Looking for tube advice [message #9509] |
Mon, 30 January 2006 17:42 |
blades976
Messages: 20 Registered: May 2009
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The tube preamp section in the Hartke 3500 basshead we are using is hissing pretty bad. The hiss goes away when the tube channel is turned down (we normally like it about half way up) but then the bottom end drops out (for us anyway). I'm just wondering if anybody knows a good replacement tube to get. I believe the preamp uses a 12AX7. I've done a few searches and the name Sovtech seems to come up a bunch. Thanks John
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Re: Looking for tube advice [message #9514 is a reply to message #9512] |
Fri, 03 February 2006 19:11 |
blades976
Messages: 20 Registered: May 2009
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Chancellor |
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I will be buying an EH tube from Aki in a couple of days, in the mean time I've picked up a groove tube 128X7C (gotta get the amp up and running ASAFP), I bought it because the plate structure looks kewl compared to the other offerings. Will be cool to compare it to an EH tube. John
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AMP FREAKS OUT [message #9522 is a reply to message #9518] |
Sun, 05 February 2006 22:24 |
blades976
Messages: 20 Registered: May 2009
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Well the new tube was great yesterday when I replaced it. We played it for about 15 minutes at a moderate volume just to make sure the thing works. It did and sounded nice and clean. Well today we fired it up and the bass amp worked great for about 45 minutes then just totally went to shit. Horrible distortion (VERY loud crackling and grating noises) kicks in when the amp is pushed to anything beyond quite operation. I'll try and replace the old tube tomorrow to see if maybe I got a bad tube. I hope the output section of the amp didn't get shorted out. The distortion comes out in the amps speaker level outputs and the balanced XLR as well. At first the distortion was heard as faint crackling in the PA then within 10 minutes the damn thing went nuclear and had to get turned off. The old tube is a plain old Groove Tubes 12AX7. Could this malfunction be from not having the amp re-biased? I understand that the tube can wear a bit quicker but an hours worth of playing? I bought the tube from a local guitar store, but I honestly don't think the tubes where individually tested there. I hope this doesn't get expensive John
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Re: AMP FREAKS OUT [message #9529 is a reply to message #9523] |
Tue, 07 February 2006 23:15 |
blades976
Messages: 20 Registered: May 2009
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Ran the amp tonight with the old tube in it. No problems except for the excess hiss that made me buy a new tube to begin with. I guess I'll try and order another tube and see if I get better results. John
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