Dear Members,
one of my friends would like to buy the aforementioned amplifier, the RCA version.
Is it a viable option for him to simply buy the XLR version for future-proofness and use it without any additional (pricey) electronics via RCA->XLR adapter 'til he has the money for a true balanced-out DAC ?
It's a beginner set.. he would pair it with the Topping E30 (RCA only) and maybe after 1-2 years he might consider a XLR-capable DAC - or stay at RCA.
I know there are 3 ways of performing the act of using XLR inputs with RCA outputs:
1. adapter, in these case RCA hot wire becomes XLR hot, RCA shield will be XLR shield (XLR cold, the inverted signal is usually connected to this shield/ground too by the adapter).
2. transformer
3. active electronics
Options 2-3 don't play now due to budget reasons, but option 1 could be viable for some future-proofness, am I right ?
The RCA and XLR versions of the amplifier cost the same. Would it be worth buying the XLR version and feed it by the Topping E30's RCA outputs via a simple (passive) adapter ?
I know it wouldn't utilize the full potential of common-mode noise rejection of XLR, but at least from physical connection (and sound of course) 🙂 point of view, would it work ?
The normal RCA-input version of the amplifier doesn't utilize balanced either, so unbalanced is okay for the start but he at least would have the opportunity to upgrade to truly balanced output (XLR) DAC later, without swapping the amp itself.
How does this sound ?
Due to sensitivities and in case of option 1, the lack of the inverted signal, I assume the differential amplifier on the NCore side is still amplifying the difference between hot and cold signals, which in case of cold is a ground potential (zero signal) so instead of doubling signal strength at the end of the input stage, still only a single-signal strength gets amplified. Which would also mean, whereas the E30 is capable of 2Vrms output, it easily drives the RCA version of this amplifier to the maximum output (max power @ 1.66Vrms) while it can drive the XLR version to maximum power (via adapter) even sooner (max power @ 1.66Vrms too, but from 2 signals, so 0.83Vrms per signal for maximum.. so if I only have the hot signal and the cold is tied to ground via the adapter, I reach 0.83Vrms more quickly on the E30 - this as a side effect. And of course a somewhat increased SNR which I doubt would be audible on a Monitor Audio 88dB pair of speakers).
For a little help, here are the RCA and XLR versions, respectively.
Input sensitivity is 1.66Vrms for both, for the XLR version there's a remark about 2x0.83V so input sensitivity is doubled actually if I'm not mistaken.
Can you confirm/correct me pls ?
Transformer/active electronics is no option now, really.
I just want to understand if the amp's XLR inputs could be driven with some minor, probably negligible disadvantages by the RCA unbalanced outputs or absolutely not. Cable run is 0.5m so the unbalanced nature of the signal transmission is not an issue.. normal room setup.
Thank you.
one of my friends would like to buy the aforementioned amplifier, the RCA version.
Is it a viable option for him to simply buy the XLR version for future-proofness and use it without any additional (pricey) electronics via RCA->XLR adapter 'til he has the money for a true balanced-out DAC ?
It's a beginner set.. he would pair it with the Topping E30 (RCA only) and maybe after 1-2 years he might consider a XLR-capable DAC - or stay at RCA.
I know there are 3 ways of performing the act of using XLR inputs with RCA outputs:
1. adapter, in these case RCA hot wire becomes XLR hot, RCA shield will be XLR shield (XLR cold, the inverted signal is usually connected to this shield/ground too by the adapter).
2. transformer
3. active electronics
Options 2-3 don't play now due to budget reasons, but option 1 could be viable for some future-proofness, am I right ?
The RCA and XLR versions of the amplifier cost the same. Would it be worth buying the XLR version and feed it by the Topping E30's RCA outputs via a simple (passive) adapter ?
I know it wouldn't utilize the full potential of common-mode noise rejection of XLR, but at least from physical connection (and sound of course) 🙂 point of view, would it work ?
The normal RCA-input version of the amplifier doesn't utilize balanced either, so unbalanced is okay for the start but he at least would have the opportunity to upgrade to truly balanced output (XLR) DAC later, without swapping the amp itself.
How does this sound ?
Due to sensitivities and in case of option 1, the lack of the inverted signal, I assume the differential amplifier on the NCore side is still amplifying the difference between hot and cold signals, which in case of cold is a ground potential (zero signal) so instead of doubling signal strength at the end of the input stage, still only a single-signal strength gets amplified. Which would also mean, whereas the E30 is capable of 2Vrms output, it easily drives the RCA version of this amplifier to the maximum output (max power @ 1.66Vrms) while it can drive the XLR version to maximum power (via adapter) even sooner (max power @ 1.66Vrms too, but from 2 signals, so 0.83Vrms per signal for maximum.. so if I only have the hot signal and the cold is tied to ground via the adapter, I reach 0.83Vrms more quickly on the E30 - this as a side effect. And of course a somewhat increased SNR which I doubt would be audible on a Monitor Audio 88dB pair of speakers).
For a little help, here are the RCA and XLR versions, respectively.
Input sensitivity is 1.66Vrms for both, for the XLR version there's a remark about 2x0.83V so input sensitivity is doubled actually if I'm not mistaken.
Can you confirm/correct me pls ?
Transformer/active electronics is no option now, really.
I just want to understand if the amp's XLR inputs could be driven with some minor, probably negligible disadvantages by the RCA unbalanced outputs or absolutely not. Cable run is 0.5m so the unbalanced nature of the signal transmission is not an issue.. normal room setup.
Thank you.
Ignoring the main 2 solutions so... let him buy the RCA version and be done with it.
Many Class D amplifiers hiss when using them like that. The shortest path is both units either unbalanced or both balanced. Any other attempt will cost more money and time.
There is n
Hypex NC-MP amps are all balanced, but according to Hypex, they can be used from unbalanced sources by using the wiring as in the picture:
How is the performance then? Also this device may or not behave like the Hypex. Let me rephrase:
The shortest path to success is both units either unbalanced or both balanced. Any other attempt will cost more money and time in the end after eventually buying the "right" item to make the set as intended and the interim solution may possibly lead to lower or less optimal performance during the interim period. This more or less curses with the thought of enjoying best performance audio averaged over the time from buying the first item to EOL of all items.
So it would be a good thing to save some money and then directly buy the complementary items. Just a personal opinion of course. Nothing more, nothing less 😉
The shortest path to success is both units either unbalanced or both balanced. Any other attempt will cost more money and time in the end after eventually buying the "right" item to make the set as intended and the interim solution may possibly lead to lower or less optimal performance during the interim period. This more or less curses with the thought of enjoying best performance audio averaged over the time from buying the first item to EOL of all items.
So it would be a good thing to save some money and then directly buy the complementary items. Just a personal opinion of course. Nothing more, nothing less 😉
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Okay, let's look at this actual situation. The unbalanced source is given, the looked amplifier is balanced, but this amplifier has an RCA input version, which is actually a rewired balanced input (like in the picture above), because there is no unbalanced version of this amp (Hypex NC-MP).
If the given unbalanced source would not work properly with this balanced amplifier somehow, then he could still buy a balanced source, because the said amplifier is balanced anyway, even if it has RCA inputs only.
If the given unbalanced source would not work properly with this balanced amplifier somehow, then he could still buy a balanced source, because the said amplifier is balanced anyway, even if it has RCA inputs only.
That amp is nothing more than Hypex module in a box, so it could be that RCA version is the same as using XLR version with basic adapters. To be sure you could contact audiophonics to ask how RCAs are wired. Recomendations from Hypex are in this NC400 datasheet
Theres also a good article about ground loops which also shows how to connect unbalanced sources to balanced inputs: https://www.hypex.nl/img/upload/doc/an_wp/AN_Legacy_pin_1_problems.pdf
That said, I have this exact amplifier in XLR (chose it for future proofiness). I was thinking about making adapter cable as described in Bruno Putzeys article above, but tried it with basic RCA to XLR adapters and have no issues with them. Although it might depend on your source, mine is not grounded, so theres no ground loops and therefore hum.
Theres also a good article about ground loops which also shows how to connect unbalanced sources to balanced inputs: https://www.hypex.nl/img/upload/doc/an_wp/AN_Legacy_pin_1_problems.pdf
That said, I have this exact amplifier in XLR (chose it for future proofiness). I was thinking about making adapter cable as described in Bruno Putzeys article above, but tried it with basic RCA to XLR adapters and have no issues with them. Although it might depend on your source, mine is not grounded, so theres no ground loops and therefore hum.
@YSDR: nailed it. Thanks for the comment.
@Cerniu: very good links, I knew and saw the NC400 datasheet but the 2nd link with the proper RCA -> XLR connection is some hidden gem for me, I'll do that cable and go with that, together with the XLR version of the amp. After 1-2 years we can upgrade DAC to a real balanced (XLR) one anyway but until then, the little Topping E30 will be at least connected well to this XLR amplifier. Many-many thanks, I'm grateful for this article mentioned here. (Just for peace of mind I also asked Audiophonics guys but I'm pretty sure this pin1-problem article's method is the right way to go).
@Cerniu: very good links, I knew and saw the NC400 datasheet but the 2nd link with the proper RCA -> XLR connection is some hidden gem for me, I'll do that cable and go with that, together with the XLR version of the amp. After 1-2 years we can upgrade DAC to a real balanced (XLR) one anyway but until then, the little Topping E30 will be at least connected well to this XLR amplifier. Many-many thanks, I'm grateful for this article mentioned here. (Just for peace of mind I also asked Audiophonics guys but I'm pretty sure this pin1-problem article's method is the right way to go).
Just for reference - if we're talking about unbalanced to balanced - I just found a "Unbalanced to balanced - Jensen impedance correction circuit.png" in my DIY folder from many years ago.
It converts an unbalanced RCA output to truly balanced XLR output. Of course it's intended for device modding/DIY.
Don't ask me where it is from, I just put it here for all those who're interested. 🙂
.
It converts an unbalanced RCA output to truly balanced XLR output. Of course it's intended for device modding/DIY.
Don't ask me where it is from, I just put it here for all those who're interested. 🙂
.
Ah, here it is. (Long PDF, full article)
And some more useful articles. (Aforementioned one was AN003).
And some more useful articles. (Aforementioned one was AN003).
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Audiophonics confirmed via email: even the simplest RCA to XLR cable is working flawlessly with the XLR-input Hypex.
(I asked about this one).
(I asked about this one).
