Does anyone have info about the clock used in the Musical Fidelity M1 DAC - photo for an early model is below but the later ones look similar. Ideally I would like to view the datasheet - reason for asking is I am looking to replace it with TCXO or maybe OCXO - natrually I'm interested if someone has alredy done similar.
This is a typical all-in-one crystal oscillator. The frequency is written on the top in MHz. Three of its four legs are used: Vcc (3.3 V or 5 V, you can find it with a DMM), GND (connected to the case), oscillator output. The latter is usually a TTL-compatible square wave, not sine. The fourth leg does nothing.
What's wrong with the original oscillator?
TCXO an OCXO are terms related to absolute frequency stability. You won't hear that small frequency deviation from the nominal even if you have absolute hearing. The important parameter in a DAC is signal clarity (phase noise or jitter) that is seldom specified, and it is difficult to measure. Unless you know the jitter specs of the original oscillator, how can you find any better?
What's wrong with the original oscillator?
TCXO an OCXO are terms related to absolute frequency stability. You won't hear that small frequency deviation from the nominal even if you have absolute hearing. The important parameter in a DAC is signal clarity (phase noise or jitter) that is seldom specified, and it is difficult to measure. Unless you know the jitter specs of the original oscillator, how can you find any better?
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Thanks for taking the time to reply. I'm aware of what you write and have looking at specs for different oscillator, some do specify jitter and noise.
If I had the data sheet for the one fitted, I may be able to find a device that has better spec. I don’t know if I'd be able to hear the difference but isn't that part of the fun of tweaking?
I'm aware that TCXO and OCXO have better long term frequency stability and it is short term deviation - jitter - is what can be heard.
If I had the data sheet for the one fitted, I may be able to find a device that has better spec. I don’t know if I'd be able to hear the difference but isn't that part of the fun of tweaking?
I'm aware that TCXO and OCXO have better long term frequency stability and it is short term deviation - jitter - is what can be heard.
That looks like a standard oscillator frequency.
For CD players, some info at:
https://www.tentlabs.com/Components/cdupgrade/xo2xo3/index.html
https://www.tentlabs.com/InfoSupport/page21/page21.html
Also, you may or may not find that jumpering out any ferrites in the clock power circuit may help the sound.
A linked article on the history of ferrite use in PCB power distribution systems attached to a post at:
https://www.diyaudio.com/community/threads/general-purpose-dac-clock-board.413001/post-7765137
For CD players, some info at:
https://www.tentlabs.com/Components/cdupgrade/xo2xo3/index.html
https://www.tentlabs.com/InfoSupport/page21/page21.html
Also, you may or may not find that jumpering out any ferrites in the clock power circuit may help the sound.
A linked article on the history of ferrite use in PCB power distribution systems attached to a post at:
https://www.diyaudio.com/community/threads/general-purpose-dac-clock-board.413001/post-7765137
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