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USB to SPDIF converters shoot-out : EMU 0404 USB vs. Musiland Monitor 01 USD vs. Teralink-x vs. M2Tech hiFace - Page 103  

post #1531 of 1712
Quote:
Originally Posted by joseph k View Post

Hm, ok.

I had brought up this idea on the 6/5/2010 at diyhifi.

Then, on the 6/7/2010 appeared this post here, in this thread:

http://www.head-fi.org/forum/thread/449885/usb-to-spdif-converters-shoot-out-emu-0404-usb-vs-musiland-monitor-01-usd-vs-teralink-x-vs-m2tech-hiface/1455#post_6693884

 

that is, post #1461 of this thread.

And so on to post #1470, again in this thread, and then post #1476...

 

And since then, up to now, never any mention of diyhifi, anywhere..


I didn't give any information about what it was or where it came from for the reasons I already stated - I'm not going to say that again! Since you guys have come on the thread it has hardly advanced the knowledge much now has it? So maybe if you give some real info & stop being self-appointed, hard-done by, victims then you could really contribute!

 

Is your participation in this thread to help out & answer questions & convey some real info or are both of you just here for another reason?


Edited by jkeny - 6/17/10 at 4:14pm
post #1532 of 1712

BTW, Joseph K,  if you cared to read the post that you linked to you would see that I said then exactly what I'm saying now

 

 

Quote:
I will be getting a range of "special" BNC adaptors to test shortly which should improve the sonics of the Hiface yet again BUT there is a limited supply so don't ask me for one. These adaptors use a trick which will work perfectly with the Hiface & will solve a number of problems about cables making it possible to have less regard for the cable length or quality even allowing BNC to RCA without penalty. I will post on my website when I have tested & settled on the correct one in the range.

I have underlined the words that you seem to have missed!


Edited by jkeny - 6/17/10 at 4:21pm
post #1533 of 1712

Quote: "Since you guys have come on the thread it has hardly advanced the knowledge much now has it?"

 

John, up to today fellow Headfiers did not know anything about the nature of "your" misterious new activities. Now they know that these are attenuators, to be put into the SPDIF line, preferably at the receiver end, that is at the Dac.

They know where to go to get them. They know why it can be a good thing.

 

Would you not call it some "advance" in the knowledge?

post #1534 of 1712
Quote:
Originally Posted by joseph k View Post

Quote: "Since you guys have come on the thread it has hardly advanced the knowledge much now has it?"

 

John, up to today fellow Headfiers did not know anything about the nature of "your" misterious new activities. Now they know that these are attenuators, to be put into the SPDIF line, preferably at the receiver end, that is at the Dac.

They know where to go to get them. They know why it can be a good thing.

 

Would you not call it some "advance" in the knowledge?

Yes I posted the link to the cheapest ones available after having done my research, did you? 

 

They don't know which one to buy or are you going to answer this & give them some advice?

Or do you suggest, like Jocko does, to buy a range of them & test for themselves?

This was all going to be released when I had done my tests so tell me what the point is in knowing this now?
 


Edited by jkeny - 6/17/10 at 4:27pm
post #1535 of 1712

post #1536 of 1712

post #1537 of 1712

I have told it already: the 10dB 75ohm attenuators are to be tested first. Get it from minicircuits. Then anyway, given that the right value might depend on the input stage of each individual dac, I don't think that you can do these tests for everybody in general.

 

Ciao, George

post #1538 of 1712

@joseph k

 

What would be the best attenuator for the Audio-GD Reference One DAC? This is a high end DAC that is very popular on the head-fi forums. Many own this DAC and the hiFace.

If you do not know which attenuator is best maybe I can send an email to Kingwa (Owner of Audio-GD and designer of the DAC). Which question should I ask him? 

 

Here are the specifications of the DAC: http://www.audio-gd.com/Pro/dac/RE1/RE1EN.htm


Edited by punk_guy182 - 6/17/10 at 4:39pm
post #1539 of 1712
Quote:
Originally Posted by joseph k View Post

I have told it already: the 10dB 75ohm attenuators are to be tested first. Get it from minicircuits. Then anyway, given that the right value might depend on the input stage of each individual dac, I don't think that you can do these tests for everybody in general.

 

Ciao, George


OK, what are the parameters of the DAC input stage that determine the best attenuation range?

post #1540 of 1712
Quote:
Originally Posted by joseph k View Post

I have told it already: the 10dB 75ohm attenuators are to be tested first. Get it from minicircuits. Then anyway, given that the right value might depend on the input stage of each individual dac, I don't think that you can do these tests for everybody in general.

 

Ciao, George


These are quite pricey: http://search.pasternack.com/q-T-Pad-Attenuator/a-10-dB-3722/v-grid/search.htm


Edited by punk_guy182 - 6/17/10 at 4:59pm
post #1541 of 1712

I posted the minicircuits link already - http://www.minicircuits.com/products/attenuators_coax_fixed.html

These are only $12 each

 

 

The 75ohm attenuators at the bottom is what you want - there are 5 in the range 3, 6, 10 ,15, 20dB. I bought some which I had delivered to somebody in the US to test - the 10,15 & 20dB ones - he said he preferred the 10. Although he thought the improvement was marginal with all of them.

 

This didn't tally with my experiments using "Huber & Suhner" 6dB ones (€40 each) - I found the sound noticeably improved, knocking down any edginess on the sound. So he's sending me these minicircuit ones & I'm going to test them.


Edited by jkeny - 6/17/10 at 5:05pm
post #1542 of 1712

Ok, look. The SPDIF standard prescribes the 500mVpp level. Any well made dac should be OK with this level. On the other hand, the crystal receivers for example,

are a bit happier with high input levels, like the 2500mVpp, what the Hiface puts out.

Applying the attenuator brings this back to the level of the generally excepted standard. The 10dB attenuation brings it down to ~700mVpp.

I would expect an AudioGd dac to be happy with such a level. A test / a sign could be the Musiland converter, which on the contrary, gives less than standard levels.

If in Your setup a musiland was sounding smoother than the Hiface, it  would mean for me that the dac is able to process lower level spdif signals well, and I would expect some good result from inserting a 10dB attenuator after a Hiface.

 

But I would like to emphasize: the better result does not come from the attenuation itself, that's a byproduct, the main / good effect is the better impedance control in the SPDIF line!

 

Ciao, George

post #1543 of 1712

Punkguy!

 

That Pasternack attenuator looks to be a nice one!

 

PE7009-10

post #1544 of 1712

That's good info, Joseph K, thanks - I knew the crystal receivers liked a higher signal level. but I guess this can be weighed against the lower reflections on the line. Depending on how high the SPDIF signal is to start with, we can lower this level (& the reflections) while still staying somewhat above 0.5VPP SPDIF spec - it's perhaps a balance of what you gain by lowering the reflection energy against what you lose in an overall signal level

 

The better impedance control on the line results in lowered reflections & hence probably lower jitter BUT is it not true that the attenuation also knocks down both the signal & the reflections & each round trip of the reflection is attenuated further. Is this not the same effect as a well terminated cable where less signal is reflected to start with & each round trip it is attenuated even more? A visual of reflectionshttp://en.wikipedia.org/wiki/Reflection_coefficient

 

Is this not giving the same effect as Jocko's claims for his high return loss, well terminated systems ie. less reflection energy? http://www.analogresearch-technology.net/ubyte.html


Edited by jkeny - 6/17/10 at 5:44pm
post #1545 of 1712

Seeing as the dust has now settled - (hope you guys enjoyed the travelling circus which will be coming to your town soon ) - I may as well tell the next bit I was thinking of doing.

 

This is what I was going to experiment with but I'll state it now & no it doesn't relate to anything that anybody else said on any other thread (& if anybody uses this idea I expect to get full accreditation ).

 

It is possible to raise the existing high SPDIF output of the Hiface even further! Why? Well if we are starting with a higher level, can we use a higher attenuator to bring the signal down to SPDIF level & thus knock down the reflections even further with this higher attenuation?

 

This was something that I intended. to play with along with the attenuator tests,


Edited by jkeny - 6/17/10 at 6:05pm
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Head-Fi.org › Forums › Equipment Forums › Dedicated Source Components › USB to SPDIF converters shoot-out : EMU 0404 USB vs. Musiland Monitor 01 USD vs. Teralink-x vs. M2Tech hiFace