jmv
New member
Okay, so i've got a 1966 fender bassman, circuit AB165. The cabinet is the original 2x12 with the original Jensen C12N speakers. The amp AFAIK is all original besides having replaced caps that needed it, which was about 3-4 years ago i believe. At that point all the tubes were replaced as well.
As far as the tubes that are in it now, for the poweramp its got two 'fender' labeled Sovtek 5881WXT's. In the preamp, the first two positions are Electro-Harmonix 12AX7EH's (iirc, provided to me free of charge by member Wattage, to replace some groove tubes that i had in there when i got it). The third position is a Groove Tube "Fender" GT-12AX7, but underneath that printing it says Sovtek 7025/12AX7WA. The phase inverter is not clearly marked, the only thing i see on it is a small dark blue mark, possibly handwritten, by the pins of the tube. Its faded and unreadable. Now, the marked specs for the preamp are 3 7025s and a 12AT7 for the phase inverter spot. Fairly sure the PI tube right now is a 12AX7, the guy i bought it from had it set up that way for earlier breakup.
Okay, so now that i've exhuasted myself telling what i know about the amp, let me get to my problem.....
I've got what seems to be a great lack of bass. I can plug into my moms silverface vibrochamp, and while its nowhere near as satisfyingly dirty, it feels as though it actually pumps out MORE lowend than my bassman. I can 'feel' the vibrochamp more than a cranked 50w amp!! Granted, the bassman is not directly on the floor, its in a flightcase on wheels, but you can hear the problem as well.
Its most apparent with clean tones. It feels like when i turn up the volumes on everything, and turn up the bass knob a little, the lowend can be felt, but thats always at a point that is very saturated. The bass also starts to feel a little 'flabby' at that point, i.e. when i do some palm muting on chords i don't get as defined and percussive of a sound. (mind you, this experimenting i was doing last night was with a jimmy vaughn tex mex strat, not my Les Paul). This amp gets WAY, WAY dirtier than my moms vibrochamp.... The vibrochamp dimed will hardly breakup, while the bassman at 7 on the amp can get me more distortion than i'll probably ever need for the styles that i play. So how can i get more bass out of my clean sounds, and keep it going while dirty without having flab??
One of my sneaking suspicions (which i really hope isn't the case), is that the wonderful original Jensens have had all they can take. Would this possibly lead to this sound issue?? If anyone has any other suggestions for causes of the problem i might look at, please let me know. I love the solo tone of this amp, and i looooove its wonderful breakup, but i need some beef.
As far as the tubes that are in it now, for the poweramp its got two 'fender' labeled Sovtek 5881WXT's. In the preamp, the first two positions are Electro-Harmonix 12AX7EH's (iirc, provided to me free of charge by member Wattage, to replace some groove tubes that i had in there when i got it). The third position is a Groove Tube "Fender" GT-12AX7, but underneath that printing it says Sovtek 7025/12AX7WA. The phase inverter is not clearly marked, the only thing i see on it is a small dark blue mark, possibly handwritten, by the pins of the tube. Its faded and unreadable. Now, the marked specs for the preamp are 3 7025s and a 12AT7 for the phase inverter spot. Fairly sure the PI tube right now is a 12AX7, the guy i bought it from had it set up that way for earlier breakup.
Okay, so now that i've exhuasted myself telling what i know about the amp, let me get to my problem.....
I've got what seems to be a great lack of bass. I can plug into my moms silverface vibrochamp, and while its nowhere near as satisfyingly dirty, it feels as though it actually pumps out MORE lowend than my bassman. I can 'feel' the vibrochamp more than a cranked 50w amp!! Granted, the bassman is not directly on the floor, its in a flightcase on wheels, but you can hear the problem as well.
Its most apparent with clean tones. It feels like when i turn up the volumes on everything, and turn up the bass knob a little, the lowend can be felt, but thats always at a point that is very saturated. The bass also starts to feel a little 'flabby' at that point, i.e. when i do some palm muting on chords i don't get as defined and percussive of a sound. (mind you, this experimenting i was doing last night was with a jimmy vaughn tex mex strat, not my Les Paul). This amp gets WAY, WAY dirtier than my moms vibrochamp.... The vibrochamp dimed will hardly breakup, while the bassman at 7 on the amp can get me more distortion than i'll probably ever need for the styles that i play. So how can i get more bass out of my clean sounds, and keep it going while dirty without having flab??
One of my sneaking suspicions (which i really hope isn't the case), is that the wonderful original Jensens have had all they can take. Would this possibly lead to this sound issue?? If anyone has any other suggestions for causes of the problem i might look at, please let me know. I love the solo tone of this amp, and i looooove its wonderful breakup, but i need some beef.
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