This is actually the main problem i have right now... (I think many of you understand)
I will try to make small rewiring, and make zerodc offset adjustment's today on my
... Well just to tell, my
has been working, but only with normal stereopot directly soldered onto pcb's... Also i can use with my 4deck, but then -in connection must be left open to avoid huuge hum. When doing that there is absolutly no noise... Just had to get rid of it, before Magura come's ... that's the main goal for now!!!
Jesper.
Men--men--men--men.......we are men.....
From Monty Python's flying circus. 😀 😀
And the things we do for honor. 😀 😉 😀
From Monty Python's flying circus. 😀 😀
And the things we do for honor. 😀 😉 😀
Evening all...
Today i tried to cut some unused gnd (black wire's) connection, and this way i got rid of the visible hum, seen on my CRO!
Humm stil happens though, now it just can't be seen anymore 😉
I attached a picture of my initial setup.
Middle just below blue output cap's you can see the cutout black gnd.
It's very hard to explain how i attach everything on picture's.
But i will try anyway:
The 2 orange wire on right picture is pwr-gnd goes to 'star' gnd.
Going from right to left on picture, red wire is +out which goes to +out(rca for now) Yellow goes to -out (attached on gnd rca connection at end of cable) RCA connectors gnd goes to 'star' gnd.
Left picture the input connection's are located. yellow = -in , black=sgnd , red=+in
All 3 goes to 4deck attennuator.
On input rca, the gnd goes to 'star' gnd.
Yellow is attached to gnd too, at my testsetup.
Don't think my description could be usefull though...
Jesper.
Today i tried to cut some unused gnd (black wire's) connection, and this way i got rid of the visible hum, seen on my CRO!
Humm stil happens though, now it just can't be seen anymore 😉
I attached a picture of my initial setup.
Middle just below blue output cap's you can see the cutout black gnd.
It's very hard to explain how i attach everything on picture's.
But i will try anyway:
The 2 orange wire on right picture is pwr-gnd goes to 'star' gnd.
Going from right to left on picture, red wire is +out which goes to +out(rca for now) Yellow goes to -out (attached on gnd rca connection at end of cable) RCA connectors gnd goes to 'star' gnd.
Left picture the input connection's are located. yellow = -in , black=sgnd , red=+in
All 3 goes to 4deck attennuator.
On input rca, the gnd goes to 'star' gnd.
Yellow is attached to gnd too, at my testsetup.
Don't think my description could be usefull though...
Jesper.
I attach a picture of my shielded cable... would like to know what is best to use.
I mean should i use the shield as gnd, or just the black one as i do now.
Any other hint, for my next rewiring would be nice 🙂
Jesper.
I mean should i use the shield as gnd, or just the black one as i do now.
Any other hint, for my next rewiring would be nice 🙂
Jesper.
Ok, basic question. Do people mostly use shielded wire for internal hookups? say for the wire that goes internally from a phono jack to the circuit board? OR just a pair, twisted ?
This could be a whole thread by itself.
For internal wiring, I just use wire, not even a twisted pair.
What does the twisting together do, really? I noticed with shielded microphone (balanced) cable (the kind PE sells for making XLR interconnects) that if I feed a signal in one wire, I can easily read the signal in the wire running parallel to it, but with a slight phase difference.... even when the parallel wire was connected to ground through a 600 ohm resistor.
To me, this says there is a lot of capacitive coupling between the two wires, and I haven't been able to convince myself of any reason why this would be good.
JJ
Variac said:
If the wires are arranged away from the transformer, I think no
special thing is necessary. When the wires have to go near to
the transformer, I prefer to cover the transformer with copper
plate, instead of the shielding of wires..
I use twisted as well. As for things near the transformers, I agree with Babowana. However, what about things near mains voltages? I have one design that has mains power that goes to a large barrier strip to supply several toroids and this happens to be a few inches away from the output of the supply. Might this be bad? I'm just using teflon-coated stranded 18 awg for the mains connectors that's rated up to 800VDC.
Update...
Forget all, i wrote before... I will start over!
Problem moved.
I am having some humming/groundloop problem's with my... I thought that it was due to my alps 4deck pot, but seem's that problem moved.
If i connect input, either at -in or +in, and if i leave the oppisite input 'open'... then there is 100% silence e.g is working 100%. nomatter if output is shorted or not . eg. it dosen't make any difference if i short -out or +out to gnd.
I have moved a lot of humming away, by rewiring the hole thing, but stil you can hear if i touches some cables, or attenuator. I also found out, that if i connect a wire from isolated 'star connection / central gnd' to chassis bottom, even more hum dissapear's.
Now almost every hum is gone... but stil this microphone like sensitivity. (still only when -in or +in grounded)
I would like to tell, that i still only use my leach amp, for testing, as i told before the is (still i don't know for sure until i try in next few day''s) working with my F4 ... (it used to work)... Could it be due to using balanced signal from to F4, and due to the much better stabilization of F4 compared to LeachAmp ??? ...
I also would like to tell, that the still is in no chassis, and that i had set gain to 20x (double up, that ZenMod schm. describes)
Any hint ???
If my / F4 combination still work's 100%, i just might end up with a switch closing / opening the -in connection - so that i can use it safe with other amps too...
Jesper
Forget all, i wrote before... I will start over!
Problem moved.
I am having some humming/groundloop problem's with my
... I thought that it was due to my alps 4deck pot, but seem's that problem moved.If i connect input, either at -in or +in, and if i leave the oppisite input 'open'... then there is 100% silence e.g
is working 100%. nomatter if output is shorted or not . eg. it dosen't make any difference if i short -out or +out to gnd.I have moved a lot of humming away, by rewiring the hole thing, but stil you can hear if i touches some cables, or attenuator. I also found out, that if i connect a wire from isolated 'star connection / central gnd' to chassis bottom, even more hum dissapear's.
Now almost every hum is gone... but stil this microphone like sensitivity. (still only when -in or +in grounded)
I would like to tell, that i still only use my leach amp, for testing, as i told before the
is (still i don't know for sure until i try in next few day''s) working with my F4 ... (it used to work)... Could it be due to using balanced signal from to F4, and due to the much better stabilization of F4 compared to LeachAmp ??? ...I also would like to tell, that the
still is in no chassis, and that i had set gain to 20x (double up, that ZenMod schm. describes)Any hint ???
If my
/ F4 combination still work's 100%, i just might end up with a switch closing / opening the -in connection - so that i can use it safe with other amps too...Jesper
lykkedk said:
jesper - ya're nutz as AC 3-phase current , and I'm nutz as 100phase AC current with you ............
you trying dreky preamp with 20 times gain with Leach , which needs 1V5 for input ??????
and you probably still have some gnd problem .........
rewire entire thing to 5x gain , put back pot where it belong and enjoy
what you are trying now is same as that you connect CD out to MC input
lykkedk said:
I also would like to tell, that the
Jesper
Det forklarer en del.....
Tak for snapsen Jesper 😀
Magura 🙂
