5150 mods... revealed w/ pictures

So when are we going to start mass producing our own "new" amp with this? Could make some money after some good marketing. If you delete this thread before many others get wind, anyway. Cameron won't mind.
 
Dude... thanks to Mark and you so much for posting this!!! I am also wondering if your amp had a bias mod done on it to make the 6L6 tubes run a little hotter. I dont like how cold the 5150's are cold biased with those 6L6 tubes.
 
psychodave":2ek1pv2e said:
I spoke to Mark Cameron tonight and he said it was okay to reveal the mods he gave me for the 5150.... so here is what has been done to my amp:

V5B(middle preamp tube:) add 10pf silver mica cap to pins 7 and 8. This is the main mod!!!
R9: piggyback a resistor on top of the 1 meg resistor. I used a 120k based on feel. You can try out 68k, 100k, 120k, 150k, etc. This tightened up the map a lot!
(Please note that JerryP gave me some other ideas, but I didnt use them and I wont reveal ;) )
Click to expand...

What does the 10pf change about the sound on it? And the R9, does it tighten up the higher you go? I'm very interested, been looking for ways to tighten up my 5150's sound.

Thanks a lot for posting! I feel giddy thinking about changing up the amp. :D
 
psychodave":1j5tpd29 said:
I spoke to Mark Cameron tonight and he said it was okay to reveal the mods he gave me for the 5150.... so here is what has been done to my amp:

V5B(middle preamp tube:) add 10pf silver mica cap to pins 7 and 8. This is the main mod!!!
R9: piggyback a resistor on top of the 1 meg resistor. I used a 120k based on feel. You can try out 68k, 100k, 120k, 150k, etc. This tightened up the map a lot!
C26: cut one leg for less bottom end on the rhythm channel
C15: bypass cap for better "feel"

I tried tinkering with R15 and using Marshall vlaues, but it took too much away from the original sound. The 39k is the SLO value as well.

There you have it. Have fun getting a killer 5150 sound :thumbsup:

Thanks Mark!!


(Please note that JerryP gave me some other ideas, but I didnt use them and I wont reveal ;) )
Click to expand...

Hanging out with Mark makes wish I knew more about working on amps... :D I can barely change a guitar string :doh: Totally wasted on me :LOL: :LOL:
 
psychodave":3jhn5ycc said:
The 10pf cap creates another negative feedback loop getting rid of some or most of the fizz. I told Mark it "Cameron-ized" the amp. :) It makes the amp slightly tighter as well. R9 tightens up the amp a lot depending on how low you go with a resistor. ...but too low and you choke out the amp. Too high and the amp is still flubby. Try testing a 68k, 120k and a 220k resistor. Get a feel for what it changes.
:)
FWIW, I did do a bias mod.
Click to expand...

PMed
 
Very Cool! :rock: Hopefully this isn't too much of a noob question but here goes...will this work on the 5150 combo as well? I'm pretty sure it will but just want to make sure. Thanks.
 
Ok dave, one more question. When you say "bypass the cap", do you mean remove it and put in a jumper? :D

Firing up my iron as we speak. :rock: Have all the componets ready to go. Your clips sounded awesome. I hope my amp sounds like that when Im done :thumbsup:

Thanks for the Info :thumbsup:
 
loudgtr":3udgbyxo said:
Very Cool! :rock: Hopefully this isn't too much of a noob question but here goes...will this work on the 5150 combo as well? I'm pretty sure it will but just want to make sure. Thanks.
Click to expand...

THIS!!!

Inquiring minds and combo owners want to know.....
 
Props to you and Mark for posting! The 10pF cap sounds like a very interesting mod. I assume that going with a larger capacitance value would darken the amp quite a bit?
 
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