Anyone know how to do a clean channel mod on a peavey 5150?

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Please point me in the right direction... I really want to do this mod for someone.

Thanks, Chad
 
Installing a bias pot and setting the bias correctly removes a lot of crossover distortion. This helps channel one clean up better.
 
Is this what a clean channel mod consists of? Im curious to do a bias mod, clean channel mod, and the cameron mod to a 5150 when I get back... I would love to compare it to a stock 5150 and see how that goes.
 
I don't think the bias mod really improves the amp that much. With the bias at 18mA per tube, it sounds fantastic to me. 6L6 sound much better cold to me, but not EL34s.
 
at low volumes you would still be better off doing a variable bias installation simply to adjust for new tubes. anyone with the amplifier above 3 on the volume will see a large improvement in low end response and overall headroom with the tubes biased into proper class AB - how much of a difference depends on the tube itself and that particular amplifier. anyone at bedroom levels or just above 1 will not see much, if any improvement simply due to the amount of gain involved in the preamp section.
 
I see that these secrets are tightly held, but could probably be understood through DIY books. Im guessing I could tackle that when I get back home, but wish someone would cough up the goods! I know how to do a bias mod, and those cameron mods... but as far as anything else, its just not available out there... Ive checked. Anyone care to share?
 
Get ahold of psychodave, he did some mods to a 5150 if I remember right, I dont know what they were but it sounded great as do all of his amps!
 
yeah... he did a great job of sharing those with everyone. Those were the Cameron mods I was speaking about... very cool of him and mark.
 
pfapin05":5z0v7wxd said:
I see that these secrets are tightly held, but could probably be understood through DIY books. Im guessing I could tackle that when I get back home, but wish someone would cough up the goods! I know how to do a bias mod, and those cameron mods... but as far as anything else, its just not available out there... Ive checked. Anyone care to share?
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I'm not sure what you want to hear? I seriously doubt anyone here would hold out on you in the first place. All you have asked for so far is a "clean channel mod" which is a bit vague. Even being an avid modder, I have little to no idea what you are asking for. Different voicing? Different feel? More details would help. The main reason that the 5150 cleans suck is that the tone has to travel through all three gain tubes to get to the EQ and power amp section. If you wanted to "fix" the 5150's clean channel, you would have to cut the trace and rig up some clever switching so that the clean channel went straight to the channel EQ after the initial gain stage, but so that the OD channel would still travel its natural path through all tubes. You could do this with an SPDT switch, but it won't be automatic when the channels switch, you would have to do it manually. Somebody correct me if I am wrong.
 
JakeAC5253":3n32a7am said:
pfapin05":3n32a7am said:
I see that these secrets are tightly held, but could probably be understood through DIY books. Im guessing I could tackle that when I get back home, but wish someone would cough up the goods! I know how to do a bias mod, and those cameron mods... but as far as anything else, its just not available out there... Ive checked. Anyone care to share?
Click to expand...

I'm not sure what you want to hear? I seriously doubt anyone here would hold out on you in the first place. All you have asked for so far is a "clean channel mod" which is a bit vague. Even being an avid modder, I have little to no idea what you are asking for. Different voicing? Different feel? More details would help. The main reason that the 5150 cleans suck is that the tone has to travel through all three gain tubes to get to the EQ and power amp section. If you wanted to "fix" the 5150's clean channel, you would have to cut the trace and rig up some clever switching so that the clean channel went straight to the channel EQ after the initial gain stage, but so that the OD channel would still travel its natural path through all tubes.
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which gets complicated really quick due to how james brown used multiple different relay's controlling the crunch channel, one of them fired by a trigger source from a BJT into a thyristor into a JFET. not exactly easy to work around, still possible, but the clean channel is a balancing act they did around the crunch - its like having your finger against someone on the edge of falling off a skyscraper - its barely a clean as it is, fuck with it too much and you've created more problems for the crunch and vise-versa.

to get something like that drawn up and working would take a bit of math and clever thinking. Ive got a few ideas but im not willing to spill the beans on a public forum as it's not perfect for one, and took me a while to get around to.
 
Get a 5150II, cleans are much better (still could be improved for sure though)
 
Im guessing a 3 channel mod that FJA does, and a clarity mod... maybe that makes it more clear to as what I was looking for. Im guessing there are those who hold on to those secrets though since they put in alot of effort to find out themselves... I just wanted to skip that whole process and have a nice 5150 for myself... I love to do this stuff myself and cant justify paying $800 for about $20 in parts or less.

Oh yes, by chance... does anyone know how to perform a choke mod as well? I forgot that I want to see how that tightens things up.

Thanks, Chad
 
pfapin05":2w9zsp6o said:
Im guessing a 3 channel mod that FJA does, and a clarity mod... maybe that makes it more clear to as what I was looking for. Im guessing there are those who hold on to those secrets though since they put in alot of effort to find out themselves... I just wanted to skip that whole process and have a nice 5150 for myself... I love to do this stuff myself and cant justify paying $800 for about $20 in parts or less.

Oh yes, by chance... does anyone know how to perform a choke mod as well? I forgot that I want to see how that tightens things up.

Thanks, Chad
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pm'ed on the choke :thumbsup:
 
Out of curiosity.can the Cameron mods be performed on a 5150 II?
 
Just my 2 cents. I have the 5152 and the clean channel is better that the first 5150, and honestly the way i get it to sound best is just roll back some of my guitar volume and it doesn't drive the tubes too hard (they breakup real easy, obviously you noticed) I have gotten some really nice jazzy tones this way with a EMG60, and decent rock-sh cleans as well with any of my other guns.

The real problem though, is honestly, the cleans just aren't that great no matter what you do to it. Friend of mine had a modded 5150 and it didn't sound that much different to me and it still breaks up fairly easy. If your looking for just a project to do to practice modding, or hobby type curiosity, that is fine. But if your looking to get an amazing clean tone out of it, i would suggest looking into a different amp.

Its good, just not great.
 
You can get a really nice clean out of the +/II versions, the extra preamp tube is dedicated to the clean/crunch modes only so it's much easier to work with than the shared EQ models. If you install a choke you'll probably have to relocate the standby switch in the circuit or it will pop very loudly when switching off.
 
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