Re: Ground center tap of filament secondary?
- From: Lord Valve <detritus@xxxxxxxxxxxxx>
- Date: Wed, 04 Nov 2009 16:39:00 -0700
Mandrake's Rootwerx wrote:
connect the two reds to the bridge rectifier, and no connection for
the red/yellow. Sound correct?
yes ... but you have a schematic reference ?
My question is how to handle the filament coil, which will be going
directly to the tube heaters. Should I ground that center tap
(grn.yel, or yel.blk), or leave them unconnected?
unconnected ... follow the polarity of each lead to the same
pin ( grn -> pin x, grn/yel -> pin y) for every tube. Dressing is
important to reduce hum.
Whatever you do .. do one step at a time && test it !... measure it
with a volt meter. If gets you use to probing voltages .. one hand
behind your back to start with .
in regards to the filament, the correct routing should be green to green.
There is no real "polarity" there, it's AC.
Anyway the filament wiring has to be referenced to ground. Either by
grounding the y/g wiring, or by an artifial center tap via two 100ohms
from each leg to ground, or a 250-500 ohms pot as an adjustable hum
balance. IMHO the "artificial way" has at least one positive side
effect: If you have an arc over at the finals socket (Plate connection
to heater) due to a "no load condition", the Rs can burn out and not the
filament wiring of the PT.
If you don't reference the Heater to ground its "freefloating" and can
induce serious problems and artifacts.
just my 2 cts
See? I *told* you he was an idiot...
(imagine something which pisses you off here)