5150 mods... revealed w/ pictures

[glip22]

I added pictures to show how easy it is....

Thanks Dave.....I have a 2nd 5150 lined up coming in........


gonna try your mods on it.......
Should be fine....

Dan, Does your FJA 5150 really do the Herbert?

 

[Mailman1971]

I added pictures to show how easy it is....

Thanks Dave.....I have a 2nd 5150 lined up coming in........


gonna try your mods on it.......
Should be fine....

Dan, Does your FJA 5150 really do the Herbert?

Havent gotten it yet......
but my Mesa Recto KILLS the Herbert and Jerry said the 5150 is equal or greater to that.... so..........

 

[droptrd]

I added pictures to show how easy it is....

Thanks Dave.....I have a 2nd 5150 lined up coming in........


gonna try your mods on it.......
Should be fine....

 

[Giga]

Ive only done the 10pf mod. Its noticable. Took some presence off the lead ch and made the mids more dimensional if that makes sense. Dont know how else to describe it.

I dont know if ill try the other mods as im not looking to "tighten" the amp up any more

but anyway, so far i really like the mod

yeah, the 10pf cap changes the presence a little bit...but for the better IMO. For me, I wanted the amp tighter so I didn't have to use a pedal to keep it together when cranking the resonance. As it is now, I can crank the gain on the rhythm channel and not fart out. Slap a pedal in front and the amp slays. Stock, the 5150 is a cool amp, with these mods, it is a killer amp.

Damn Dave......have a 5150 on the way to FJA to mod.......
now I want to pick up a 2nd one to do these mods too......
Your amp sounds great!!

Dan

These mods don't take away from the fact that Jerry has some killer mods for the 5150. You can't go wrong with an FJA modded 5150

Yeah, I would LOVE to have mine done by Jerry, but shipping alone from where I am in Canada would come to 250-300 bucks, so that kind of makes that idea a no go. So if I can find out what these mods are and have them done locally, that's awesome.

James Peters maybe ?

Giga

 

[madrigal77]

Ive only done the 10pf mod. Its noticable. Took some presence off the lead ch and made the mids more dimensional if that makes sense. Dont know how else to describe it.

I dont know if ill try the other mods as im not looking to "tighten" the amp up any more

but anyway, so far i really like the mod

yeah, the 10pf cap changes the presence a little bit...but for the better IMO. For me, I wanted the amp tighter so I didn't have to use a pedal to keep it together when cranking the resonance. As it is now, I can crank the gain on the rhythm channel and not fart out. Slap a pedal in front and the amp slays. Stock, the 5150 is a cool amp, with these mods, it is a killer amp.

Damn Dave......have a 5150 on the way to FJA to mod.......
now I want to pick up a 2nd one to do these mods too......
Your amp sounds great!!

Dan

These mods don't take away from the fact that Jerry has some killer mods for the 5150. You can't go wrong with an FJA modded 5150

Yeah, I would LOVE to have mine done by Jerry, but shipping alone from where I am in Canada would come to 250-300 bucks, so that kind of makes that idea a no go. So if I can find out what these mods are and have them done locally, that's awesome.

James Peters maybe ?

Giga

He doesn't do mods on other manufacturers amps, unfortunately. Thanks for the thought though.

 

[glip22]

The 10pf cap should be installed on pis 6 & 7, not pins 7 & 8. It's purpose is to add a little feedback like Dave said.. This is why I was confused. I have never heard of adding a cap to grid and cathode, but plate and grid I have. I beleive Mark has contacted Dave about this.

 

[nico22]

thought the same that it should be between pin 6 and 7, but pictures shows us the cap is well between pin 7 and 8
Maybe someone could try between pin 6 and 7, it should remove more fizz, but maybe to much...

 

[Jimmie]

Great thread, and why I stay here beyond the coolness of you all.

 

[tweed]

You need to come up with some mods for a Peavey XXX head Dave. I am on the verge of selling mine as it doesn't get used often now that I have the Fortin DSL. This thread is making me want to grab a 5150 and chop it up.

 

[rbasaria]

Alright, now Im considering doing this lol. I have a couple of questions those. First, I dont really care about bottom end on the rhythm channel, since I use it for cleans, Im not too worried about that. I may skip this, but I dont know. Do you think it makes cleans on that channel sound siginificantly better? For the C15 mod, what do you mean when you say better feel? Probably will try the V5B, bias, and R9 mods. I would LOVE the amp to be tighter. How much tighter would you say the 120k makes the amp? My 6505 212 combo is SIGNIFICANTLY tighter than my 5150 head...if I can get it as tight as the combo, I would be VERY happy!!

Thanks for posting these man!!

 

[JerryP]

Pins 7 & 8 is correct.
Jerry

 

[glip22]

Pins 7 & 8 is correct.
Jerry

That's strange. Mark pm'd me out of nowhere and said it was 6 & 7.

 

[JerryP]

I should clarify, I don't know how Mark told Dave to do it, but you can put a cap across 7 & 8. Look at the Marshall 2210 schematic.
Jerry

 

[rbasaria]

Which picture shows R9? I think thats the main one I want to do. I like the fizz of the 5150. I dont really feel I need the bias mod. The only thing I really want is for the amp to be A LOT tighter than it is, so Im gonna try some of these values on the R9 res and see what happens.

 

[glip22]

Well, I just spoke to Mark and he said that you can go between pins 6 and 7 and/or 7 and 8. Mark said between pins 6 and 7 will be more noticable and that's what the original mod should have been... Looks like I get to tinker some more tonight.

Cool. Mark had me worried there.

 

[Digital Jams]

this is making me want to grab a 5150 now, can't go wrong for what they go for used.

 

[skoora]

Is this a 5150 or 5150II?

 

[nico22]

a 390pf cap between pin7 and 8 should have the same effect as 10pf between pin 6 and 7

 

[droptrd]

Damn it I just put my head back together

 

[bravedude2]

this thread has been a great read.