T+a dac 8 dsd

[shahed99]

I have a i7 4770T (base frequency 2.5GHz, max turbo frequency 3.7GHz). Is it too unrealistic to expect to upsample redbook to DSD 512?

 

Right now, my CPU load is about 39% with DSD 256 upsampling using HQP and Roon server running. And this is using hyper threading and turbo boost disabled.

[shahed99]

Shahed,

your i7 seems identical to my xeon 1265L, so here is my experience:

First you should enable hyper threading and turbo. It is not much but it helps a bit. Also enable the pipeline feature in HQP.

The turbo on all 4 cores maxes out at about 3,1 Ghz which is definitely enough for upsampling everything (including high res PCM) to DSD512 with the -2s family.

I even got 16/44 PCM to 512 using non -2s, but the CPU was totally maxed out then and even opening the explorer caused playback skips.

So for the better non -2s filters, you want something faster. But it will work with the -2s filters which are not bad either.

 

This is very helpful information. Thank you!! I am perfectly fine with -2s filters. Do you use Roon server? It'd be nice to simulate DSD 512 on HQP to get the server load.

[shahed99]

Not every tweak is beneficial and depends a lot on your preference and how your system sounds in general. RAM disk was an absolute no go for me. It dried up the sound.

[shahed99]

I wonder why the price is so high in USD. It is priced 2750 euro which is $3072 in USD. But it is sold for about $4000 in US.

[shahed99]

...and $5600 in Canada!

 

ouch! It's great for this hobby when a product represents great value and punches above its price class. T+A Dac8 DSD seems to fall into that class. However, increasing price due to market demand may negate the whole reason it got so popular to begin with. I hope there's an appropriate reason for the higher than usual price in the north american market. Import tax?!

[shahed99]

Great points by Miska and audio.bill. However, even in UK the MSRP for Dac8 is 2400 GBP ($3150 in USD). So, I guess north american market is usually more expensive for european product and vice versa.

[shahed99]

I received my T+A dac yesterday from AudioArt. I had less than 30 minutes to spend with it. So I won't talk about my impression just yet. However, cold right out of the box, I am impressed upsampling to DSD 512.

 

One good news I would like to share with people considering to build new server for DSD 512, you may not need to. I have a i7 4770T processor. And upsampling to 24.6MHZ, poly-sync-short-mp-2s, ADSM7 my processor use is about 37%. I have turned on hyperthreading and enabled turbo mode in the bios.

 

Few questions for Dac8 owners:

 

1. What is the recommended filter settings on T+A Dac8? I am using wide mode now.

2. For DSD upsampling, 24.6MHZ vs 22.6MHZ which one would be ideal?

3. Should I leave the dac ON 24/7 like any other SS dac?

4. A suitable power cord recommendation. Currently I am using a DIY western electric power cord connected to PiAudio UberBuss. If RFI/EMI is filtered through a power conditioner, do I need a power cord specialized for digital use?

5. Does good footers make a noticeable difference for T+A Dac8?

[shahed99]

Thanks Juanitox! I have sold my USB Regen and W4S RUR as it wasn't making any noticeable difference using with my max tricked out music server using PPA V3 OCXO usb card. Do you notice a noticeable difference using INTONA in the chain?

 

Also it seems, you are using T+A Dac8 as your preamp/volume control. Have you compared its preamp performance with other stand alone preamp? What is your impression?

[shahed99]

Here are my answers:

 

1. I think people generally are sticking with Wide mode, and find that sounds the best.

2. If you have any 48k source that you're upsampling to DSD512, I would go with max sample rate of 24.6mhz, and set the auto-sample rate family in HQP so that it automatically upsamples to 22.6mhz for your 44.1k source material

3. Internally, the T+A supplies internal power to the DAC chips to keep them "warm", even when it's turned off but plugged in, and I believe that T+A recommends turning off the DAC when not in use.

4. I'm not a believer in upgrading power cords (believe it to be snake oil), so "no comment" will be my official response to this question

5. I'm a headphone only guy, so don't really think I need any special vibration damping for the DAC (no booming speakers to contend with). Again, a "no comment" from me on this one.

 

Really helpful answers! Thanks!

[shahed99]

Any T+A Dac8 owner using Windows Server 2012? I am using WS2012 R2 with AO in minimal server mode. It happens frequently that when I start my music server, it doesn't recognize the dac. If I restart the server, it does. Sometimes it takes multiple restart for the OS to recognize the T+A dac. Anyone has the same problem?

[shahed99]

Cold start as in restart the server. It takes several restarts before the server locks on to the USB on dac. I think T+A is using amanero USB board. I had a lampizator which used the same board too. But locking on to USB signal on the dac was more consistent.

[shahed99]

Not sure if this is a coincidence or not. I went back to GUI mode from minimal server mode. Used my serial# to activate the OS, PC restarted and locked on to USB signal right away.

 

On a different note, I asked T+A about the highest output impedance when using the Dac8 as analog preamp. They replied the output impedance is always 22 ohms. I think that is EXCELLENT. Once my dac is broken in a bit, I will try it as a preamp.

[shahed99]

My music server which is passively cooled, hence absolutely silent uses i7-4770T processor. This has TDP of 45W. After I enabled turbo boost and hyperthreading, DSD 512 upsampling with ASD7 and poly-sync-short-mp-2s is taking only 29-34% processor uses.

 

What is surprising that few days ago, I started upsampling to DSD 512 using poly-sync-short-mp which are significantly more processor hungry than -2s. But my music server is handling them with ease with no hiccup at all. Not just that, I am able to upsample to poly-sync-short-mp even the 24/96 recordings. I will check how much CPU is being used and report back.

 

So from my experience, you don't need to have a fan in your music server and use it next to your dac. No microRendu is required. I should mention that I am using Windows Server 2012 R2 with Audiophile Optimizer in minimal server mode.

[shahed99]

I think I might have the same processor laying around and could put it to good use but the consensus here has been that you at least need i7 6700K to do DSD512. Could you list what kind of power supply and case are you using i7-4770T ?

 

I am using Teradak ATX 275 linear psu with Streacom FC10 case with my i7 4770T. I just ran a test to see CPU consumption:

 

Redbook -> DSD 512, poly-sync-short-mp-2s DSD7 => CPU 32%

Redbook -> DSD 512, poly-sync-short-mp ASD5 => CPU 37%

Redbook -> DSD 512, poly-sync-short-mp ASD7 => CPU 38%

24/96 -> DSD 512, poly-sync-short-mp ASD7 => CPU 40%

[shahed99]

I have only put 20 hours on my T+A so far. I sold my amp and hence it is not being used anymore. However, my early impression about the dac is phenomenal. It is very musical without making the sound anymore warmer than it is staying perfectly neutral and yet very detailed. I think that would be the highlight for me about this dac. The soundstage is big and very realistic. I was also very impressed with it's non unsampled PCM playback too. I used it as a analog volume control for a couple of song. It did sound harsher as a preamp compare to my Melody P2688 preamp. Which is not surprising given my preamp is suppose to be world class.

 

However, due to a recent change in my situation, I am planning to sell my entire audio system as I need cash. My amp is already sold. PM me if you are looking for a good deal on T+A which is practically new and my other equipments. The T+A comes with 2 years manufacturer warranty.

[shahed99]

T+A Dac 8 DSD now appears on Stereophile A+ list.

[shahed99]

The new beta of HQP is significantly slower than the older beta. I was able to upsample to DSD 512, non -2s filter from PCM 24/96 without sweat on my i7 4770T. And now, after downloading the newer HQP, even PCM 24/48 upsampled to DSD 512, even using -2s filter stutters a lot.

[shahed99]

What are the exact versions you are comparing? >=3.14 is somewhat slower than <3.14, due to some algorithm changes to accommodate the AMSDM7 modulator and some things coming later (internal experimental testing stage). But there are also some new optimizations that largely offset this difference.

 

So it could be something else. Have you checked the power profile you have in Windows? On my new machine I needed to change it to "Performance" because the "Balanced" was throttling the CPU too much.

 

This is happening using the latest beta (3.14beta8). The performance degradation (in terms of CPU load) is very noticeable. Between my last version of HQP and the newest beta 8, I haven't made any single change to my OS. Btw, I am using Windows Server 2012 R2 with Audiophile Optimizer. Not sure about the power profile.

[shahed99]

My incoming preamp is single ended. My Rogue amp has transformer coupled balanced input but still single ended. According to the report, I should be using balanced output of the T+A dac.

 

Can anyone please suggest the best way to take advantage of the balanced output of the T+A dac?

 

XLR to RCA cable vs Jensen transformer vs something else?

[shahed99]

I was playing with HQPlayer settings last night and a small change increased the sound quality quite significantly. Try the following and see if it is replicated in your system:

 

Uncheck "Auto rate family" and set DSD upsampling to 24.576 MHz.

 

Holy s**t. I've no idea why this would change anything for better. I mean using multiples of 48KHz instead of 44.1 KHz for red book music sounds wrong. But no it sounds so good. Better prat, musicality, definition, warmth, etc.

 

I should mention that I noticed this with my previous dac Exasound E22 Mk2 while upsampling to DSD 256. But with T+A DSD 512, the change is more significant.

[shahed99]

My preamp to amp connection was single ended as I didn't have an extra balanced interconnect at hand. Last night, I was able to make my system all balanced from the T+A dac to amp after I received my new balanced cable.

 

It has been reported before that T+A sounds way better when using in a all balanced system, but WOW - a very noticeable improvement of sound. My DAC to preamp connection was balanced, so I wasn't expecting much as I was already using the balanced output of T+A dac.

 

I strongly suggest all the T+A DAC8 user out there to make their system all balanced to see what this DAC is capable of.