i recently sold a 6545, very quiet amp, a bit too much for me,, bought a 97' z amp with 4 el84s that was recently serviced and re-tubed by Z this february,,, i get a pretty pronounced 60 cycle hum,, other amps, no... is there anything i can try before i take it to my amp tech? puzzled by this because the other amps i have dont do this and none of the other z amps had this noise. i have read somewhere about a ground lift adaptor but cant find much aobut it,, i am thinking there might be some easy fix inside the amp.. would the rectifier do this? i put a weber copper cap inside and took out the jj that was in there, no change... thanks for any help,, james
Post by benttop (Steve) on Mar 24, 2007 13:24:19 GMT -7
A lot of different things can cause hum, not the least of which are your power tubes. If they aren't matched, you can get quite a lot of hum. That's the easy thing to check.
I'm assuming you have hum even when there is nothing plugged in to the front of the amp. If that's not so, you're looking in the wrong place.
If it is so, check those power tubes first. You don't want to lift the ground as that would be an unsafe operating situation. The ground is there to protect you - don't defeat it. The amp can be quiet without having to lift the ground.
you are right,, but the tubes are new and biased or replaced by dr z. geuss one could be bad. but, i had this plugged in a socket in the bedroom. so i took it back into the living room with the tv with all the dvd sattellite hookup stuff and it quieted down. i had thought that maybe the tv was doing it, but i geuss not. you know how you can have a single coil guitar and turn just the right way and get a lot of hum then it goes away if you turn another way? well, when it does it, it does it all the time. well i geuss i wil try some jjs i have. by the way this is a RX and i never had one, i am really really pleased with the variety i can get out of it. i had a maz 38 with reverb and this one sounds way different. great cleans on this amp, just a different tone than the 38. love the enhance and the bright to use with different guitars. thanks for the info
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