Tweakers' Asylum

Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ.

Return to Tweakers' Asylum

Message Sort: Post Order or Asylum Reverse Threaded

Digital output tweek

207.241.64.66
Posted on March 17, 1999 at 14:58:38
T. Buns


 
I read the following here; http://www.audiotweaks.elosoft.com/(last tweek listed in the last section). This guy suggest getting a spare RCA jack and shorting it with a 75 ohm resistor and plugging it into the unused digital out of CD players. Has anybody heard of this? Peace, Tim

 

Hide full thread outline!
    ...
This Should Work Fine., posted on March 17, 1999 at 17:06:29
Chris Fagas


 
He's just terminating the unused ports in their characteristic impedance, which is fine as it is a standard for commercial systems. It should improve the balance of the splitter preceding the output connectors, as well as reducing the liklihood of RFI egress through the unused open connectors.

An easier and more consistent way to do this is to simply buy some 75 ohm F connector terminators from any Radio Shack, along with some F to RCA adapters.

Kind Regards, Chris

 

Re: Digital output tweek, posted on March 17, 1999 at 17:36:10
Adam O


 
I've read that Sound Valves provides shorted output plugs for the unused outputs on its 101i preamp, but I haven't verified that. You might want to check with John Peterson of Sound Valves (I think the number is still 1-614-279-2383).

 

Yes, it works. (nt), posted on March 18, 1999 at 18:51:49
Jon Risch


 
.

 

it just help the splitter / improve something else 2? (NT), posted on March 21, 1999 at 05:36:31
Mart


 


 

Re: it just help the splitter / improve something else 2?, posted on March 21, 1999 at 08:40:11
Jon Risch


 
By loading the digital output, the output circuit is not radiating extra EMI/RFI into any of the other digital circuits. If you have followed my posts on jitter, LIM and the like, you would then realize that this is just another source of potential jitter, adding to the timing error within the digital signal chain.

By terminating either a transformer based output, or an electronic one, the output signal is now in a more controlled and intended state. Reflections from the unterminated line are no longer occuring, the unterminated signal is no longer twice the amplitude it was, and any funky backload effects from either a transformer OR a digital chip are now reduced. Logic chips do not like having signals sent into their outputs at all, and many will react with degraded performance.

Jon Risch

 

Hi Jon, as far as analog out...., posted on March 25, 1999 at 07:39:53
mike b


 
Jon,

If I read your reply correctly, you are suggesting it would be good practice to terminate unused analog outputs as well? That is, I have both
variable and fixed analog outputs on my CD player. If so, what is the appropriate load for the analog termination? I would imagine it is not all that critical what value one uses.

Thanks,
Mike

 

I believe that's what buffer circuits are for, posted on March 25, 1999 at 08:25:08
Mart


 
which should be on inputs as well. It's only passive splitters where there could be a problem.

 

interesting .., posted on March 25, 1999 at 08:53:39
James


 
My Pink Triangle CD player came with a terminator for the digital out - I wondered what it was for. But I normally have it permanently wired to an MD player which is usually switched off - should I reconnect the terminator each time after recording?

James

 

Re: Hi Jon, as far as analog out...., posted on March 26, 1999 at 20:46:01
Jon Risch


 
My above comnment was aimed at digital outs, whether transformer coupled or electronic drive.

Now that you mention it, it may be that this would od some good, the values to try would be much higher, say 100K ohms, just enough to load the open circuit, without drawing too much current to koad the rest of the system.

Only way to find out is to try it!

Jon Risch

 

Page processed in 0.565 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]