Ahhh.... sounds perfectly normal with the limiter in. measure the input voltage, I'll bet it's dropped dramatically due to the limiter. Take the limiter out and I'll bet she sounds great.dab wrote:With all tubes in I get 180ish vdc where I got 350vdc before. Light bulb limiter glows (although not at full brightness.
Dave
Help, Voltage problem in Power Section
Moderators: pompeiisneaks, Colossal
Re: Help, Voltage problem in Power Section
Re: Help, Voltage problem in Power Section
Sounds like it could be a parasitic oscillation generating a LOT of output above human hearing.
Do the following one-handed! (works best if you can clip a wire to the ground connection and poke with the other end, leaving the meter attached to your power tube plate and ground) You're messing with the highest voltages in the amp, so be extra careful.
Starting at the power tube grids, ground one grid at a time, working your way back to the first preamp grid. See if the voltage jumps up toward normal at any point. If that happens, you grounded the triode where the oscillation is happening. Study it there.
Do the following one-handed! (works best if you can clip a wire to the ground connection and poke with the other end, leaving the meter attached to your power tube plate and ground) You're messing with the highest voltages in the amp, so be extra careful.
Starting at the power tube grids, ground one grid at a time, working your way back to the first preamp grid. See if the voltage jumps up toward normal at any point. If that happens, you grounded the triode where the oscillation is happening. Study it there.
Wife: How many amps do you need?
Me: Just one more...
Me: Just one more...
Re: Help, Voltage problem in Power Section
It's cookin now!! Took it off of the bulb limiter and all the voltages straightened right up. THANKS!!
It's got that glitchy oscillation kind of sound when you pick hard with it turned up a bit. I will try out the advice on locating the offending triode now. i will also mess around some with lead dress and see if I can get it to go away.
Thanks to everyone for the help. You guys are awesome!!
Dave
It's got that glitchy oscillation kind of sound when you pick hard with it turned up a bit. I will try out the advice on locating the offending triode now. i will also mess around some with lead dress and see if I can get it to go away.
Thanks to everyone for the help. You guys are awesome!!
Dave
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skyboltone
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Re: Help, Voltage problem in Power Section
<snip> Late to the party.
Just a thought
Dan
Just a thought
Dan
The Last of the World's Great Human Beings
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Seek immediate medical attention if you suddenly go either deaf or blind.
If you put the Federal Government in charge of the Sahara Desert, in five years time there would be a shortage of sand.
Re: Help, Voltage problem in Power Section
It's got that glitchy oscillation kind of sound when you pick hard with it turned up a bit. I will try out the advice on locating the offending triode now. i will also mess around some with lead dress and see if I can get it to go away.
A gentleman that lives close by has a TW kit from Nik and brought it to the shop. I'm not sure if there are any revisions or updates however this model had the circuit board up against the control pots and input jack (not sure if this is the case with the amp you have).
As most here know the layout on the TW's are critical and if your board is really close to the control pots/input jack then you the use of shielded wire would most likely be of help.
Hope it helps & happy holidays!
Trace
A gentleman that lives close by has a TW kit from Nik and brought it to the shop. I'm not sure if there are any revisions or updates however this model had the circuit board up against the control pots and input jack (not sure if this is the case with the amp you have).
As most here know the layout on the TW's are critical and if your board is really close to the control pots/input jack then you the use of shielded wire would most likely be of help.
Hope it helps & happy holidays!
Trace