New SMSL A300 BTL Class-d Power Amp

[Johannesthalos]

It uses MA5332MS

MA5332MS
MA12070

 

[Kitarist]

Does anyone have A300 D300 combo and how well it performs?

 

[Kitarist]

Can someone confirm that volume only goes to 60 on this amp?

 

[Johannesthalos]

Can someone confirm that volume only goes to 60 on this amp?

Yes. That is the case with any amp using the NW1194 volume controller as a pre-amp.

 

[Kitarist]

Does the NW1194 volume controller still work in logarithmic way? So basicly when its at half (30) it gives around 10% output?

 

[Johannesthalos]

Does the NW1194 volume controller still work in logarithmic way? So basicly when its at half (30) it gives around 10% output?

On the A20a-2019 it is linear. On the SMSL AS300 it is linear. I do not own the SMSL A300, but strongly assume it is the same, since all these amps use the same controller and go from -0db to 60db.

 

[Kitarist]

On the A20a-2019 it is linear. On the SMSL AS300 it is linear. I do not own the SMSL A300, but strongly assume it is the same, since all these amps use the same controller and go from -0db to 60db.

Hmm but i get around 85db when i'm on 30 35 volume on A300 with 85db sensitivity speakers.

 

[Johannesthalos]

Hmm but i get around 85db when i'm on 30 35 volume on A300 with 85db sensitivity speakers.

https://www.nisshinbo-microdevices.co.jp/en/pdf/datasheet/NJW1194_E.pdf

Look at page 20 characteristics. It is all linear, but maybe I am missing something.

 

[Kitarist]

Basicly just did measurements again with db meter i get like 75db on 40 volume. So in theory its not even outputting 1 watt at 40 volume ? Is possible my drivers are so hard to drive? I have Fullrange Markaudio Pluvia 7HD

 

[Johannesthalos]

Are you using the internal DAC of the A300? If so try putting an external DAC to it to see if it's the DAC causing lower volume/gain than expected.

 

[Kitarist]

Yes i'm using the internal DAC, also tried bluetooth and line in both same thing Also i think the volume on amp works as LOG when you increase it.

 

[Toku]

Are you using the internal DAC of the A300? If so try putting an external DAC to it to see if it's the DAC causing lower volume/gain than expected.

The A300's USB input is a simple bonus function that uses the DAC function of the BT module. This is the same method as AO200.
The USB input sampling rate is fixed at 48kHz 16bit, and the input level is about 6dB lower than RCA.

 

[Kitarist]

The A300's USB input is a simple bonus function that uses the DAC function of the BT module. This is the same method as AO200.
The USB input sampling rate is fixed at 48kHz 16bit, and the input level is about 6dB lower than RCA.

So the bluetooth also is 6db lower than RCA?

 

[Toku]

https://www.nisshinbo-microdevices.co.jp/en/pdf/datasheet/NJW1194_E.pdf

Look at page 20 characteristics. It is all linear, but maybe I am missing something.

The change in volume at the bottom of page 20 is represented by logarithmic change in db, not linear.
In terms of volume pot, it is the change characteristic of taper A.

 

[Kitarist]

Yea i thought so. Thanks for answering my questions

 

[Toku]

So the bluetooth also is 6db lower than RCA?

BT and RCA levels are the same.
I think that the reason why the level does not match with USB is that the level cannot be easily adjusted because the DAC function of the BT module is used.

 

[TonyJZX]

Just to clarify... 85w is basically at untenable THD? Like 5-10%?

At realistic THD say... 0.05% is power still at say 75w? less?

 

[keenerz]

for those using the master-slave mode how do you balance these things. I just setup two of them in BTL mode just trying to balance them out is little tricky, I have the right one set like 6(db?) higher than the left one.

edit: gonna experiment with two separate "left" channels

 

[Toku]

for those using the master-slave mode how do you balance these things. I just setup two of them in BTL mode just trying to balance them out is little tricky, I have the right one set like 6(db?) higher than the left one.

edit: gonna experiment with two separate "left" channels

Please read my report on page 3. I've posted a few about BTL connections.

New SMSL A300 BTL Class-d Power Amp

Immediately after purchase, the sound quality is very high resolution, transparent and smooth, which is my favorite sound quality. I switched to the A20a 2022 and compared it, but the sound quality is very similar and I can't clearly distinguish it. Let's see how it changes over time. Any...

www.audiosciencereview.com

 

[nsfgp]

for those using the master-slave mode how do you balance these things. I just setup two of them in BTL mode just trying to balance them out is little tricky, I have the right one set like 6(db?) higher than the left one.

edit: gonna experiment with two separate "left" channels

Yes please try both Master-Slave method(Using BTL-R loop back RCA R-ch out to slave) and direct-BTL (L-ch only on both) mode.
6 steps on the volume is significant.
In your Master-Slave setup => have you tried swapping the 2 unit (old master becomes new slave while keeping all source settings the same) and does the R-ch becomes the louder channel??