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Pro Jr died after Valvulator pulsed


 
10/10/2004 7:42 AM
MitchMAlloy
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Pro Jr died after Valvulator pulsed
The VHT Valvulator has been nothing but trouble since I plugged it in. I finally got it to work and then turned it off and the next day came back and turned it on with the amps and it started knocking through the spaeksers. It sounded like someone was knocking on the door. It was making my pedals flash too. So it seems to have torched the Pro JR. All the tubes light up and the power light lights up but there is no sound coming out of it. Did I blow a transformer? Thanks,  
 
Mitch
 
10/10/2004 6:09 PM
Nick
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Hi Mitch,  
 
If the sound was very loud it could be a tube or even the speaker that died.  
 
You should check the speaker first by disconnecting it and testing it with a 9 volt battery.  
 
Do you have spare tubes? You could change the tubes one by one to see if the sound is coming back.  
 
Give me some news about it!  
 
Nick
 
 
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10/10/2004 10:04 PM
MitchMAlloy
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Thanks for the repply. It's not the speakers. And I changed the power amp yupes and the 2 preamp tubes are glowing and seem fine. Can the tubes glow if the transformer is blown? I cannot figure out what is the matter with it. I've giggled everything and replugged everything and tried everything. All the same cables work with my other heads. ????? I would think the tubes would be not glowing if it didn't have sound but what do I know? I don't haev extra pre amp tubes but like I said these are glowing and look fine. What to do?
 
10/10/2004 10:34 PM
Nick
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If the tubes are glowing it only means that the heater voltage is coming from the power transformer but that's a good start. It's possible that a preamp tube or the output transformer blew even if they still glow. Do you have preamp tubes (same type) in your other head to swap them and make a test?  
 
Do you have a multimeter to check the voltages in your amp? It would confirm that your power transformer is good. You could also check the output transformer for opened winding. The schematics can be found here:  
http://www.ampwares.com/ffg/  
 
Like I say to everybody, always be careful if you play inside the amp because there is high voltage involved but I suppose you already know that.  
 
Nick
 
10/10/2004 11:27 PM
MitchMAlloy
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I would have to take my Aiken apart to get at some 12ax7s but I can do that. I'm not going to touch the inside of the amp. This is one area I have managed to avoid in my years of learning every other aspect of this business. So I'm sort of cluless I'm afraid. BUt I'll try the pre amp tube swap and see. Thanks again, :>)  
 
Mitch
 
10/10/2004 11:29 PM
MitchMAlloy
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OK it's not the tubes. I changed them all. All glowing. Still dead. Now it's out of my abilities I'm afraid. Could the transformer be blown and the tubes still light?
 
10/11/2004 1:59 AM
Nick
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Yes, it could be the transformer.  
In that case, I think you should bring it to an amp technician.  
 
Give me some news about it.  
 
Nick
 
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