Search found 3083 matches
- Sat May 18, 2024 6:28 am
- Forum: Technical Discussion
- Topic: Princeton Reverb tremolo squeal
- Replies: 5
- Views: 129
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: 6
- Views: 189
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: 16
- Views: 493
- Thu May 16, 2024 12:15 pm
- Forum: Technical Discussion
- Topic: Dual Triodes with Common Cathode
- Replies: 2
- Views: 105
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: 104
- Views: 3084
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: 104
- Views: 3084
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: 104
- Views: 3084
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: 8467
Re: Modded Tremolux
I would be nervous. It's very common to use two 350V caps in series for the reservoir cap.
- Mon May 13, 2024 3:49 pm
- Forum: Technical Discussion
- Topic: Can I Parallel 2 Mosfets in VVR?
- Replies: 31
- Views: 789
Re: Can I Parallel 2 Mosfets in VVR?
For an 18W amp in an aluminum (not steel!) chassis I'd just bolt to the chassis. Don't forget heatsink grease/paste or one of those fancy silicone pads. For a 50W amp I'd use a real adequate heatsink.
For a larger amp I'd just get an 18W amp.
For a larger amp I'd just get an 18W amp.
- Mon May 13, 2024 1:31 pm
- Forum: Technical Discussion
- Topic: Can I Parallel 2 Mosfets in VVR?
- Replies: 31
- Views: 789
Re: Can I Parallel 2 Mosfets in VVR?
If power handling is a worry and I'm worried about that MosFET, can I just add a second MosFET in parallel? I can't imagine a tube amp needing parallel MOSFETs for VVR. Thes devices are rated for high power/high current with proper heatsink. For example, the NTE2973 that is commonly seen in many VV...
- Mon May 13, 2024 12:57 pm
- Forum: Technical Discussion
- Topic: Modded Tremolux
- Replies: 39
- Views: 8467
Re: Modded Tremolux
My electrolytics are rated for 450V, but with a 5U4, my B+ nears 500V while warming up. Is this okay, or should I get higher rated caps? I would be nervous. I like to measure the AC voltage on pin 4 or 6 of the rectifier tube, multiply that number by 1.414, and chose filter caps with a voltage rati...
- Thu May 09, 2024 5:54 pm
- Forum: Garage Talk
- Topic: Anyone else having issues with the board?
- Replies: 10
- Views: 248
Re: Anyone else having issues with the board?
... and this I what I get when using my new favorites link. This is correct.
- Thu May 09, 2024 5:46 pm
- Forum: Garage Talk
- Topic: Anyone else having issues with the board?
- Replies: 10
- Views: 248
Re: Anyone else having issues with the board?
I can't get "Board index" or "New posts" to show any content. Only "Your Posts" and "Unread posts" work. I've tried deleting cookies, relaunch, restart; no luck. Safari browser. I have a similar issue. My MS Edge favorites link to the forum takes me directly to "Unread posts". About two weeks ago i...
- Tue May 07, 2024 6:08 pm
- Forum: Technical Discussion
- Topic: Modded Tremolux
- Replies: 39
- Views: 8467
Re: Modded Tremolux
That's a very useful frequency range.johnnyreece wrote: ↑Tue May 07, 2024 1:47 pm My range is now (from memory) 2.6-4 Hz on slow, 3.9-9.6 Hz on fast.
- Mon May 06, 2024 11:33 pm
- Forum: Technical Discussion
- Topic: Gibson GA-50 tone stack
- Replies: 16
- Views: 454
Re: Gibson GA-50 tone stack
That's the same schematic I have. All four pots in this snip are connected to ground. The 2.2K cathode resistor is also directly connected to ground. The 2.2K does not have to go through the bass pot to get to ground. Could it have been drawn more clearly? Absolutely. But that's not the Gibson way! ...