Hi,
Has anyone been testing the Dither modes on the PMD-100?
It is used with PCM63P in my setup. It should be easy to implement a switch "Dither on/off" according to the datasheet?
How does dither sound, and why is it typically NOT used?
😉
Has anyone been testing the Dither modes on the PMD-100?
It is used with PCM63P in my setup. It should be easy to implement a switch "Dither on/off" according to the datasheet?
How does dither sound, and why is it typically NOT used?
😉
I don't think you need it if you're using a 20 bit PCM63P, but if you're using the PMD100 to feed 16-bit DACs I'd probably use it.
Rigging a PMD100 to turn dither on/off should be pretty simple to do - tie the DITH pin one way with a resistor, and switch it the other way with a toggle switch or something. Then put on some music and toggle the switch back and forth and see what you prefer.
Rigging a PMD100 to turn dither on/off should be pretty simple to do - tie the DITH pin one way with a resistor, and switch it the other way with a toggle switch or something. Then put on some music and toggle the switch back and forth and see what you prefer.
Yes, that was my idea...to have a switch to judge by....
I just wondered why noone other had tried this?
I just wondered why noone other had tried this?
I have one for my TDA1541A DAC. I admit I haven't really played with it. Very quickly tried it once, and I'd say the difference is subtle.
I might go and have a play and see if I can hear anything less subtle 🙂
I might go and have a play and see if I can hear anything less subtle 🙂
While the PMD-100's dither is non-adjustable, the PMD-200 offers a choice of several dither modes from none to maximum. In addition to having different gross magnitudes, the dither modes also use different algorithms to produce their dither. We ran in the factory default of minimum dither. (The no dither mode is disrecommended for listening purposes by Pacific Microsonics.) Comparing the different available dither modes would be an interesting future experiment.
http://www.jeffchan.com/audio/filter-comparison.html
http://www.jeffchan.com/audio/filter-comparison.html
Taken from below link:
"While the PMD-100's dither is non-adjustable, the PMD-200 offers a choice of several dither modes from none to maximum. In addition to having different gross magnitudes, the dither modes also use different algorithms to produce their dither. We ran in the factory default of minimum dither. (The no dither mode is disrecommended for listening purposes by Pacific Microsonics.) Comparing the different available dither modes would be an interesting future experiment. "
http://www.jeffchan.com/audio/filter-comparison.html
"While the PMD-100's dither is non-adjustable, the PMD-200 offers a choice of several dither modes from none to maximum. In addition to having different gross magnitudes, the dither modes also use different algorithms to produce their dither. We ran in the factory default of minimum dither. (The no dither mode is disrecommended for listening purposes by Pacific Microsonics.) Comparing the different available dither modes would be an interesting future experiment. "
http://www.jeffchan.com/audio/filter-comparison.html
In trying to implement dither in my Rotel RCD-971, I just realized that the player har dither as standard 😀
Pin 4 on PMD-100 is connected to 5V via 10k resistor....
So I guess I still have haven't heard PMD-100 WITHOUT dither 😱
Pin 4 on PMD-100 is connected to 5V via 10k resistor....
So I guess I still have haven't heard PMD-100 WITHOUT dither 😱
Hi,
Well, I tried with or without dither on mine last night (feeding dual TDA1541A) and I have to say it was immensely subtle, if noticable at all.
I think I *might* have heard a better soundstage, or more detail, but I could also be kidding myself.
Cheers,
Phil
Well, I tried with or without dither on mine last night (feeding dual TDA1541A) and I have to say it was immensely subtle, if noticable at all.
I think I *might* have heard a better soundstage, or more detail, but I could also be kidding myself.
Cheers,
Phil
With max dither, same settings on the 7L5.
centre of the screen is 50kHz and it's 10kHz per division.
So you see 0 to 100kHz. Peek at 0 kHz is not there in real live, comes from the SA.
Top is at -40dB and it's 10dB per division. So -40 to -120dB on the screen. But don't think this thing is calibrated after decades.....
But you can clearly see the difference: Much more noise outside the audio band, but a few dB less within the audio band.
centre of the screen is 50kHz and it's 10kHz per division.
So you see 0 to 100kHz. Peek at 0 kHz is not there in real live, comes from the SA.
Top is at -40dB and it's 10dB per division. So -40 to -120dB on the screen. But don't think this thing is calibrated after decades.....
But you can clearly see the difference: Much more noise outside the audio band, but a few dB less within the audio band.
Attachments
Yes, I'm sure my quiet listening conditions and other weak links meant I couldn't discern much difference - if any. I need to sort out other problems first.
Good traces, really demonstrate the effects!
Cheers,
Phil
Good traces, really demonstrate the effects!
Cheers,
Phil
When starting upgrading the player I found something interesting. The Rotel RCD-971 has a jumper for turning the dither on or off. It is located close to the PMD-100 chip.
I did not notice it before, because it is not in the schematic, there dither is permanent connected (10k to +5Vd), but in layout you can se the jumper...
So, everyone can easily test the dither influence...
As I have made a discrete I/V stage without filter, directly after the PCM63, I have disided for the non-dither, perhaps because of the increased HF noise might upset my system further down...
🙂
I did not notice it before, because it is not in the schematic, there dither is permanent connected (10k to +5Vd), but in layout you can se the jumper...
So, everyone can easily test the dither influence...
As I have made a discrete I/V stage without filter, directly after the PCM63, I have disided for the non-dither, perhaps because of the increased HF noise might upset my system further down...
🙂
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