[ShinOBIWAN]

I was reading back some old threads and discovered mention of an AKSA DAC. As far as I can tell this was being discussed as far back as 2003.

Did it get scraped? I'm a big digital fan and would be interested in more details if it is indeed still alive.

Hugh, are you planning to use internal clocking for the DAC or will you be offering to use a masterclock to slave the device from? What DAC's are using - multibit parallel's, delta sigma's or FPGA's? Any details such as SNR, THD, crosstalk etc.

Thanks,
Ant

[AKSA]

Anthony,

Yes, it's a future project, yes, it's been postponed due to business issues, no, there's a pcb but no prototype at this stage.

It uses internal reclocking, 1702 chips, and folded cascode I to V conversion with Sallen Key eight times oversample filtering.  It's very trick, but a way off yet for reasons beyond my control at present.

Thanks for asking - this project is something of a dream DAC....

Cheers,

Hugh

[ShinOBIWAN]

Anthony,

Yes, it's a future project, yes, it's been postponed due to business issues, no, there's a pcb but no prototype at this stage.

It uses internal reclocking, 1702 chips, and folded cascode I to V conversion with Sallen Key eight times oversample filtering.  It's very trick, but a way off yet for reasons beyond my control at present.

Thanks for asking - this project is something of a dream DAC....

Cheers,

Hugh

Hugh, I would be incredibly interested in this, not merely interested. Would it available by the years end perhaps?

Also can you speak of your new amps yet? I really would like a 200N+ to appear but I'm guessing that's not going to happen.

[netaron]

This actually brings up something I had thought about for those interested in the 200W version. Hugh, can the 100's be bridged?

Haron

[rabbitz]

Bridging can be a trip to hell. The low impedance capabilities are lost, distortion goes up and if someone accidently hooks it up wrong, it's all over red rover.

BTW, who needs more than the 109W into 8R and 218W into 4R that the AKSA 100 supplies and why? I run the AKSA 55N+ and supplies more than enough grunt for my needs and I'm not gentle on the volume pot.

[ShinOBIWAN]

Bridging can be a trip to hell. The low impedance capabilities are lost, distortion goes up and if someone accidently hooks it up wrong, it's all over red rover.

BTW, who needs more than the 109W into 8R and 218W into 4R that the AKSA 100 supplies and why? I run the AKSA 55N+ and supplies more than enough grunt for my needs and I'm not gentle on the volume pot.

Driving inefficient speakers comes to mind, 3dB might not sound like much but it makes a world of differences when your dealing with 16ohm drivers from the likes of ATC.

What about subs too? Reliability also factors in when using amplifiers for long periods with high levels. There's clearly a market for high power amplifiers otherwise there wouldn't be any amps over 100w into 8ohm.

[rabbitz]

I'm not familiar with the ATC and would appreciate a link to them as it's very unusual for a speaker to have 16R.... I'm curious. You normally design a speaker to hit the amp sweet spot of 4R to 8R.

I was just referring to normal stereo amps and not subs and I agree that subs need grunt. It's just that most of the nicest amps I've heard have all been low powered and appear to have better speed and timing... a personal observation.

System matching is so important and I normally design a speaker to suit a particular amp or build an amp to suit a speaker. The best amp and speaker combination I have heard recently ran a 8W class D (battery powered and not a Sonic Impact) driving an OB with an SPL of 99dB using Visaton B200's but only works due to the combination.

The beauty of the AKSA is that it is less dependant on partnering equipment and performs well on almost any speaker you throw at it.... a rare quality. All my other amps can sound great but are speaker and load dependant.

[ShinOBIWAN]

Hi Rabbitz,

The ATC I was refering to is the SM75-150 and SM75-150S both are 16ohm designs and are intended for active's.

The specs for those drivers are here:

http://www.atc.gb.net/drive_units/studio_bass/driver_specifications_sb.xl.zip

I'm using a pair of the SM75-150S in my latest DIY effort. Its the best midrange I've heard yet but they just soak up power despite being 94dB sensitivity. They actually remind me more of horns in their presentation but without the colouration.

[rabbitz]

Thanks for the links as it's always good to see what other builders are using.

[Grumpy_Git]

Hugh

its been a while and while we all know your policy these days on providing proposed release dates I was wondering if you've been able to make any progress on the DAKSA.

I've just gone and blown a wad on a squeezebox and NAS drive so am planning to sell the cd player as soon as the music is all ripped to flac, I now want to blow another wad on a dac (without even having heard the squeeze box, i must be starting to believe these customer reviews!).

just a hint on some movement for this would be great.

Nick.

[Builder Brad]

Hugh,

DASKA...

count this as another vote

I will order one straight away

1. Grumpy Git
2. me

anyone else willing to help make the long awaited DASKA a reality

out of interest Hugh, what sort of numbers, in terms of firm paid up orders, do you need to get this piece of kit in your line up?

[AKSA]

Thanks Brad, Nick,

Much appreciated.

I embroiled myself in a mess on this one........

I will be frank and say the likelihood of the DAKSA in the product lineup will not happen soon.

Why?

Huge digital complexity which, as a digital incompetent, I cannot service and will therefore need to farm out, at least partially, at prohibitive cost.

Large inventory required to meet the IC MOQs.  This is very costly.

Continuing uncertainty over digital formats.  Whither DVD-Audio and SACD?  What effect will this have down the track, or at least for the life of this product?

Very complex board, with attendant service problems, at least double those of the GK1, which is simple but which causes angst over grounding issues - all of which are completely solveable, but which are system and layout dependent.  This has bitten me very hard, and tied me to my PC more than I believed possible.

Huge competition from the non-oversampling DACs, which would mean I could not compete in the open market.  I would expect only to sell the DAC to existing customers who know my reputation and are prepared to pay the higher price for the more complex beast.

So, I ain't sayin' it's shelved, far from it, I've invested thousands, but it remains on hold until some of these matters resolve.

My core business remains amps and preamps, and as time goes by, and I tire of sweatshop conditions and poor service returns, I'm coming to the conclusion I have far more options by producing fully built product.

But the amps, preamps and speakers will continue as DIY, I promise you that!

Cheers,

Hugh

[Grumpy_Git]

Hugh.

Thanks for the reply, it's pretty much what I expected you to say, ah well it looks like I'll be going elsewhere for the moment, but I'll try and keep it cheap so that I can come back if it ever does make it.

Any suggestions anyone?

Nick.

[rabbitz]

I've got one of Peter Daniel's NOS DAC kits on order.

http://www.diyaudio.com/forums/showthread.php?postid=609968#post609968

It's the same insides as what is inside the Audio Zone DAC-1.
http://www.inthezonenet.com/DAC-1.htm

There's always the ones from Scott Nixon.
http://scott-nixon.com/

... and of course Monica
http://diyparadise.com/dackit/1545bdackit.html

.... and the Chinese Lite NOS from DIYFidelity
http://www.diyfidelity.com.au/product_info.php?cPath=0_35&products_id=41

For some reason, all of these are NOS DACs.... whether that is good or bad, I don't know until I build mine.

[PSP]

Another interesting DAC option is Jim Hagerman's stuff:
http://www.hagtech.com/hagdac.html and http://www.hagtech.com/chime.html

Apparently, you can build the HagDac and add a basic power supply and be in business.  With the Chime, you can select between two S/PDIF inputs and one USB.  The HagDac functions as a daughter card that fits into the Chime's mother board... so you can do this stepwise and spread out the costs.

Hugh, I will hang in with my modded ART DI/O as long as there is a glimmer of hope that you will eventually do the DAKSA.  I really like the way your stuff sounds (organic, muscular with finesse).  I hope that you will let us know when you have made a decision.  

Peter

[aurelius]

Mr Rabbitz,

I do no think you will be disappointed with your Peter Daniel DAC.  I can't listen to the stock SB2 DAC anymore without getting aggitated and needing to swap back... very fluid and musical.

I will probably end up trying the Monica2 (has asynchronous reclocking) and maybe the Chime as well to compare what a good Oversampling DAC does.

Other options include the RAKK DAC
http://www.kandkaudio.com/digitalaudio.html

Mr Dean,

To what extent is the IP of the design complete?  Ben's reclocking and your IV conversion sound pretty interesting.  Perhaps you would consider an alternative business model?  A half kit like Jim Hagerman or an IP only model like Sigfried Linkwitz; could be supported by an online forum?  The truth is that the business issues you have articulated are likely to get worse over time, not better.  It would be a shame to see your work on this end in naught.

[rabbitz]

Mr Rabbitz,

I do no think you will be disappointed with your Peter Daniel DAC.  I can't listen to the stock SB2 DAC anymore without getting aggitated and needing to swap back... very fluid and musical.

Good to know and anything from Peter Daniel should be quite good as sonics is his main goal rather than measurements.

[hifryer]

Shinobiwan,

The ATC are not inefficient and dont soak up power.

Your amps just cant produce it.

It is simple ohms law.

For a given rail voltage SS amps produce so much current into 8R and if good amps almost double into 4R. The corrollary is they produce half into 16R!!

probably just need to increase the rail voltage by 1.4 times, if filter caps can take it and adjust dropping R to earlier stages.  

You will get 100W from a 200W amp which is more than enough but hardly the economic way to do it!  SS designs simply do not cater for 16R speakers. They will love them and sound great but not produce their power which is specified for lower impedance loads.

Of course, with a tube amp you simply rewire output for 16R setting and get blown away!!

cheers

[SamL]

Another interesting NOS DAC is the Twins TDA1541a Non-oversampling DAC from http://www.diyaudiocraft.com/  
It come with Dual TDA1541a PCB that is fully funish and tested, Opamp output PCB, tube buffers, power supply and transformer. There seems to be a reclocker but not display on his site.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=55808&perpage=10&pagenumber=1  
(for those who like to read)

Have fun,
Sam