[macky112]

Unloaded measurements don't say much about the real performance of the device. The only thing that can be said of those is that the walnut sucks.

And the channel imbalance is because of the potentiometer of the walnut. Usually you want it to be under 1dB from its max output voltage (the potentiometer all the way up) to -40 dB in reference to the max output voltage, you can do this with the calibration signal of rightmark, since it reports the amplitude of both channels, however its likely you will saturate your line in with the walnut at full volume, and really the thing already has other problems of major concern. Like a 100 Ohm output impedance.

I read through this thread twice trying to figure out how each graph relate to sound and music. But I am still very confused. Is there a guide I can look over? For example, if unloaded is flat but loaded is like a rollercoaster then is it going to sound bad for all headphones?

I was very curious about the Zishan because of its spec and features, but after looking over its charts on this thread, I am not sure if it's going to sound good

 

[castleofargh]

I read through this thread twice trying to figure out how each graph relate to sound and music. But I am still very confused. Is there a guide I can look over? For example, if unloaded is flat but loaded is like a rollercoaster then is it going to sound bad for all headphones?

I was very curious about the Zishan because of its spec and features, but after looking over its charts on this thread, I am not sure if it's going to sound good

if unloaded is flat but loaded isn't with some IEMs, then the information you have is that different IEMs/headphones may alter at least the signature(added to the obvious fact that IEMs and headphones aren't flat ^_^). it will usually be a matter of impedance ratio over frequencies and you need to have a look at the impedance graph of your IEM to make an educated guess as to what may happen if plugged into the device.
 
depending on the load and the result you can also diagnose for other potential problems, but all in all it's still only frequency response into a few different situations, more measurements may reveal a lot more.

 

[macky112]

hi all,

I just tried RMAA for the first time, and am not sure if I did it correctly, so comments/suggestion welcomed.

all DAPs has EQ turned off, all DAPs volume set around 80%, laptop mic-in volume set to 100% and pre-gain at 0%.

I dont have a 3.5mm Y-splitter, so I am only able to get the unloaded chart.

Walnut at 50% volume (12 o clock position, with 6 o clock being off), laptop mic-in volume adjusted to 20% due to clipping




Walnut at 25% volume (9 o clock position), does this chart illustrate channel imbalance at this volume?




Fiio X3ii




AGPTek M20 (Benjie S5)




Ruizu X02 (AGPTek A02)




here is the info table for all 4 above DAPs

@ruben123 brought up a good point in another thread

So basically I am hearing what he is hearing, which is the Ruizu X02 has a noticeable amount of bass roll off comparing to my x3ii and m20, however, the rmaa chart is not showing what i hear. Did I do something wrong during my setup or measurement?

 

[castleofargh]

well you're not listening to it unloaded are you?

this all topic is basically to show that depending on what IEM you plug, the resulting signature can change from unloaded measurements because of impedance variations or capacitors at the output or something really wrong in a device. 

 

[h1f1add1cted]

M-Audio Micro DAC 24/192
 

 
Very good 100 buck DAC/AMP combo with very low output impedance. I measured with multimeter ~ 0,6 ohms output impedance, which is just right if you see the RMAA result with my very senstive 12 driver CIEM. Only a bit much hiss, but still a great little DAC/AMP combo.

 

[macky112]

  well you're not listening to it unloaded are you?

this all topic is basically to show that depending on what IEM you plug, the resulting signature can change from unloaded measurements because of impedance variations or capacitors at the output or something really wrong in a device. 

ah, thank you for the clarification!

 

[HiFiChris]

@h1f1add1cted
 
Thanks! I've added it to the third post. 

 

[Samueru Sama]

  M-Audio Micro DAC 24/192
 

 
Very good 100 buck DAC/AMP combo with very low output impedance. I measured with multimeter ~ 0,6 ohms output impedance, which is just right if you see the RMAA result with my very senstive 12 driver CIEM. Only a bit much hiss, but still a great little DAC/AMP combo.

 
Can you measure its max output power into the 32 Ohm load? Just set up everything as if you were going to run a RMAA test with the load in parallel, generate a 0dB 1 KHz tone in audacity, hit record only in RMAA (and don't go any further, you can use the RMAA's calibration to determine if the device is clipping), and play the 1 KHz tone. increase the volume with the load in parallel until you see clipping and check the voltage which the device starts clipping or until you hit 0dBFS.
 
Obviously you have to make sure that you're not clipping your line in, your FiiO X7 AM1 max outputs 1.8 Vrms without load, you can use it to make sure that your line input doesn't clip up to 1.8 Vrms.

 

[h1f1add1cted]

Sorry but I have no glue from what do you talk here. How do you think I own a FiiO X7 and why you talk about this gear which I have never mentioned in my posting above o.O
 
 
I have already measured the outputpower of the M-Audio Micro DAC 24/192 with my multimeter which is 2,001 V @ no load and 1,964 V @ 33 ohms load.

 

[music4mhell]

  Walnut V2
 
DAP/Amp.
 
(I've repeated these tests some times, because I got puzzled when got that graph from Zishan DAC + Walnut as amp: the bass roll-off when unloaded has gone! While when used with iBasso D14, the bass roll-off became even more exaggerated than in mode DAP Walnut).
 
They are unusable for sensitive multi-BA phones.
 
Unloaded curve is far from being flat. Some people say they remind you 80's players; it must be due to the premature roll-off at both sides, lows and highs, together with a slight mid centric bump. Energetic, but I guess congested as well. Unloaded curve from line out shows less roll-off both sides, specially highs roll-off.
It sounds like 80's players, I must agree.
 
My measures (@ 1KHz, 0dBFS), using DMM (Zishan as source for amplifier mode, 1.874Vrms in-signal):
Output impedance: phones out, 100Ω!!!; line out: >3KΩ.
Max. output unloaded: phones out, 3.328Vrms; line out: 0.333Vrms; amplifier mode, 6.43Vrms.
But measured 3.67Vrms max., before it started clipping/distorting too much.
 
Hiss with MR3 is awful; it's like loud metallic machines; it's no hiss, it's pure high noise.
 
Strange excessive high out impedance, low line out power, and high power (for the price) up to 3.67Vrms.
 
But the amplifier, while powerful, is almost unusable. First, the bass roll-off is enormous [Edit: .. in the case of D14; no bass roll-off unloaded, when amplifying Zishan].
Second, the steps in volume potentiometer; usable volumes are located in a 45º arc of the wheel. Starts at1.30h, 0.18 at 2h, 0.4 at 2.30h; 3 at 3h, 5 at 4h, 5.8 at 5h, and 6.1 to 6.4 from 6h to 10h (Vrms); so suitable volumes are from 2h to 3:30h; impossible for volume fine adjusting.
 
 
Edit: added hiss info
 
Edit2: added more info about amplifier mode
Edit3: corrected max Vrms no clipping/distortion, added more multi-BA phones

How many hours did you burn-in your Walnut before taking this test ? Please share !

 

[hakuzen]

  How many hours did you burn-in your Walnut before taking this test ? Please share !

maybe 1 hour?
but don't worry: output impedance is not going to change after 3000 hours burn-in. and unloaded and loaded frequency responses aren't going to change either (i can test it again after 400 hours, if you feel better with this)

 

[Samueru Sama]

  Sorry but I have no glue from what do you talk here. How do you think I own a FiiO X7 and why you talk about this gear which I have never mentioned in my posting above o.O
 
 
I have already measured the outputpower of the M-Audio Micro DAC 24/192 with my multimeter which is 2,001 V @ no load and 1,964 V @ 33 ohms load.

Thanks a lot. I know you have (or had) a FiiO X7, because I checked your profile (you have a review of it). xD
 
~2 Vrms 33 Ohm, very nice, that's even more than what the dragonfly red can output at that load (it clips @1 Vrms with 32 Ohm load).
 
https://www.seeko.co.kr/zboard4/zboard.php?id=m_device&page=1&sn1=&divpage=1&sn=off&ss=on&sc=off&select_arrange=headnum&desc=asc&no=69
 
Hopefully you checked that M-audio wasn't clipping (you can't do that with just the multimeter alone).

 

[bartzky]

@ruben123 brought up a good point in another thread


So basically I am hearing what he is hearing, which is the Ruizu X02 has a noticeable amount of bass roll off comparing to my x3ii and m20, however, the rmaa chart is not showing what i hear. Did I do something wrong during my setup or measurement?

You're not hearing wrong. Here are my results with a RME ADI-2 Pro:



The RME ADI-2 Pro's ADC is absolutely solid, so you can trust noise, THD and so on measurements as well. Btw: The X02's output impedance is 2.54 ohm, and it puts out 7.96 mW into 30 ohm.

 

[HiFiChris]

 

 
How does the ADI-2 Pro perform with super sensitive low impedance multi-driver in-ears in terms of hissing and output impedance?

 

[bartzky]

How does the ADI-2 Pro perform with super sensitive low impedance multi-driver in-ears in terms of hissing and output impedance?

It's a beast. No hissing and an output impedance only slightly above 0 ohm.