Gieseler Audio Posted May 18, 2015 Share Posted May 18, 2015 After a few minor tweaks & upgrades I have finalized the AKM 4490EQ Klein DAC design. The changes were custom AKM firmware for the Amanero Combo 384 USB board, rear panel filter switches, improved muting & psu layout. Sonically there is not much difference but I’m happier as it is a more polished & flexible product. I will be contacting all current AKM Klein owners & offering a free upgrade. Currently the AKM version is outselling the PCM version by ten to one. Sound-wise the AKM has much more three dimensional & involving sound compared to the PCM (IMHO) I can now ship to the UK & will add more overseas destinations when I find suitable AC power adaptors. Pictures & tech stuff will be posted shortly. 6 Link to comment Share on other sites More sharing options...
Darren69 Posted May 18, 2015 Share Posted May 18, 2015 Here you go @@bhobba Link to comment Share on other sites More sharing options...
bhobba Posted May 19, 2015 Share Posted May 19, 2015 (edited) Here you go @@bhobba As soon as Clay gives the word I will go down and pick up one. Clay may have been trying to contact me to let me know there is one available to check out, but my mobile phone decided to pack it in hence may not have been able to contact me. I ordered a new one yesterday but it will take a while to arrive. I will contact Clay to see when one can be picked up. Thanks Bill Edited May 19, 2015 by bhobba 2 Link to comment Share on other sites More sharing options...
Gieseler Audio Posted May 19, 2015 Author Share Posted May 19, 2015 (edited) The new PCB's ( final release) arrived today so I will populate one & post pics tomorrow. Also Amanero have just informed me that a fresh batch of Combo 384 USB boards are on there way to me now - yippee! There will now be no more parts hold ups untill the AK4490EQ chips run out. Sold another AKM Klein last night so that leaves fifteen AKM chips remaining. Digikey are quoting me a fifteen week lead time on more AK4490,s so hopefully my stock will last untill then. Regards Clay Edited May 19, 2015 by Gieseler Audio 1 Link to comment Share on other sites More sharing options...
Gieseler Audio Posted May 20, 2015 Author Share Posted May 20, 2015 As promised a photo of the new AK4490EQ final revision pcb. Also scope output photos of a 20k 44bit sign wave. Both DAC’s have the same post analogue filter. The perfect one is the AKM, the wonky one is the PCM. Take note of the component quality, all film caps are Wima polypropylene/foil & made in Germany. Regulators are Linear Technology low noise (expensive) & power diodes are Cree SIC. Large caps are Elna Silmic II’s As you can see I have gone totally overboard on the power supply section & this has a major effect on sound quality. 7 Link to comment Share on other sites More sharing options...
ljmac Posted May 20, 2015 Share Posted May 20, 2015 Why do you use a "post analogue filter" at all? Surely the digital filters take care of everything? Link to comment Share on other sites More sharing options...
Gieseler Audio Posted May 20, 2015 Author Share Posted May 20, 2015 No you still just need a gental analogue filter on the DAC output. With no filter on the AKM it is pretty good but with no filter on the PCM it is really bad. My filter is a gental second order roll off staring at 100k so has minimum effect on the sound. 1 Link to comment Share on other sites More sharing options...
Jventer Posted May 20, 2015 Share Posted May 20, 2015 (edited) Hi Clay Good to see you are improving the DAC continiously and providing such good customer service. Johannes Edited May 21, 2015 by Jventer 1 Link to comment Share on other sites More sharing options...
qwerter Posted May 20, 2015 Share Posted May 20, 2015 Does it support DSD? Link to comment Share on other sites More sharing options...
~Spyne~ Posted May 20, 2015 Share Posted May 20, 2015 Does it support DSD? Not yet. Link to comment Share on other sites More sharing options...
Jventer Posted May 20, 2015 Share Posted May 20, 2015 DSD could be handled by software? Link to comment Share on other sites More sharing options...
Addicted to music Posted May 20, 2015 Share Posted May 20, 2015 Haven't heard this DAC yet, but love your work Clay. 1 Link to comment Share on other sites More sharing options...
ljmac Posted May 20, 2015 Share Posted May 20, 2015 No you still just need a gental analogue filter on the DAC output. With no filter on the AKM it is pretty good but with no filter on the PCM it is really bad. My filter is a gental second order roll off staring at 100k so has minimum effect on the sound. Have you tried listening to the AKM without an analogue filter? Might be an improvement. Link to comment Share on other sites More sharing options...
Gieseler Audio Posted May 20, 2015 Author Share Posted May 20, 2015 Re: filters. Good idea ljmac, next one I build I will leave out post filtering & compare it to a standard version. Probably the main reason I have the filter is when it is reviewed I don't want the 15 - 20k measurements to look bad. Also its hard to imagine anyone would hear the effect of a 100k post filter but you never know. Don't worry when you order yours I'll just leave the filter caps out - Ha Ha DSD - the hardware is all compatible but I would need to run the AK4490 in software mode. I have a good range of Arduinos, pics, avrs & small displays all ready so I soon as I get a bit of spare time I will get cracking on developing a micro controlled version with a display. I must admit it would be great to look at the Klein & see 384k! rate displaying. However sometimes simple hardware mode with less bits & no mico can sound a bit cleaner. Also this thing sounds so darn good on PCM it's hard to imagine DSD improving things. 1 Link to comment Share on other sites More sharing options...
Gieseler Audio Posted May 21, 2015 Author Share Posted May 21, 2015 (edited) I had a good listen today & compared the final revision version against the previous version. The final revision is definately better, soundstage a bit wider, higher & bass a little more solid. They are subtle differences but a definite improvement. It is probably due to the extra capacitance & new star earth layout in the psu section. As I said before all Klein owner with the older version will be updated, yes Naggots that means you! The other good news is Digi-key now has AK4490EQ's in stock so I put a big order in. It is weird as they initially said there was quite a delay & today I checked & they had stock. Edited May 21, 2015 by Gieseler Audio 4 Link to comment Share on other sites More sharing options...
ljmac Posted May 21, 2015 Share Posted May 21, 2015 Re: filters. Good idea ljmac, next one I build I will leave out post filtering & compare it to a standard version. Probably the main reason I have the filter is when it is reviewed I don't want the 15 - 20k measurements to look bad. Also its hard to imagine anyone would hear the effect of a 100k post filter but you never know. Don't worry when you order yours I'll just leave the filter caps out - Ha Ha I've joined the crowd funding program for the MDAC 2, which John Westlake claims will be the finest DAC ever made (as he's probably Europe's number one digital designer he should know). But its rarity will make it an easy re-sell, so I'm following your ventures with interest. It will be shipped as a replacement board for the existing MDAC, so I was thinking of asking you to swap them for me (I'm not confident with that sort of thing) - then you can audition what should be a state-of-the-art SABRE DAC. Link to comment Share on other sites More sharing options...
bhobba Posted May 21, 2015 Share Posted May 21, 2015 I've joined the crowd funding program for the MDAC 2, which John Westlake claims will be the finest DAC ever made Where have I heard that before? When you get it we will see how it fares against the Klein, Killer and Direct stream - should prove interesting. Thanks Bill 1 Link to comment Share on other sites More sharing options...
Gieseler Audio Posted May 21, 2015 Author Share Posted May 21, 2015 Hi ljmac, Yes no problem on me doing the board swap over. I will be good to listen to a SOTA Sabre DAC too. 1 Link to comment Share on other sites More sharing options...
Suopermanni Posted May 21, 2015 Share Posted May 21, 2015 I would also be interested in getting the MDAC2 to MDAC1 chasis board swap done professionally. Depends on where you are based, Geiseler Audio. I'm also hoping you might know where I can get an enclosure/chasis for the spare MDAC board I will have? Link to comment Share on other sites More sharing options...
Gieseler Audio Posted May 21, 2015 Author Share Posted May 21, 2015 The board swap over would be an easy job for any competent tech. I mainly suggested to ljmac I would do his is because I would love to have a first hand listen to a MDAC 2. My DAC manufacturing is taking over now so I am backing off repair work. Wow - just noticed the cost for a MDAC 2 board upgrade 400 to 500 GBP. - right? Makes my Klein DAC look like good value - I use better psu caps too! http://www.shaoerduo.com/upload/images/20130708_172609.jpg 4 Link to comment Share on other sites More sharing options...
Suopermanni Posted May 22, 2015 Share Posted May 22, 2015 Ahh, I see. Apologies for barging in like that then. I dont suppose you would know of anyone that could do the board swap in the Brisbane area would you? Preferably on the northside. 1 Link to comment Share on other sites More sharing options...
lemnoc Posted May 22, 2015 Share Posted May 22, 2015 (edited) It's great to see an aussie made DAC compete with the imported stuff and even better when people buy it. We need more local content !! Like Joe says "Have a go !" cheers Edited May 22, 2015 by lemnoc 3 Link to comment Share on other sites More sharing options...
Gieseler Audio Posted May 22, 2015 Author Share Posted May 22, 2015 Suopermanni - AV Digitech maybe able to help with board swap, Southside unfortunately. Website update - I realise I have no Klein AKM DAC info at all on http://www.gieseler.com.au so keep an eye on it & hopefully this weekend I will get it updated. Specs, photos etc.. 1 Link to comment Share on other sites More sharing options...
henry218 Posted May 22, 2015 Share Posted May 22, 2015 hi Clay, Any of your DAC in Sydney? love to try them.. . Great work so far cheers Henry 1 Link to comment Share on other sites More sharing options...
ljmac Posted May 22, 2015 Share Posted May 22, 2015 (edited) The board swap over would be an easy job for any competent tech. I mainly suggested to ljmac I would do his is because I would love to have a first hand listen to a MDAC 2. My DAC manufacturing is taking over now so I am backing off repair work. Wow - just noticed the cost for a MDAC 2 board upgrade 400 to 500 GBP. - right? Makes my Klein DAC look like good value - I use better psu caps too! http://www.shaoerduo.com/upload/images/20130708_172609.jpg Actually, John's looking at building his own full size case later as an optional upgrade, with an upgraded power supply. It will be cheap for a SOTA DAC, but still far more expensive than a Klein! BTW, the image you've used here is an entirely different product with the same name (the MDAC's power supply is external). Thanks for doing the board swap, although at John's current glacial pace we could both be waiting a while! Edited May 22, 2015 by ljmac 1 Link to comment Share on other sites More sharing options...
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