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Review and Measurements of Monoprice THX Desktop DAC & Amp

Veri

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Using FiiO FH5
Ah, right. Well they are IEMs, this kind of low-level 'pink noise' is sometimes exaggerated on sensitive IEMs. Ideal measurement to test this is the '50mW' signal to noise ratio. The higher, the lower your chance on hiss/noise is. But I don't think this dac/amp received this measurement.
 

silver2545

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I had similar problems and ended up using an optical cable. Problem solved.
Can you try optical input to the DAC? That would show if it's a ground loop coming from USB, or if it's the unit itself..

Also what are you using for listening, what headhones/earphones?
So i unplugged the USB, changed input setting to every input option it has, with no luck (nothing connected) the noise is still there. With it simply connected to power and powered on. The thing that gets me is that the pink noise sounding thing is louder than what i hear on my FiiO Q1 Mark II
 

Veri

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So i unplugged the USB, changed input setting to every input option it has, with no luck (nothing connected) the noise is still there. With it simply connected to power and powered on. The thing that gets me is that the pink noise sounding thing is louder than what i hear on my FiiO Q1 Mark II
Well that's not good. Looks like it is not usable with IEMs, then. There's a solution though. Something like this can lower noise:
https://www.amazon.com/s?k=ifi+ie+buddy
 

mgmate

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So i unplugged the USB, changed input setting to every input option it has, with no luck (nothing connected) the noise is still there. With it simply connected to power and powered on. The thing that gets me is that the pink noise sounding thing is louder than what i hear on my FiiO Q1 Mark II
Hi Silver2545,

I have this issue with IEMS and it was solved "grounding" the case to "ground" cable on the plug. Perhaps this would help. See post #55,
Regards,

Manuel.
 
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Monstieur

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Is the digital volume control linked to Windows over USB? Is it possible to mix USB and one of the analog inputs at the same time without switching sources?
 

Monstieur

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Monstieur

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I found that Dirac Sensaround II doesn't destroy the HRTFs already present in stereo sources. With other renderers like Waves NX on the Audeze Mobius, you must disable any HRTFs at the source - set the game to non-HRTF "Stereo" or "7.1" instead of "Headphones", disable "Dolby Atmos for Headphones" or "DTS Headphone:X" etc. Even if source HRTFs are enabled, they are seemingly destroyed and sound only comes from the front virtual speakers, so you might as well run the source in non-HRTF "Stereo".

Dirac Sensaround II expands the soundstage but the original positional audio from the source HRTFs are preserved. I tried it with games in "Headphone" mode, and in 7.1 movies downmixed to stereo with "Dolby Atmos for Headphones" and "DTS Headphone:X". By default, "Dolby Atmos for Headphones" has a small but positionally accurate soundstage, and "DTS Headphone:X" has a wider but still positionally accurate soundstage. Dirac Sensaround II expands the soundstage further, but reduces positional accuracy a bit. This is a surprising result as I expected stacking HRTFs to destroy each other. This is similar to the Dolby Surround Upmixer on Atmos AVRs which accurately places stereo source HRTFs in a 5.1.4 speaker setup.

It's great for ear-piercing mono sounding YouTube videos, and it's not too bad if you accidentally leave it enabled during HRTF content.
 
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Monstieur

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It clips when using XLR input from my Steinberg UR44C which has a line out level of +16 dBu. Fortunately the amp has an OVER symbol on the LCD to indicate this. I had to set the output on the UR44C to -1 dB to stop the OVER symbol. I'm not sure if it's still micro-clipping.
 

Veri

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It clips when using XLR input from my Steinberg UR44C which has a line out level of +16 dBu. Fortunately the amp has an OVER symbol on the LCD to indicate this. I had to set the output on the UR44C to -1 dB to stop the OVER symbol. I'm not sure if it's still micro-clipping.
Note that this amp digitizes the analog inputs. Fidelity could be noticeably higher using its digital inputs, clipping aside.
 

Monstieur

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Note that this amp digitizes the analog inputs. Fidelity could be noticeably higher using its digital inputs, clipping aside.
I can't hear a difference between the digitized analog inputs and the USB input, and it's dead silent up to +6 dB. I prefer the convenience of switching between multiple sources on my UR44C mixer (PC, console, guitar, microphone) over switching sources on the PC and amp.
 

Veri

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I can't hear a difference between the digitized analog inputs and the USB input, and it's dead silent up to +6 dB.
That's good to hear actually, must be that the ADC at least is well executed :)
 

zaraki

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i was interested in getting a thx amp and i know the 887 is slightly better and newer stand alone amp, but i cant seem to find any good priced balanced dac to go with it, to equal the same price as the 788 thx combo

i am also considering the dx7 pro since it has a 4.4mm balanced jack which would be cool to use with the hd 800 s i have on the way to me, but i dont know if its better then the thx combo since i see so much hype about thx everywere i look but i am very limited in this subject, i have only ever owned magni 3 amp and nothing else

and for balance if i am using my gaming pc as my source do i need a balanced cable running from my pc to the dac also? if so im not sure how that would work

if balanced is not a big deal iyo then i can just get the 887 thx amp and pair it with a schiit modi 3 dac for the same total price of the thx 788 combo unit unless you think the thx or dx7 pro combo units are still worth it

i was also considering the asgard 3 amp but i cant find as much info/reviews about them compared to the thx amps

and is balanced worth it iyo

and i currently have the magni 3 amp that came out before the + and heresy models, and no dac with my lcd2 classics that i own and the hd 800 s i ordered

also i know its not important but i really like how on the dx7 pro it says "see you" when you turn it off like i saw in a video
 

Darvantus

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In looking at the specs, looks like it isn't enough power for 600ohm DT880? (or really any 600ohm SE?) 73mw@600ohm doesn't seem adequate. Too bad they don't make balanced/replaceable cables for the 880 or really any beyer 600ohm headphone under $300?
 

Monstieur

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In looking at the specs, looks like it isn't enough power for 600ohm DT880? (or really any 600ohm SE?) 73mw@600ohm doesn't seem adequate. Too bad they don't make balanced/replaceable cables for the 880 or really any beyer 600ohm headphone under $300?
The higher the impedance the lower the power needed. The 600 ohm model of the DT880 doesn't need more than a few mW.
 

Darvantus

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So the 73mW @600 ohms would be sufficient? There are reviews of people having issues with even the mighty 789 distorting before getting to decent sound levels
 

Monstieur

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So the 73mW @600 ohms would be sufficient? There are reviews of people having issues with even the mighty 789 distorting before getting to decent sound levels
It shouldn't distort as the current will be very low. At worst you'll max out the volume knob.
 

Darvantus

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That concerns me, as even with my quite inefficient Sundaras and HE4xx, it will hit overtemp protection at quite less than max volume. (Not overcurrent/short, as i use balanced cables, but temp protection.)
 

Monstieur

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That concerns me, as even with my quite inefficient Sundaras and HE4xx, it will hit overtemp protection at quite less than max volume. (Not overcurrent/short, as i use balanced cables, but temp protection.)
There's no benefit to the 600 ohm Beyerdynamic models. You should replace them with the 250 ohm models so they're easy to drive.
 
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