1. Things you need to know about the new ‘Conversations’ PM system:

    a) DO NOT REPLY TO THE NOTIFICATION EMAIL! I get them, not the intended recipient. I get a lot of them and I do not want them! It is just a notification, log into the site and reply from there.

    b) To delete old conversations use the ‘Leave conversation’ option. This is just delete by another name.
    Dismiss Notice

Tour of Supercapacitor powered Ciunas devices

Discussion in 'audio' started by Ciunas Audio, Jan 17, 2019.

  1. deebster

    deebster Half Man Half Biscuit

    Here’s my experience of the ISO-SPDIF

    System is Mac mini with Audirvana Free > Optical to Rega DAC > Recently serviced Audiolab 8000a > Epos ES11s, listening near-field (about a 5ft equilateral triangle). The ISO-SPDIF slotted between the Mac and DAC and I used the video part of an old AV cable I had kicking around to link them.

    I’d expected the optical out I was using to the DAC would have been possible to improve upon – hence trying this unit out – but have no experience of any other output converters to compare with.

    As with previous posts, describing sounds isn’t terribly easy for me to do and I’ll try to avoid clichés and wild statements but inevitably some of that will creep in. So here goes.

    Concentrating on a favourite, well-produced album, namely Paul Simon’s Hearts & Bones (original rather than remaster, so to be able to compare a bit more easily with the vinyl) the ISO-SPDIF gave a wider and deeper soundstage, with more space/air between the instruments and voices. Particularly Simon’s voice had a nicer echo / reverb around it so I could more easily get a feel for the effect of him being in the studio surrounded by instruments.

    Background vocals and those little studio touches gained more clarity and feel, but were no brighter than before. It felt as though the music had been expanded, in the sense of the whole soundstage spreading out and becoming even more of a wall of sound than I already had (yay for nearfield).

    Perhaps the easiest way for me to express this is that for the first time digital gave me that tingle that listening to really good vinyl does (I use a WTL Amadeus and DV20X2L). No feeling of harshness and it was easy to just play track after track without becoming tired of the presentation. Lest this comes across the hyperbole of saying ‘it was night and day’, it was more of a subtle change than that, but significant nonetheless. As the great Mr Duffy once said, it was the icing on the cake.

    I found the best sound came with the grounding switch down. I’ve had occasional hum issues but our house electrics are a bit iffy sometimes and I don’t know enough about the subject to comment further. Not had chance to try the white USB cable but will try to before I pass the unit on (who’s next by the way?).

    Thanks for letting me try it out. I could happily live with this ISO-SPDIF.

    Can I keep it?
  2. Heckyman

    Heckyman pfm Member

    Nice one!

    I should be somewhere on the list...curious to see how the ISO-SPDIF compares to my SUPER-PS powered Allo DigiOne Sig streamer.
  3. Ciunas Audio

    Ciunas Audio Trade: Ciunas Audio

    Thanks, deebster, appreciate posting your impressions. I particularly liked this bit "it was more of a subtle change than that, but significant nonetheless." I completely agree with this even though it seems contradictory.
    My theory on this seemingly contradictory perception is because what my devices seem to do is improve something in the reproduced soundfield which clicks with our auditory perception. I know this sounds very wishy-washy a statement but I don't know what particular aspect in the soundfield is changed that better matches what our auditory perception expects?

    All my efforts in my device development has been towards reducing dynamic noise i.e electrical noise that mainly arises when the device is handling/processing signals. My efforts started with battery power & lately with supercapacitor power. This is direct power to sensitive components, not power that is delivered through voltage regulators. This approach seems to result in an electrical noise stability which most voltage regulators don't. Once this type of stable, clean power is used on an audio device, other improvements can then be optimally realised. The USB isolation & reclocking along with the I2S synchronous reclocking add the additional improvements in dynamic noise reduction.

    The result of all of these techniques is heard in the resultant sound which, IMO, just has a perceived correctness across the board. So this is "subtle" in that it can't be identified to a specific change in frequency or timing but rather in the accumulated effect on the soundfield which is "significant" in it's effect on our perception.

    All the above relates to my ISO-DAC device as I have direct control over the digital to analogue conversion from the USB digital input signals through to the analogue signal outputs. When it comes to ISO-SPDIF device which converts USB digital input signals to SPDIF digital output signals. The clean, stable power plus USB isolation & reclocking plus I2S reclocking still applies in this ISO-SPDIF device but the SPDIF digital signals are then being transmitted to a DAC which I have no control over - all I can do is present it with the cleanest SPDIF digital signal I can design. How the receiving device handles it determines the final analogue output.

    For instance, I've found that ASRC (asynch, sample rate converters) often used in these SPDIF receivers to reduce jitter, can mask the benefits of an improved SPDIF signal - asrc can improve bad, jittery SPDIF signals but doesn't allow the benefits of a better signal to be realised.

    OK, it's a bit of a chore to keep the list up-to-date & in order - can I ask people to self-administer this list please?
    I just need to validate anybody wishing to be added to the list & also to keep control of the adresses & who has the device

    supercap ISO-SPDIF tour list from above in thread
    Steve Taylor

    Heckyman should be on this list from his post above - are there any others I'm missing?

    Deebster, can you send it to Heckyman - I will PM you his address
  4. Heckyman

    Heckyman pfm Member

    Yep, cool thanks!
  5. deebster

    deebster Half Man Half Biscuit

    Got it and will try to post tomorrow
  6. deebster

    deebster Half Man Half Biscuit

    On its way to you now @Heckyman

    1st class so might be tomorrow
    Heckyman likes this.
  7. Heckyman

    Heckyman pfm Member

    Got it thanks!
    First impressions good, will post a write up in a day or two.
    Who’s next?
  8. Bourneendboy

    Bourneendboy pfm Member

    That's a bit of a 'below the belt' posting Julf.
    Last edited: Nov 1, 2019
    eastone likes this.
  9. Julf

    Julf Facts are our friends

    Objective measurements are below the belt? OK, removed.
    Bourneendboy likes this.
  10. Ciunas Audio

    Ciunas Audio Trade: Ciunas Audio

    Thanks, Heckyman
    I'm not sure that there's anyone else interested to post to so hold onto it & compare to Allo USBridge
  11. Heckyman

    Heckyman pfm Member

    Thanks John, will do!
  12. Ciunas Audio

    Ciunas Audio Trade: Ciunas Audio

    Heckyman is finished with ISO-SPDIF - is there anybody else who wants to audition it?
  13. Heckyman

    Heckyman pfm Member

    I compared the ISO-SPDIF with my Art Legato. The Legato is 16/44 only and no longer available but a few years ago it was considered to be about as good as it got.

    I fed the converters both "dirty" and "clean" USB sources (respectively, a MacBook Pro and Allo USBridge). In both cases, the ISO-SPDIF and Legato sounded pretty much equal to each other. Unsurprisingly, the clean USB source sounded a lot better than the dirty one. Neither converter was able to magically transform a dirty signal into a clean one.

    My current "reference" SPDIF source is the Allo USBridge sig with the Digione sig RPi SPDIF hat all powered by the excellent Ciunas SUPER-PS. Going back to this device from the converters, it was an easy win for the streamer. Even family members could easily hear the improvement. That said, it's not a like-for-like comparison as the Allo doesn't accept USB audio input from a computer.

    In conclusion, for anyone who is still sure they want a USB converter as opposed to a streamer, I would recommend the ISO-SPDIF. It performs on a par with the Legato and has the added advantage of hi-res support.

    Thanks to John for the opportunity to test the device.
  14. Ciunas Audio

    Ciunas Audio Trade: Ciunas Audio

    Thanks, Andrew
    The AR-T Legato is a well regarded SPDIF converter designed by Pat diGiacomo aka Jocko Homo who recently spewed some bile about me & my audio devices on another forum. Interesting that the ISO-SPDIF equates with it.

    What DAC was the SPDIF signal being sent to?
    Last edited: Nov 8, 2019
  15. Heckyman

    Heckyman pfm Member

    Sugden AU-51 – it's a great sounding vintage DAC, but one that's highly sensitive to the quality of the SPDIF source.
  16. Ciunas Audio

    Ciunas Audio Trade: Ciunas Audio

    Hi All
    I suspended any touring of devices at the start of 2020 & wonder if it there would be an appetite to start it up again or indeed if it would be socially responsible, given the current circumstances?

    What do people think? Any interest in hearing the supercapacitor ISO-DAC with medical grade SMPS ?
    Last edited: Apr 18, 2020
  17. suzywong

    suzywong Wot, no electrons?

    I would certainly recommend a trial with John’s Supercapacitor PSU
  18. davidjt

    davidjt pfm Member

    I'm curious about the Supercap ISO-DAC and the PSU. Currently using an upgraded Maverick TubeMagic which is impressive in my set-up, better than D10 and MyDAC. My Audiolab MDAC died so comparison with that is no longer possible. I'll pm and/or check the website when back in the UK.
  19. Ciunas Audio

    Ciunas Audio Trade: Ciunas Audio

    I was going to offer the supercap PS on tour when I have an adjustable version (not too far off), Chris but thanks for the recommendation.
    @davidjt, you' probably won't be in the UK for a while but keep an eye on the tour if it resumes

Share This Page


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice