Tweed Amp Preamp Input Wiring
CJK
Which do you prefer, and why?
(1) Unshielded wiring from (a) input jacks to 68K's on circuit board,
and (b from 68k's to V1 inputs [ grids, pins 2&7, standard schematics
for tweed amps ]
(2) Shielded wiring from 68K's [installed directly at input jacks] to
V1 grids [shielding grounded at jacks only].
Thanks, Chris
Lord Valve
CJK wrote:
Shield it. Obvious.
LV
Miles O'Neal
I'll always take the shielded. In fact,
I now shield inputs routinely, unless I
am working on someone else's amp and they
don't want it done. Can really help with
noise, and with any decent wire there's no
tonal loss at all.
-Miles
RoccaforteAmps
to the preamp tube socket,
use shielded wire.
Doug
CJK
honestly cannot tell the difference! Shielded it is.
Chris
CJK
Curious, how many older fender amps have you seen with the 68K's at
the tube socket (vs. either the circuit board or the input jacks)?
All of the tweeds and "brown" fenders I've seen - on the board; most
of the BF/SF - at the input jacks.
CJK
I suppose shielded wire was not plentiful at the time the older amps
were made and, also, Leo & Co. probably would not have used it anyway
given the profit margin focus, huh?
I remember from a thread long ago, that we both use the same shielded
wire - it is easy to work with, and I know YOU hear the difference
(noise reduction). As I told Miles, I wish I had my hearing of years
ago, but it's getting worse. I REALLY miss being able to hear various
sounds as well as I used to.
RonSonic
wrote:
Fender NEVER put these R's at the socket. Still, that is where they
belong. On the stuff I build, the R connects the input jack to the
grid pin.
Ron
RoccaforteAmps
68K's at
the tube socket
None,
Im not sure if it was
the lack of knowledge,
or just to build them
cheaper.
(vs. either the circuit board or the input jacks)?
>All of the tweeds and "brown" fenders I've seen - on >the board; most
>of the BF/SF - at the input jacks. >>
In some low gain amplifiers
you can get away with this,
but even they benefit having
shielded wire from input to tube.
Maybe why old Sunn amplifiers
had their preamp tube right
next to the input jack to keep
the distance as short as possible,
some SoundCity amps are like
this too.
Doug
greg z
you can get away with this,
but even they benefit having
shielded wire from input to tube.
Maybe why old Sunn amplifiers
had their preamp tube right
next to the input jack to keep
the distance as short as possible,
some SoundCity amps are like
this too.
Doug
I noticed that on my 1200s, resistor is on the jack and on the tube,
I wonder if this is why this is one of the dead quietest amps I've ever
heard?(or not heard).Shit, I left it on for 3 days awhile back and didn't
even notice, and thats with a 12' cord plugged in and the V on 8.
Walking by with bare feet and stepped on the tip of the plug.
HMMMMMMM boy I jumped,woke my ass up.
Hell the transformers were barely warm.
Greg Z
to thine own sound be true
Miles O'Neal
|Thank you Miles. My hearing loss has got to the point where I just
|honestly cannot tell the difference!
That sucks. I'm pretty amazed
that I still have most of my
hearing. I have friends who
went legally deaf (mostly bass
players) from being in front of
too loud amps. One guy a few
years older than me had spent
a bunch of time jumping off a
top bunk to become flat footed,
because he didn;t want to go to
Nam. He walked in to the army
testing center, and flunked out
on the hearing test.
CJK
M.Magnetics. Thanks for mentioning them to me kind sir.
Chris Keklak
Calvin Associates
RoccaforteAmps
>M.Magnetics. Thanks for mentioning them to me kind >sir.
>>
They Rock!
Tell them I sent you,
Doug
tonehenge
you also need to do the heater wiring mod to get the hum out see post
on todays from tonehenge Chris.