301
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American Style / 5E3 Tweed Deluxe / Re: It lives!!
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on: January 25, 2009, 03:13:07 AM
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Good Heavens that is a nice looking head!!! Is there a big advantage to adding screen resistors? I changed my bias resistor from 250 to 470 and that brought the MA's down from about 41 to 27. Thank You post script em - I would like to request some gut shots also please.
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302
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British Style / JTM 45, 50 / Re: jtm50 blowing fuses
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on: January 25, 2009, 03:06:15 AM
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Did you try a new/different rectifier tube? When you put in the new tubes did V4 still red plate? Have you checked the bias, maybe a bad plate resistor? Those are a couple things to check.
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306
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British Style / Plexi Lead, Bass, Superlead / Re: Overly Bright, Bright Channel
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on: December 12, 2008, 06:35:29 PM
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I would say you are starting in the right place. Remove (un-solder, cut) that cap off the bright volume pot, and see how that sounds. You could also take a look at the "bass lead layout" and take note of the different component values. These amps are well laid out and easy to work on. No real need for a tech unless you do not have a soldering iron, small amount of electronics knowledge. Do you know how to check/drain the caps?
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307
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Custom amp building, Prototypes and other amps / SoundClips / Re: YOU'VE GOT TO SEE THIS
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on: November 24, 2008, 03:56:46 AM
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The guy is a good player. I could listen to him for a long time. He covered a lot territory with one amp/one guitar. Jazz, country, and in that last video he was starting to loosen the reigns on his blues/rock skills. Too bad the video ended. Paul86 - Who is that guy? Is it you? Very nicely done.
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308
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Tw Clones / Expression / Re: Fun days ahead...
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on: November 20, 2008, 10:30:55 PM
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Lead dress, and anybody vaguely related to lead dress, will be very important. The presence knob can be another source of trouble for the TW. Component changes at any location can garner huge results also. Have as many pre tubes as possible on hand. Get some chopsticks. Good Luck
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310
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American Style / BF Champ, Vibro Champ / Re: Bias
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on: November 19, 2008, 11:06:29 PM
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OK- Took awhile to get that resistor... So now I have a 3 watt 680 ohm cat resistor. That voltage reads 26.7V, the plate is at 360V, and a steady 369V coming off the rec tube. If I am doing the correct math, that makes about 39.2 mA. So the numbers look "better" but the current still seems kind of high. The amp sounds good. So if their are no objections, I think I will just leave everything where it is. Thanks again for all the help. Ooops, another math question. Does this add up to 14 watts? Thank You
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312
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Custom amp building, Prototypes and other amps / Discussion / Ceriatone Transformers
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on: November 08, 2008, 04:28:50 PM
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http://www.promitheusaudio.com/transformers.htmlWhat do you guys think of the company that makes the power and out trannies for Ceriatone? They seem to be a large and diversified company. We have five amps with the stock Ceriatone trannies, 2 Fender, 2 Marshall, and a TW clone. All the iron seems to be well made and function without trouble. But I am no expert on transformers. Nor have I ever done a direct comparison with a Ceriatone tran to a Merc Mag, Heyboer or any other brand of tranny. So what do you guys think. How do they compare? Has anybody done any real investigating? Thank You
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313
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American Style / BF Champ, Vibro Champ / Re: Bias
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on: November 08, 2008, 04:01:58 PM
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Thanks W. - I have calls into a few friends to see if they have any large resistors in the 5-600 ohm range. If not, then it's Mouser time. Will post again ASAP. Thank you so much for the guidance.
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314
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American Style / BF Champ, Vibro Champ / Re: Bias
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on: November 07, 2008, 11:23:02 PM
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My apologies, the plate voltage was not 390. The rec tube is a JAN Phillips 5Y3. Pin 2 - 352 Pin 4 - 319VAC Pin 6 - 318VAC Pin 8 - 352 TungSol reissue 6V6 Pin 2 - 229 Pin 3 - 345 Pin 4 - 345 Pin 7 - 22.9 Pin 8 - 22.9 So if I am reading things the right way, I have almost 23 volts on top of a 470 ohm resistor. That is about 47 milli amps. Seems like I almost have a small camp fire sitting on my desk. This is what made me think I might need a higher value cat resistor, to get the amps down. But would that make the plate voltage too high? I'm at your mercy.
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315
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American Style / BF Champ, Vibro Champ / Re: Bias
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on: November 07, 2008, 10:11:22 PM
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Yeah, OK, Let me pull the chassis out again and double check all the numbers I gave you. I will check to see what rec tube I have in there also. Thank You
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