Shielded cable from valve to OT

What a learning experience that has been. I solved a few problems with that
move. I found the other day I altered a few things inside my amp and all but
reduced the coupling squeal. Then a day latter when I did a few more mods
the noise came back.
Tonight I finally go it and put it right. Shielded mic cable is all I hade
and its worked.

tony.r http://www.ncable.com.au/~tony.r/

indeed;
first time I saw that in old movie-theater monoblocks,and since then I
always do the same

--
Choky
Prodanovic Aleksandar
YU


"tony.r" wrote in message
...
Shielded cable from valve to OT

What a learning experience that has been. I solved a few problems with
that
move. I found the other day I altered a few things inside my amp and all
but
reduced the coupling squeal. Then a day latter when I did a few more mods
the noise came back.
Tonight I finally go it and put it right. Shielded mic cable is all I hade
and its worked.

tony.r http://www.ncable.com.au/~tony.r/

Good idea! Hmm... a good application for RG58A/U ??? And RG8 or LMR400
for the really big amps.

Cheers,
Fred

Choky wrote:
indeed;
first time I saw that in old movie-theater monoblocks,and since then I
always do the same

--
Choky
Prodanovic Aleksandar
YU


"tony.r" wrote in message
...

Shielded cable from valve to OT

What a learning experience that has been. I solved a few problems with

that

move. I found the other day I altered a few things inside my amp and all

but

reduced the coupling squeal. Then a day latter when I did a few more mods
the noise came back.
Tonight I finally go it and put it right. Shielded mic cable is all I hade
and its worked.

tony.r http://www.ncable.com.au/~tony.r/






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| Projects, Vacuum Tubes & other stuff: |
| http://www.dogstar.dantimax.dk |
+--------------------------------------------+

"tony.r" wrote in message
...
Shielded cable from valve to OT

What a learning experience that has been. I solved a few problems with
that
move. I found the other day I altered a few things inside my amp and all
but
reduced the coupling squeal. Then a day latter when I did a few more mods
the noise came back.
Tonight I finally go it and put it right. Shielded mic cable is all I hade
and its worked.

tony.r http://www.ncable.com.au/~tony.r/


What are you on about ?? Send me a wrap. Shielded cables from OP valves
to OPT. ?? There's enough bounce in them buggers to frighten the B+ tranny
!!
Peace, man !!
jim

tony.r wrote:

Shielded cable from valve to OT
I found the other day I altered a few things inside my amp and all but
reduced the coupling squeal. Then a day latter when I did a few more mods
the noise came back.
Tonight I finally go it and put it right. Shielded mic cable is all I hade
and its worked.



The shielding must have stopped an undesired feedback loop. Depending
on the
circuit involved, it may be a better choice to shield the high signal
level/ low
impedance (relatively speaking) then to try to shield all the low level
/high
impedance input and intermediate circuits. You might not need to use
microphone
or other shielded cable; a grounded wire twisted around the high signal
level
line might be enough. Or slip braid over wires coming from output
transformers,
though care is needed to avoid shorting the tube socket terminal to
ground with the
braid. Also this can be used to treat hum coming from the AC powerline
running to the power switch and power transformer.

Shielding can be used for both: Protecting low level input signals from
high level
signal sources, and contain high level signals from leaking into low
level inputs.