ECdesigns

[realDHT]

45 minutes ago, murphythecat87 said:

I dont agree

personally, I let my headphone connected at all time to my headphone amp. its not like I will unplug my headphone 10 times a day. headphone jack are extremely sturdy. never actually heard of one failing in high end gear. and if it eventually fail, chaging the jack is stupid easy for anyone.

 

now using a rca to headphone adapter goes against what ECD are praising (getting away from any interconnects...)

 

The fact the Powerdac headphone only offer one set of outputs and no headphone jack is a bad joke to me. Focal Arche is a perfect example on how a DAC-headphone amp all in one should look like

I did not say anything about jack reliability in my post. It is not "stupid easy for anyone" to change a jack by the way. You would have to dissassemble the dac and desolder it from the board. If you can do that easy, then you can just as well install a new jack somewhere and connect it with cables to the board.

 

And the powerdac R is NOT a combined DAC/headphone amp, John stated that clearly in the blog. 

[realDHT]

1 minute ago, juanitox said:

 

this thread is a joke ,  month and month of teasing with technical B.S  to end up with a picture of a prototype of Waffle iron with recessed RCA     , guys you make my day ! 😁

Just because you are not able to understand it does not mean that it is technical BS.

[realDHT]

Great news. Very interesting! 

And interesting news that ECD are designing a complementary tube amp too.  

 

So if I understand you correctly, you think the powerdac + rasperry is better than the UPL + fractal DAC in subjective listening tests? How much better would you say it is? Is it sort of a "must-do-upgrade-immediately" :) or just a little bit better in your opinion?  

 

[realDHT]

John told me earlier it runs at 200 MHz.

[realDHT]

Yes agree 100% with you guys on this. We really don't need to complicate it for ourselves when evaluating..either it moves us, or it doesn't. If it does not move us when listening, it is not good no matter what,  even if it has the best "tight bass" and "extended hights"

 

Lynn Olson described it very well

"What do audio systems do? At the most basic level, they are Illusion Engines. I'll repeat that: a hi-fi system is really an Illusion Engine, a type of mechanical contrivance that hypnotizes the audience into thinking musicians are somehow present (or at least nearby). If the contrivance fails in this, it fails utterly, just as a magic trick entertains or it doesn't."

 

http://www.nutshellhifi.com/library/illusion-engines.html

 

[realDHT]

Another thing that Lynn Olson argues in the text I linked is also very true in my experience: measurements at "the box level" usually does not correlate much at all with audio perception, so they tend to be rather meaningless. On the other hand, during development, measurements are very powerful tools to evaluate a design change, subcircuit etc, provided the designer has skills and experience to select the right measurements and correlate them with perception. 

[realDHT]

21 hours ago, tims said:

In my case, if I was to buy the PowerDAC-R, I would like to connect it to my active speakers (which has it's own volume control) and also use it to drive my headphones.  Ideally, both would be permanently connected to the PowerDAC-R so I would avoid the hassle of changing the RCA connections each time I wanted to swap to the headphones or vice versa.
To do this,  the only solution I can only think of is to install a RCA switcher like this one:
https://www.amazon.com/dp/B07MLQ6YH4?tag=offthebroiler-20&linkCode=osi&th=1&psc=1&keywords=Toslink Switch

I'm thinking the RCA switcher would disconnect the headphones when feeding my speakers avoiding any problems with both connected at the same time. 
I would want to use the PowerDAC-R's volume control for my headphones but bypass the volume control to feed my active speakers but John Brown confirmed that enabling the link (at the rear) of the PowerDAC-R just sets the volume to its maximum rather than bypassing the volume control completely so I would have the volume set to it's maximum when connected to the speakers.
Other than having the switcher and extra RCA cables in the circuit (that may degrade the SQ), anyone think there would be any drawbacks in setting it up this way or have any ideas how I could have my speakers and headphones connected permanently? 

Cheers

This looks to be a fairly high quality RCA switchbox: https://www.ebay.com/itm/192864171577?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D232195%26meid%3D122b5be7179346d4a059a0b830e4ec7d%26pid%3D101195%26rk%3D1%26rkt%3D12%26sd%3D284246139866%26itm%3D192864171577%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseUnbiasedWebWithSearchFilterPromotion&_trksid=p2047675.c101195.m1851&amdata=cksum%3A192864171577122b5be7179346d4a059a0b830e4ec7d|enc%3AAQAFAAACEClKviNOdewYUBffQVCCI2t2UH65%2BGLEzS88JNzc3G9KoPgmfUFC6HTUubVM1cj1KavzFCKmsAzut1k134GZwW6ARRxQ81mSdRMfiLXGB%2F5rcaFf5JQZgLTc8qeitDSxyGKAjSjVB4%2FaYomfEX0JlcGoyIU%2F5gIG1DjaCX14a1UGxFzqR%2FPr9hvZ4mzzL4aNNQ7E5DvYU4wrYlSrXILI3106nCqg5yQiWF911SoIQOs1MeeAWfL9Y5rpZwoF75WXBSN46wlJ3umNLBSd9H2SiURzhMIzGLGLqFlIHXb8JxlWAXgO6jcOTtuu4OcqFdCrPDzmbx4Lkr76Oll8CqeAGx8V1o1IaRAlaBqcEX15cNQ1I2PFvOp5%2BUiQXppqR04TCidbxiyEWlO17GQnvXclOeSwTLpID0JQM14s7I32cKqw1EunknfYM0S7MwrsrhFmm%2Fk0aZeAPciQoIqwCe44fqNaSeYebIAFFq27iq9bjDMqgGnSHUhsfUfSHQHJjlckVGLBxRxa0QppZ1qMVtZ98PElBppYWKA1A%2FxzodZr8%2ByvpgJyg6j8kk71AsnvMud5%2F%2BGze5rTzj47yWm9GtlImu2IUWqPIKrV0IUnGYKu2mzBkytSoZa2rWLhc8YEGzt4E7WJClwT0iSRvCOpiKZm8Hqylw5%2BINS28Xnq68PPIX1Cj2mHeSjEahGOvzyQRrYbTA%3D%3D|ampid%3APL_CLK|clp%3A2047675

 

You could reverse-connect it so that the R+L outputs will be your inputs

 

Then you could remove 2 of the 6 RCA inputs, expand one of the holes with a drill to make it fit a headphone jack like 

https://www.thatcable.com/6-35mm-stereo-panel-mount-solder-connector-audio-jack-socket-chassis-patch

 

Then you can take the L, R and ground wires previously connected to the removed RCA connectors, and solder to the headphone connector.

 

This would make a suitable switchbox without the need for an extra headphone adapter cable. 

 

 

 

[realDHT]

I expect my long planned major master clock upgrade with the U192 will soon materialize. I friend will buy the new DAC immediately, so then I will have the opportunity to compare mine with the new one and after that I will know if I have to buy one :)

 

 

   

[realDHT]

28 minutes ago, hopkins said:

 

Cool. Though I would tend to think that even with a "perfect" source the DA96 will show some limitations. Let us know when your friend gets it and you can compare. 

The DIR9001 reciever chip in the DA96 might be a bottleneck for the clock performance, and probably also the noise from the XMOS in the U192. It will be interesting to find out how the ultralow jitter clocks will affect the sound. Otherwise the DA96 is pretty much reused in the new DAC as I have understood it (?) with the main differences being the DAPI, clocking and output stage. I will definately report here 😃 

[realDHT]

Thanks for the pics. The DAC board seems to be quite different to the DA96. Nice that its only 2 boards with (I hope) the same size as the DA96 bords. If I feel I need to buy this I can probably re-use my case and have extra space available in it for a DHT output stage for example 😁   

[realDHT]

18 hours ago, uber2 said:

Dac is in place, great design!

 

Acapella speakers? Looks like a nice turntable too. 

[realDHT]

The very low sensitivity of the hifiman is for sure the problem. 50 ohms should be okay. Many headphones have 100-110 dB/mW sensitivity. I also read that the HE-6 sensitivity might be even lower than the stated specification, some guy measured 77 dB/mW.

 

This looks to be a good webpage, with some info and a lot of examples

https://mynewmicrophone.com/the-complete-guide-to-headphones-sensitivity-ratings/

 

[realDHT]

1 hour ago, bodiebill said:

I do not quite understand "between 32 Ohms and up".

I think John means he did not test headphones below 32 ohms. Lower impedance requires more current from the DAC to drive and would at some point give a problem with distortion and/or freq. response. Higher impedance would not be a problem other than the SPL goes down.   

[realDHT]

BTW, there is an interesting topic about NOS (non-oversampling) dacs and their sound over at DIY audio. 

There are some guys with knowledge in signal processing etc, that try to understand more what is the reason for the "NOS sound", so they posted listening test files etc to try to learn more. Very interesting, although I don't know enough to understand all the details discussed.

 

https://www.diyaudio.com/forums/digital-line-level/371931-makes-nos-sound.html

 

Sometimes ECD dacs get critique for having "soft bass", "lack of punch" and similar. There was someone in this thread proposing that would be because of no output stage, but someone was mentioning in the thread above that this is typical for NOS, and that character can be changed by upsampling in software.  

 

Personally I have no issue with the bass reproduction in the DA96.  

[realDHT]

1 hour ago, Vincent des Champs said:

I must say, having used the PowerDAC for over a week now, the lower registers seem to be more present and better outlined in comparison with the DA96. Your claim regarding electronic noise seem to fit with the "source immunity" claim made by ECdesigns.

 

Can other people relate to this..?

Seems to make sense. Several times I have also read that low jitter is important for percieved bass depth and definition. It is also possible that ECD improved (the already good) jitter levels of the DA96 with the new clocking system. I'm now running the U192/DA96 with very low jitter clocks by Andrea Mori but can't say for sure yet how it has affected the sound until I set up a listening comparison with Rowli and his unmodified UPL/DA96 combination. 

 

[realDHT]

8 minutes ago, tapatrick said:

Nice, did you replace both the 22 and 24Mhz clocks?

 

Yep. Also plan to replace the third one, 24.0 USB/XMOS clock as well, but that one i'm sceptic if it will make any difference.

 

  

[realDHT]

This summer @rowli came for a visit to my town, bringing with him the new powerdac-r as well as his UPL / DA96 combo 😊. So this means that we finally had the opportunity to do a listening comparison between the final clock-upgraded version of my modified ECD U192 / DA96 combo and rowli’s  stock UPL / DA96 combo. And, even more interesting to me, my first listening and comparison with the powerdac-r.

 

The mods I made on my fractal setup some year ago was to move the circuit boards into a good metal casing, integrating  a shunt attenuator and upgrading the power supplies, as well as to add some new separate regulators for subcircuits. The purpose was to have a convenient one-box solution that improved the looks, shielding, and hopefully the sound of the original.  

 

Early this summer I extended this mod by exchanging the 2 audio oscillators with very low phase-noise Driscoll oscillators designed by Andrea Mori.    

 

Before comparisons we level-matched the 2 dacs tightly with a 1 kHz sine signal and accurate voltmeter.

To summarize, my heavily modded U192 combo sounded very similar to rowli’s stock UPL combo. Even with sighted listening, we both had trouble hearing clear differences and picking a preference in loudspeaker or headphone listening. When we moved on to blind testing none of us could reliably tell them apart during the time we had available.

 

Not sure what takehome message to make out of this, other than that it takes a lot of effort (if even possible) to beat the UPL, using an USB source. For my U192 we were using a very good DIY music server that I spent a lot of time and money on developing. If we had been using an average computer I’m guessing that the UPL would have won.   

   

Obviously the most relevant comparison to evaluate the modding would have been against a stock U192/DA96, but none of us own one. 😳

[realDHT]

6 minutes ago, hopkins said:

 

Congrats on your work!

Too bad indeed that you did not have a stock U192. It would have been interesting then to compare the two with both DACs... 

What did you think of the powerDAC-R? Remind me: are you using active speakers with DSP? 

Tnx ! Yes indeed that would have been the relevant comparison. 

The speakers use ASP, so all filtering/bass-compensation etc. is in the analog domain using OPA1656 op-amps

 

I will write about my impressions of the powerdac -r :) 

[realDHT]

BTW the ASP is located in the upper box above the DAC in the picture, so I made a very similar enclosure for that one. 

[realDHT]

Next up was the listening to the powerdac-r, that I had very much been looking forward to!

This time it did not take a long time until I could hear a difference.

After maybe only half an hour I knew I would have to order one to replace my modded U192/DA96 😊

 

I agree with what has been said here before, you can clearly hear that it is a sibling to the former fractal dac, it has very similar qualities IMO, and on some records/tracks, it sounds very similar. Yet, at some recordings, it is like the powerdac brings out another layer in the music 😮 and makes it easier to perceive and follow some rhythmic/melodic content in the music that were not as obvious before (I noticed this for example with Eva Cassidy, Wayfaring stranger from ‘Songbird’ album .

Another clear example was in Bach - Concerto for Oboe & Violin in C Minor BWV 1060 (English concert /Trevor Pinnock) in how real the solo oboe sounded, and how the ‘color’ of the oboe very clearly contrasts to the strings. Big difference. And then I really find the former fractal dac amazingly good.     

 

So the last iteration of clockmodding on the fractal dac was only used for some week until I heard and then ordered the powerdac-r and had to tear everything apart again 😂. But a good thing is that the PD-r boards (2) takes less space than the U192+fractal boards (3), so that I can re-use the enclosure and most of the other components for some powerdac modding 😀

[realDHT]

6 minutes ago, hopkins said:

 

I'm assuming you read John's explanations which I quoted above. The design of the powerDAC seems pretty "air tight" with little opportunity for modding/improvement. Do you have any ideas? 

Yep, the mod is for looks and convenience, as I want/need a shunt attenuator in my system. The built in volume of the PD doesn't go well with my ASP/speakers (when changing volume its sends out a DC pulse that is amplified by the ASP and makes things somewhat scary (moves my bass cones several centimeters). I hope to reach a sound improvement too, but I consider that a bonus and not something I count on. In fact I already did the mods 😀, I will post about them here. 

[realDHT]

2 minutes ago, numlog said:

Better clocks? The driscoll clocks from Andrea Mori are without a doubt better than any off the shelf clocks.

Stay tuned 😁

[realDHT]

1 minute ago, hopkins said:

 

I noticed exactly the same thing with my speakers one day I took the grills off (after posting my initial review). I asked John and there is nothing to worry about, but I understand it could make you nervous :) 

Yep but in my system the bass cones moves much longer than a normal speaker because of the ASP/dipole compensation in the bass..

[realDHT]

2 minutes ago, numlog said:

if its enough to move a woofer a few cm, what do you think it will do to a headphone driver?

It think it will probably be no danger except perhaps for a system like mine with large active bass dipole-compensation.

[realDHT]

9 hours ago, yogibear said:

 Same here with my high dB FRs. Plan to add woofers which will be 103 dB, so will be very scary. But am not so sure / confident to mod PD.

I only think it is a real problem in very unusual DSP/ASP compensated setups like mine, but can be somewhat scary/annoying I agree

 

 Although I do not think John would recommend DSP volume, I have not really noticed any SQ degradation using 64 bit volume control in JRiver/HQplayer etc, so in my opinion, PD set for full volume and using 64 bit software volume is a viable alternative too.

 

BTW I also like the combination of good tube amps and high sensitivity FR drivers, I can imagine those go well with the ECD dacs :)