Yes, that might be possible. But all the PCBs ties signal ground and system ground together, so I'll have to so some major modifications on each PCB to make that possible. and yes, I did the wiring on each individual PCB.
take one rca cable and connect between input from the opposite sides, sub and front. If i am right you will hear a hum
My cable TV ended up being my hummmmmmm. Drove me nuts ran it through a surge suppressor that had the coaxial ins and outs and she is quite as can be
Since my DVR from cable company was hooked into my pioneer through the coaxial digital line it ....there was a loop somehow
Hansibull, is it your intention to use the 5/1 diy amp in addition to the 7 amps already present in the receiver or are you building to upgrade the receiver?
Can I just screw a 2 ohm resistor at the input terminal, and solder the input wire to it? that's a much simpler process than cutting all the traces underneath each PCB. Bu if I do this, what should I do with all the ground wires I've connected to each input terminals? Aren't these necessary anymore?
My idea was to use the pre out connectors that the Marantz have, and make my own, quality amplifier, instead of the the internal amplifier in the AV receiver. It will just be a 5.1 system, and no extension 🙂
When it cones to noise, the center speaker, left front speaker, the subwoofer and the surround right speaker is completely silent. I still got some hum in the front right speaker, and the surround right speaker.
I don't think any of the LM3886 kits sold on ebay will outperform the Marantz amps, not in quality or in power.
hehe that's not helping him, it's sorta like kicking a guy when he's down.
yes that would be in series with the input gnd, as a work around try 10 -100 ohms in series like you described, (yer still in trouble shooting mode).
Based on symptoms you reported, we are trying to reduce any stray PS or line AC currents from running thru the coax cables.
No. That puts the added resistance into the input pair and INCREASES the interference voltage fed to the amplifier.
Download D.Joffe's article. He shows where the ADDED resistance should be located to REDUCE the interference voltage fed to the amplifier.
The ADDED 2r resistor is NOT in the signal pair feeding the sig hot and sig return.
Putting an added resistor into the sig return is NOT the place to locate the interference reducing resistor.
I don't agree with Mark.
I have only the experience of opening up one "all in one" surround capable amplifier.
If the Marantz is anywhere near as bad as the Yamaha, then a well built 3886 will easily beat it.
don't stop him, its just an experiment in trouble shooting. He reported the hum comes when the coax cables are connected to other gear. BTW maybe you missed the part where I gave him the link for a thread that describes a better fix for XY PCBs.
My next post addressed the possible two locations for the added resistor.
The link you gave may be correct.
The signal return lead is definitely not the correct location for an added resistor to reduce interference.
well maybe you can explain the cause after he reports back with the data.
Im just helping the symptoms like any Rx
Hum is generated at ground wire of the signal cable and resistor helps to decrease currents through loop. only what need to do to make correct is input RCA connectors can not be soldered ground between them
D.Joffe article on hum loop and attenuating interference
two recent links to Joffe's paper.
http://www.diyaudio.com/forums/soli...ichael-bittner-our-mikeb-198.html#post4024136
http://www.diyaudio.com/forums/analog-line-level/265232-comment-grounding-scheme-11.html#post4170245
two recent links to Joffe's paper.
http://www.diyaudio.com/forums/soli...ichael-bittner-our-mikeb-198.html#post4024136
http://www.diyaudio.com/forums/analog-line-level/265232-comment-grounding-scheme-11.html#post4170245
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