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Post by guitargeorge on Mar 7, 2006 6:17:46 GMT -7
I retubed my MAZ 18 with all brand new JJ's all around, cleaned all the tube sockets and did all the obvious stuff and I am still getting some weird overtones-background hum only when playing notes around the 12th fret area. I e-mailed the doc about this and his response was that this is normal, do any of you other MAZ owners experience this? I have the amp sounding great now with no other problems but this. I have a feeling that something is still wrong (a bad cap maybe?) When I bend the B at the 12th fret to C# I hear a hum behind the note abd on some lower notes I get an actual note in the background. How much of this is normal and at what point should I start thinking I should have a tech check it out?
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Post by mazmaster on Mar 7, 2006 12:39:28 GMT -7
I retubed my MAZ 18 with all brand new JJ's all around, cleaned all the tube sockets and did all the obvious stuff and I am still getting some weird overtones-background hum only when playing notes around the 12th fret area. I e-mailed the doc about this and his response was that this is normal, do any of you other MAZ owners experience this? I have the amp sounding great now with no other problems but this. I have a feeling that something is still wrong (a bad cap maybe?) When I bend the B at the 12th fret to C# I hear a hum behind the note abd on some lower notes I get an actual note in the background. How much of this is normal and at what point should I start thinking I should have a tech check it out? I've gigged my Maz 18 heavily for several years now and have been through several re-tubings, but I don't ever recall hearing what you're hearing. Maybe it's there and I haven't noticed it. What guitar, amp settings, pedals and speaker(s)/cab are you using when you notice this effect? If possible, I'll try to duplicate it on mine and let you know. Ghost notes are most commonly caused by insufficient power supply decoupling and/or speakers without sufficient doping. The "insufficient" power supply decoupling can be an intentional effect in order to make the amp sound more open and feel more responsive to the touch. Same is true with speakers. Some manufacturer's, like Weber VST, actually allow you to specify how much doping is used so you can tailor the trade-off between openness and cone cry (i.e. ghost notes).
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Post by guitargeorge on Mar 7, 2006 13:42:25 GMT -7
It is not subtile, with the amp by itself it is quite noticable, in a room with other janglin guitars bass and drums it's there but not that noticable. It only happens when there is a note being played and it seems to be centered around the b, 2nd string 12th fret and when i bend a whole step from that position. It does it on other speakers, when the amp is not in the cabinet, and when plugged in in other locations. My maz has 2/10" webber (Dr Z special design speakers) I doubt that it is cone cry. When the amp is set for distorted sounds it's more there, some notes have a lower "ghost note" that follows the bend. My maz is an older model from the 90's and I've had mixed reactions to this question on other forums. I noticed a chassis pic posted of a MAZ 18 and it had 2 big filter caps underneath, mine has only one, maybe this humming-ghost noting is a charachteristic of older MAZ 18's because of the filtering. If you havent noticed it, then yours probably is'nt doing it.
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Post by kruzty on Mar 7, 2006 14:16:51 GMT -7
Does this happen with different guitars?
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Post by guitargeorge on Mar 7, 2006 19:10:21 GMT -7
PRS Custom 22, Tokai TST-62. Fender Tele w/ Humbuckers, the amp does this with all guitars.
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Post by donniemac on Mar 9, 2006 21:36:35 GMT -7
George, As i e mailed you a few days ago...and said I had a similair issue...I found my problem. Took the back off my combo and started checking tubes while playing that one note and sure enough one of the power el84 power tubes are setting up a harmonic rattle-was able to quiet it by dampening the tube with a pencil. Hope this helps......
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Post by guitargeorge on Mar 10, 2006 5:56:38 GMT -7
I got your message, my amp does exactly the same thing that you described. I get a good bit of tube rattling when playing loudly on my z but I did'nt think that it was coming through the speakers. It's hard to find EL84's that don't rattle and I've discussed this with my amp tech who told me of a heat resistant foam material that may prevent this, I'll have to find out what the stuff is called and I'll post it here. I am going to try what you did and see if that solves the problem, I did test the chassis out of the cabinet and this still happened but I'll check it anyway. I have brand new tubes in my z with very little hours on them but that does'nt mean that they are good, I have another brand new set I could test also. One tech told me that all EL84's rattle but maybe some old stock ones made for the military my help, Thanks for the reply, Its the most info I've gotten so far on what may be causing my problem, Ive done everything else. Thanks again.
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