I'm using shielded cable in my gainclone, for the input and output signal (should I use shielded cable for the supply rails, too?)
But I don't know where to connect the shield
To analog ground?
To chassis (earth)
Not connected?
But I don't know where to connect the shield
To analog ground?
To chassis (earth)
Not connected?
Connect the shield to analog ground at one end only. The last is very important to avoid ground loops.
Shielding of power supply leads is pointless, since they're already at AC ground.
Shielding of power supply leads is pointless, since they're already at AC ground.
In addition, AC power wires can be twisted tightly together to possible radiated interaction with the audio signal.
were the shield go?
Hi Bricolo!
Don' t use shielded cable at the output...you can find problems of stability!
Use only at the input!
Salut!
Jorge
Hi Bricolo!
Don' t use shielded cable at the output...you can find problems of stability!
Use only at the input!
Salut!
Jorge
Re: were the shield go?
I use ofc speaker cable, shielded
what's the problem with this? since it's the same as the one used between the amp and the speakers
Tube_Dude said:
I use ofc speaker cable, shielded
what's the problem with this? since it's the same as the one used between the amp and the speakers
To bricolo!
The problem is capacitance at the output....power amps with lots of feedback as yours (after all is a power op amp) don't like to see to much capacitance at the output
Have you wonder why you don't see shielded cables as speaker cables outhere??
Au revoir!
Jorge
The problem is capacitance at the output....power amps with lots of feedback as yours (after all is a power op amp) don't like to see to much capacitance at the output
Have you wonder why you don't see shielded cables as speaker cables outhere??
Au revoir!
Jorge
to Bricolo!
A shielded cable....is a shielded cable!!!
Monacor...or other trad mark!
Cheers
Jorge
A shielded cable....is a shielded cable!!!
Monacor...or other trad mark!
Cheers
Jorge
I'm on the way to put my gainclone in it's final chassis, and to rewire everything
since the only "quality" wire I have is this shielded ofc cable, and thant the chassis is aluminium
is there any advantage in using shielded cable INSIDE the metal chassis?
Connecting every shield to star ground will add a mess in the chassis.
If shielding is nonsence in the chassis, what would be better:
use the cable as if, and leave the shield unconnected
remove the shield?
since the only "quality" wire I have is this shielded ofc cable, and thant the chassis is aluminium
is there any advantage in using shielded cable INSIDE the metal chassis?
Connecting every shield to star ground will add a mess in the chassis.
If shielding is nonsence in the chassis, what would be better:
use the cable as if, and leave the shield unconnected
remove the shield?
I. Why shielded cable if everthing is inside a grounded enclosure?
Even if you have a gounded metal enclosure there may be value to shielded input: A- protection from noise on the poer lines AC or DC, however a few inches (=2.54cm) will oftem resolve that problem, B- crosstalk from the output of the other channel (monblocks eliminate this).
II. Self's book shows a diagram where one end of the shield is connected to the outer ring of the RCA connector and the other end of the shield joins up withe the ground from the NFB return and both then go to the star point. However, the same diagram also shows a direct connection betweenthe outer ring of the RCA connector to chassis earth but the star point NOT connected to the chassis earth. As much as I admit that Self knows more than me, this looks odd. Certainly there is no room for a loop but not connecting the star point to the chassis ground (except indirectly back through the shield anf the outer RCA ring seems like there might be a safety issue.
Even if you have a gounded metal enclosure there may be value to shielded input: A- protection from noise on the poer lines AC or DC, however a few inches (=2.54cm) will oftem resolve that problem, B- crosstalk from the output of the other channel (monblocks eliminate this).
II. Self's book shows a diagram where one end of the shield is connected to the outer ring of the RCA connector and the other end of the shield joins up withe the ground from the NFB return and both then go to the star point. However, the same diagram also shows a direct connection betweenthe outer ring of the RCA connector to chassis earth but the star point NOT connected to the chassis earth. As much as I admit that Self knows more than me, this looks odd. Certainly there is no room for a loop but not connecting the star point to the chassis ground (except indirectly back through the shield anf the outer RCA ring seems like there might be a safety issue.
thanks 🙂
So, shielded cable in a metal enclosure is not nonsense.
Nice, I'll keep my shielded cable!
But connecting each shield to star ground will give me an enormous star in the chassis 🙁
Could I, in example on a RCA connector, use the wire for the signal, and the shield to connect the outer ring to the star ground?
Instead of using a cable for the signal, and another for the ground
So, shielded cable in a metal enclosure is not nonsense.
Nice, I'll keep my shielded cable!
But connecting each shield to star ground will give me an enormous star in the chassis 🙁
Could I, in example on a RCA connector, use the wire for the signal, and the shield to connect the outer ring to the star ground?
Instead of using a cable for the signal, and another for the ground
"Could I, in example on a RCA connector, use the wire for the signal, and the shield to connect the outer ring to the star ground?
Instead of using a cable for the signal, and another for the ground"
I think so. That's basically what I've got planned for my current project. There seem to be more than one opininion regarding the "One correct way". And unfortunately, it seems like all the diagrams and explanations are ambiguous. The two criteria, to my mind, are that A- it is safe and B- you don't pick up any hum. If those two are met, then it is right.
Instead of using a cable for the signal, and another for the ground"
I think so. That's basically what I've got planned for my current project. There seem to be more than one opininion regarding the "One correct way". And unfortunately, it seems like all the diagrams and explanations are ambiguous. The two criteria, to my mind, are that A- it is safe and B- you don't pick up any hum. If those two are met, then it is right.
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