They had only 9v feeding them because that's the voltage linn had to play with given the penny pinching decision to continue using one of their existing smps, it wasn't a musical choice, it was a fiscal one.
I doubt it was the reason . Its a very expensive player. They use a very soft power supply ( If you read the whole modification thread you will understand.) The reason for this is probably to gain less noise, and (maybe) to have a softer more mellow sound. The power supply in the Akurate DS is so soft it collapses from 16 V to 10,6 volt , and after the regulator its only 9 volt.
From Google translate:
”and I did some measurements on his Akurate DS. The situation is more difficult than I thought. First of all, it is actually clear what needs to be done. I count on:
The clock fraction looks decent, but the power supply of the clocks can clearly be improved - this power supply is quite crucial for the achievable cleanliness of the clock signals.
The exit stages. Oh man, same drama as in the O-Sneaky. Although LM4562 are already in there as OPs (good!), but then 300 ohms output resistance :roll: . Sure, there have to be output buffers. However, six pieces, two for the asymmetrical outputs and four for the symmetrical. The assertion in the audio test that discrete output buffers with Mosfets came after the OPs is a clear misinterpretation by the author: Both in the Akurate DS and in the Akurate DS/1, the Mosfets are only responsible for muting. This also applies to the Majik, which has the same circuit board but is not fully populated.
The RCA outputs of the O-Akurate are simply fed from the OP output, which is responsible for the positive half of the symmetrical signal. That's half-assed. That the RCA output is supposed to be the better one, as is sometimes claimed in the Linn forum (I'm not reading along there, but I was told that) is, from a technical point of view, sheer nonsense. You then only hear with half of the built-in DA converter. If you don't want to neglect the cinch outputs, you would have to do it like this: Take the symmetrical signal, calculate the difference with an OP and then feed the outputs via their own output buffers.
The output stages of the Akurate DS are only supplied with +-9V. That's a bit little in my experience. Above all, the output buffer should be supplied with at least +-12V. And there lies the problem: The original power supply does not supply enough voltage. In standby it's -19V and +16V, which come from the power pack (was already a dynamic or whatever the newer name is). But they collapse to -13.8 and +10.6V when the Akurate is turned on. This is just enough for the positive supply half so that the low-drop regulator (LM2941) can still work with the remaining difference of 1.6V. The power pack is designed to be extremely "soft". If I branch off 6x 15mA for the six buffers, 20mA for the clocks and 10mA for a double OP, i.e. a total of 120mA, the voltage of the power supply, which is much too meager for my taste, collapses completely.
Now you could say, ok, you need your own power supply for the additional installations. There's enough space in the case. However, this approach would torpedo the Linn concept that no 50Hz mains hum occurs in the electronics housing because the completely encapsulated switched-mode power supply already supplies DC voltage to the electronics compartment.”
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my thoughts:
I have tested driving lm4562 and the opa2604 with low voltage and the dynamics are clearly better with 15 volt. This is my (limited) experience .
