RCA Splitters?

[08Boss302]

Wondering what is the general concensus?

I am in the situation where I would like to use a pair so I can use my external DAC to with 2 amplifiers.  Obviously only 1 amp is operational at any time but it means I can use my external DAC for both applications when either is in use -

 

Whilst I am kind of sure there should be no degredation of sound as the signal will only be sent to the active amp, what I dont know is whether or not any signal is lost down the "dead" line to the amp that is not in use.....or in fact if this has any potential issue to the DAC?  Does it still send a signal down the dead line even and does that take power from the "active" line?  None of this might even be a thing that happens but I am not sure.

 

I can use the traditional cable Y splitter or something like this which I like too as its so compact.

 

Does anyone else use a splitter for this type of thing?

 

[joz]

Fine., if your DAC has a voIume control or your going into intergrateds can't see any issues

[08Boss302]

Thank you.

DAC has no volume control but both amplifiers do.

 

I should lose no perfomance from the DAC even with a dead line so to speak also connected?

Edited September 4, 2020 by 08Boss302
added text

[Bisguittin]

It's certainly another piece of metal in the signal path, but I've never noticed any audible difference in any applications I've used them (and I've sure listened!). Amplifier internals often feature similar anyway.

[08Boss302]

Thank you.

I think I might try this. I'll get both types of splitters and see which one suits me best in terms of fit.

...now just have to wait for postage as we are in lockdown but there is no rush..

[Bunno77]

I vaguely remember Zaph saying a long time ago that there were downsides I could be wrong and/or it may have referred to a specific case. Can't find the post now though.

I have some of the solid types that I have used from time to time and all seems fine.

[andyr]

2 hours ago, 08Boss302 said:

 

I am in the situation where I would like to use a pair so I can use my external DAC to with 2 amplifiers.  Obviously only 1 amp is operational at any time but it means I can use my external DAC for both applications when either is in use -

 

... what I dont know is whether or not any signal is lost down the "dead" line to the amp that is not in use.....or in fact if this has any potential issue to the DAC? 

 

 

What you are doing with these splitters is making the DAC 'see' both amplifiers at the same time.  Therefore the input impedance (Zin) that the DAC will be 'seeing' is - if they are identical amps - half the input impedance of one amp.

 

If the amps' Zin is 50K, and the DAC's Zout is 500 ohms, say, then you probably will be fine (500 into 25K is 50x).  But if it's a tube DAC with a Zout of, say, 3K … or the Zin of your amps is only 10K … you will be in trouble.

 

Andy

 

[Wimbo]

52 minutes ago, andyr said:

 

What you are doing with these splitters is making the DAC 'see' both amplifiers at the same time.  Therefore the input impedance (Zin) that the DAC will be 'seeing' is - if they are identical amps - half the input impedance of one amp.

 

If the amps' Zin is 50K, and the DAC's Zout is 500 ohms, say, then you probably will be fine (500 into 25K is 50x).  But if it's a tube DAC with a Zout of, say, 3K … or the Zin of your amps is only 10K … you will be in trouble.

 

Andy

 

Isn't this if you have both amps on at once.

[muon*]

1 hour ago, andyr said:

 

What you are doing with these splitters is making the DAC 'see' both amplifiers at the same time.  Therefore the input impedance (Zin) that the DAC will be 'seeing' is - if they are identical amps - half the input impedance of one amp.

 

If the amps' Zin is 50K, and the DAC's Zout is 500 ohms, say, then you probably will be fine (500 into 25K is 50x).  But if it's a tube DAC with a Zout of, say, 3K … or the Zin of your amps is only 10K … you will be in trouble.

 

Andy

 

I'm trying to picture this in circuit and am a tad confused about what the result would be. As the amp not in use would be like a load to ground off before the input of the active amp....hmm

Personally I wouldn't use a splinter and instead would go for a source selector used in reverse. DAC into the out and amps connected to the multiple source inputs.

Edited September 4, 2020 by muon*
typo

[08Boss302]

1 hour ago, andyr said:

 

What you are doing with these splitters is making the DAC 'see' both amplifiers at the same time.  Therefore the input impedance (Zin) that the DAC will be 'seeing' is - if they are identical amps - half the input impedance of one amp.

 

If the amps' Zin is 50K, and the DAC's Zout is 500 ohms, say, then you probably will be fine (500 into 25K is 50x).  But if it's a tube DAC with a Zout of, say, 3K … or the Zin of your amps is only 10K … you will be in trouble.

 

Andy

 

Thanks Andy,

The DAC is a Denafrips Ares II, not a tube DAC but both amps have tubes.

I will be using the RCA outs on the DAC and specs are as follows taken from the website, not sure if I am providing the right details on this....

 

DAC

Analog Ouput RCA at 2.2Vrms 625Ω / XLR at 4.4Vrms, 1250 Ω

The Integrated Amps input impedences are (assuming I have the right datat from each amp) as taken from the spec from websites:   Amp #1 Input Sensitivity: 300 mV Input Impedance: 47 kOhm   Amp #2 Input sensitivity: 380mv (when Integrated amp input), 820mv (when pure power amp input) - I only will be using as Integrated amp not as power amp. Input impedance: 100KΩ
Hopefully I have the right data listed above.

[andyr]

7 minutes ago, 08Boss302 said:

Thanks Andy,

The DAC is a Denafrips Ares II, not a tube DAC but both amps have tubes.

I will be using the RCA outs on the DAC and specs are as follows taken from the website, not sure if I am providing the right details on this....

 

DAC

Analog Ouput RCA at 2.2Vrms 625Ω / XLR at 4.4Vrms, 1250 Ω

 

OK, so the Zout is 625 ohms.  Not high. 

 

7 minutes ago, 08Boss302 said:

The Integrated Amps input impedances are (assuming I have the right data from each amp) as taken from the spec from websites:   Amp #1 Input Sensitivity: 300 mV Input Impedance: 47 kOhm   Amp #2 Input sensitivity: 380mv (when Integrated amp input), 820mv (when pure power amp input) - I only will be using as Integrated amp not as power amp. Input impedance: 100KΩ

 

They sound right.    In which case … 47K in parallel with 100k = 32K.

 

Which is 51x the DAC's Zout.

 

So you should be OK. 

 

Andy

 

Edited September 4, 2020 by andyr

[08Boss302]

Just now, muon* said:

I'm trying to picture this in circuit and am a tad confused about what the result would be. As the amp not in use would be like a load to ground off before the input of the active amp....hmm

Personally I wouldn't use a splinter and instead wouldld go for a source selector used in reverse. DAC into the out and amps connected to the multiple source inputs.

Cheers for this,

This is where I was not sure and prior to running this was curious if there was any potential danger or mismatch, I have no electrical circuit or engineering knowledge but am certain I do not want to (potentially) damage any equipment for the sake of some splitters. 

 

To paint the full picture..

 

- Coaxial OUT of BlueSound Node 2i INTO the Denafrips Ares II DAC

- RCA out of Denafrips into Amp 1 and Into Amp 2 if using the splitter otherwise its RCA only into Amp 1.

 

Right now I only have the 1 amp set up, I have another on its way and would like to use the Denafrips DAC with it too but would prefer not to switch RCA at the back of the DAC with each alternating use as its kinda difficult to get to for each listen.

 

The Bluesound runs its own DAC so I can use it to the 2nd Amp but I prefer the Denafrips hence the thinking of splitters so I can use it for both Amps. 

[muon*]

Andy could likely be correct with his numbers, he's better than I at this I think.

 

I'd definitely use a selector used in reverse over a splitter, a splitter won't damage anything except potentially the SQ.

 

Edit: Not sure what you are doing on the output of amps to speakers end, but if the amps are valve amps remember that they need a speaker load any time they are active with a signal.

Edited September 4, 2020 by muon*

[andyr]

  @08Boss302, Ian's suggestion is the ideal way to go.  But a lot more expensive than using RCA splitters! 

 

12 minutes ago, muon* said:

 

Personally I wouldn't use a splinter and instead would go for a source selector used in reverse. DAC into the out and amps connected to the multiple source inputs.

 

 

Andy

 

 

[andyr]

51 minutes ago, Wimbo said:

Isn't this if you have both amps on at once.

 

AIUI, W - no. 

 

(But then as I am an amateur - not a 'licenced' (ie. degreed) EE - I may well have the wrong end of the stick! 

 

Andy

 

[muon*]

No, you are correct, Andy, as even with one off it is still presenting a load to ground at the splitter point

 

This being said, I'm more of a anteater

 

Edit: note to self "I must stop stating the bleeding obvious"

Edited September 4, 2020 by muon*

[08Boss302]

10 minutes ago, muon* said:

Andy could likely be correct with his numbers, he's better than I at this I think.

 

I'd definitely use a selector used in reverse over a splitter, a splitter won't damage anything except potentially the SQ.

 

Edit: Not sure what you are doing on the output of amps to speakers end, but if the amps are valve amps remember that they need a speaker load any time they are active with a signal.

 

I only have x1 set of speakers - but I have speaker cable for each amp so I am not changing cables at the amp all the time.

Each time I use an amp I just disconnect and connect at the speaker which amp I am using. 

When an amp is not being used the speaker cable is still connected to the amp but not the speaker end).  An amp not being used is is off but not switched off at the wall, just at the amp.

The concern now might be if an amp is off and there is a "dead" signal being sent to it via the DAC would it damage the amp - even if the the amp is off and no speaker is connected?

 

 

8 minutes ago, andyr said:

  @08Boss302, Ian's suggestion is the ideal way to go.  But a lot more expensive than using RCA splitters! 

 

 

Andy

 

 

 

I'll look into a source selector and weight up the cost.  Splitters sound a bit smaller and cleaner, I was hoping it might work,  If the Splitters cannot damage anything I may try them but I would not do this if there is any damage that can be done.

 

Might also be an opportunity for me to start mentioning to my wife how nice the Topping D90 Dac would look in the rack next to the Denafrips too

[muon*]

The amp is fine if off before disconnecting the speakers from it, and speakers connected before turning on the amp and passing a signal.

 

I like to wait a few minutes after switching an amp off before disconnecting speakers.

[mbz]

The DAC will present an audio signal on both RCA cables from the splitter, think of it as a varying AC voltage.

All will be ok IF there is no path to ground on the "not in service" amp. Powering down might not be enough, think if somewhat passive preamp... Deselecting that function (eg, RCA into AUX) "should" take care of any impedance issue but then again some amps short to GND any unused/selected inputs which would kill all audio. Knowing what amps (schematics) might be helpful.

[08Boss302]

8 minutes ago, mbz said:

The DAC will present an audio signal on both RCA cables from the splitter, think of it as a varying AC voltage.

All will be ok IF there is no path to ground on the "not in service" amp. Powering down might not be enough, think if somewhat passive preamp... Deselecting that function (eg, RCA into AUX) "should" take care of any impedance issue but then again some amps short to GND any unused/selected inputs which would kill all audio. Knowing what amps (schematics) might be helpful.

Thank you,

ok, so with that information, unplugging at the wall would absolutely ensure full safety on the above situation if it were an issue.

 

I am not sure I would be able to obtain schematics, I could find open (lid off) pictures of the amps though as they are online.

For reference the amp here now is the Vincent SV237mk and the amp coming is the Willsenton R8.

 

 

[mbz]

6 minutes ago, 08Boss302 said:

ok, so with that information, unplugging at the wall would absolutely ensure full safety on the above situation if it were an issue.

The question about loss/reduction of audio signal is still open. Depending on the amp, the audio path via AUX to the volume pot can be passive, one side of the vol pot is connected to GND, also deselecting AUX MAY connect the AUX input to GND, ie, grounding the DAC output, which may end badly. Unplugging the unused amp would remove the GND reference via the third wire/chassis so would be a good move. Will try and track down the schematic...

[08Boss302]

22 minutes ago, mbz said:

The question about loss/reduction of audio signal is still open. Depending on the amp, the audio path via AUX to the volume pot can be passive, one side of the vol pot is connected to GND, also deselecting AUX MAY connect the AUX input to GND, ie, grounding the DAC output, which may end badly. Unplugging the unused amp would remove the GND reference via the third wire/chassis so would be a good move. Will try and track down the schematic...

thank you!

 

In reality I guess this is question of laziness too, I could just use the DAC in the Bluesound but I feel the Denafrips is better.  I also have the DAC in my Oppo 205 which IMO is superior to the Bluesound too.

The Denafrips sounds great with the Vincent and I would love to use it with both amps but not at the expense of any of them.

 

The Oppo is easy as it has 2 paths out of it via different RCA outputs so I can run it safely to multiple analog and digital sources easily with no sound loss and no splitters required - its a beast like that.

I guess it could also argued it will be safer to just unplug and plug the RCA at the DAC to which amp I am going to use - I am switching speaker cables per amp so messing around with the RCA is not a diabolical disruption, just less accessable than the speakers are.... 

Doing this then removes an GND issue and is in reality not any more difficult than unplugging the amp at the wall - albeit maybe just a tad more fiddly.

 

Though they are not off the table yet the splitters in theory seemed like such an easy option, but also too easy which is why I threw the question up and I am glad I did. 

 

Thank you for all the information/guidance thus far.

[Irek]

That one might help.

[keinesorge]

5 hours ago, 08Boss302 said:

Wondering what is the general concensus?

I am in the situation where I would like to use a pair so I can use my external DAC to with 2 amplifiers.  Obviously only 1 amp is operational at any time but it means I can use my external DAC for both applications when either is in use -

 

Whilst I am kind of sure there should be no degredation of sound as the signal will only be sent to the active amp, what I dont know is whether or not any signal is lost down the "dead" line to the amp that is not in use.....or in fact if this has any potential issue to the DAC?  Does it still send a signal down the dead line even and does that take power from the "active" line?  None of this might even be a thing that happens but I am not sure.

 

I can use the traditional cable Y splitter or something like this which I like too as its so compact.

 

Does anyone else use a splitter for this type of thing?

Hi 08Boss302,

 

I have had them at the back of my DVD player whenever i wanted to get some hours on a new interconnect pair before installing them in my main system.

DVD player -> splitter -> Preamp

                                          ->  interconnects playing into a resistive load.

 

I didnt listen out for sound quality.  I've kept a sensible load on the "interconnect line" and the DVD player been going for years.

[08Boss302]

5 minutes ago, Irek said:

That one might help.

 

This has me confused.

Bluesound to Denafrips and then a split RCA to both amps.  This would sit between the DAC and the AMPs?

Is this the RCA type switch @muon*   &    @andyr were referring to earlier where reverse the inputs and plug the Denafrips in the "out" and the amps into the "in"?

3 minutes ago, keinesorge said:

Hi 08Boss302,

 

I have had them at the back of my DVD player whenever i wanted to get some hours on a new interconnect pair before installing them in my main system.

DVD player -> splitter -> Preamp

                                          ->  interconnects playing into a resistive load.

 

I didnt listen out for sound quality.  I've kept a sensible load on the "interconnect line" and the DVD player been going for years.

Thanks for this.  Just a standard Y cable splitter or one piece like I pictured above?