You are still ignoring the Loop created before the DCB1 where both the Source and the DCB1 have commoned Returns.Can use double core and return the shield to one end only if there is some measurable interference problem in a system. I haven't seen hum region or other interference spikes rising above -118dB in conventionally wired DCB1 with coax when looped through a 24 bit audio card.
It's the commoned returns at BOTH ends that creates the loop.
coax and other screened cables does not remove that loop.
type d.joffe into search.Wher can I read about The standard D.Joffe explained solution?
there are about a dozen mentions in the past year, some now have live links to his paper.
This is the short, concise, to the point response I have been seeking for nearly two weeks! Thanks so much.
No prob, glad I could help.
type d.joffe into search.
there are about a dozen mentions in the past year, some now have live links to his paper.
K. Found a pdf posted by you. http://www.updatemydynaco.com/documents/GroundingProblemsRev1p4.pdf
Coffee time
I'm using a tablet today and my patience has all but gone with it now. I'm trying to source an affordable cable in the UK which has low capacitance and would be good for 5m interconnects. I thought of blue jeans lc-1 but its way overpriced here and seems to only be available pre terminated. Next I tried to find some suitable mogami cable, no capacitance or any other spec on their site and i cant find any off the reel anyway. Why is such a simple task so dam hard in this country?
Use a low source output impedance and the cable capacitance becomes less of an issue.
100r for Rs can drive 1nF of cable and attenuation capacitance to an F(-1dB) of ~ 800kHz
Rs=50r can drive 10nF to an F(-0.1dB) of ~30kHz
where's the problem?
A B1 and DCB1 has Rs ~ 250ohms.
100r for Rs can drive 1nF of cable and attenuation capacitance to an F(-1dB) of ~ 800kHz
Rs=50r can drive 10nF to an F(-0.1dB) of ~30kHz
where's the problem?
A B1 and DCB1 has Rs ~ 250ohms.
I'm chasing the ideal in a less than perfect world, not really a problem as such. The van damme stuff is higher in capacitance than l would have liked but will still work. Just as well too. It's all I can afford at present and decent alternatives that are available here in the UK seem few.
I am sorry I failed, you.
It seemed from my perspective that the routes were quite clear.
Source >> interconnect >> Receiver
It's that simple !
Andrew,
You didn't fail me. On the contrary, you provided much needed information that I will be able to use in future builds. I prefer to think of the problem as one related to the inadequacies of email. Thanks for all your patience and help.
If you get noise/hum picked up then yes, if not then whatever floats your boat. I did the same thing using ballanced mic cable at one point, one core each for the signal feeds and the screen for common return. I had a bit of hum so i changed to twisted pairs. Turned out it wasn't the cable at fault anyway......
This discussion about loops is very interesting. I can figure out just this... In my "still cabriolet" build I used just the three wires, so only one return. Is that so bad?
Based on measurements of the DCB1 i would say that is not a problem.
I'm chasing the ideal in a less than perfect world, not really a problem as such. The van damme stuff is higher in capacitance than l would have liked but will still work. Just as well too. It's all I can afford at present and decent alternatives that are available here in the UK seem few.
Canare star quad cable Canare Corp.: Star Quad Microphone Cables: Star Quad Microphone Cable(L-4E6S / L-4E5C) sounds as good as any to me, and better than many others, including some exotic and ridiculously expensive things I've tried. Needs to be wired appropriately. Surely easily available in the UK...
Canare star quad cable Canare Corp.: Star Quad Microphone Cables: Star Quad Microphone Cable(L-4E6S / L-4E5C) sounds as good as any to me, and better than many others, including some exotic and ridiculously expensive things I've tried. Needs to be wired appropriately. Surely easily available in the UK...
Canford have it at £1.58 per metre ex vat but they list it's capacitance at 160pf/m which is quite high. I spent 6 hours yesterday trying to source affordable low cap cable, gave up in the end and ordered 5m of the van damme stuff i linked to earlier. £24.40 delivered.
Almost everything commonly used has to be imported and most low cap cable comes from the US. It seems they like to price themselves out of the market
I dont have a capacitance meter or access to my old workshop so i am going by ear. My current VOM does not go low enough to record an accurate total resistance but it is very low, it sees a short circuit so it's useless in this case. The volume seems about the same as it was with 0.5m interconnects, there is no noticable difference in level or sound quality at any setting. Thats good enough for me.
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DSC00845 - My Photo Gallery
I need help with wiring my Antek As-0515 Toroidal transformer to my IEC power inlet. I have referenced above photos of the inlet that has on/off switch, fuse in one housing. The back of the inlet shows terminals A,B,C and D as well as a Safety/ground terminal. The question is how to wire the four transformer wires from the primary to the inlet terminals.
Inlet is a Tyco Electronics PE0SSSSX0
DSC00845 - My Photo Gallery
I need help with wiring my Antek As-0515 Toroidal transformer to my IEC power inlet. I have referenced above photos of the inlet that has on/off switch, fuse in one housing. The back of the inlet shows terminals A,B,C and D as well as a Safety/ground terminal. The question is how to wire the four transformer wires from the primary to the inlet terminals.
Inlet is a Tyco Electronics PE0SSSSX0
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Your second diagram shows how to connect the filtered power inlet to your transformer and where to place the jumpers depending on mains voltage. I take it you are in the states and have 115v mains? The right hand side of your second diagram shows how to set jumpers for your mains voltage and where to connect the primarys. For 115v place jumpers between A&B AND C&D. For 230v you only place a jumper between B&C.
If in doubt, get a qualified electrician to check your work.
If in doubt, get a qualified electrician to check your work.
Davym, thanks for your reply. Now I understand the diagram with respect to the placement of jumpers necessary for ones specific mains voltage. In my case I am working with USA home voltages 110-115v. As a newcomer to this hobby I need to ask how does one either purchase or fabricate the required jumpers? I suspect the jumpers are integrated into the fuse module that allows one to choose either 115v or 230v by inserting the module with one side or the other upward according to the printed voltage printed on the end of the module. Yes?
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