galvanic isolation for the I2S lines, reclocking with a nice master clock ect.

Unfortunately there are quite a few technical issues that prevented me from doing this. All AKM DAC's operate in "slave mode" so I can't just plonk a gun clock next to the AK4497EQ & run it from that. There are ways around this though  like using a sample rate converter ahead of the dac but the sonic results aren't always they best & I feel it adds unnecessary complexity. At one stage I did have success by runing the Amanero in slave mode & then added the isolation/reclocking. Unfortunately when the Amanero is in slave mode I lose the DSD & mute flag lines which I need to operate the DAC correctly.

HOWEVER there is a solution for for those who insist on isolation & better clocks.

Singxer make a nice plug in USB board called the F1 

https://www.shenzhenaudio.com/singxer-f-1-xmos-usb-digital-interface-board-xu208-chip-high-end-u8-upgraded-version.html

Apparently it has the same pinout as the Amanero so in theory it should be a drop replacement option. I will order one & do some testing shortly. If this works out ok I can offer a choice of either Amanero or Singxer USB input when ordering. The Singxer option will cost about $165 more. 

At the moment the GroB DAC (to me anyway) sounds incredibly good & it's hard to imagine it getting much better but when I have a Singxer version I will do a side by side comparison & let you know the results.

 

 

Hi Clay,

please do NOT offer a SRC, the experiences with the AK4137 in the Holo Spring DAC are not good.

Very good idea to compare different USB interfaces.

And please do not forget the USB only version to keep the price as low as possible.

Thanks

Matt

 

[sir sanders zingmore 11,982]

3 hours ago, matth said:

 

Hi Clay,

please do NOT offer a SRC, the experiences with the AK4137 in the Holo Spring DAC are not good.

Very good idea to compare different USB interfaces.

And please do not forget the USB only version to keep the price as low as possible.

Thanks

Matt

 

 

Whats an "SRC"?

[Gieseler Audio 2,470]

Hi Matt - definitely no SRC (Sample rate converter) & yes a USB only version will be available.

 

[Raffinator 483]

Clay, is DSD512 over USB available? Windows and Linux (eg for microRendu or Antipodes servers)?


Sent from my iPhone using Tapatalk

[Raffinator 483]

Clay, is DSD512 over USB available? Windows and Linux (eg for microRendu or Antipodes servers)?


Sent from my iPhone using Tapatalk

[Gieseler Audio 2,470]

I have  just been listening to DSD 256 over USB using a windows based server & that plays fine.

I don't actually have any DSD 512 material so I can't test at that rate

I will have to get back to regarding Linux based servers.

 

Update - just tried some DSD using my little Celeron NUC running Daphile.

The native DSD setting was greyed out in Daphile  so I enabled DOP. 

DSD 128 played fine  but DSD 256 was garbled so too much processing for the little NUC  I think.

 

Sorry for the edit but I just realised my highest rez DSD material is DSD256 Not DSD512.

 

Edited August 31, 2017 by Gieseler Audio
update

[Snoopy8 3,334]

2 hours ago, Gieseler Audio said:

I will have to get back to regarding Linux based server.

Plus the Sotm SMS-200.   It seems to able to recognise my current dac by its name, so I assume it reads the info from dac???

[bhobba 1,059]

Hi Guys

 

Sent Clay an email to order one.  Just spoke to soimeone whose ears I trust, but cant name who was VERY impresssed - that good enough for me.

 

Want the Singxer version.

 

Will be giving Clay a special notebook I have purchased just for Music.

 

It will run HQPlayer and upsample everything to 768K - which is getting close to DSD anyway.  My current experimentation showed music was dull then up-sampled it to DXD (354k) and it came alive.  Used the Direct Stream DAC which does massive up-sampling itself, so obviously HQPlayer up-sampling is better than what the DS does.  But it really up-samples - to 10XDSDS- wow.

 

Thanks

Bill

[jermaink 46]

Nice work Clay, I'm interested!

 

With so many clever things going on inside I thought my suggested name, Klug DAC ('clever' DAC) would've been perfect!

 

Is there any reason why the power button appears to be mounted sideways?

 

Very keen to hear the final price.

[matth 134]

Hi Clay,

some info from kitsunehifi.com, the US Singxer distributor.

 

The Singxer F-1 is under SALE, so maybe there is a new one upcoming.

There is a second best Singxer C-1 in two versions with different clocks, less expensive than the F-1. All versions are Amanero compatible.

 

I have read that the F-1 has DC-DC converters onboard, maybe not the best solution.

 

Please be so kind to check this out.

Thanks

 

Matt

[Gieseler Audio 2,470]

Whoops on the power switch orientation - I was looking at the back of it & kept the terminal text upright but obviously not correct.

I should have done a quick Google on the symbol & the correct orientation comes up instantly.

Name - it is a bit tricky but just think small DAC - Klein or big DAC - Groß

Matt thanks for the info on the Singxer boards, I will look into it.

Bill - thanks for the order - left work early so didn't see the email.

Yes our mutual  friend was most impressed.

Guys sorry for few small glitches - my offsider who normal handles all this was away & my skills are in electronic area & not marketing.

 

Edited August 31, 2017 by Gieseler Audio

[Raffinator 483]

A few of us have Singxer SU-1 devices. Would these still provide better USB performance fed into your DAC via SPDIF than the Amanero board natively?

Other than that - I think you’d better get ready for orders as soon as you put the indicative price out.


Sent from my iPad using Tapatalk

[Raffinator 483]

A few of us have Singxer SU-1 devices. Would these still provide better USB performance fed into your DAC via SPDIF than the Amanero board natively?

Other than that - I think you’d better get ready for orders as soon as you put the indicative price out.


Sent from my iPad using Tapatalk

[Gieseler Audio 2,470]

Raffinator I would have thought directly in via the Amanero USB would sound best especially since it has a vastly superior PSU but you never know. A listening test is the only certain way to verify this.

 

Guys I feel the sound of this unit is quite exceptional so I would love to get a few of them out there into the field where you can try it in your own systems for a decent audition. That is the only way you are going to know what  it really sounds like.  My plan is to build three or four demo units & distribute them around for you to try for three or four days & then ship on to the next participant. It should fit into a 5kg Express post satchel using suitable strong carton. Cost would be about $25 per participant. What do you think? 

 

Edited August 31, 2017 by Gieseler Audio

[Snoopy8 3,334]

7 minutes ago, Gieseler Audio said:

My plan is to build three or four demo units & distribute them around for you to try for three or four days & then ship on to the next participant. It should fit into a 5kg Express post satchel using suitable strong carton. Cost would be about $25 per participant. What do you think? 

 

Count me in. And instead of mail, perhaps for the major cities, holder of unit takes it to next person. Less chance of damage?

[Jventer 1,667]

19 minutes ago, Gieseler Audio said:

Raffinator I would have thought directly in via the Amanero USB would sound (best) especially since it has a vastly superior PSU but you never know. A listening test is the only certain way to verify this.

 

Guys I feel the sound of this unit is quite exceptional so I would love to get a few of them out there into the field where you can try it in your own systems for a decent audition. That is the only way you are going to know what  it really sounds like.  My plan is to build three or four demo units & distribute them around for you to try for three or four days & then ship on to the next participant. It should fit into a 5kg Express post satchel using suitable strong carton. Cost would be about $25 per participant. What do you think? 

 

Hi Clay

An excellent idea. 

Maybe if members can take it to QLD Audio Club, Sydney Audio Club or just a few GTG's - these events are always fun and a good platform to get an opinion and an experience.

Mike Lenehan has been promising a GTG for a while now - an it is high time that we have one to listen to ML5, kit speakers, etc. Would be good to see how yours do against what he has in his shed.

@tasso and @chanh  out west might be interested too. I know they are fully in Accuphase land, but you never know. 

I will ask the guys around NNSW and let you know - I am always trying out stuff so will ask the guys around here and Coffs if they are interested in a GTG.

Edited August 31, 2017 by Jventer
Typos

[Gieseler Audio 2,470]

Snoopy8 - brilliant idea. I might need some help in each major city to coordinate this.

 

[Snoopy8 3,334]

Just now, Gieseler Audio said:

Snoopy8 - brilliant idea. I might need some help in each major city to coordinate this.

 

Happy to do Melbourne

[Gieseler Audio 2,470]

Johannes - thanks for the excellent suggestions.

[Wiffle 611]

Count me in for a trial too Clay!!

Sent from my SM-G900I using Tapatalk

[Gieseler Audio 2,470]

Holy smokes- I better start building these demo units!

[Gieseler Audio 2,470]

Slight problem - Just had a email from  Dom in Pizza Italy - Amanero  Combo 384 USB boards currently out of stock.

He should have more stock in about a week so that should be OK.

Next move is to get some more Jensen Transformers as they take a while.

 

[Stereophilus 1,046]

Looks like a labour of love Clay.  Put me down for a trial unit if you need any more opinions.  I can compare it to the Mola Mola DAC.

[BATMAQN 1,833]

I'm in too Clay love to trial one of these there'd have to be more ACT members that would want to participate as well.

Edited August 31, 2017 by BATMAQN

[Gieseler Audio 2,470]

Thanks guys I really appreciate all the enthusiasm. OK I will get some more DAC's built & PM you for address details when I have a few to ship. I can't wait to see what see what think of sound of this. I am seriously convinced that it is extremely good & that was reinforced today when a very experienced colleague confirmed  this as well.

[bhobba 1,059]

2 hours ago, Gieseler Audio said:

Guys I feel the sound of this unit is quite exceptional so I would love to get a few of them out there into the field where you can try it in your own systems for a decent audition. That is the only way you are going to know what  it really sounds like.  My plan is to build three or four demo units & distribute them around for you to try for three or four days & then ship on to the next participant. It should fit into a 5kg Express post satchel using suitable strong carton. Cost would be about $25 per participant. What do you think?

 

Hi Clay

 

When you build mine you can use it for that around the Brisbane-Gold Coast area with my special computer and the iso regen which should be arriving sometime in September.

 

I have done it with other stuff and an issue is getting it back in the same state you sent it.  It's not really the person who got it is at fault - its what happens in transport.   That's why I will limit mine to picking it up from you and coming along to comparisons I hope to organise -  especiallly with the Queensland Audio Club I am a member.

 

I would suggest people in major areas like say Sydney put up their hands and have it sent to them.   They can then lend it out to people and ensure its packed well when returned to you.

 

Thanks

Bill