316
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American Style / BF Champ, Vibro Champ / Re: Bias
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on: November 06, 2008, 11:45:57 PM
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Hey Winston- Every thing seemed to be OK, so I put the chassis back in the cab. But I think it was up there pretty high, like 390 volts at the plate. But maybe I don't know how to check the bias on a cathode biased amp. Do I take the voltage at the cat (pin 8?) and divide that by the cat resistor? I am assuming the parallel cap does not affect the impedance because there is no DC going thorough this "by-pass" cap. Afraid I need wiser men to guide me at this point. I can tell you that the reissue TungSol draws more current than the RCA 6V6. I think.
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317
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American Style / BF Champ, Vibro Champ / Bias
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on: October 29, 2008, 04:41:49 AM
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What kind of bias, output, cathode resistor voltage etc. etc. are you guys seeing with your VC's? Seems like i am running at 42MA's. Was thinking of changing the cat resistor to a 2 watt 6-700 ohm. What are you guys experiencing? Thank You
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318
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British Style / JTM 45, 50 / Re: JTM 45 tube choices
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on: September 02, 2008, 02:25:34 AM
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Are you talking about modern day TungSol KT66, the ones with a metal base? If so, I would advice extreme caution with those tubes. Pin 1 is tied to the metal base. If being used in a chassis with metal tube grabbers, there is a danger of shorting the tubes to ground. If in doubt, contact your amp tech or tube dealer. Otherwise, enjoy one of Rock N Roll's best loved guitar amplifiers.
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319
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Website, Store / Support / Re: Setting up and testing a ceriatone jcm800 2203
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on: July 04, 2008, 06:10:36 PM
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If you have never built an amp before, I would say a 100 watt (or 50 for that matter) JCM 800 is a lot to start with. But HEY, if you already ordered it.... I do not know if I would get too concerned with math calculations. Jump on one of the many forums(Metro, Plexi, etc.) and you will see where most guys run there tubes in a 2203. There will only be one bias pot, hence the need for a "Matched Quad" of tubes. The preamp tubes will not need to be biased or matched. I am just skimming the surface of all this of course. If you will, take this advice, join The Amp Garage and Metro Amps forums. Do as much reading as you can before your kit arrives. Pay special attention to the FAQ and "Stickys" at the beginning of each forum. Try to read as much as you can before bombarding the members with questions that they have heard a Billion time before. Use the SEARCH function on the forums before you ask a question. You will see that A LOT of your questions have already been asked and answered many times before. Good Luck
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320
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Website, Store / General / Re: Malaysian Export and US Import Duties?
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on: July 02, 2008, 08:32:13 PM
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Just got a note that DHL has me in collections for $35.00. I called the collection agency and they said it was for an amp I bought in August of 2007. I wonder why I am getting charged for just this one amp, and none of the others? Also, why would DHL make a delivery and then send the customer a bill? Seems like they would hold the package till all fees were payed. But then again, maybe it is not that simple. Perhaps foreign shipping gets complicated. Any of you guys work for DHL, UPS, FedEx, etc. etc? Could somebody shed some light on this topic? Thank You
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321
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British Style / JTM 45, 50 / Re: Strange noises from my JTM45
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on: June 20, 2008, 06:15:45 PM
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72sq may be right on the money. We have a Wreck clone that had a Presence problem (among others). You might want to just try increasing the value of the Presence cap and see if that will give you some relief. Good Luck
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323
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American Style / BF Champ, Vibro Champ / Re: Humm - Vibro Champ
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on: June 14, 2008, 08:52:24 AM
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Defensive? I will rephrase. I will defer to your knowledge and the tech, as I was a painter and have absolutely no background in electronics or electricity. I can sort of follow along the website you linked to, but it really stretches my abilities with troubleshooting amplifiers. My limited knowledge of heaters and noise always makes me think of lead dress and not grounding. That is assuming you are working with a "proven circuit". And maybe the Ceriatone circuit is not "proven", I really do not know how closely it follows the Fender schematic. All I know is that my head is dead quiet and has bees in the studio a few times with no complaints. But maybe I got lucky. I am just one guy with one amp. Like you say, some other Ceriatone V-Champ owners have had the same problem. At any rate, it would be interesting to know the final outcome of your situation. I had a noisy TrainWreck clone, it is dead quiet now but it was almost responsible for a suicide. Good Luck
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324
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American Style / BF Champ, Vibro Champ / Re: Humm - Vibro Champ
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on: June 13, 2008, 03:30:34 PM
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I would be very curious to know what the "glaring" problem is that your tech is referring to. I have a Ceriatone Vibro Champ in a head. There is absolutely no problems with any noise or oscillation. Who built your Champ?
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326
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British Style / JTM 45, 50 / Re: Help replacing dead ON lamp/bulb
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on: June 01, 2008, 06:01:03 PM
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Are you talking about the Red, Square shaped, Marshall style lights? If so, I can mail you the one I took out of my 1987. When I changed mine over to a 1986 I also did a pilot light mod/change which rendered my LED (or whatever it is) unusable. If you give me your address (you could do it in a PM or email if you prefer) I can send it off to use in your chassis.
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328
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Website, Store / Suggestions / PPIMV Faceplates
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on: May 12, 2008, 09:55:12 PM
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Come The F### On Already! You would think by now that Ceriatone would have dished out a few dollars to make a faceplate that fits those Marshall 1986 and 1987 clones with a master volume. It makes the company look real 2nd class to keep selling amps that have an "indicator" knob. Then do away with the "JMP" (only Marshall made a JMP and this is not a Marshall it is a Ceriatone) and install the indicator light where it works best. Thank You
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329
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British Style / 18 Watt / Re: Output jacks
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on: May 03, 2008, 06:21:19 PM
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Hhhhhmmmm - Not sure if I completely understand the question. The out jacks are mostly parallel wiring with the exception of 2 wires from the Out Tranny and 1 wire from the Stand-by I think it is. There is the Trem out, but that does not seem to be your question. Am I remembering this correctly or am I way out of bounds?
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330
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American Style / 5E3 Tweed Deluxe / Re: Build issues
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on: April 24, 2008, 07:42:34 PM
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Sounds like you have some bad oscillation (the squealing noise) going on. Lead dress can be a culprit, but you need to check with a more capable tech than me. The Tweed Deluxe has very active controls, one affects the other. Take a look at the layout and you will see the relationship between the input jacks and the volume controls. As far as the lack of headroom is concerned... did you make sure that you have a 12AY7 in V1 and not a 12AX7. Wish I could be of more help. Good Luck
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