hi everyone!
I'm new to tube projects,but i recently
found schematic of this bass preamp
and i want to build it for myself.
Like i said,i don't have experience with
tubes so i will be grateful if someone could help
me with this project. I found only this scheme
so i don't know some details...
in power supply i don't see gratz,just one diode.
is it ok to have only half-wave rectifier?
which power of transformer and voltage on secondary do i need?
thx!
here is the scheme:
I'm new to tube projects,but i recently
found schematic of this bass preamp
and i want to build it for myself.
Like i said,i don't have experience with
tubes so i will be grateful if someone could help
me with this project. I found only this scheme
so i don't know some details...
in power supply i don't see gratz,just one diode.
is it ok to have only half-wave rectifier?
which power of transformer and voltage on secondary do i need?
thx!
here is the scheme:
Attachments
It is a voltage doubler, not a half-wave rectifier, note capacitor in series with transformer winding. My guess at the winding voltage would be about 100VAC
I am also starting to build a pre-amp, based on this F-2B schematic. Alembic is using the Stancor PS-8415 transformer which has 125V secundaries.
Please note the schematic you posted has faults! Pins 6 and 8 of the tube are mixed up!!
Please note the schematic you posted has faults! Pins 6 and 8 of the tube are mixed up!!
Definitely a half wave voltage doubler, and I concur that the transformer secondary ought to be in the 100V - 120V range.
The pins on the first section of the 12AX7 are reversed, plate =6, grid=7, cathode=8 on a 12AX7A.
It is important to keep that power transformer away from the 12AX7.
Build the thing in a nice metal box, preferably aluminum as it is much easier to work than steel, and using a socket with shield for the 12AX7.
For this application I would recommend the Sovtek 12AX7LPS, it's quiet and the spiral filament construction cancels the hum inducing ac magnetic field around the filament.
The pins on the first section of the 12AX7 are reversed, plate =6, grid=7, cathode=8 on a 12AX7A.
It is important to keep that power transformer away from the 12AX7.
Build the thing in a nice metal box, preferably aluminum as it is much easier to work than steel, and using a socket with shield for the 12AX7.
For this application I would recommend the Sovtek 12AX7LPS, it's quiet and the spiral filament construction cancels the hum inducing ac magnetic field around the filament.
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