Absolutely horrible was an overstatement. By noise I mean some kind of unpleasant distortion. I took a while before I noticed it, and I would not be surprised if a lot of people are impressed by the sound. But in the long run, it's better without the metronome.
It was wired up correctly and set up as recommended, unfortunately. 😉
It was wired up correctly and set up as recommended, unfortunately. 😉
Did you try any kind of shielding around the metronome? Maybe something is getting in? I was impressed by the one build where he used the unetched PCB for shielding for power cables and what not and he said it got rid of his problems? Just an idea I just find it strange not more people have picked this up. I won't have the metronome for a few weeks so won't be able to say from a first person point of view I just find it odd is all.
Thanks Guys.
(Martin, maybe we can pick up this conversation over a glass of ale soon!)
I shall have my metronome and Opus boards up and running soon with any luck, so I'll be able to add my experiences with this combination then. I am not using any SPDIF connections, so that should be one less variable in the mix.
In terms of physically locating the boards, there are certain minor compromises in terms of fitting everything into the space I have available and I have the choice of either 15-20cm I2S cabling and nice short runs between the Metronome, 2 DACs and Ballsie, with a short run to the output sockets. Or a few centimetres to the Metronome/Opus's and longer analogue signal runs. It would seem that is the better approach.
Given there are a few regulators and the transport in the same physical space, maybe shielded signal cables would be advised. Comments, advice, welcome.
Mark
(Martin, maybe we can pick up this conversation over a glass of ale soon!)
I shall have my metronome and Opus boards up and running soon with any luck, so I'll be able to add my experiences with this combination then. I am not using any SPDIF connections, so that should be one less variable in the mix.
In terms of physically locating the boards, there are certain minor compromises in terms of fitting everything into the space I have available and I have the choice of either 15-20cm I2S cabling and nice short runs between the Metronome, 2 DACs and Ballsie, with a short run to the output sockets. Or a few centimetres to the Metronome/Opus's and longer analogue signal runs. It would seem that is the better approach.
Given there are a few regulators and the transport in the same physical space, maybe shielded signal cables would be advised. Comments, advice, welcome.
Mark
Goto said:
Modern 75 Ohm multi-video-cables like these:
An externally hosted image should be here but it was not working when we last tested it.
are perfect for I²S connection. This way, you don't have to worry about 15 or 20 cm of cabling.
I would shield any SE signal wires. Balanced signal wired should be fine, but shielding wouldn't hurt.
Hi Painkiller,
It sounds as though your system (with the Metronome) has some noise contamination issue. Try fitting ferrite beads to the signal wires (NOT the ground) between Metronome and Opus, then evaluate any difference.
The other route is the PSU. Ideally the Met and Opus will have seperate PSUs (seperate transfomer windings) to isolate any ground return paths. Otherwise try fittting a ferrite clamp or two over the PSU inlet wires.
Or just stay as you are without the Met! Someone here fitted a high quality clock to the WM8804 receiver board to good effect, if you are interested.
Dan
It sounds as though your system (with the Metronome) has some noise contamination issue. Try fitting ferrite beads to the signal wires (NOT the ground) between Metronome and Opus, then evaluate any difference.
The other route is the PSU. Ideally the Met and Opus will have seperate PSUs (seperate transfomer windings) to isolate any ground return paths. Otherwise try fittting a ferrite clamp or two over the PSU inlet wires.
Or just stay as you are without the Met! Someone here fitted a high quality clock to the WM8804 receiver board to good effect, if you are interested.
Dan
Painkiller,
The WM8740 seems to me to sound better at 96khz (or even 48khz) than at 192khz. I think this is because of the digital filters. You might just try changing your setup a bit and see if you like it better. 🙂
I trust you followed directions, but I suspect something must still be wrong as your perception is quite the exception to the rule. I am confident it is something very fixable.
Still, use it or don't, its your preference and enjoyment that matters.
Cheers!
Russ
The WM8740 seems to me to sound better at 96khz (or even 48khz) than at 192khz. I think this is because of the digital filters. You might just try changing your setup a bit and see if you like it better. 🙂
I trust you followed directions, but I suspect something must still be wrong as your perception is quite the exception to the rule. I am confident it is something very fixable.
Still, use it or don't, its your preference and enjoyment that matters.
Cheers!
Russ
Yes, I had some background noise at 192kHz. After a bit of switching back and forth I concluded that the 48kHz setting was noise free. Maybe I'll try to get hold of a WM8741 and see if it's responding better to higher sampling frequencies. They are awfully expensive though. 
There could be a shielding issue which causes distortion/noise with the metronome. I don't know. Maybe I'll reconnect it in a couple of weeks. Then it'll be easy to identify any differences. For now I'll just enjoy the sound without the Metronome. The Opus is really a great dac!
There could be a shielding issue which causes distortion/noise with the metronome. I don't know. Maybe I'll reconnect it in a couple of weeks. Then it'll be easy to identify any differences. For now I'll just enjoy the sound without the Metronome. The Opus is really a great dac!
short wires from the 8804 to the metronome to the DACS cured all my noise problems. Metronome sounds really fine. Better with than without.
Painkiller said:
Yes, it is. I was listening to music last night and early today, and both times I just couldn't believe the fidelity of my system. It's hard to imagine much better, but there must be some reason for $10k+ sources, right?
fierce_freak said:
I'm running a variant on the OPUS with a receiver module and slightly modified mono CODS and IVY which I built over the course of a few days. They differ significantly in component values and brand from the built up modules with one of the biggest differences being that I used PCM1798 dac chips on hand instead of the 1794 which is relatively costly. The supplies are my own design and I am using output transformers to convert the balanced outputs from the THS4131s to unbalanced.
I am very impressed with the dac, I have not had much time to listen to it so far, but it seems to get better as I get a few hours on it. (Caps forming, etc.) It is better than any other dac I have owned so far.
langtuhanoi said:
Hello,
In regard to the Opus (WM8740/8741) well to be honest, I can only answer I don't know if it is a class A filter section. I can't really be sure how it works. 🙂 It is a voltage output DAC, so there is no output stage required at all, just the DAC chip.
Now, I do have a discrete output stage (I/V converter) for the COD (a different DAC module I designed for the PCM1794/1798), which is in development (I have tested it) which is run class A.
This is the active stage I am working on:
http://www.diyaudio.com/forums/showthread.php?postid=1444986#post1444986
More correctly it is a super symmetrical amplifier which is especially suited for I/V conversion. 🙂
Kevin is running a couple of COD boards with yet another I/V stage I designed called the IVY, it runs class A or A/B, for I/V purposes into > 4.7K load or so it will definitely be running class A. It is based on the THS4131.
Cheers!
Russ
I just read the informations about Wolfson WM8741, it is great chip what it have a volume control intergrated on chip. It is we can use this chip in DAC and Preamp mode combo with volume control? It is the big difference between WM8740 and WM8741?
When you finished the DAC with WM8741?
Is it much better between WM8741 chip and ESS Sabre8 chip?
Thank
When you finished the DAC with WM8741?
Is it much better between WM8741 chip and ESS Sabre8 chip?
Thank
I'm pretty sure the Sabre is going to be quite a step up from the 8741. But that doesn't mean the 8741 is bad at all in fact its very good.
The WM8741 is not yet in full production, and we have been unable to even get samples yet. Wolfson reps tell us they will be available soon, but that daye seems to keep shifting. The current Opus board is designed to support the 8741, whenever they are available.
We also have not heard the Sabre, so any comparison at this point would be 100% speculation on our part.
We also have not heard the Sabre, so any comparison at this point would be 100% speculation on our part.
yes, by connecting the I2S connections to the DAC board.
I think you have to disable the analog outs for the USB board to make the I2S work... I may be wrong though.
I think you have to disable the analog outs for the USB board to make the I2S work... I may be wrong though.
Pulse-R said:
Indeed on the dddac usb board you have to disable analogue out to get I2S out (just a jumper). For the pin out, I thought it would be possible just that the pin-out labelling is different on the dddac and opus usb boards:
dddac USB: DATA - FS - BCK - GND
Opus USB: BCK - SCK - LRCK - DOUT - GND
... and trying to figure out from the schematics which match which, if at all...
ssmith said:
It would work except its missing a master clock output (should be 128, or 256fs or so).
You have a couple simple options here.
1) Find it (it may be on the PCB maybe I am just missing it).
2) Use the metronome. This way you can use its master clock. You don't input a master clock into the metronome, just wordlock (fs), bitclock (bck), and data.
Cheers!
Russ