HydrogenAudio

Hydrogenaudio Forum => General Audio => Topic started by: sawdin on 2012-12-23 13:58:29

Title: Okay to use Y-Cable?
Post by: sawdin on 2012-12-23 13:58:29
I am purchasing an iFi iDAC (http://www.ifi-audio.com/en/iDAC.html), which has one set of RCA outs.  However, sometimes I will go from the iDAC to a headphone amp and other times I will go from the iDAC to an AVR.  I have two choices:

1.  Use two pairs of RCA cables:
A.  Have one end of a pair of RCA cables hooked up to my AVR and leave them connected, and have the other end near the iDAC.  When I want to go from DAC to AVR, I plug in the RCA cables that are already connected to the AVR.
B.  Have one end of another pair of RCA cables hooked up to the inputs of the Headphone Amp and leave them connected, and have the other end near the iDAC.  When I want to go from DAC to Headphone Amp, I plug in the RCA cables that are already connected to the Headphone Amp.
Question:
Is it okay to leave one end of the pair of RCA cables from the AVR unconnected while I am playing CD’s on my DVD player that is connected to the AVR?  Will this somehow cause noise and/or other type of interference or problems?

OR

2.  Use a pair of Y-Cables:
Connect a pair of “RCA Male to Two RCA Female Audio Y-Cables” to the iDAC RCA outs and run one set of RCA cables to my AVR and another set to my Headphone Amp.  Benefit is that I will not be plugging and unplugging cables all the time, which might loosen the connectors or the outs on the iDAC.
Question: 
Will I degrade the sound by using a Y –Audio cable, or degrade the sound enough so that I could hear the difference?  I would use a decent quality Y Cable (Cable 2 Go 6in SonicWave (http://www.cablestogo.com/product/29737)).

Any suggestions on which option is better, or suggestions for other options, will be greatly appreciated. 

TIA!
Title: Okay to use Y-Cable?
Post by: pdq on 2012-12-23 14:53:36
The rule is very simple: connecting two inputs from the same output is OK; connecting two outputs to the same input is not. In your case, the Y connectors should be no problem.
Title: Okay to use Y-Cable?
Post by: sawdin on 2012-12-23 14:53:42
Would a switch box (http://www.cablestogo.com/product/28750) be better than using a Y-Cable?
Title: Okay to use Y-Cable?
Post by: Glenn Gundlach on 2012-12-23 17:48:13
The rule is very simple: connecting two inputs from the same output is OK; connecting two outputs to the same input is not. In your case, the Y connectors should be no problem.


I ran into an exception to the rule. I have 2 Technics receivers (1 for headphones and one for speakers) connected to the PC analog output and was getting some strange soft clip distortion. The input selector 'switch' in each Technics is actually a JFET IC. When the power is off on either receiver the PC 'powers up' the IC through the protection diodes in the JFET IC. Since I didn't want manual switches the solution was an analog Distribution Amplifier (DA) where each receiver and the cheesy monitor speakers gets a private clean feed independent of the others.

Title: Okay to use Y-Cable?
Post by: sawdin on 2012-12-23 19:14:37
The rule is very simple: connecting two inputs from the same output is OK; connecting two outputs to the same input is not. In your case, the Y connectors should be no problem.


I ran into an exception to the rule. I have 2 Technics receivers (1 for headphones and one for speakers) connected to the PC analog output and was getting some strange soft clip distortion. The input selector 'switch' in each Technics is actually a JFET IC. When the power is off on either receiver the PC 'powers up' the IC through the protection diodes in the JFET IC. Since I didn't want manual switches the solution was an analog Distribution Amplifier (DA) where each receiver and the cheesy monitor speakers gets a private clean feed independent of the others.




Why did you not want to use a manual switch or  Y-cables, or were you using one of those and had the clipping problem? 
Thanks.
Title: Okay to use Y-Cable?
Post by: Glenn Gundlach on 2012-12-23 23:05:32
The rule is very simple: connecting two inputs from the same output is OK; connecting two outputs to the same input is not. In your case, the Y connectors should be no problem.


I ran into an exception to the rule. I have 2 Technics receivers (1 for headphones and one for speakers) connected to the PC analog output and was getting some strange soft clip distortion. The input selector 'switch' in each Technics is actually a JFET IC. When the power is off on either receiver the PC 'powers up' the IC through the protection diodes in the JFET IC. Since I didn't want manual switches the solution was an analog Distribution Amplifier (DA) where each receiver and the cheesy monitor speakers gets a private clean feed independent of the others.




Why did you not want to use a manual switch or  Y-cables, or were you using one of those and had the clipping problem? 
Thanks.


I didn't want a switch because it would bug the wife and kids. I told you the problem with the 'Y' cords. The DA makes everyone happy.

Title: Okay to use Y-Cable?
Post by: Woodinville on 2012-12-26 06:18:04
I've also experienced a couple of amps that shorted idle inputs. This would be inconvenient, but you would notice quickly.
Title: Okay to use Y-Cable?
Post by: Speedskater on 2012-12-26 15:34:53
I recall that twenty or thirty years ago, a lot of analog tape recorders would in effect put a diode across the record input when the recorders power was off.  So pre-amps had to add a buffer stage to the tape out circuit.