RCA-splitter / Y-Adapter, do they degrade sound quality?

[PeterHans]

Hi everyone,

I have a question, I already googled it and mainly found personal opinions, so I was curious if somebody could give me an answer to my question in this forum?

- I ordered the Topping E30 which has one RCA out:

- I want to buy 2 RCA-splitters:

- my active sub is on the other side of the room and needs 2 pretty long RCA cables (left, right,10 metres)
- my active speakers will be close to the DAC, 2x RCA cables (left,right, 1,5 metres)

Generally speaking (but also including my coming setup), can I expect some loss in audio quality if RCA-splitters are used?
Looking forward to get some answers, thank you!

 

[sergeauckland]

There is no quality loss whatsoever from a splitter, provided that the source can drive the impedance of the two destinations in parallel.

I can't find a spec for the minimum load the E30 will support, but I very much doubt it would be any less than 600 ohms, possibly even down to under 100 ohms with no degradation to performance.

That being the case, the load the E30 will see using the splitter cable will not be less than perhaps 5kohms, depending on the actual loads presented by the 'speakers and sub. I'm assuming no less than 10k in each case.

So, unless I'm wrong about my assumptions, you'll be fine using the splitter. 10m cable to the sub isn't particularly long, I'd use some well screened low capacitance cable like RG59 or RG6 which can be bought cheaply and is easy to terminate.

S.

 

[eric-c]

Do your active speakers have line level or sub outputs? If so I would attach your subs through those connections vs a splitter. If not, consider a small external active crossover. DAC>x-over>a) active speakers b) subwoofer.

 

[solderdude]

It will work fine as long as the active speakers and sub are powered.
When one of the devices is turned off there could (but is not always the case) be some audible distortion.

 

[bboris77]

It will work fine as long as the active speakers and sub are powered.
When one of the devices is turned off there could (but is not always the case) be some audible distortion.

I have often heard that this is a possibility, but have never been able to obtain a clear technical explanation of why this may be the case in certain types of situations. If you have the patience to try and explain the technical reasons for this, I (and many others) would be grateful.

Anecdotally, I have heard that it has something to do with certain types of amplifiers/receivers "shorting" their inputs when they are turned off whatever this means.

If this situation does occur, what level of distortion are we talking about? I have been running a Y-splitter from my EL DAC II between my headphone amplifier (EL AMP II) and my integrated amplifier (Yamaha A-S501) for a while now, and I would like to know if there is any potential for trouble.

 

[PeterHans]

Thank you guys, that's what I really appreciate in this forum, just precise and informative responses.

Do your active speakers have line level or sub outputs? If so I would attach your subs through those connections vs a splitter. If not, consider a small external active crossover. DAC>x-over>a) active speakers b) subwoofer.

They don't offer this kind of solution just balanced and unbalanced IN.

 

[sergeauckland]

I have often heard that this is a possibility, but have never been able to obtain a clear technical explanation of why this may be the case in certain types of situations. If you have the patience to try and explain the technical reasons for this, I (and many others) would be grateful.

Anecdotally, I have heard that it has something to do with certain types of amplifiers/receivers "shorting" their inputs when they are turned off whatever this means.

If this situation does occur, what level of distortion are we talking about? I have been running a Y-splitter from my EL DAC II between my headphone amplifier (EL AMP II) and my integrated amplifier (Yamaha A-S501) for a while now, and I would like to know if there is any potential for trouble.

When power is switched off to a device, the input impedance is no longer what is was when powered. Also, the input impedance will most likely not be symmetrical to positive and negative going voltages, both because of any electrolytic input coupling capacitors, and because of semiconductor devices' junctions being reverse-biased with the 'wrong' polarity voltage.

This asymmetry in impedance will cause distortion as the input voltage goes up and down, which will be passed directly to any other powered devices in parallel. How much distortion depends on the output impedance of the source, and the specifics of the unpowered device.

S.

 

[solderdude]

I have often heard that this is a possibility, but have never been able to obtain a clear technical explanation of why this may be the case in certain types of situations. If you have the patience to try and explain the technical reasons for this, I (and many others) would be grateful.

Anecdotally, I have heard that it has something to do with certain types of amplifiers/receivers "shorting" their inputs when they are turned off whatever this means.

If this situation does occur, what level of distortion are we talking about? I have been running a Y-splitter from my EL DAC II between my headphone amplifier (EL AMP II) and my integrated amplifier (Yamaha A-S501) for a while now, and I would like to know if there is any potential for trouble.

It totally depends on the actual input circuit of the connected devices. When powered down the transistors or diodes that are not conducting when powered on will be conducting and thus act as diodes. There could be resistors in series with the input as well.
In case of te latter they act as a passive 'soft limiter'. This can be symmetric or asymmetric (both signal halves or only one signal half).
The voltage where diodes start working is 0.5V to 0.6V, when the input citcuit is an opamp with schottky diodes as protection it could be lower, in the 0.2V to 0.3V range.
Since a 2V output signal +/-2.8V it can clip the output. How severe this is depends on the output resistance of the source. The higher the resistance the worse the effect.

Edit: was typing the same ramblings as @sergeauckland at the same time...

 

[PeterHans]

Sorry, one more mini question. I already have the long RCA cable (for the sub) at home but I would have to buy new RCA cables for the active speakers.
I found those two cables in my old cable box:

Would it be okay to use it and plug it in the balanced IN of my active speakers (JBL LSR) (although the connection is not balanced) or is there a chance of damaging my speakers? Or would it be the better solution to just buy a new pair of "normal" RCA cables for the speakers?

 

[bboris77]

Thank you for your quick responses! Practically speaking, is this a common or a rare issue when using modern DACs and amplifiers based on your own experience? I am wondering if anyone has actually measured this and published the results.

I am fairly sure that my type of setup as described in my previous post with an RCA Y-splitter between the headphone and speaker amp is not uncommon. I generally turn off whichever amplifier I am not using at any given time rather than simply turning down the volume on it.

I wish I could measure this input impedance of my amplifiers easily, but I have a feeling that it is not a simple matter.

 

[solderdude]

Measuring the input impedance of an amplifier generally is not easy. This is because active components, capacitors etc. can be in its path.
Both the output resistance of a source as well as the input resistance of devices should be measured using an AC signal and a resistor + some math.

Whether or not it is a problem depends. I don't think it is a common thing. As long as you don't hear distortion with one of the loads turned off it isn't a problem.

 

[solderdude]

Sorry, one more mini question. I already have the long RCA cable (for the sub) at home but I would have to buy new RCA cables for the active speakers.
I found those two cables in my old cable box:

Would it be okay to use it and plug it in the balanced IN of my active speakers (JBL LSR) (although the connection is not balanced) or is there a chance of damaging my speakers? Or would it be the better solution to just buy a new pair of "normal" RCA cables for the speakers?

Using those cables from RCA out to balanced IN will not be an issue. Assuming pin 1 and 3 on the XLR both are connected to RCA shield.

 

[sergeauckland]

Measuring the input impedance of an amplifier generally is not easy. This is because active components, capacitors etc. can be in its path.
Both the output resistance of a source as well as the input resistance of devices should be measured using an AC signal and a resistor + some math.

Whether or not it is a problem or not depends. I don't think it is a common thing. As long as you don't hear distortion with one of the loads turned off it isn't a problem.

Indeed. I see it more as 'good practice' not to have unpowered devices in parallel rather than a real problem. Having said that, whenever I've done it, it just bugs me that it could be introducing distortion I can't hear...

S.

 

[izeek]

Imho, it mostly makes so small a difference my golden ears have not been able to hear it if it did.
My system is passively vertically bi-amped using y adapters. I 've not been able to hear any difference between before and after after 3 tries.
So if a tree falls in the woods...

 

[AudioX3]

I have a question that goes along with this thread.

Attached drawing shows setup, easier to follow than my explaination probably.....

Coming out of my pre/pro which I use for both 2 channel and 5.1, there is the L/R RCA out that would go to my amplifier. I would like to split that output and have a Schiit SYS 2 RCA In, one out (essentially a switched Y) that would allow the signal path out one path or the other. My amp would have a Y cable, so there would be path A and path B. The switch would make it that only one path would be active at a time. Path A would go straight to the amp. Path B would allow me to go to an tube buffer (I know frowned upon) that would typically be shut off. That buffer output would go to the other Y and to the amp.

Since electronically the A path hitting the Y would be when active connected to the A Path of the switch for input and the B Path while switched off on the input side, the buffer's output (whether turned off or on) is going to be in parallel through the B of the Y, and thus could affect the signal from A to the amplifier.

Effectively, at least when the buffer is turned off, (there is no vampire power I am aware of but not sure), would that essentially make the B Path switched off both at the A/B Switch SYS, as well as the backend of the buffer attached to the B end of the Y. Yes/No?

Could this setup cause any concern for the health of my amp?
Could this setup cause any sound degredation of any realistically hearable proportion?

PS: You may pelt me for the buffer , as long as you please answer the other aspects as I doubt I will cause any issue to my equipment, but want to know if electronically from those with electronics knowledge what the affect would be in my specific situation before I go and do it. Really, the tube buffer is an experiment that may or may not last, but want to play with it for months and thus want something better than manually switching cables for different inputs.

Thanks!

 

[0800 Dub]

I have sort of the inverse question

Theoretical scenario with one set of RCA inputs (powered speakers or amp)

Would it be better to use two of these splitter cables

or a switcher like this

to connect two devices to the one set of inputs?

Devices would be Schiit SYS (w/ two sources connected to it) and Topping BC3

So it's kind of the same question as OP except it's 2 devices (SYS and BC3) going in to 1 set of inputs (either active speakers or amp) instead of 1 device (E30) going in to 2 sets of inputs (active speakers and sub), but I don't know whether the considerations will be different or the same so I'm asking

 

[aceace262626]

i found that cheap rca splitter is downgrade my sound quality.

is there any good rca splitter that won't downgrade sound quality ? or just bit downgrade ?

i buy it around us$ 3 for right and left channel

 

[Speedskater]

If it makes good low impedance firm contacts, the audio will be good.
With corrosion or loose connections, maybe not.

 

[DVDdoug]

i found that cheap rca splitter is downgrade my sound quality.

It's probably not the splitter.

In what way does it degrade the sound?

What happens when you plug in one thing at a time?

Exactly what is plugged-in?

Note that "splitting" is usually OK - One output into multiple inputs.
"Mixing" two outputs into one input is NOT OK. For that, you need a mixer.

 

[aceace262626]

It's probably not the splitter.

In what way does it degrade the sound?

What happens when you plug in one thing at a time?

Exactly what is plugged-in?

Note that "splitting" is usually OK - One output into multiple inputs.
"Mixing" two outputs into one input is NOT OK. For that, you need a mixer.

yes i try it plug in just from the source to 1 rca cable first .

check the sound .

sound a bit different than going straight away to rca cable . i prefer the sound from the RCA cable directly without the RCA splitter .

I plan to divide it into 2 rca. but I tried to test the sound first to see if there was no change or there was a change in sound quality .