[art]

Tried to talk several manufacturers of "audiophile accessories" into making a kit of attenuators. No, they couldn't wrap their head around that concept. They would rather stick to selling $2 pieces of wire for megabucks. And other silliness, with no basis in anything other than audiophoole think-speak.

(All it would take is the ability to produce them inexpensively, and the only real cost was that of a decent connector. That, and the ability to market and promote them. The last part should tell you why we didn't do it!)

[audioengr]

Tried to talk several manufacturers of "audiophile accessories" into making a kit of attenuators. No, they couldn't wrap their head around that concept. They would rather stick to selling $2 pieces of wire for megabucks. And other silliness, with no basis in anything other than audiophoole think-speak.

(All it would take is the ability to produce them inexpensively, and the only real cost was that of a decent connector. That, and the ability to market and promote them. The last part should tell you why we didn't do it!)

I don't understand why you would want an attenuator on a digital signal.  It would not meet spec anymore and would be more susceptible to noise at the receiver, assuming that it was still matching the impedance.

[art]

You could read that thread. I think it provides the answers.

(One of the advantages of getting old is forgetting that thread ever existed! Yes, now I recall some schmuck, that we lovingly called "wacky tabacky", went out of his way to insult me, saying there is no way I could have ever worked on a microwave receiver. This was after he got his lunch handed to him, by a cohort, on one of the silly DIY forums. WT claimed he  could measure the impedance of any SPDIF circuit, with just a DMM. So, after that debacle, he came over here to attack me. Along with some other guy, who also argued, ad nauseam, over the "long cable theory", with yet another of our cohorts. Who, after spreading lies and disinformation about that, on other manufacturer's forums, went on to start his own audio company, and with his very first product........................

Offered attenuators for sale. Just as I predicted!)

So, might I suggest we take this subject up back at that location, assuming the thread has not been locked down. It got worse after I bowed out, when another chap tried to educate ol' WT. To no avail, I might point out.

If not, let me leave you with this one post I made:

I come here, as a manufacturer, to interact with potential customers. Not educate manufacturer wanna-be kids, or participate in a flame war, with a self-appointed expert. I chose Audio Circle, because it is not like those other forums, some of you like to frequent. Kindly take your personal feud, back to where it came from.

Anything else? If not......................the salt mine awaits.................

Cheers!

[audioengr]

You could read that thread. I think it provides the answers.

(One of the advantages of getting old is forgetting that thread ever existed! Yes, now I recall some schmuck, that we lovingly called "wacky tabacky", went out of his way to insult me, saying there is no way I could have ever worked on a microwave receiver. This was after he got his lunch handed to him, by a cohort, on one of the silly DIY forums. WT claimed he  could measure the impedance of any SPDIF circuit, with just a DMM. So, after that debacle, he came over here to attack me. Along with some other guy, who also argued, ad nauseam, over the "long cable theory", with yet another of our cohorts. Who, after spreading lies and disinformation about that, on other manufacturer's forums, went on to start his own audio company, and with his very first product........................

Offered attenuators for sale. Just as I predicted!)

So, might I suggest we take this subject up back at that location, assuming the thread has not been locked down. It got worse after I bowed out, when another chap tried to educate ol' WT. To no avail, I might point out.

If not, let me leave you with this one post I made:

Anything else? If not......................the salt mine awaits.................

Cheers!

I read it:
https://www.audiocircle.com/index.php?topic=90454.0

Looking at your scope traces, where was the first trace measured on the transmission-line?

This looks like an unterminated line with the scope probe looking at the source.  I see from the "shoulders" that it is not well-matched to the 75 ohm terminator or cable.  The shoulders should be at exactly the same voltage, and one shoulder is higher than the other. Either the source, the cable or the destination is mismatched.

Your attenuator looks like it is trying to match the line to other than 75 ohms.  What is the risetime here BTW?  It's not really .8psec is it?

The better solution is to use a BNC terminated cable and coax cables inside the components.  Then you get a signal like this:



This is a 7GHz B/W sampling scope.  This is what is needed to properly characterize fast digital signals.

However, the source impedance must be 75 ohms. 99% of manufacturers don't have a S/PDIF output matched to 75 ohms. That is the problem that might be helped by your attenuator.  I suspect that the glitch that we see in your waveforms that is reduced by adding series resistance is actually caused by the source mismatch or by a poor cable, not by the RCA connector and internal cabling.

Did you replace the RCA and internal cabling with BNC and coax internal cabling and see the glitch disappear?

If you changed the cable and the glitch disappeared, then you know the cable is not 75 ohms.

If it's the cable, then the obvious thing to do is replace it with a true 75 ohm cable, not add attenuators.  If the cable is on the high-side, you could add series resistance to the source to match it, but now the cable is still not matched with the parallel terminator.  If it's on the low-side, you can add parallel resistors at the destination, but now the cable and the driver output impedance are not matched.  Neither will be very good however because they are not being added right at the source driver or right at the destination parallel terminator.  A kludge at best IMO.  There must be a match at the source, the cable and the destination, all three and preferably at all of the connectors in-between.

BTW, early-on I used Belden 1694A as my impedance reference to "tune" my outputs.  It turns out that it's not very close to 75 ohms.  If you are using sub-nanosecond risetime outputs, there are more accurate cables to use as reference, aerospace-grade.  Even a "broadcast quality" BNC cable from Markertek is closer to 75 ohms IME.

Steve N.

[AmpDesigner333]

So, one is to conclude that all of your products are "well designed" and everything else is crap?

Ok.

It may shock you, but a lot of folks still use megabuck DACs, from years ago. I guess they should all throw them out, right?

I didn’t even mention my own products.  The burden of proof is on the manufacturers of devices meant to fix a problem that doesn’t exist in modern equipment.  I’m not talking about price, either.  If you want to know where I’m coming from, read this:
https://positive-feedback.com/interviews/tommy-obrien-digital-amplifier-co/

[audioengr]

WT claimed he  could measure the impedance of any SPDIF circuit, with just a DMM.

Not possible.

Pat - I'm not sure what you mean by "long cable" theory, but here is my white-paper analysis on minimum lengths for S/PDIF cables:

http://www.positive-feedback.com/Issue14/spdif.htm

Here is one A/B test that was independently performed that confirms it (not a controlled test):

https://www.whatsbestforum.com/threads/is-a-s-pdif-coax-cable-longer-than-1m-better.27733/

[GregC]

I am using a Kitsune KTE SU-1 DDR and I am happy with what it sounds like.  I have only tried the AES/XLR and SPDIF RCA outputs.

[OrangeCrush]

Michael, any updates?

[mresseguie]

Update time:

I have been extra busy in the last month or so - taxes, my 89-yr-old mother was in the hospital, one of my KT88 tubes died, and my DAC's rectifier tube died(!). Taxes are done or extended; Mom is out of the hospital and in Hospice care (do not post condolences in this thread, please!), dead tubes have been replaced.

The Digital Audio Company converter was returned to Tommy last week. Thank you, Tommy, for the opportunity to try it in my system. I still have the Ciunas converter. I received the AR.T Legato a few days ago, but the dead tube and my spending the weekend at Smith Rock State Park in Central Oregon have kept me from inserting it into my system. I will get off my butt tonight and get it up and running.

I subjectively decided I would not try the Schiit Eitr after all.

This afternoon, Steve N (audioengr) graciously allowed me into his home to listen to his system. Wow! Awesome sounding.

More to come before too long I hope...

Michael

[A_shah]

@ Michael
My son likes the KEF LS 50 (wireless ) by the way  how does the USB to SPDIF converter  work  what is the benefit sonically for using it ? I having being looking at the possibility trying to figure out how to use the I2S of the PS audio Directstream with an adapter for OPPO 205 no success yet , just today replaced the fuses in the DAC with the Esoteric Audio-magic Ultimate Bee-wax fuses costly affair , well they did surprise me  with the expanded sound stage when I replaced them in my QS mono amps and then someone suggested I try that in my DAC 

Asghar   

[AmpDesigner333]

Update time:

I have been extra busy in the last month or so - taxes, my 89-yr-old mother was in the hospital, one of my KT88 tubes died, and my DAC's rectifier tube died(!). Taxes are done or extended; Mom is out of the hospital and in Hospice care (do not post condolences in this thread, please!), dead tubes have been replaced.

The Digital Audio Company converter was returned to Tommy last week. Thank you, Tommy, for the opportunity to try it in my system. I still have the Ciunas converter. I received the AR.T Legato a few days ago, but the dead tube and my spending the weekend at Smith Rock State Park in Central Oregon have kept me from inserting it into my system. I will get off my butt tonight and get it up and running.

I subjectively decided I would not try the Schiit Eitr after all.

This afternoon, Steve N (audioengr) graciously allowed me into his home to listen to his system. Wow! Awesome sounding.

More to come before too long I hope...

Michael

Thanks for checking out the Cherry USB, Michael.  Was setup truly plug-and-play?  Please let us know your computer configuration.  Did you try changing the settings in the control panel to enable 96/24 or 192/24 mode?  What playback software did you use?

[audioengr]

@ Michael
My son likes the KEF LS 50 (wireless ) by the way  how does the USB to SPDIF converter  work  what is the benefit sonically for using it ? I having being looking at the possibility trying to figure out how to use the I2S of the PS audio Directstream with an adapter for OPPO 205 no success yet , just today replaced the fuses in the DAC with the Esoteric Audio-magic Ultimate Bee-wax fuses costly affair , well they did surprise me  with the expanded sound stage when I replaced them in my QS mono amps and then someone suggested I try that in my DAC 

Asghar

A USB converter is useful if the DAC does not have USB input or if the USB input on the DAC is substandard and the S/PDIF input on the DAC is not reclocked.  In this case, it will improve performance by reducing jitter, assuming that the jitter from the converter is lower than the on-board USB interface, which is the case with my converters.

If the DAC has a reclocker on the S/PDIF input, then the improvement will be smaller or none at all.

The USB converter has an asynchronous interface for USB which usually outputs I2S and S/PDIF.  My converters have multiple outputs, including I2S on RJ-45, I2S on HDMI, AES/EBU and S/PDIF coax, all active at the same time.

Steve N.

[mresseguie]

@ Michael
My son likes the KEF LS 50 (wireless ) by the way  how does the USB to SPDIF converter  work  what is the benefit sonically for using it ? I having being looking at the possibility trying to figure out how to use the I2S of the PS audio Directstream with an adapter for OPPO 205 no success yet , just today replaced the fuses in the DAC with the Esoteric Audio-magic Ultimate Bee-wax fuses costly affair , well they did surprise me  with the expanded sound stage when I replaced them in my QS mono amps and then someone suggested I try that in my DAC 

Asghar

Ashgar,

Thanks for clarifying. Encourage that young man. 

My DAC only has SPDiF input. In order to connect my DAC to my Mac Mini or iMac, I must use a converter. I'm attempting to find an appropriate and acceptable converter that doesn't cost $1000, $2000, or more $$$$.

Michael

[mresseguie]

Thanks for checking out the Cherry USB, Michael.  Was setup truly plug-and-play?  Please let us know your computer configuration.  Did you try changing the settings in the control panel to enable 96/24 or 192/24 mode?  What playback software did you use?

Tommy,

I imagine you must be pretty busy, and you were very busy before, during and after AXPONA, but you really need to slow down as you read emails from me. You'll pick up more information. My DAC is a NOS DAC. NOS means Non Over-Sampling. My DAC does not play anything beyond 96. It does not play MQA. [I played the Eagles MQA Hotel California last night and it sounded like shit.] My DAC does not do DSD. My DAC's chip is the vintage and venerable TDA1541. It predates all the fancy new fangled up-sampling techniques. I'm quite happy being a dinosaur.

Yes. Your converter was plug and play. My computer is a 2012 Mac Mini with 16Gb RAM, a 2013 iMac, and 2018 MacBook Pro. Since my DAC excels at playing 44.1 (CD quality), I left the settings at 44.1. I'm currently not using any special software, but I plan to try ROON and thanks to my visit with Steve yesterday, I'll look into Linn Kinsky.

I also own an OPPO BDP-103 that I can (and will) connect directly to my DAC to play the 400 or so CDs that I own. I anticipate that the music coming out of the OPPO will sound better than my computers.

[audioengr]

Linn Kinsky is for playing using Ethernet, not USB.

When we got together, everything I played using USB was using Amarra with iTunes picking the tracks. Amarra is what you need, or maybe Audirvana.

Steve N.

[mresseguie]

The Legato is in my system and burning in. Right off the bat, it sounds very nice. I did not play a song on the Ciunas just before I switched to the Legato, so I cannot offer any comparison.

Eliane Elias was kind enough to be the first artist. She sounds wonderful. Somehow, I managed to persuade the Stones to stop by to play Angie. I think this is the first time I played this song on this system. What took them so long? 

 

Gregfisk will arrive mid-afternoon tomorrow. I'm certain he'd like to add a comment....if he is permitted to do so. [Please.]

[art]

[I played the Eagles MQA Hotel California last night and it sounded like shit.]

Well.................all I can say is.....................

[tubesguy2]

The Legato is in my system and burning in. Right off the bat, it sounds very nice. I did not play a song on the Ciunas just before I switched to the Legato, so I cannot offer any comparison.

Eliane Elias was kind enough to be the first artist. She sounds wonderful. Somehow, I managed to persuade the Stones to stop by to play Angie. I think this is the first time I played this song on this system. What took them so long? 

 

Gregfisk will arrive mid-afternoon tomorrow. I'm certain he'd like to add a comment....if he is permitted to do so. [Please.]

Michael - I posted a bit about my impressions of the Legato today in the jitter thread in the Lab circle. I have been very impressed, and have retired my previous Amanero to SPDIF interface. I've described the sound with the Legato in the system as "master tape without the hiss" but I realize that I may have borrowed that characterization from someone else. I won't tell you who I listened to very early on (at the risk of sounding old and sappy) but I will say that she's half of The Carpenters.

[mresseguie]

Michael - I posted a bit about my impressions of the Legato today in the jitter thread in the Lab circle. I have been very impressed, and have retired my previous Amanero to SPDIF interface. I've described the sound with the Legato in the system as "master tape without the hiss" but I realize that I may have borrowed that characterization from someone else. I won't tell you who I listened to very early on (at the risk of sounding old and sappy) but I will say that she's half of The Carpenters.

Hi, tubesguy2!

I've got the Legato in now, but I also still own the Ciunas converter. I have been either too busy lately or too flustered to do any critical listening, so I cannot definitively declare one converter as the winner. I place the Legato in my system and I love the music. I do the same with the Ciunas and it sounds lovely as well. [Remember: I'm not comparing them.] I'm keeping both just in case one someday fails.

My SW1X DAC III STD is an amazing DAC.

Michael