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#2,783
Thank's all..
speaker cable is cat 5
audio is silver wire in silk sheath
power cable is made CAT5E shielded and cotton sheath
Amp is in the office, it does not move and before the cotton sheath is damaged, peace will reign over all the earth.
Then there will be damaging to the metal sheath.

About earthing, it's my choise, but I said : never do like me !
Always connect earth to the case.

Phil.
 
#2,788
>> recycled cord from a broken electric iron !
Funny, yes it looks like this !!
My next projet with LM' :

72004.jpg


on/off in red, pot at center in blue, heatsink is the metal bottom !
Phil.
 
#2,789
mhouston said:
You don't need shielded wire for internal hookup. Nice job by the way.
Click to expand...

... Well, as long as the case is metal and connected as chassis ground, maybe.

Purists might shield all signal connections between boards and I/O. Shields connected on one end would do it, to avoid a lot of ground loops.

I build with plastic cases and thus of necessity shield all I/O and interconnects, of course, but best practices might suggest shielding on any and all "line level" signals. :xfingers:
 
#2,791
AndrewT said:
shields of coax also act as return route for the signal in the core.
If one breaks the shield connection at one end then this CREATES LOOPS of very large area.

DO NOT break the signal return of a close coupled pair. NEVER !
Click to expand...

Further: http://en.wikipedia.org/wiki/Ground_loop_(electricity)

220px-Ground_loop_solution_-_resistor.svg.png

220px-Ground_loop_solution_-_broken_shield.svg.png

These images are not balanced cables. [AndrewT: "DO NOT break the signal return of a close coupled pair. NEVER !"]

But, sometimes one must experiment and find out what works on a particular design ... I generally connect the balanced, twisted pair, audio shield to chassis ground at one end only (usually the source end), then occasionally add a small capacitor, shield to chassis ground, at the other end (to bleed off any stray AC).

"Your results may vary ..."
 
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#2,792
Hi,
New LM3886 at home !
Kit from Chipamp, ps (27 volts) with snubber, one safety loop breaker per side, direct input (no cap, no resistor), gain is 28, one output for bass amp..

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


Great sonics !!
Special thank's for Andrew T, Mark Whitney and Chipamp.
Phil.
 
#2,796
Hi Pjotter,
Yes it's silver wiring with natural silk sheath.
About grounding, it's safety loop breaker, see figure 4 :
Earthing (Grounding) Your Hi-Fi - Tricks and Techniques
and schematic from Mark for dual ps :
http://www.diyaudio.com/forums/chip-amps/262633-one-two-transformers-4.html#post4098151

I have not build thread here..
Pcb and few componants are ordered from Chipamp, schematic are the same :

http://chipamp.com/docs/lm3886-manual.pdf
except : remove R1, R3 1 Ko and Rf 27 Ko, add 220 pF between pin 9 and 10, power suply is fig 1.3 (one per side).
Phil.
 
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#2,797
Philfr said:
Hi Pjotter,
Yes it's silver wiring with natural silk sheath.
About grounding, it's safety loop breaker, see figure 4 :
Earthing (Grounding) Your Hi-Fi - Tricks and Techniques
and schematic from Mark for dual ps :
http://www.diyaudio.com/forums/chip-amps/262633-one-two-transformers-4.html#post4098151

I have not build thread here..
Pcb and few componants are ordered from Chipamp, schematic are the same :

http://chipamp.com/docs/lm3886-manual.pdf
except : remove R1, R3 1 Ko and Rf 27 Ko, add 220 pF between pin 9 and 10, power suply is fig 1.3 (one per side).
Phil.
Click to expand...
Thanks for your reply!

Safety loop breaker, now I remember it. For some reason I didn't implement that in my amp, I'm thinking of doing so.

Thanks again!
 
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