This morning i upgraded to new firmware. With VU i can now see i have also low output. Approx. 48db - 35. If volume is set at -30dB.
If i play loud volume is around -24dB.
But never as low as -72dB.
I have used different digital sources the last year. And upgrading from Allo DigiOne to Digione signature did matter. Recently changed the RPI to the USBridge signature and got the Shanti as power supply. Also a change fot the better in my opinion.
Well, I don't want to be the one pointing the finger at me, but it reminds me of when I got my dedicated digital player. Well, I didn't think before that it could sound so much better than a PC (with digital output as well). After a while, however, I noticed that both source devices sound the same (of course). So after the magic of the new toy had passed, the perceived difference was gone, no matter how I tried to hear it.
Indeed removing Rg reduces the gain of the first (differential) stage, with about 13 dB. You also need to investigate whether you need headroom for boosting filters. E.g. in my case on channel1 I do a +12 dB boost on low bass frequencies (around 30 Hz), and may add 3 dB more bass boost later. As I have the channel gain at 0 dB, I should not go over -15 dB master volume to avoid clipping at the output. Furthermore, I do -8 dB on channel3. In my current understanding, I will lose almost 2 bits due to this attenuation, so biquad processing will be with 22 bits precision effectively. So probably it is better to do +8 dB on channel1 instead. But this would change max volume to -23 dB.
All in all, I am considering to give channel1 additional gain and headroom. Maybe I will put the resistor back. Noise was not such a big issue for this woofer anyhow. So I would recommend to skip modding channel1, probably max power is still required there.
Fedde
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By the way, it is not so strange that with the initial configuration, sound quality was not so good. With a master volume I used of -54 dB, you would lose 9 bits. On PC side I had one more bit for pre EQ headroom. So I already lost about 10 bits of the 24 bits, making it a 14 bit solution (assuming music at full 24 bit level, even less bits for softer material). And that would assume you get the LSBs out, but given the system SNR of about 110 dB.... probably not. With the Rg remove mod and removing pre EQ, I get three more bits which helps. But this is still not optimal IMHO.
Fedde
Fedde
No DAC out there is any better than 22 bits. Not that it matters, I haven't come across source material or listening rooms that do better than 16 bits.
Gain and headroom are kind of opposite things - less gain gives more headroom.
14 bits is still at least 2 bits more than vinyl.
As to "softer material", show me any modern recording that doesn't use the top 6 dB (so top bit)...
How do you mean that it not fills the ADC properly? The Soekris DAC doesn't put out the standard 4V on XLR?. This is would be almost enough for max power output because the Fusion needs 6.15V (2.18V with RCA) for max power at default and 2.18V (0.98V with RCA) for max power can be selected with a jumper soldering.
The problem is that you lose MSBs, not LSBs. So even if the fusion had effectively 22 bits, by losing two MSBs it would become 20 bits. But indeed, 20 bits is not too shabby yet...
Regarding headroom, I was referring to avoiding digital clipping. By raising amp gain, it will be less likely that digital clipping will occur. And I could remove tweeter attenuation...
Fedde
Then you can drive the Fusions to almost full power at default, and more than full power with adjusted analogue input gain.
Many times, for some reason whenever I shut the amp off and power it back on it reverts back to -96... but only when it's in slave mode, in Master it doesn't do this, it keeps it's volume where it was before it was powered down.
Not sure about the digital mode, I will check and report back.
Which is most sensitive? 1 or 4?
I did set the slave volume. I've tried setting it and I've tried the "lock" feature but nothing works; in slave mode, whenever I shut the amp off then power it back up the volume returns to -96.