Low end farting out on palm mute chugs 36watter
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- bigdakota
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Low end farting out on palm mute chugs 36watter
I have a 36 watt TMB head with a 4x12 cab and I've had some ongoing issues, I didn't build it. Overall has great tone but now I notice when I have my distortion pedal (trex mudhoney) on and chugging (palm muting) on lower notes (low e and f) the amp farts out a bit. Doesn't happen when chugging higher notes. I tried on other amps and it does not do this. Any ideas?
Has new JJ tubes.
I've been playing a while but not great diagnosing tube amp issues.
Thanks,
J
Has new JJ tubes.
I've been playing a while but not great diagnosing tube amp issues.
Thanks,
J
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- bigdakota
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With a distortion/OD pedal engaged I don't think you'd hear blocking distortion. You'd notice blocking distortion when playing loud pushing the amp by it's self. What drivers are in the 4 x 12? It sounds to me more likely that the speakers are running out of excursion. Have you tried it through a different cab? Can you make it happen at low volumes?
-Paul
-Paul
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- bigdakota
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Well usually I have the amps volume on about the 10 o'clock range. Without distortion pedal it has a nice light crunch to it. With distortion on (gain to 12 o'clock) it has a nice fatness great open chord sound but as soon as I chug on E or F it farts out.
The cab is a Marsh, not sure what speakers, it's the rehearsal spaces. I'll try their other cabinet tonight.
Any use of matching the ohms differently? It's 16ohm out to 16ohm cab.
The cab is a Marsh, not sure what speakers, it's the rehearsal spaces. I'll try their other cabinet tonight.
Any use of matching the ohms differently? It's 16ohm out to 16ohm cab.
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- BooBird
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I know the OD pedal's Gain is up, but is the Volume or Level set really high too?
As mentioned EL84's aren't known for giant bottom end, but I just can't see a 4x12" running out of excursion. Not saying it isn't the case, but looking at all angles won't hurt.
You mentioned you've had ongoing issues with the amp... what other issues?
As mentioned EL84's aren't known for giant bottom end, but I just can't see a 4x12" running out of excursion. Not saying it isn't the case, but looking at all angles won't hurt.
You mentioned you've had ongoing issues with the amp... what other issues?
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- bigdakota
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When I first bought it. it had some grounding issues that I took to a tech and they had fixed it. It died on me once after putting new tubes in it, tubes that came with it were doing the frying pan bacon crackle.
Happened the second time I fired it up after the tech fixed it.
Volume on the pedal is at 12 o'clock, to match level of the amps clean sound. It doesn't happen until the amp is pushed hard.
Any chance a fan on the back to cool things down may help a little?
Happened the second time I fired it up after the tech fixed it.
Volume on the pedal is at 12 o'clock, to match level of the amps clean sound. It doesn't happen until the amp is pushed hard.
Any chance a fan on the back to cool things down may help a little?
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- bigdakota
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Ok last night was a good rehearsal. No FARTING! lol. But really, I had picked up a 12AY7 to reduce some gain and put it in the position directly next to the EL84's as I was told. I tried moving it to the furthest from the power tubes and voila! No farting out..pretty weird. I did have the bass turned down to 1, since its very bass heavy to begin with.
Thanks for your help guys!
Thanks for your help guys!
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I've been following this post, glad you getting some results. A 12AY7 has a gain facter of 44, low compaired to a 12AX7, 100. Maybe trying a 12AT7 in the first position, gain of 60 might sound better and no farting. If the the 12AT7 sounds OK and you like the tone, yo ucan get closer with a 5751, gain of 70. Just some suggestions for more versatility.bigdakota wrote:Ok last night was a good rehearsal. No FARTING! lol. But really, I had picked up a 12AY7 to reduce some gain and put it in the position directly next to the EL84's as I was told. I tried moving it to the furthest from the power tubes and voila! No farting out..pretty weird. I did have the bass turned down to 1, since its very bass heavy to begin with.
Thanks for your help guys!
I commonly use a 5751 in the first stage of an overly gainfull amp to tame her a bit. That 12AY7 without a pedal will definitly put a damper on the gain and probably too tame...?
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- zaphod_phil
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Here's a quote from the Trex site about the MUDhoney pedal.
Quote: The Mudhoney is a Distortion/Fuzz pedal with a very wide tonal range. It features a typical 3-knob gain/volume/tone layout plus a boost switch. I played this for a few minutes with the boost off and it is quite impressive; very thick tone with warmth that could quickly find its way to being your main dirt for jazz, blues, etc. Then I pushed the boost and cranked up the gain! The speakers in my little Princeton cried for mercy.
It sounds to me like you have the volume on the amp too high when hitting it with this pedal,and it simply overdrives the preamp too much.If you just put the 12AX7 back in and set it to about 1/2 or even less,it would eliminate any farty bass problems.
Quote: The Mudhoney is a Distortion/Fuzz pedal with a very wide tonal range. It features a typical 3-knob gain/volume/tone layout plus a boost switch. I played this for a few minutes with the boost off and it is quite impressive; very thick tone with warmth that could quickly find its way to being your main dirt for jazz, blues, etc. Then I pushed the boost and cranked up the gain! The speakers in my little Princeton cried for mercy.
It sounds to me like you have the volume on the amp too high when hitting it with this pedal,and it simply overdrives the preamp too much.If you just put the 12AX7 back in and set it to about 1/2 or even less,it would eliminate any farty bass problems.
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