I assume there is enough signal coupling to the mains due to interwinding capacitance in the supply transformer that runs your shigaclone, ( or do you have 3 wire power connection with safety ground?) and in the audio amplifier supply that connects to that dac either through a safety ground or the interwinding capacitance of that power transformer.
Incidentally you should properly terminate the spdif coming out of the shigaclone with the 300/100 ohm (or other combo posted here that gives a 75 ohm source) In some instances you may damage the spdif receiver IC in the dac with such high levels, (Ones designed to operate on 3.3V supplies or less.) and they actually can perform quite poorly when overdriven. Somewhere between 500mVpp and 1Vpp is acceptable.
I am not sure whether or not the rest of your equipment provides sufficient resolution to allow the Shigaclone to sing. Getting the source right however is a very good start..
I agree. Based on my experience, different mechanical setups can lead to very different sonic results.
Thanks for your support kevinkr.
As i sad before the only thing connected to mains was the shiga clone.
The dac was powered with battery, listening to headphones just to verify
any ground loops.And it still worked with only the lead connected.It didnt
sound crackled but not specially good either.
Yes i understand that mounting the transport is important but that wasnt the main thing now, sorry, i maybe blaming for sound as an ordinary player to quick.
I have excellent sound thrue my Tripath 3020-Kingrex T20-Behringer dcx2496,passive mod-Monacor sph 200ke-Seas T25CF002.
I think i buy a new one and start over.
Display Problem
Hi All,
I just installed everything in line with my new DAC and am very, very pleased with the overall sound.
Thanks to Peter and the others who have given me advice on the way.
The Shigaclone, which is albeit still not housed, is quite noisy mechanically. I installed a completely new mechanism but there is a lot of gear noise when changing tracks and even the motor which spins the CD is audible from close range. I don't know how much the housing that I eventually make will contribute to reducing these noises. I do think I saw some other remarks on this topic somewhere in this thread but don't remember seeing any remedies. Anybody have any ideas. What is that white grease they use. Maybe I can put some more on the gears.
Another problem is that my display does not show the 2 of 20 correctly , see pic. Anybody have an idea what's causing this. I have had the ribbon between display board and main board in and out a lot of times but I don't think the problem is there, although it could be.
Hi All,
I just installed everything in line with my new DAC and am very, very pleased with the overall sound.
Thanks to Peter and the others who have given me advice on the way.
The Shigaclone, which is albeit still not housed, is quite noisy mechanically. I installed a completely new mechanism but there is a lot of gear noise when changing tracks and even the motor which spins the CD is audible from close range. I don't know how much the housing that I eventually make will contribute to reducing these noises. I do think I saw some other remarks on this topic somewhere in this thread but don't remember seeing any remedies. Anybody have any ideas. What is that white grease they use. Maybe I can put some more on the gears.
Another problem is that my display does not show the 2 of 20 correctly , see pic. Anybody have an idea what's causing this. I have had the ribbon between display board and main board in and out a lot of times but I don't think the problem is there, although it could be.
Attachments
Most likely the problem with the display is the cable. Its a hard one to solve without a spare cable to hand....
Mech is noisey alright, but surprisingly quiet when its in a case. I don't hear any noise when playing, but at end of the CD I can hear the noise as the sled moves to home. Greasing most likely won't help - and be careful as you don't really want a dust magnet in there.
Solve: Don't know about your situation. So you don't have any ground connection between the shiga output and the DAC? What is the shield of the coax cable connected to? Chassis is important to the sound of this thing. i remember somewhere someone saying chassis was 40% of the sound - and I would tend to agree with that.
Pics might help...
Fran
Mech is noisey alright, but surprisingly quiet when its in a case. I don't hear any noise when playing, but at end of the CD I can hear the noise as the sled moves to home. Greasing most likely won't help - and be careful as you don't really want a dust magnet in there.
Solve: Don't know about your situation. So you don't have any ground connection between the shiga output and the DAC? What is the shield of the coax cable connected to? Chassis is important to the sound of this thing. i remember somewhere someone saying chassis was 40% of the sound - and I would tend to agree with that.
Pics might help...
Fran
No ground connected, just the shiga to main.
No shield just beacuase it shoudnt work without
and it does...
Spdif is RF so it is quite possible that stray capacitance to other nearby devices is providing sufficient ground path for the receiver to recognize what is probably a very distorted and degraded waveform. (Capacitance between the dac case/pcb and shigaclone chassis might be enough if sufficiently close for some level of electro-static coupling to occur.) I wouldn't get too obsessed over this issue - I suspect lengthening the cable and moving the dac further away from the shigaclone chassis will result in a non-functioning dac with no ground connected as you would expect. Honestly speaking you are wasting your time.. Move on!!
No, use the circuit detailed elsewhere on this thread (300/100) - it provides the proper loading on the DSP digital output, the proper attenuation required for the SPDIF standard, and the proper terminating impedance for the coaxial cable. What more do you want?
The dsp chip's digital driver stage on the spdif output is guaranteed for about 11 - 12 mA - your T attenuator will overload it, degrading performance and causing unnecessary die heating, possibly it will destroy the driver as well over time. Note that the T attenuator is meant to be driven by a source impedance of 75 ohms, not the < couple of ohms of source impedance provided by the Sanyo DSP IC.
I recommend using proper 75 ohm BNC jacks and plugs as opposed to the usual RCA jack which is not 75 ohms (more like 110 - 120 ohm IIRC). All my digital is handled this way, and IMHO it does make a difference.
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Usually there is a capacitor ahead of the spdif receiver input, and the spdif pulse transformers don't seem to have a problem with the dc either, but it cannot hurt as long as you use the appropriate capacitor in this application. Hint:It should not be an audiophile grade film/foil cap.. Think RF, precision COG/NPO types with low internal inductance.