[ninetylol]

Is it during playback and using USB interface ? - I experienced the same, wrote about this earlier ...

Haven't noticed that when using optical. Might be losing synchronization or something for a moment, maybe losing a few samples etc., but there are no crackling noises in audio playback, no pops or other distortion - it's only for like half a second and it goes back to 44,1/48k. Completely forgot about it since it has no influence on the audio signal.

USB cable is not attached - you can have a look at the list, what should be in the box (user manual).

yes its with usb, i noticed the same, no sound errors but still weird. I gotta try optical, not having any dsd files anyway

Why not to use cma400i as a pure dac in this case ? Bypassing completely analog volume regulation by setting switch into FIX position (the one on the back of the unit, next to RCA outputs) to provide highest audio quality

How to control volume then? I thought by using it as a variable pre-amp you would get the highest sound quality (windows volume at 100% - player volume 100%)

 

[148124]

How to control volume then? I thought by using it as a variable pre-amp you would get the highest sound quality (windows volume at 100% - player volume 100%)

With the pot of your speakers only (this is by the way very safe way because when you use full volume on the speakers amp and only control them by using preamp from cma400i, imagine what will happen when you forget to lower it previously listening on headphones with full volume @ low gain etc). Every pot in analog path may introduce channel imbalance or some change into the sound (not so strong like capacitor in the signal path but still if you are able to completely bypass it - the better for you, unfortunately you can't completely bypass both pots in this case).

Keep the windows volume always at 100%. But it olny makes sense when not using WASAPI, KS or ASIO (these are bit perfect and will ignore any windows settings, also windows kmixer and resampling stuff). So it only makes sense with some windows KMIXER stuff like youtube, games or movies.

For DSD capabilities of this DAC and true DAC technology, you should at least download free samples from oppo site:

https://www.oppodigital.com/hra/dsd-by-davidelias.aspx

especially "vision of her" might be enlightning ;]

 

[ninetylol]

With the pot of your speakers only (this is by the way very safe way because when you use full volume on the speakers amp and only control them by using preamp from cma400i, imagine what will happen when you forget to lower it previously listening on headphones with full volume @ low gain etc). Every pot in analog path may introduce channel imbalance or some change into the sound (not so strong like capacitor in the signal path but still if you are able to completely bypass it - the better for you, unfortunately you can't completely bypass both pots in this case).

Keep the windows volume always at 100%. But it olny makes sense when not using WASAPI, KS or ASIO (these are bit perfect and will ignore any windows settings, also windows kmixer and resampling stuff). So it only makes sense with some windows KMIXER stuff like youtube, games or movies.

For DSD capabilities of this DAC and true DAC technology, you should at least download free samples from oppo site:

https://www.oppodigital.com/hra/dsd-by-davidelias.aspx

especially "vision of her" might be enlightning ;]

Well sadly I cant control the volume on the speakers themselves, because its 2 separate analoge knobs at each speaker and hard to balance :/

Gonna try some DSD later using optical right now!

EDIT: i also get heavy distortion when using as a fixed dac out to active speakers (Nubert A20). Maybe my speakers dont like the high voltage output?

 

[Pings]

1. Is it normal, that the sampling rate LED sometimes switches between the input sampling rate and "UNLOCK" ? It does that for me sometimes even though its only for half a second

I had this problem 2 different times, one time it was my mic picking up sound. It stopped for a few days and then it started again so I went into my Sound/Speaker Properties > Advanced > Then I changed my Default Format to "24bit, 192000 Hz (Studio Quality)" and it hasn't done it since. Hope this helps.

 

[148124]

I had this problem 2 different times, one time it was my mic picking up sound. It stopped for a few days and then it started again so I went into my Sound/Speaker Properties > Advanced > Then I changed my Default Format to "24bit, 192000 Hz (Studio Quality)" and it hasn't done it since. Hope this helps.

This is something different, we are talking about going to unlock during playback, not in "idle state" and not between the tracks - that would be normal for USB.

Setting 24bit 192kHz is not good idea in your mixer since it will resample everything, adding artificial overtones and a lot of different resampling artifacts. Most of materials are in 44.1k. Especially when listening to youtube, gaming or watching movies (here usually 48k).

I asked about this issue in cma600i thread - this is not the problem for cma600i, but they are facing much bigger issues with clicking, popping, etc when using USB. Questyle never replied on any of their emails - very inappropriate and unprofessional. Nevertheless, some guy was able to update firmware of the device and was able to fix all issues - hopefully we'll be also able to do that.

 

[148124]

EDIT: i also get heavy distortion when using as a fixed dac out to active speakers (Nubert A20). Maybe my speakers dont like the high voltage output?

Yes indeed. You would have to check "input sensitivity" parameter in your manual. Might be very small value like 0,2Vrms or something. If so, you can't use any of standard line out level sources because that could easily overdrive power output section of your active speakers. In this case the best option will be using volume pot of cma400i only, the best would be from the notch where there is no channel imbalance - at 8-9 o'clock should be fine. This depends on the unit and analog pot, mine is perfectly fine since the beginning of the scale.

 

[ninetylol]

Yes indeed. You would have to check "input sensitivity" parameter in your manual. Might be very small value like 0,2Vrms or something. If so, you can't use any of standard line out level sources because that could easily overdrive power output section of your active speakers. In this case the best option will be using volume pot of cma400i only, the best would be from the notch where there is no channel imbalance - at 8-9 o'clock should be fine. This depends on the unit and analog pot, mine is perfectly fine since the beginning of the scale.

Yeh its says this in the manual:

Eingangsempfindlichkeit 700 mVeff (analog)
für Vollauss teuerung
max. Input 1 Veff

I didnt have any problems with my Dragonfly Red though which should output 2.1 Volts at 100% line out mode. Whats the output voltage on the CMA400i in fixed mode?

 

[ld100]

...an improvement from... a USB cable.

...

...aight then.

 

[148124]

I didnt have any problems with my Dragonfly Red though which should output 2.1 Volts at 100% line out mode. Whats the output voltage on the CMA400i in fixed mode?

That's the thing I'd like to also know because the manual has no info about that, I only know that with preamp it is able to put about 4Vrms and 8Vrms for RCA/XLR output which is quite high. I think I will prepare the test and will measure the max output with 1kHz sinus at 0dbFS file.

This side may be handy when generating the files:
https://www.audiocheck.net/audiofrequencysignalgenerator_sinetone.php

Then it is enough to use multimeter to see what is the rms value of output voltage. Even if it's not TRUE RMS device, when using sinus & 50Hz it should tell you the right value because it uses formula to calculate it from this signal based on the amplitude of sinus (sinus, 50Hz, 0dbFS is max output). Will also check 1kHz as analog output of DAC may have some attenuation at low frequency (but it shouldn't here and not with very high input impedance of multimeter)

EDIT:

There are the measurements (both the same for 50Hz & 1kHz sinus wav file @0dbFS):

FIX mode RCA output:

3,44Vrms which is very high signal indeed

ADJ mode RCA output:

at 12 o'clock it's about 0,4Vrms

at 1 o'clock it's about 0,57Vrms

at 2 o'clock it's about 0,73Vrms (730mV, so here you get input sensitivity for your active speakers, would be best to hang around 1 o'clock for safety reasons)

with volume pot maxed out, it is like in fix mode = 3,44Vrms

Hope this helps :> because we would never get answers from questyle ... Actually similar results are in the manual but it was in preamp mode as max, nothing about FIX mode level, and you have as a bonus some values on certain pot's positions.

So this is passive preamp, all you can have is just attenuating max output from the DAC analog section with volume pot.

Nice review here:

 

[Suppa92]

Questyle cma 400i has fully balanced amp section but it doesn't mention about dac section. They're using only one AKM AK4490 DAC chip which is two channel dac chip. Isn't it necessary to have two of these or one 4 channel dac chip to have fully balaned dac section?

 

[ninetylol]

@Suppa92 i guess so.

Anybody tried the Fostex T60RP with the Questyle? There are fully balanced cable available too and the have a max input of 3Watts so looks like a sweet combo. I ordered one, but the balanced cable is too expensive for now.

 

[Suppa92]

Is it good idea to buy cma400i if only use in single ended mode? Is there any other benefit other than power difference using an amp in balanced mode specially does it affect the sound signature?

 

[Paulo Abreu]

Is it good idea to buy cma400i if only use in single ended mode? Is there any other benefit other than power difference using an amp in balanced mode specially does it affect the sound signature?

Good question, straight answer YES. I really didn’t A/B on SE vs balanced but ... maybe, just maybe, balanced seems a bit brighter. Lately I've been listening my Focal Clears out of the SE and that seems just perfect for longer listening sessions.

 

[ninetylol]

Is it good idea to buy cma400i if only use in single ended mode? Is there any other benefit other than power difference using an amp in balanced mode specially does it affect the sound signature?

I bought it without wanting to use the balanced outputs, but i guess its always good to have, especially since i just purchased the T60RP and WILL try it on balanced mode sooner or later

 

[Azirius]

I have used the T60RP with the CMA400i, it's a nice pairing. I certainly think it would benefit from having some extra power from some extra power from the balanced output, but I cannot test this as I don't have a balanced cable for it. I'm looking to get a balanced cable for my Aeon Closed too. Has any one had the pleasure of using them with one of the balanced out puts on the CMA400i?