AliExpress Cirmech WM-013 CS4398 DAC - review and measurements

[niamex]

I can see an LP 2950 3.3 added there but coudn't find the sorce of negative 3.3 V for CS 8416 ?

Sorry for not looking carefully to the circuit , now I see that there is still connenction from 7812 /+12 V/ to AMS 1117 -3.3 and AMS 1117 - 35.0 from where CS 8416 digital and analog parts are powered.
Seems my questions reffering PS of CS 8416 are not actual

 

[audio_tony]

Since I am not an EE and do not understand circuits clearly, please have a look at the attached which seems to be kind of a mod /not clear by whom/ and explain the reason for that mode ? I can see an LP 2950 3.3 added there but coudn't find the sorce of negative 3.3 V for CS 8416 ?

All that's been done there, is the 3.3v is sourced from a 12v regulator instead of the raw DC. This is highly unlikely to make any difference.

With regard to the way you have it connected - there will be a 2.5v DC offset on pins 20/23 - as a result you'll only be getting half the voltage swing, higher distortion, loss of common mode rejection and almost certainly increased noise.

As per my (updated) measurements of this DAC here - performance for a DIY DAC is very, very good.

Bypassing / removing the OPAMP (because OPAMPS are bad right?? LMAO) is utterly futile, and will only result in worse performance.

However... if you want to believe that opamps are bad etc. etc. then carry on.

By the way - the USB input on these DACs is not good either. The CM102 is limited to 48kHz IIRC, so unless you are using the COAX input.....

 

[niamex]

With regard to the way you have it connected - there will be a 2.5v DC offset on pins 20/23 - as a result you'll only be getting half the voltage swing, higher distortion, loss of common mode rejection and almost certainly increased noise.

Many thanks your comments, but please advise whether I have to notice somehow /by ears not scope/ the distortion and noise. I mean audible worstening of the sound ?

 

[niamex]

the USB input on these DACs is not good either.

I will not use it anyway

 

[niamex]

Bypassing / removing the OPAMP (because OPAMPS are bad right?? LMAO) is utterly futile, and will only result in worse performance.

I will try some OPAMPS like Oracle II or more advanced and decide, thanks

 

[audio_tony]

I will try some OPAMPS like Oracle II or more advanced and decide, thanks

The stock NE5532 (so long as it's genuine) is more than adequate and other opamps won't sound any different (unless something is wrong).

However... if you believe that different opamps can change the sound that's entirely up to you.

Op-amp Rolling Using Sparkos on Fosi V3 Mono

This is a study of measured differences if one swaps up the TI NE5532p dual IC op-amp in a Fosi V3 Mono amplifier with a "discrete" opamp from Sparkos. It is a test requested in the youtube comments of my video test of the same using Douk A5 and Sonic Imagery op-amp. The Sparkos SS3602 retails...

www.audiosciencereview.com

Sparkos SS3602 Opamp Rolling In Fosi P4

This is a detailed measurements of effect of swapping the stock NE5532P op-amp in Fosi P4 preamplifier with Sparkos SS3602 "discrete" opamp. The SS3602 costs US $79.80 and the NE5532P, US $0.47. Swapping opamps in P4 is more challenging due to back connectors/switches that need to be...

www.audiosciencereview.com

 

[niamex]

With regard to the way you have it connected - there will be a 2.5v DC offset on pins 20/23

Exept OPAMP returning to place, do you have a suggestion hou to connect the DAC chip to a direct output ??

 

[audio_tony]

Many thanks your comments, but please advise whether I have to notice somehow /by ears not scope/ the distortion and noise. I mean audible worstening of the sound ?

As I said earlier - there will almost certainly be more noise, especially ultrasonic noise which can in some cases cause amp instability as well.

 

[audio_tony]

Exept OPAMP returning to place, do you have a suggestion hou to connect the DAC chip to a direct output ??

Follow the original schematic. The output is already DC coupled. There's no need to change anything.