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Topping L50 Review (Headphone Amp)

Veri

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Does the volume pot work with pass through? Or is it no volume control at all? The product description says use DAC pre-amp function, so I'm understanding that L50 doesn't do anything to the signal at all.

Also with the L30, in pre-amp mode, do the gain settings have an impact?

I know these are basic questions but it's appreciate the help!!
-Pass through is pass through, L50 has no variable pre-outs
-L30 only has pre-amp/variable output and no passthrough. Gain setting affects it.
 
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Neil.D.S

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I respect the passthrough has been referenced a few times in this thread already but I was hoping someone could confirm if I understand this correctly.

I am currently experiencing noise in my system which I presume is due to a ground loop issue after introducing a sub with my Adam monitors. I did not experience this issue using an E30 and L30 with the monitors (no sub).

I respect the L50 is not a balanced amp but the passthrough would still technically be balanced and in theory, should eliminate the ground loop issue?

Thanks.
 

usern

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I am currently experiencing noise in my system which I presume is due to a ground loop issue after introducing a sub with my Adam monitors. I did not experience this issue using an E30 and L30 with the monitors (no sub).
Which sub are you using? How is it connected? What kind of noise (static or hum with stable tone or erratic "computer noise")?
 

Neil.D.S

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Which sub are you using? How is it connected? What kind of noise (static or hum with stable tone or erratic "computer noise")?
Adam TV5 monitors and a KRK S10.4 sub. Obviously all run single ended with rca cables. E30 > L30 > sub > monitors. Exaggerated hiss and static noise over and above the normal hiss that the monitors produce. I would say it’s somewhat stable. If I unplug the rca cables the noise goes away. Prior to the sub I did have issues with noise when using usb, I switched to optical and that eliminated the issue.
 

usern

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I respect the L50 is not a balanced amp but the passthrough would still technically be balanced and in theory, should eliminate the ground loop issue?
TRS passthrough is balanced, RCA passthrough is not. If you use E30 RCA > L50 RCA > S10.4 RCA, then this chain is not balanced.
Obviously all run single ended with rca cables. E30 > L30 > sub > monitors. Exaggerated hiss and static noise over and above the normal hiss that the monitors produce. I would say it’s somewhat stable. If I unplug the rca cables the noise goes away.
Static hiss is a hint that the issue might not be ground loops or USB computer noise, but might be low quality and high noise floor circuitry of KRK S10.4 sub. Is the noise still there if Adam monitors are directly connected to L50?
 

Neil.D.S

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TRS passthrough is balanced, RCA passthrough is not. If you use E30 RCA > L50 RCA > S10.4 RCA, then this chain is not balanced.

Static hiss is a hint that the issue might not be ground loops or USB computer noise, but might be low quality and high noise floor circuitry of KRK S10.4 sub. Is the noise still there if Adam monitors are directly connected to L50?
Hey sorry guys I currently have an e30 and l30. Want to purchase a balanced dac to hopefully sort out the noise issue. I am still using optical. No noise if the sub is removed from the chain. Only one way to find out I guess is to try the e50 and l50 and hope it’s not a result of the sub circuitry.
 

usern

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Only one way to find out I guess is to try the e50 and l50 and hope it’s not a result of the sub circuitry.
You would have to get additional cables with correct ends (TRS to TRS to connect E50 to L50 for example) for balanced connections. Besides that, have you tried to adjust input gain and volume on the sub to see if the noise gets lower?
 

Neil.D.S

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I'm more than happy getting the required cables etc if it means I can get rid of the noise. The noise is not unbearable but it's there and the fact that it shouldn't be there is bugging me. I have made several adjustments on the monitors and sub including a grounding and high sensitivity toggle, that's why I am shopping around for a balanced source. Appreciate the feedback!
 

nothingman

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I’m wondering if anyone could explain to me why headphone amps like the L50 have such high input sensitivity. In this case it’s 2.7V on single ended input, and in the L30 it’s a full 3V. Meanwhile, both of their matching E30 and E50 DACs have a max output of 2V on single ended. Why this mismatch? Why would a manufacturer leave a bunch of heaphone amp output on the table like this when they are making a matching pair?

I’m used to loudspeaker power amps which have input sensitivities a good bit below the standard consumer line level output, e.g. my power amp is at 1.43V input sensitivity and my preamp is the normal 2V out max when they are run single ended. This makes sense to me. What is going on with these headphone amps makes no sense to me, especially when a lot of people are using EQ ahead of the headphone amp which bites into the signal strength. If anything, headphone amps should be even more sensitive to make up for EQ, no?

(yes, I asked this question more in full here but got zero replies two days later)
 

half_dog

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I’m wondering if anyone could explain to me why headphone amps like the L50 have such high input sensitivity. In this case it’s 2.7V on single ended input, and in the L30 it’s a full 3V. Meanwhile, both of their matching E30 and E50 DACs have a max output of 2V on single ended. Why this mismatch? Why would a manufacturer leave a bunch of heaphone amp output on the table like this when they are making a matching pair?

I’m used to loudspeaker power amps which have input sensitivities a good bit below the standard consumer line level output, e.g. my power amp is at 1.43V input sensitivity and my preamp is the normal 2V out max when they are run single ended. This makes sense to me. What is going on with these headphone amps makes no sense to me, especially when a lot of people are using EQ ahead of the headphone amp which bites into the signal strength. If anything, headphone amps should be even more sensitive to make up for EQ, no?

(yes, I asked this question more in full here but got zero replies two days later)
One reason that I remember was to avoid saturation (clipping) of the amplifier when drive a really heavy load (<16ohm) even at maximum volume...
 

citysoundman

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I'm pretty new here and I'm looking around for headphone amps with balanced inputs in the under $200 range. I just purchased the D30 Pro DAC and have a long cable run from DAC to HP amp so I need to go balanced. Any other amps to look at for comparison? I see the SMSL SP200 is $140 at drop.com and I like that it has no wall wart power and XLR connectors. No passthrough but I don't need it. But people write about some hiss issues? Anyhow, would like to ask about options if they are out there. thanks!
 

rikstaker

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Topping L50..had it for 1 week and now blinking power light. No output.

Sending it back along with e50. Screw this.
 
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jdoe

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How am I supposed to check that
Use multimeter. Plug power supply into the socket, set multimeter for AC measurements and connect probes to the inner and outer contacts of it. Here is example:
(in this particular video power supply provides DC, in case of L50 it should be AC, some multimeters also require to set correct measurements range in order to avoid potential damage (like volts, millivolts, etc.)).
Mine power supply unit for L50 shows 19V AC, which is a bit higher that 15V, but still fine. In case if voltage is too low unit might not be able to properly start.
Another advice is to try another power outlet. L50 power supply contacts are very thin and don't have good contact in my case (I have EU plugs at home, they require EU plugs, but topping unit has old-style thin contacts).
 

Bow_Wazoo

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New toys 4 daddy

IMG_3799-1.jpg
 
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Orion76

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So my Topping E50 / L50 stack just showed up. This is probably a silly question, but I've never shopped for such a thing before- can you get a 3 or 4 foot extension cable for the AC transformer? At the moment I can barely get to my power strip and don't have much room to rearrange my desktop.
 
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