Well, they are clearly not the same, though JCally could argue that the extra chips are not needed to get the same measurements. Still it was a bad move from them...
Around September, AliExpress found AP90(60$),AP98(100$) that look the same as Moon River 2(161$),
and I purchased them. In this post I will post the results of the RMAA of Moon River 2, AP98 and additionally AP90.
The biggest difference between Moon River 2 and AP98 is that when connected, gain setting is different. High gain is the default for Moon River 2, and low gain is the default for AP98.
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On 4.4 (24/192)
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I also upload the RMAA results of AP90 with the same appearance and different chipsets used. It is a great USB Dongle DAC built using AKM 4493.
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As a mobile headphone amplifier and DAC, Jcally's AP90, 98 are all recommended products. I am using 4.4 to 2XLR cable as a DAC.
Thx you.
Endpoint Descriptor:
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0x01 bEndpointAddress (OUT endpoint 1)
0x05 bmAttributes (Transfer: Isochronous / Synch: Asynchronous / Usage: Data)
0x0308 wMaxPacketSize (1 x 776 bytes)
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best to measure the unloaded voltage without dummy load at all, straight into the DMM or Voltmeter. Those usually have Zi in the MΩ range.2.028Vrms across a 314.6ohm load, and 2.001Vrms across 19.6ohms
When I used mine on uapp android and looked at hardware volume settings, the second set of sliders (that aren't controlled by the usual phone up /down) was less than full. Built in safety perhaps?The one thing I did notice is that it's quieter than the TempoTec I was using, and I need to turn the volume up. I'm not quite sure why this is, as both have a 2V output, but maybe I should go back and check things again.
Well it should but … my multimeter is a rather cheap one, so I thought it best to use a couple of dummy loads.best to measure the unloaded voltage without dummy load at all, straight into the DMM or Voltmeter. Those usually have Zi in the MΩ range.
Whatever your DMM's Zi is, adding an additional load resistor to measure unloaded voltage will make your results less accurate.Well it should but … my multimeter is a rather cheap one, so I thought it best to use a couple of dummy loads.
The Cirrus Logic cs43131 chip used in the AP98 and MoonRiver 2 is capable of perfectly good performance, but it has a bug that’s exposed by full-range multitone signals. See here and here for examples. I experienced the same issue with my TempoTec. It’s easy to work around the bug by ensuring that the signal being sent to the DAC never quite reaches 0dBfs, but the AKM4493 used in the AP90 doesn’t have any bugs and is preferable for that reason.question is: is there any reason to choose ap98 over ap90? does anyone have photos of 90's intestines?
The 98 and the MR2 both use cs43198 https://shenzhenaudio.com/products/...dac-amp-headphone-amplifier-hifi-device-specsThe Cirrus Logic cs43131 chip used in the AP98 and MoonRiver 2 is capable of perfectly good performance, but it has a bug that’s exposed by full-range multitone signals. See here and here for examples. I experienced the same issue with my TempoTec. It’s easy to work around the bug by ensuring that the signal being sent to the DAC never quite reaches 0dBfs, but the AKM4493 used in the AP90 doesn’t have any bugs and is preferable for that reason.
Using two DAC chips and averaging across the outputs should lead to slightly lower noise figures, but noise from the 4493 is already at the limit of most measurements (as here), so I don’t see this as having any utility.
I can’t really see any reason to pay more for the AP98.
excellent reply, thank You.The Cirrus Logic cs43131 chip used in the AP98 and MoonRiver 2 is capable of perfectly good performance, but it has a bug that’s exposed by full-range multitone signals. See here and here for examples. I experienced the same issue with my TempoTec. It’s easy to work around the bug by ensuring that the signal being sent to the DAC never quite reaches 0dBfs, but the AKM4493 used in the AP90 doesn’t have any bugs and is preferable for that reason.
Using two DAC chips and averaging across the outputs should lead to slightly lower noise figures, but noise from the 4493 is already at the limit of most measurements (as here), so I don’t see this as having any utility.
I can’t really see any reason to pay more for the AP98.
Well, then there is the moral side of it, right. I get the impression from previous posts that this might be a counterfeit and Moondrop (that provides us with cheap items and oder gadgets we adore) is not very happy about it....
Not claiming that this is true, maybe it deserves some research, but I personally would not order for the moment.
Odd, I was sure I read somewhere that it was the 43131, but you're right. Both chips use the same DAC core, but the 43131 has an integrated headphone amp.The 98 and the MR2 both use cs43198 https://shenzhenaudio.com/products/...dac-amp-headphone-amplifier-hifi-device-specs
But Id agree that unless power output differs significantly between the 90 and the 98 not sure why you should choose one over the other. .
perhaps the gain setting reported as another volume? how does this correlate to "hardware" controlled gain? by the way i've had weird double volume control experience in ALSA before with XU208/ES9038Q2M DAC. i think alsa knows too muchAn update on the volume issue on Linux systems (running moode which is basically a wrapper for mpd and alsa).
I have volume set to “Fixed (0dB)” in moode, but found that amixer -c2 controls listed two devices with volume capability (one of which is probably the RPi’s built in headphone jack).
amixer -c2 get PCM showed a stereo device set to maximum volume
amixer -c2 get PCM,1 showed parameters for a device it regards as mono with volume set to -20dB.
So I tried amixer -c2 set PCM,1 100% and … boom (literally, make sure to turn down the volume on your amp before doing this) I’m now getting full volume from the DAC.
One thing I’ve also found is that you must restart mpd (in moode you can do this by going to configuration->mpd and simply pressing SAVE without changing anything) after any change to the system settings (or indeed simply unplugging and plugging back in). Otherwise the sound is severely distorted. But after mpd restarts it all works fine.
An update on the volume issue on Linux systems (running moode which is basically a wrapper for mpd and alsa).
I have volume set to “Fixed (0dB)” in moode, but found that amixer -c2 controls listed two devices with volume capability (one of which is probably the RPi’s built in headphone jack).
amixer -c2 get PCM showed a stereo device set to maximum volume
amixer -c2 get PCM,1 showed parameters for a device it regards as mono with volume set to -20dB.
So I tried amixer -c2 set PCM,1 100% and … boom (literally, make sure to turn down the volume on your amp before doing this) I’m now getting full volume from the DAC.
One thing I’ve also found is that you must restart mpd (in moode you can do this by going to configuration->mpd and simply pressing SAVE without changing anything) after any change to the system settings (or indeed simply unplugging and plugging back in). Otherwise the sound is severely distorted. But after mpd restarts it all works fine.
It's odd, alsa seems to treat the card as if it has two volume controls. If I set the volume type to "Hardware" or "Null" then I get no sound at all. On these settings the output of amixer -c2 contents isperhaps the gain setting reported as another volume? how does this correlate to "hardware" controlled gain? by the way i've had weird double volume control experience in ALSA before with XU208/ES9038Q2M DAC. i think alsa knows too much
numid=3,iface=MIXER,name='PCM Playback Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=127,step=0
: values=0,0
| dBminmax-min=-63.50dB,max=0.00dB
numid=4,iface=MIXER,name='PCM Playback Volume',index=1
; type=INTEGER,access=rw---R--,values=1,min=0,max=127,step=0
: values=127
| dBminmax-min=-63.50dB,max=0.00dB