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I have a Marshall JCM2000 DSL100 that has been emitting a low pitched squealing noise. It starts to do it after about ten minutes of playing. If the standby switch is flipped off and then back on, the noise goes away for about five minutes and then returns. It isn't a constant noise either. When it does happen, it will do it off an on periodically. any thoughts?
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Possibly a preamp tube. I'd remove the sheilds & lightly tap the 12AX7's. They get noisey..........glen -
And turn down the reverb to see if it is involved. Does the reverb work? SOme Marshalls aer sensitive to open reverb pans.Education is what you're left with after you have forgotten what you have learned.Comment
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I've kept the reverb on zero. I have some backup preamp tubes I will try out tonight to see if that solves the problem. The preamp tubes that are in it now, I just put in a little over a month ago. I did have an issue with the head a couple of months ago where it was just cutting out and then coming back on later. I took it to a tech and it had a bad resistor. I've been using it five or six times a week for the past month and this just started the other day. I was in a basement at the time in a new area so I am hoping it may be a signal interferring. I brought it back home but haven't hooked it up yet. If the squealing persists I'll try the preamp tubes. If it stops, then it may have been some interferrence with something. this is what I am hoping it is. thanks for the input guys, i will post back with my progress.Comment
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I swapped out the preamp tubes and still had the issue. Now it is cutting volume in half every once in a while and I can correct by hitting the top of the head. The standby switch pops when i switch into standby mode. I am ready to burn this thing!!!!Comment
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It needs the solders retouched 100% at every single multipin, pot, switch, jack, LED, tube socket, and at every large and/or heat-producing component on every board. Additionally there may be other joints that are simply "solder starved" and also need a retouch.
That's just the nature of the DSL/TSL series due to crappy factory soldering and single-sided boards.
Sure, there can be other problems. But until the solder issues are addressed it will keep you chasing round & round with a new symptom every time.
Don't get me wrong - I actually like those amps a lot - after the solders are squared away...
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coincidentally i played a show saturday night and the guitarist in the band after us had the same head and mentioned the same symptons he had had and said he had the solder points retouched and it took care of it. Off to the tech tomorrow, thanks for the info. I'll place a post once i get it back. Hopefully that's the issue.Comment
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I got this back from the shop. The tech touched up all the solder points and replaced the output tubes again (no charge thankfully). Worked great for a couple of weeks. No more humming, etc. Last week it pulled a repeat of what originally put it in the shop several months ago. Level just bottomed out. I pulled the effects loop out and everything came back up to normal. I cleaned the effects loop jacks and everything seemed to be ok again. However, the head sounds somewhat muffled, like it isn't as punchy as it was or bright. I have to turn the presence and treble on 10 and the bass on 0 to over compensate for the muffled/muddied sound. This is with or without the effects loop plugged in. But it is now back to the level just dropping out after about twenty to thirty minutes of play time. I pull the effects loop and the level comes back. I thought it might be a component in the effects loop so I have swapped with my other guitarist. His rig runs my effects fine. my DSL100 still has the same issues even if I use his. He and I have identical set ups for out effects loops (head->chorus->wah->tuner->bbe sonic maximizer482->head). I'm thinking something has went whack and in the process it spoiled one of the output tubes.
any thoughts or suggestions?Comment
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