101B high gain ringing/feedback from microphone type sound

R

RG955TT

New member
Hey guys, minor issue but when engaging the higher gain modes in blue and red I hear a faint ringing like feedback from a mic might cause. I replaced V1 and tapped on all the other pre's and nothing seems to influence this sound. The higher the gain or adding the boost seems to make the ringing more prominant. Any thought? Any suggestions on which tube or tubes I should be looking at first other than V1? Thanks
 
What sort of PU's in your guitar? Usually a little gating will take care of it. Hotter pick ups in some of my guitars cause a little discomfort with feedback.

Some preamp tube covers would be handy on the XTC's probably.

Steve
 
Hey Steve, Suhr Guitars ands pickups but the sound is there with the guitar volume turned all the way down. On red channel boosted, gain at 12 to 1 oclock it literally sounds like a microphone lightly feeding back, same type of high frequency. This is definitly an amp issue, sounds like a tube is microphonic but tapping on each one I can't seem to find it. I use a ISP dec G in the loop so that helps but it's still there in the background when playing. I tried turning the loop off and it's still there. What other tubes are common to both blue and red channels? Thanks for trying to help.
 
Preamp tube covers huh? There seems to be a lot of talk about them lately here. Do they really make a difference? I've played tube amps all my life and have never used them.

I have a 101b, 1971 Marshall Superlead, 1978 2204, and a 1992 Dual Recto.


Maybe I should reconsider?
 
I'd say, if you haven't experienced this before with the same set up, it's simply some preamps going sour. Nothing more, nothing less. The glass needs to be replaced once in a while - so it goes.

V.
 
reverymike":3ujl02n9 said:
Preamp tube covers huh? There seems to be a lot of talk about them lately here. Do they really make a difference? I've played tube amps all my life and have never used them.

I have a 101b, 1971 Marshall Superlead, 1978 2204, and a 1992 Dual Recto.


Maybe I should reconsider?
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Yeah, I was just shittin because of it............ :D :D :D

Back to the OP, if it is doing it with the volume down on the guitar, definitely a preamp tube:

Channel 2: V1, V2, V3, (V4 only used if effects loop is on), V5

Channel 3: V1, V2, V3, (V4 only used if effects loop is on), V5

Channel 2 and 3 PLEXI MODE: V1, V3, (V4 only used if effects loop is on), V5
 
OK, I replaced all the pre tubes in V1, V2, V3, V4 and V5 and I have still have the ringing, most easily heard in red mode boosted. Could this possibly be a power amp tube issue? Never heard of this before. Thanks V and Steve for trying to help.
 
I had an issue like this with my 5150. Steady feedback on the lead channel with the guitar volume down. It turned out to be the power tubes, or just one of them. Put in a new matched set and all was good.
 
Thanks guys, turned out to be an issue with my Strymon Brigidier in the loop, I think it may be power supply but I need to check, took it out and noise went away. Wierd that it's there bypassed or not. Thanks for all the advice.
 
RG955TT":1ppaoqas said:
OK, I replaced all the pre tubes in V1, V2, V3, V4 and V5 and I have still have the ringing, most easily heard in red mode boosted. Could this possibly be a power amp tube issue? Never heard of this before. Thanks V and Steve for trying to help.
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Could be a power tube as well. Ususally it's the pres but I have had some KT88's in my Shiva go a little microphonic. I have had this in all three of my Bogners when you crank them up. There is a point on the volumes and gain when the amp will squeel some. Moreso than with other amps I have owned. I use tube dampers in my Bogners.
 
Do the dampers really help with the feedback? Man my 20th XTC really like to make my Suhrs feedback, hard to control even with noise reduction in the loop (ISP deciminator G) Any little allowance of my muting to not be complete she wants to screech like a pig. I think though the gain is so high there may be no way around it. Gain on red channel at 10 oclock too!
 
RG955TT":3btcblp5 said:
Do the dampers really help with the feedback? Man my 20th XTC really like to make my Suhrs feedback, hard to control even with noise reduction in the loop (ISP deciminator G) Any little allowance of my muting to not be complete she wants to screech like a pig. I think though the gain is so high there may be no way around it. Gain on red channel at 10 oclock too!
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Thet won't help with pickup feedback. Moving further away from the amp will. The dampers do help though keeping the tubes a little more stable.
 
I just started having this issue with my 101b tonight. I have a Strymon volante in the loop. If I bypass it, feedback stops. Anyone figure this out?
 
jimmynorrisjr said:
I just started having this issue with my 101b tonight. I have a Strymon volante in the loop. If I bypass it, feedback stops. Anyone figure this out?
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Bypass it how? With the amp that takes out V5? Or physically remove the pedal but keep the effects loop engaged with a loop back cable?
 
I sometimes have issues with multi-pedal power supplies getting clock noise from certain pedals but it's always two pedals not playing nice together. I can usually cure it by using dedicated power supplies for both pedals. Are there any other pedals involved?
 
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