[regal]

Quote:

 
 
You gave up the ideas of changing the output stage?
 

I installed the SC pulse transformer per the AES paper here:
http://www.scientificonversion.com/AES1998.pdf

 

[mmerrill99]

Any change in sound with this xfmr?

 

[regal]

I can't honestly say, I  just changed everything at once.  They have a good reputation if you check out their website.
 
I ordered a 9db minicircuit attenuator to try.

 

[ccschua]

Just wonder if anyone else can confirm if the mod hiface is already HIFI. meaning how does it compare to the highend transport like belt drive, cdm1, cdmpro , etc.

 

[Sebhelyesfarku]

Would it make sense to try BNC attenuator on an RCA hiFace/DAC? (with RCA-BNC converters). It would work the same way, decreasing the output level, no? Impedance, well, be damned!...

 

[regal]

better,  ground breaking,

 
Quote:

Just wonder if anyone else can confirm if the mod hiface is already HIFI. meaning how does it compare to the highend transport like belt drive, cdm1, cdmpro , etc.

 

[ccschua]

After I hook up the blackcat velose, it is more ground breaking.
 
I am not sure if blackcat + attenuators helps again ?

 

[mmerrill99]

Quote:

Would it make sense to try BNC attenuator on an RCA hiFace/DAC? (with RCA-BNC converters). It would work the same way, decreasing the output level, no? Impedance, well, be damned!...

PLEASE, It's NOT about reducing the output level - it's about reducing the reflections. The high output level is probably not a problem for 90% of DACs i.e. it doesn't over-drive them (some of them even prefer high levels). Yes the attenuators reduce the SPDIF output level & as a result doubly reduce reflections. So your conundrum is, will the extra reflections introduced by the RCA-BNC converter be eliminated & more by the attenuators - nobody knows. It's a $30 experiment, why not do it & let us know? You can always sell the attenuators & converter if it fails. 

 

[regal]

I thought it was a $15 experiment, the one I bought was only $15 from minicicuits,   did I get the wrong one?  It was the 9dB version.
Quote:

 It's a $30 experiment, why not do it & let us know? You can always sell the attenuators & converter if it fails. 

 

[punk_guy182]

Quote:

I thought it was a $15 experiment, the one I bought was only $15 from minicicuits,   did I get the wrong one?  It was the 9dB version.

Where did you get this 9dB version?
The only versions I see are: 3-6-10-15-20dB http://www.minicircuits.com/products/attenuators_coax_fixed.html
 

 

[regal]

http://www.minicircuits.com/cgi-bin/modelsearch?model=HAT-9&search_type=model
 
I see its not rated for 75 ohms ,  dammit
 
Quote:

Where did you get this 9dB version?
The only versions I see are: 3-6-10-15-20dB http://www.minicircuits.com/products/attenuators_coax_fixed.html
 

 

[punk_guy182]

You have to pick the ones that are at the bottom of the page.
 

 [size=small]Attenuators, Coaxial (BNC)[/size] •  Precision 75 Ohm •  0.5 Watt •  3 to 20 dB, DC to 2000 MHz

 

[regal]

yea I caught that a day after they shipped the one I ordered wrong,  I guess it would be fine for someone using an RCA Hiface,   PM me if you want it.
Quote:

You have to pick the ones that are at the bottom of the page.
 

 [size=small]Attenuators, Coaxial (BNC)[/size] •  Precision 75 Ohm •  0.5 Watt •  3 to 20 dB, DC to 2000 MHz

 

[mmerrill99]

Quote:

I thought it was a $15 experiment, the one I bought was only $15 from minicicuits,   did I get the wrong one?  It was the 9dB version.

 

Yes, it's only $12 each - I'm suggesting buying two (75 ohm ones

)!

 

[regal]

I tried the 50 ohm version and it really did improve the sound quite a bit.  This doesn;t surprise me as I think that the stock hiface BNC is 50 ohm,  you can tell by the size of the dielectric surounding the TX pin,  the stock hiiface BNC is no where close the dimensions of a true Amphenol 75ohm connector (Amphenol is a trusted brand.)  I suggestion anyone swap the hiface BNC for the Amphenol version, also the pulse transformer for the Scientific Conversion,  and last add the attenuator (75 ohm)  prior to investing in a $500 digital cable.  I'll never spend that much on a cable but it just makes sense to cover the basics first.