ginetto61

Hi ! the result is splendid and i congratulate you for the great implementation. Clearly that will preserve the normal functionality of the unit. But for me is too complex. I agree that for some an external ac adapter could be very disturbing but i have many and some of very good quality, both smps and linear, that i have bought to be used with other equipment like dacs and headphone amps. But i admit your work is splendid. Regards, gino

Hi, when the box is small actually an external smps is the common solution because of the mains transformer size, weight and radiations. However I am not completely set on the external solution. I am thinking to keep only the transformer out and place inside the rectification and stabilization stage. Or use a double stabilization stage, one outside and one inside the cabinet. Not that is really needed all this complication. Regards, gino

Hi and thanks a lot for the helpful advice. Other interfaces use a very simple solution, an external smps power brick of decent quality. In this way the psu is more isolated from the circuits, a nice thing in general. No RFI or EMI from the psu contaminating the signal. And it shows in the noise floor spectrum quite nicely. Love that test. Regards, gino

Hi ! thanks a lot for the very valuable advice. When you say much quieter does this mean that this shows in a noise spectrum test ? Because I saw the noise only with tests. The unit is quite silent by ear. But clearly a very low and flat noise floor throughout the band is much nicer than a noise floor with bumps, even if low in level. Also this is very interesting and a really strange mistake by Teac. I see that even in cheap cd player they use copper screws. I will try to find some fit for the use. Thanks again indeed. I see on the psu pcb some parts missing and replaced with jumpers. It is strange. With a electrical schematic maybe some kind of troubleshooting could be possible. Ok to the expert eye also without scheme. What really amazes me is that replacing the stock even with a very cheap Dell smps 12V the noise floor looks much nicer. For me extremely low noise floor is the 1st thing. The 2nd one extremely low distortion. The 3rd one extremely low price ... (joke). For instance I am amazed when I look at the creations from ExaSound. That is a noise floor Thanks a lot again. I will try the mods you suggest. Have a nice day, gino

Hi ! thanks for the very interesting thread. Also for me an analog sounding digital is the goal. Analog can be very very good or just good but it sounds always musical. I read something about digital filters and I think their implementation is key for a natural/analog sound. If I understand well upsampling everything to dsd makes possible for the use of better sounding passive filters. If filters are really the key point that would be a very elegant solution. Thanks again, gino

Hi ! thanks a lot again for the very helpful advice. I have still to try the original psu in the out of the box mode. I am on holiday now but i will try to do it as soon as i will get back home. However i can already confirm that almost any other 12V psu i tried did not show this kind of noise. This applies to both smps and linear ones. Even some 10 USD model !!! The result noise floor has been always very low in level. Now i can also carry out some thd+noise tests with a loop-back arrangement. I will post the result with the original psu connected outside the box ... a little dangerous but worthwhile i guess. As i said before i see some parts missing and replaced by jumpers. Capacitors mainly. Thanks again, gino

Hi ! thanks a lot for the very helpful reply. I was worried because I have only sigma-delta dacs ... By the way I see a return of multibit dacs. Maybe there are just good and bad examples of both types. Thanks again, gino

Hi ! sorry to resurrect and old thread but I have seen it only now. I find the quoted statements extremely interesting and even shocking if I think that many high end converters have delta-sigma dacs inside. I wonder if there is an agreement about this. Thanks a lot, gino

Hi and thanks a lot again for the helpful advice. I think I am little biased against listening tests because I had my earing system checked and I was not able to listen above 14kHz. An instrument can listen way above that limit. Honestly I like when listening tests are backed with subjective measurements. And this is indeed what I am looking for. I am 120% confident that in Exasound they have tested many and many different psu with their dacs. If I were a Exasound dac owner I would be extremely interested to know their position on the issue. Nevertheless before asking in this thread I had already placed an order for what I think is a decent linear psu and it is arrived yesterday. This one here ... 2016 Super PSU 30VA DC12V 2A Linear Power Supply LPS for Audio Sources L1511 25 | eBay it should be a step up from the stock and cheap smps. And I like the sound for now. I will be doing some THD+Noise spectra as soon as I will receive the needed cables. As I said subjective evidences are for me extremely important. To explain I am looking for something like this article here ... http://www.cliftonlaboratories.com/power_supply_noise.htm and graphs like this one here http://www.cliftonlaboratories.com/userimages/Wall%20wart%20overlay%20ver%202.gif I searched for noise spectra of the unit you mention but I did not find anything. Thanks a lot again, gino

Hi ! thanks a lot for the very helpful reply. I used to think the same but now, as I said above, I am not so sure anymore. I have at hand a decent linear psu bought from ebay. And also many 12VDC switching mode power supplies also decent (the so called "genuine", branded Lenovo, Dell, Murata and so on). Looking at the usb soundcard noise floor with Arta software they look almost exactly the same. The soundcard has on-board dc/dc converters like in the case of the Exasound I guess. I am hearing in my low rez system, based on headphones, almost an identical sound. The fact that a brand like Exasound provide a smps for their dacs has made me think. I looked all around to find the opinion of the Exasound designer. When I see an exceptional product for me its designer becomes immediately a prophet whose words I trust completely, 120%. Just look at this graph ... It must be a record .. never seen something this low. Amazing ! So I would be extremely interest to know: 1) has this graph been obtained with the stock smps ? 2) a better (i.e. lower ripple) psu could really be beneficial ? (by the way ... I cannot imagine how it could. This noise floor looks like the noise floor of the spectrum analyzer itself... again amazing achievement indeed). If a linear power supply could give a real benefit I think the designer of the dac would be the 1st to recommend a specific model. As I said I get almost exactly the same noise floor even with 10USD smps. However I do not know anything about the distortion. Maybe that is the problem ? maybe a much better linear psu will give less distortion ? Am I looking at just one side of the story ? Thanks a lot again, gino

Hi ! thank you very much indeed. Really impressive performance. I like when ears and instruments both give an extremely positive verdict. Kind regards, gino

Hi ! very beautiful units indeed. I wonder if any measurement about residual ripple are available, in particular for the 12V models (low power). Thanks and regards gino

Hi and thanks a lot for the kind reply. I am still in an info gathering phase. I have a huge respect for the Exasound brand and designers of course. I have been astonished in particular by this graph here ... I have a personal obsession for low noise and low distortion. I wonder with which power supply has been obtained. It is not clear on the site. Maybe they have used an high end lab grade power supply I do not know. However i understand that they deliver their products with good quality smps. I have searched but not found their opinion about swapping power supply being beneficial or not. That suggests me that often the limiting factor is not the power supply but the dac/interface itself. As an example I have here a usb soundcard that exhibits a noise peak at about 35 kHz no matter which power supply I use, from a 10 USD smps to a clearly better linear power supply. Anyway thank you very much for your advice and offer. Kind regards, gino

Hi ! actually it would be very interesting to get the ExaSound designer opinion on this power supply replacement. Maybe he has already done this and I have missed it. It is a very important point. Regards, gino

Hi ! may I ask you from where did you purchase it ? could you describe the improvements after changing the power supply ? I have a similar issue here. My unit is delivered with a cheap AC adapter. Thanks and regards, gino