Audio Synthesis Dax Decade Users Thoughts / Comments Please

Hello,

It would be great if anyone who has ownded the Audio Synthesis Dax Decade DAC to share any comments or experiences with this piece of kit.

I have owned for many years a humble setup of a NAD CD player and a NAD Integrated amp with Wharfedale Evo-20 speakers. Recently I decided to splash out on a new system and dip my toe into some more serious kit.

I first bought some second hand Sheng Ya Vincent T100 hybrid mono blocks which instantly improved things relegating the NAD C320BEE to a preamp. This sounded really nice, warm and dynamic.

Next I purchased a Sonic Euphoria PLC TVC preamp with a view to adding a standalone DAC and CD transport. This has only just arrived and while waiting for this I purchased in the spur of the moment a second hand Dax Decade DAC with a TEAC VRDS T1 CD transport with a Trichord Clock upgrade and an NVA 1.5M digital coaxical cable to link the two.

I hadn't expected to buy a DAC with a preamp built in and perhaps it was a little silly to order the TVC first as it would possibly rendered useless in the equation and a needless waste of money. The TVC has only just arrived a month after receiving the TEAC and the Dax.

Something really doesn't sound like it is gelling in my system. Since adding the TEAC and the Dax and running these into the mono blocks the sound to my ears is alittle thin, closed in, a little compressed, lacks some dynamics, lacks some bass and is not very involving. I notice this mostly with full bands and less so with acoustic music.

I am sure this is down to my own mistakes / ignorance / lack of experience with hifi but any comments or advice would be a great help! Of course the Dax is not all bad there is excellent focus and detail but something isn't right. I have not read any bad comments on the Dax anywhere so I can only assume it must be down to me!

I have borrowed a few different cables and some improve a little though they don't change things greatly.

The filter setting on the Dax when turned off seems a slight improvement though this sends a loud click to the speakers in between CD tracks. I don't think this filter is supposed to be turned off from what I have heard.

I will be shortly replacing the Wharfedale Evo-20 speakers and though they are probably not up to the job they had sounded rounder and less harsh with the NADs and the Sheng Ya Vincent Mono's.


Many thanks in advance for any comments folk are willing to share.

 

Hello Woodnut

I used to own a dax decade (i still have it,just don't use it anymore) and from what i remember,my findings were the same as yours (ie thin sounding etc).Actually the reason i am replying to your post is not this,but to let you know of a very serious problem i've encountered with the dax.My then system was a theta Jade transport,Musical Fidelity MVT/A270ii pre/power and TDL reference standard loudspeakers.At first,i had the DAX connected through the mvt preamp and everything worked fine.When i tried to connect the dax directly to the power amp,after playing ok for a couple of days,suddenly,it produced a very loud noise,like full range "white noise" at full power.Luckily i was next to the rack and knowing that the a370 don't have any protection circuits (ie even if i turn it off,it wouldn't turn off right away but rather it would take some time for its cappacitors to drain off)i pulled the interconnect off of the dax.The same thing happened again a few day latter but this time it blew the whole right loudspeaker ,both woofers,both midranges,both tweeter,except the supertweeter(yes,i know its weird lol).Don't ask me why or how.i don't know ,it just happened.Being curious,brave or foolish...or perhaps a combination of all,i did connect to my newer system but this time my power amp (a jeff rowland model 8ti)has a power protection relay built in,and everything worked fine.In a few words,if your amp doesn't have a protection circuit built-in,be very cautious.There is no way to know if this thing is gonna happen to your system unless it does.

 

Thanks for the warning. I haven't experienced anything like that so far and am now using it through a TVC so it is on maximum volume anyway.

I had a bit of a break through last night by putting some cheaper copper ribbon speaker cable in and taking out the Chord Co Cable I had been using and alot of the warmth and bass has returned.

The sound is less detailed and less focused but I can only assume that some of that can be brought back with a carefully selected good quality speaker cable.

I have tried Chord Odyssey an Chord Epic and these have made things sound quite harsh at the top end with little bass or warmth.

I am sure that the Dax Decade has more to offer it definitely sounds alot better without the Chord Co. Cables.

 

My experience has been that this is a very good DAC indeed - though nowhere in the league of the DAX Discrete which I now use. For some reason I have heard of this quirk you described happening before but can't recall the explanatin. i suggest calling David Heaton at Audio Synthesis - a more helpful MD you would not find!

 

Yes I did email AS when I first got the Dax Decade Re: the clicks in between tracks with the filter off and I got a response straight away. Something to do with the transport outputting a null in between tracks and the filter dealing with this. I'm not sure why you can switch the filter off though if it is not advisable.

Is it expensive to upgrade a Decade to a Discrete? Is it worth looking at?

I have just tried a few more cables tonight and it has really helped things. Still a little thin at times but most of my original complaints have been addressed by borrowing some more speaker cables.

 

Hello again Woodnut

Here's 2 ic cables you should try.The first,a VDH MC-Gold.Mind you
not the newer one but rather the old one which you can only find in the used market.It is warm and bass heavy.The newer one is more analytical sounding and in a way approaches the sound of the mc-silver.The second one,which you can obtain new,is from a US based company (Element cables) and is called "musica ii". it is very cheap $58 per meter terminated and it is a very nice cable although not as warm or bass heavy as the old VDH mc-gold but rather a errrrrr musical cable Believe-it-or-not , i raplaced all the cables from my rather complex setup with this one and it sounds lovely and i've been using VDH mc-silver in balanced form.Also,do try a few vibrapods underneath the dax.

 

Hello,

Thanks for the recommendations, I will investigate.

I currently don't have any vibration reducing feet on the Dax but will be getting some shortly.

 

As I said too you .....the tvc will give you a thin bright forward aggressive sound in my experience .... the dax is trying to do the same but is essentially neutral but dry ....

sounds likew someone has a fault dax and should have it sent back to AS asap !

I've run my dax into my mono block cyber 800 without issue since I've had the beast ....

I don't get a loud click with filters set in any config ...I would give as a call

have you tried the dax to power amps with out the tvc ?

I don't have a downer on tvc's ..... I've tried very hard to like them ...they do some things fantastically ...imaging and depth but tend to have you sat on the edge of your chair rather than relaxed . Its a bit like passives of other types they just don't do it for me I've owned and built four or five ....I now run a class A valve unit that has a passive setting so its the best of both worlds.

As to feet ..don't spend money ......make a set of wooden cubes 25mm sq and see if this takes you in the right direction

 

I agree with Zanash's suggestions here - sounds as though the DAX has the flu! Discrete is a different beast altogether - i don't believe there is an upgrade path. Contact David Heaton via telephone.

 

Hello,


The email I got a while ago from Audio Synthesis re: the clicks says...

"The click you hear between tracks is caused by the Teac interrupting the SPDIF data when it outputs digital zero. By switching the DAX to 1 bit or more of dither the problem of interruptions in digital silence is removed. We recommend the DAX Decade is always used with a minimum of 1 bit of dither irrespective of the type of source."

So this would suggest that the Dax Decade is functioning correctly.


Adding the TVC into the equation hasn't made things any worse it seems to have made the dynamics a bit better but hasn't made the sound any more thin or bass light than it was without the TVC.

I have already ordered some cheap rubber feet before I saw your post Re: wooden cubes. I don't expect that they will make any difference but worth a try.

I borrowed two power cables for the TEAC VRDS T1 CD transport and the Dax Decade and haven't really noticed any difference. I was previously using standard leads that came with them.

Am still waiting on my speakers so should make any judgements when they are in the system and run in though I have a feeling they will probably highlight any flaws in the source.

I guess probably need to change the DAC or get an active pre which will add a bit of beef (silly phrase but I can't think of any other way to put it) to the signal.

I would like to add that after swapping speaker cables around that the Decade is sounding good and the problems have been lessened but its just not quite right still in my system at the moment.

 

Can yo use an AT&T optical cable with you transport? If so reccomend you try this, the DAX usually has this option I recall - certainly is there in my Discrete.

 

Is AT&T different from the TOSLINK optical? There are quite a few different input connections on the back I dont honestly know what all of them are used for.

When I first got the Dax I used a curry's £9.99 optical TOSLINK cable and the sound would every so often drop out then return at least once in every hour of listening.
When I emailed Audio Synthesis about this they said it could be to do with the quality of the cable or the transports clock being "off center" whatever that means.

I have tried one other coaxical cable apart from the NVA 1.5M one I am using and there was no difference to the sound.

What cable would I need for the connection you suggest and are they expensive?

Many thanks.

 

I had that exact same problem, and the same explanation, using a Chord DAC 64 with a Micromega transport. No problem when using the Micromega transport with another dac and no problem when using the Chord DAC with another transport...

 

It does sound a little less compressed and more natural without the filter on though it isn't a large difference.

When using the Dax Decade as a pre the clicks are very loud through the speakers and sound like a gas cooker hob igniter. With the Decade on full volume and using a seperate preamp the clicks are alot quieter but are still there.

Overall though the lack of bass and body I don't think is down to the strange effects of the filter and the clicks.

 

I'm not a digital person but I must say I admire your lot's perseverance. Dull sounding, compressed, clicks, cut-outs, lack of body, new cables to correct the sound. I'm afraid I would have given up and just said it was crap yonks back.

 

All of my music is on CD.

 

...it'll never catch on.

 

I am a long time and happy Dax Decade user (gosh this is better than AA!). the key to happiness with the dax is to get a transport that supports Ncode. PM Dunkyboy if he is still around and he will add to this testimony.

As to upgrade path, there is none to te Discrete which is a completly different model geared to more than simple red book CD. Instead, its the upgrade to Balanced and/or Black Gate caps.

Thin sounding its not,, and many here who have visted will testify. It is not in your face hifi like some DACs but I regard that as a plus.

hth

 

Woodnut,i took the time and did a little experiment for you.
My appologies regarding the first comments about dax but it was from memory since i did not use it for years and it was with my old system.Anyways,here's how i connected it and the equipment i used. Pre/Power/Loudspeakers Jeff Rowland Synergy ii/Model 8ti ProAc Response Four. I used my cary 306/200 as both a cd player and a transport (i could have used a Theta Jade but that would involve a great re-arrangment of my setup lol). The cary is connected to the mains using a VanDenHul mainstream mains cable the dax using a cheap MAC (MyAudioCable) soundpipe.The cary is connected on the pre using a MAC soundpipe ic,the dax using vanDenHul Mc-Gold.And last,the dax is connected on the cary using a VanDenHul The first metal free digital cable.The outputs are matched etc.To make a long story short,using the cary with no upsampling and the dax with no dither,1 bit,and 5 bit,
the sound was almost indistinguishable apart from a slight more energy from the dax through the midrange and lower treble but that could be because of the mc-gold which is a bit forward and brighter than the MACs. I really didn't bother substituting interconnects since the differences weren't that great since what i wanted to find out is whether the dax is thin sounding or not. If indeed is a bit brighter sounding (consider something in the region of 1 db brighter through the midrange and lower treble than the cary)the whole bass region from both players is almost the same.
Resume,the dax is NOT thin sounding.

 

I'll add that I don't find it thin either .....neutral and natural a relief to get back too after hearing some gear ....