onetonepony
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bought a new/old mark iv last week. was running it into my motu 2408 all week while waiting for the palmer pdi 03 to arrive. during the week it was making some weak sounds, and generally unpleasant tones while using the recording out in silent mode. didn't know what to think. the manual says that how it was behaving and the types of sounds it was making might be indicators it needs a new preamp tube. so I waited till today. the palmer arrived.
I cranked it up and while monitoring the sound it started making some new strange squealing sounds from the pre amp , or so I assume. on the lead gain and the lead treble knobs I could actually modify the squealing. I would best describe the sounds as dolphin like squealing, buzzing squawking etc.. this happened for a short time, long enough for me to find the right controls and roll them a bit left and right, trying to isolate where the sounds came from. then the fuse popped. so I went and bought two jj 12ax7's, brought them back, plugged them into vi and v3, replaced the fuse, and the amp fired up again. it still sounded a little weak though im in "trying to tweak my way to tone mode", so I assumed its just operator error. but then the fuse just goes again. no strange sounds or nothing, it just pops
well....there is this wicked ground hum. its been there from the beginning too. my guitar is a bit noisy so I assumed it was the guitar, and may be, but I notice that when I touch the chassis by the ground switch or the rails on top of the tolex, the ground hum goes away. i've played with the plugs, bought brand new cables and have the amp plugged into the wall and don't have grounding issues with my other stuff. so im wondering if this is a power tube issue or something else.
any feedback would be great.
bought a new/old mark iv last week. was running it into my motu 2408 all week while waiting for the palmer pdi 03 to arrive. during the week it was making some weak sounds, and generally unpleasant tones while using the recording out in silent mode. didn't know what to think. the manual says that how it was behaving and the types of sounds it was making might be indicators it needs a new preamp tube. so I waited till today. the palmer arrived.
I cranked it up and while monitoring the sound it started making some new strange squealing sounds from the pre amp , or so I assume. on the lead gain and the lead treble knobs I could actually modify the squealing. I would best describe the sounds as dolphin like squealing, buzzing squawking etc.. this happened for a short time, long enough for me to find the right controls and roll them a bit left and right, trying to isolate where the sounds came from. then the fuse popped. so I went and bought two jj 12ax7's, brought them back, plugged them into vi and v3, replaced the fuse, and the amp fired up again. it still sounded a little weak though im in "trying to tweak my way to tone mode", so I assumed its just operator error. but then the fuse just goes again. no strange sounds or nothing, it just pops
well....there is this wicked ground hum. its been there from the beginning too. my guitar is a bit noisy so I assumed it was the guitar, and may be, but I notice that when I touch the chassis by the ground switch or the rails on top of the tolex, the ground hum goes away. i've played with the plugs, bought brand new cables and have the amp plugged into the wall and don't have grounding issues with my other stuff. so im wondering if this is a power tube issue or something else.
any feedback would be great.
