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Sleepless night, but productive

  • Thread starter Deleted member 65547
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Deleted member 65547

This night, instead of sleeping, I decided to conduct some experiments. Initially, the idea was to instrumentally measure the distortion of a Class D stereo amplifier with coupled inputs and outputs.
The expected result was less distortion due to the halved workload for the output rolloff's ferromagnetic cores.
Then, since the amplifier was ready for testing, I thought to myself, why not listen to how it sounds? So, I connected it to the right channel of the small system I keep in the living area, and it seemed to sound good. However, judging with just one channel is unreliable, so I took a second identical amplifier, made the same connections, and it ended up on the left channel.
First problem: volume control.
The two amplifiers are identical, but it's hard to be sure I adjusted both to the same level. So, volume at maximum and adjustment from the DAC... obviously it worked and sounded good, but goodbye Bit Perfect.
I remembered having it... I rummaged through half the house, and in the end, the little box you see between the two amplifiers emerged: now I had both stereo volume and tone control!
Well, forget about the measuring instruments and let's hear how it sounds.
It sounds, it sounded really good!
Better than a pair of mono amplifiers from the same company, probably because in mono amplifiers, there are no rolloff cores sized for double the power, or at least I think that's the explanation.
At that point, another experiment came to mind: is there an unbalanced Topping DAC that uses a dual AK4493S, a configuration that has always intrigued me? But I can beat it, I thought... I have a pair of SMSL Sanskrit MK3 using AK4493SEQ (actually, I have three)... what happens if I pair them using the same method as the amplifiers?
Well, it happens that it does sound a bit better (emphasis on "a bit"). Why it sounds better, even if only a bit, is not very clear to me. In this case, there are no magnetic fluxes to halve. Yes, I agree, I'm halving the output impedance and loading the analog output of the chips less, but we're talking about minimal power levels. However, the fact remains that there is a slight improvement, and since I didn't have to buy anything more than what I already had to get it, that's fine!
At that point, it was five in the morning, and I was eager to turn up the volume, but of course, if I had done that, I would have had the Police at the door.

8 AM arrives... now I can try it out... a bit of volume. It sounds good, damn, it sounds really good!

Next step, open the Aiyima amplifiers and replace the electrolytics to switch to the 53V power supply used with the Fosi Audio amplifier (currently 32V on the Aiyima), so I can give it some serious volume.

However, collateral problem: I thought I had simplified the configuration of the main stereo by going from six mono amplifiers to three stereo ones, but after this experiment, I think I'll go back to six amplifiers (now stereo configured mono) and... six DACs.
Curse me when I don't go to sleep at night!

P.S: Please don't mind the mess of wires and power supplies; it was the middle of the night.


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