SINAD Measurements

[amirm]

Now looking at the specs of my Yamaha MG06 mixer, I see that a line input (channels 3/4, 5/6) nominal level is -10dBu (245.1mV) and the maximum before clip is +4dBu (1.228V).

Wow, that is pretty low. The rest of the mixers in that line accept 2.45 volts as it should be. You may be able to use the pad to fix that?

 

[amirm]

I just can't believe Yamaha didn't took into account this "standard" and released the product breaking all certification policies or rules. They are in audio business for a long time, doesn't this look strange?

Well, there is no written standard for audio in this regard. The 2 Volt nominal output started with the CD and hence the reason DACs follow it too. Not all sources output this level.

 

[scooter]

-10dBV is a pretty common nominal level for consumer products, like CD players

So majority of DACs measured here cannot be considered as consumer products? I doubt we can call them pro audio products (most of them under 100$ and still having +8dBu).

 

[scooter]

You may be able to use the pad to fix that?

PAD switches are only for 1/2 channels unfortunately...
What do you recommend Amir, maybe it's better for me to upgrade a mixer than pursue a DAC which has lower nominal output?

 

[Blumlein 88]

Well, long ago most devices like tape players and tuners had 250 mv as a standard. CD upped that to 2 volts though unofficial to my knowledge. You can get both XLR and RCA in line attenuators.

https://www.parts-express.com/in-line-xlr-attenuator-pad-20db--240-416

https://www.parts-express.com/harrison-labs-12-db-rca-line-level-audio-attenuator-pair--266-244
The latter are too expensive, but I think there are other brands more affordable.

 

[scooter]

@Blumlein 88 thanks for those links. They do not color the signal, do they? Only attenuation...

 

[Blumlein 88]

@Blumlein 88 thanks for those links. They do not color the signal, do they? Only attenuation...

Correct.

 

[amirm]

What do you recommend Amir, maybe it's better for me to upgrade a mixer than pursue a DAC which has lower nominal output?

Longer term, I suggest getting a better mixer. For now there are also DACs that have volume controls (e.g. Topping D50s) so you can use them without anything extra.

 

[Rja4000]

Longer term, I suggest getting a better mixer.

... like a small MacKie VLZ, as an example.
(But thet don't have effects)

 

[Rja4000]

CD upped that to 2 volts though unofficial to my knowledge.

I didn't know that.
I guess that was to improve SINAD, somehow.

 

[scooter]

... like a small MacKie VLZ, as an example.

On an upgrade path I'm considering Yamaha AG06, same compact size mixer, USB audio interface, individual compressor settings for 1/2 channels and effects. I already learned a lesson that compressor is a must during drunk karaoke sessions

 

[RayDunzl]

Doesn't the mixer have attenuation for hot inputs?

 

[scooter]

Doesn't the mixer have attenuation for hot inputs?

View attachment 36485

Those are level knobs adjusting an output signal level going to the main stereo mix. Channels itself will be overloaded by constant +8dBu input signal. On the other hand, channels 1/2 are equipped with an input gain knobs and attenuation pad switches as well. Neither are on 3/4 & 5/6 channels

 

[RayDunzl]

Those are level knobs adjusting an output signal level going to the main stereo mix. Channels itself will be overloaded by constant +8dBu input signal.

Yes, I see that now:

 

[Rja4000]

On an upgrade path I'm considering Yamaha AG06, same compact size mixer, USB audio interface, individual compressor settings for 1/2 channels and effects. I already learned a lesson that compressor is a must during drunk karaoke sessions

Well, I'd try it first.
Compressor and effect are pretty basic on those...

 

[KSTR]

The 2Vrms quasi-standard for consumer digital sources like CD seems to come from the maximum level a traditional -10dBV consumer input should always be able to handle. This -10dBV level is a "nominal" working level (with a slow averaging VU meter indicating "0dB"), not the clipping level, and the actual circuitry always has to have quite some headroom, on the order of 5x-10x, the analog sources of the day required this.
Which amounts to 14dB-20dB of headroom, giving a clipping level of +4dBV (1.6Vrms) to +10dBV (3.16Vrms). 2Vrms is 16dB of headroom, and seems to match the dynamic range (DR) figures of early CDs. Looks like the 2Vrms 0dBFS output was wisely chosen by the Sony/Philips engineers..

 

[Rja4000]

The 2Vrms quasi-standard for consumer digital sources like CD seems to come from the maximum level a traditional -10dBV consumer input should always be able to handle. This -10dBV level is a "nominal" working level (with a slow averaging VU meter indicating "0dB"), not the clipping level, and the actual circuitry always has to have quite some headroom, on the order of 5x-10x, the analog sources of the day required this.
Which amounts to 14dB-20dB of headroom, giving a clipping level of +4dBV (1.6Vrms) to +10dBV (3.16Vrms). 2Vrms is 16dB of headroom, and seems to match the dynamic range (DR) figures of early CDs. Looks like the 2Vrms 0dBFS output was wisely chosen by the Sony/Philips engineers..

Of course, makes sense when you think about it.
Thanks

 

[scooter]

Yes, I see that now:

View attachment 36495

No, this schematic is for AG06, it has gain pad switches before the level knobs. Mine is MG06 (picture of it you posted previously) without gain control, here is a schematic for it:

 

[scooter]

Well, I'd try it first.
Compressor and effect are pretty basic on those...

I don't need many effects, just reverbs or so.
Regarding compressor, I've seen various reviews on Youtube and it seems there are quite high level of compression level adjustments within Yamaha software for each 1/2 channel, completed adjustments and settings can be saved in DSP and later used by just one button click on the mixer itself (disconnected from computer and used standalone).
Do you have any personal experience that compression is basic and not effective?

P.S.: Sorry for being off-topic...

 

[Rja4000]

Do you have any personal experience that compression is basic and not effective?

Not with that specific model, but with older entry-level Yamaha model.
Looks like this one is more sophisticated.