Members russellconner Posted October 4, 2005 Members Share Posted October 4, 2005 man...im bummed. my uberschall started making some awful noises this weekend. heres what its doing: when i first turn it on cold, it sounds fine...for about 20 minutes. after it gets good and warmed up, it starts this loud background noise...like static, but with occasional LOUD screeching sounds that come and go. it also has some popping sounds mixed into this mess. i replaced the V1 preamp tube, hoping that was it...no effect however. I then checked to see if the sound was present in the clean and dirty channels...it was. from there, i replaced the PI tube...this removed the sound from the clean channel. however, even after replacing V2 and V3 (dedicated to high gain channel) i still didnt get rid of the noise. i called bogner today, and they told me that it sounds like i need to re-tube the power section with new tesla EL-34's. i explained how i only had noise in the dirty channel, and he told me that it was still likely that the problem is in one of my EL-34's. the popping noise, he said, is one of the telltale signs of power tube issues. can i pull one pair of these power valves(reducing the power by 1/2) and see if one pair will run without the noise? that will at least tell me if the noise is from one of my output tubes. i just want to make sure i troubleshoot this correctly before i start throwing money at "possible" root causes. ive had the amp for a year and a half, and keep the dirty channel volume at 10:00, with the master rarely above 11:00. i know that sometimes tubes just go bad, but i really dont punish these...and it was 6 years before i had to re-tube my dual rec after i bought it new. also, i do occasionally get some scratchiness from the master volume knob...could that have something to do with this? he did tell me to be sure when i have someone bias it, to set it at 28 mA...and to only use Tesla EL-34's (he referred me to ARS). this thing is my pride and joy, so i want to get her healthy and working right...i just cant afford to spend tons of money on things that wont fix the problem. thanks in advance for any insight you guys might have, russell Link to comment Share on other sites More sharing options...
Members FPFL Posted October 4, 2005 Members Share Posted October 4, 2005 if this is your pride and job, backup tubes are going to become replacement tubes sooner or later so its hardly wasted money either way. if the man at bogner thinks thats the problem i'd be inclined to trust him over almost anyone here. they made the amp after all! -P Link to comment Share on other sites More sharing options...
Members guitarman967 Posted October 4, 2005 Members Share Posted October 4, 2005 Just replace the tubes. That is your first course of action. You will need them eventually anyways so it would be money well spent. It really does sound like the power tubes but I would suggest checking you preamp tubes again. How do you know that the other tubes you are putting in the amp are good? I would troubleshoot the tubes by turning the amp up loud with your guitar's volume all the way down. Tap them with a pencil and listen for any kind of ringing or scratchy static when you do this. Start at v1 which is almost always closest to the amp's input and go through each one. If you find that a certain tube is prone to this then you have found your problem. You could also do the same thing with your power tubes. From your description I would say it's nothing to be worried about. This is par for the course with tubes and tube amps. Link to comment Share on other sites More sharing options...
Members Shiny_Surface Posted October 4, 2005 Members Share Posted October 4, 2005 You can call ARS and get the same tube rating as the number written on the tubes that you have. I would also replace all the preamp tubes if you can. If that doesn't work I'm sure Bogner will want it sent to them so they can check it out. Link to comment Share on other sites More sharing options...
Members Daneswede1 Posted October 4, 2005 Members Share Posted October 4, 2005 Hey whats up, Thanks for the tip on the biasing for the BOgner Uberschall. Yes I own one. Yes I know what you are talking about as far as the "crackle" or "clicking" noise when you are playing the BOGNER in the overdrive channel. My MASTER VOLUME tone pot was dirty and actually needed to be changed out. THat solved it for me anyway. I had him put in a 250K tone potwhich is correct to spec. I also had him put in a new set of JJ Tesla tubes and 9th generation Chinese 12ax7a's. I also just ordered 2 NOS MAZDA 12ax7s from the 60s which are check for leakage and microphonics and noise and are known for their extreme tonal flavoring in the V1 preamp spot! Got it from High Test TUbes in the Vintage GUitar magazine (THey have a one page ad in their. Anyway, I would go ahead and change out the tubes (all of them -just do it and be done with it0might I recommend the 9th gen. CHinese 12ax7a's which sound great in the Uberschall! I just got it back. I also had him clean ll the pots out cause as well, a couple of the other pots were a little dirty as well but not as bad as the Master Volume which was changed out all together as I stated before. Good Luck to you! I am going to either have myt tech (He does Malmsteens plexis by the way!) Do a Send Level Return mod with the FX Loop so I can match the inputs of my Marshall head and the Uberschall and run my TC Electronic G Force through both without any ground looping or phase cancellation or what you might call it. It runs some $$ BUt I want to do it. Or I might trade the head all to9gether and get Bogner Ecstacy Classic. Ill need to add some serious money to that deal I know. I have been gasin for an ecstacy for a while but I cant see owning an uberschall a JCM 800 AND an Ecstacy. I dont need that mANY HIGH GAIN AMPS ! twso is enough for my tonal pallet. Ill let my fingers do the talkin LO!L later ! Link to comment Share on other sites More sharing options...
Members russellconner Posted October 4, 2005 Author Members Share Posted October 4, 2005 bump...and thanks for the input so far, guys. russell Link to comment Share on other sites More sharing options...
Members thegame Posted October 4, 2005 Members Share Posted October 4, 2005 My Uber's presence knob on the dirty channel makes a static-y noise when turned up. It sounds like a sandstorm/windstorm in the background. Turning the overall amp volume up does not make the noise louder. This noise in the background is always at the same level, fairly low, regardless of the overall volume of the amp. Reducing the presence knob usually reduces the problem. Problem is, I like the tone with the presence cranked to max. Is my presence knob f**cked? Link to comment Share on other sites More sharing options...
Members sonixx Posted October 4, 2005 Members Share Posted October 4, 2005 does it sizzle... then pop... then stop... does lightly tapping on the amp make a difference? yes you can pull power tubes in pairs... does it do it with the PI pulled? definitely sounds like a heat issue? either a tube or a cold solder joint. Link to comment Share on other sites More sharing options...
Members Rayneman Posted October 4, 2005 Members Share Posted October 4, 2005 Are the "Telsa" EL34 tubes to which Bogner is referring the "JJ" tubes...such as the ones Bob @ Eurotubes sells? I looked on the ARS page, and they list "JJ" and not Tesla as a brand of tubes they carry. I would like to get a replacement set of power tubes for my Uber, but am a little confused about the correct brand. My uber, which I just recently picked up used, has EH EL34s in it. Does anyone know? Thanks Link to comment Share on other sites More sharing options...
Members Shiny_Surface Posted October 4, 2005 Members Share Posted October 4, 2005 Originally posted by Rayneman Are the "Telsa" EL34 tubes to which Bogner is referring the "JJ" tubes...such as the ones Bob @ Eurotubes sells?I looked on the ARS page, and they list "JJ" and not Tesla as a brand of tubes they carry. I would like to get a replacement set of power tubes for my Uber, but am a little confused about the correct brand.My uber, which I just recently picked up used, has EH EL34s in it. Does anyone know?Thanks The ARS tubes say "JJ/Tesla" on them Link to comment Share on other sites More sharing options...
Members russellconner Posted October 4, 2005 Author Members Share Posted October 4, 2005 Originally posted by sonixx does it sizzle... then pop... then stop...does lightly tapping on the amp make a difference?yes you can pull power tubes in pairs...does it do it with the PI pulled?definitely sounds like a heat issue? either a tube or a cold solder joint. how are they paired? do i just pull either the inside pair, or the outside pair? russell Link to comment Share on other sites More sharing options...
Members sonixx Posted October 4, 2005 Members Share Posted October 4, 2005 Originally posted by russellconner how are they paired?do i just pull either the inside pair, or the outside pair?russell I don't have a Uber. someone chime in, but I'd pull the two outside... then the two inside. Link to comment Share on other sites More sharing options...
Members Shiny_Surface Posted October 4, 2005 Members Share Posted October 4, 2005 Originally posted by russellconner how are they paired?do i just pull either the inside pair, or the outside pair?russell I would call Bogner to make sure. If I had to guess I would say pull the outside pair and adjust (halve?) the speaker impedence to compensate. Link to comment Share on other sites More sharing options...
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