Search found 3090 matches
- Mon Jun 03, 2024 12:50 pm
- Forum: Technical Discussion
- Topic: OT mounted to speaker
- Replies: 8
- Views: 237
Re: OT mounted to speaker
Here are some common field coil circuits I am familiar with. One circuit is often found with the OT mounted on the speaker frame.
- Sun Jun 02, 2024 1:47 pm
- Forum: Technical Discussion
- Topic: What do you think causes pins 2 and 3 to arc in octal sockets.
- Replies: 21
- Views: 490
Re: What do you think causes pins 2 and 3 to arc in octal sockets.
There's not always a visible arc trace between pins 2 and 3. Sometimes the arc simply happens inside the tube. There may be another telltale sign that pin 3 has arced to pin 2. If the heater circuit has an artificial center tap (Fender liked to put two 100Ω half watt resistors on the pilot lamp asse...
- Fri May 31, 2024 3:18 pm
- Forum: Fender Discussion
- Topic: 1976 Fender Vibrolux refresh help
- Replies: 24
- Views: 2607
Re: 1976 Fender Vibrolux refresh help
Maybe "STANDBY... Love it or hate it?"
- Thu May 30, 2024 7:54 pm
- Forum: Technical Discussion
- Topic: Tremolo Changes after EL84 to 6V6 Swap
- Replies: 7
- Views: 271
Re: Tremolo Changes after EL84 to 6V6 Swap
R63 and R64 voltage divider only allows 60% of the trem signal to reach Q6. Making R63 larger will give more trem signal.
- Mon May 27, 2024 10:47 pm
- Forum: Fender Discussion
- Topic: 5E3 build loud hum/buzz once warmed up
- Replies: 7
- Views: 236
- Mon May 27, 2024 6:57 pm
- Forum: Fender Discussion
- Topic: 5E3 build loud hum/buzz once warmed up
- Replies: 7
- Views: 236
- Mon May 27, 2024 6:43 pm
- Forum: Fender Discussion
- Topic: 5E3 build loud hum/buzz once warmed up
- Replies: 7
- Views: 236
Re: 5E3 build loud hum/buzz once warmed up
Is this jumper missing or is it underboard. It's a very important ground and if missing would explain the loud hum as soon as the rectifier warms up. If it were my amp, I'd want that ground on top of the board in plain sight.
@bepone... 5E3 has no NFB.
@bepone... 5E3 has no NFB.
- Sat May 18, 2024 6:28 am
- Forum: Technical Discussion
- Topic: Princeton Reverb tremolo squeal
- Replies: 5
- Views: 359
Re: Princeton Reverb tremolo squeal
Disconnect the NFB wire from the speaker jack. Any better?
- Sat May 18, 2024 12:53 am
- Forum: Technical Discussion
- Topic: OT Primary Question
- Replies: 7
- Views: 659
Re: OT Primary Question
I would be very nervous running a 6K6 with 350-400V on the plate.
- Thu May 16, 2024 6:42 pm
- Forum: Fender Discussion
- Topic: 1976 Fender Vibrolux refresh help
- Replies: 24
- Views: 2607
- Thu May 16, 2024 12:15 pm
- Forum: Technical Discussion
- Topic: Dual Triodes with Common Cathode
- Replies: 2
- Views: 328
Re: Dual Triodes with Common Cathode
You cannot share cathodes of series gain stages w/o creating a feedback loop.
Read this discussion. Listen to what PRR has to say.
Read this discussion. Listen to what PRR has to say.
- Wed May 15, 2024 3:50 am
- Forum: Dumble Discussion
- Topic: The Much Anticipated (?) Bluesmaster Build Thread
- Replies: 107
- Views: 4111
Re: The Much Anticipated (?) Bluesmaster Build Thread
Sorry for the filament string wild goose chase. I missed you saying you had correct voltage between the filament pins.
- Wed May 15, 2024 3:41 am
- Forum: Dumble Discussion
- Topic: The Much Anticipated (?) Bluesmaster Build Thread
- Replies: 107
- Views: 4111
Re: The Much Anticipated (?) Bluesmaster Build Thread
Remove the lamp limiter and variac. Plug the amp straight into the wall. Plug in the power tubes. Do the filaments light up? Voltage readings any better?
- Wed May 15, 2024 1:19 am
- Forum: Dumble Discussion
- Topic: The Much Anticipated (?) Bluesmaster Build Thread
- Replies: 107
- Views: 4111
Re: The Much Anticipated (?) Bluesmaster Build Thread
Most likely a bad solder joint, broken wire, or wiring error in the filament string. Easy to locate with your meter. DON'T MEASURE FILAMENT VOLTAGE WITH ONE PROBE CONNECTED TO GROUND! Connect one probe to one of the PT green wires and the other probe to the other green wire. Voltage should be as exp...
- Tue May 14, 2024 6:37 pm
- Forum: Technical Discussion
- Topic: Modded Tremolux
- Replies: 39
- Views: 9113
Re: Modded Tremolux
I would be nervous. It's very common to use two 350V caps in series for the reservoir cap.