Pictures will be awesome Ryan.
I'm whit you about the bias mod....I prefer the stock bias setting...
I'm whit you about the bias mod....I prefer the stock bias setting...
Modding 5150 II lead channel to 5150 spec
- Thread starter ::XeS::
- Start date
Lasse Lammert
HCAF Blitzkrieg
HeadCrusher
Member
lolzgreg
Cereal Shipping Sneapster
Cold= Crossover Distortion
Hot= No Crossover Distortion and lessened tube life (with an increase in tone)
Hot= No Crossover Distortion and lessened tube life (with an increase in tone)
or it's biased so cold to avoid warranty issues with failing/faulty tubes
Isn't the Recto biased cold as well?
Lasse Lammert
HCAF Blitzkrieg
mine both came about 50% plate dissipation stock...(like 28-30mA) wich is cold, but already out od xover dist...
my 6505 cam 8mA and 12mA (same or similar plate voltage as the recto)
Honestly, I'm kinda preferring the Cap A one; it is a bit too nasal, but I feel like that could be eq'ed out, and I kinda dig the upper mid punch, I feel like that's more the range the 5150 excels in (I prefer a Rectifier for the low-mid stuff), the second one just sounds very "furry" and kinda indistinct to me ¯\(°_o)/¯
Keep in mind the 2nd one isn't showing the best tone with the mod. It's showing how drastically different it is with the same EQ settings.
As for whether the "C" clip is too hairy - that's a matter of taste. I prefer the sound of the original 5150 - and according to the schematics these components are the only differences between the lead channel on the two amps. The clean channel is completely different (and is better on the 5150-II) so you're getting the best of both worlds with the mod. Again, that's as far as my ears are concerned.
I'm pretty sure the Peavey parts sheet calls for 400V capacitors, but I don't recall if the resistor was 1/4 watt or 1/2 watt. I happened to use some big old capacitors because that's what I was able to get from the old dude in town who works on amps. As you can see in the pics there is plenty of room to work on the main board. The preamp tube board is a little tighter, but I was still able to cram a huge capacitor onto it.
I'd also like to mention that the cap & resistor on the main board do not represent a shining moment in my soldering career. I did it quick & dirty just to see if I liked it and figured I'd clean it up later if I kept it that way. As it stands, that was the last time I had the amp apart until today. Since it works and I've gigged with it I see no reason to fuck around with it.
Also, I didn't reduce the resolution on these photos so they are pretty huge.
Main board. Changes circled in yellow. Legs of the original capacitor are circled in red:
http://www.ryanadam.com/5150/IMG_0532.JPG
Main board from further back to get a better idea of where it's located:
http://www.ryanadam.com/5150/IMG_0533.JPG
Pre-amp tube board from above. New cap is circled in yellow:
http://www.ryanadam.com/5150/IMG_0534.JPG
Peavey layout with location of C17 marked:
http://www.ryanadam.com/5150/IMG_0536.JPG
Peavey layout with location of C2 marked:
http://www.ryanadam.com/5150/IMG_0537.JPG
The only other mod I've done to my 5150:
http://www.ryanadam.com/5150/IMG_0540.JPG
Same shot, but with the flash which obscures the fact that the whole panel lights up:
http://www.ryanadam.com/5150/IMG_0539.JPG
If you want to check out some solder work I'm less ashamed of, check out the Metal Panel JMP 50 clone I just put together:
http://www.guitar-hardware.com/ampkit/IMG_0517.jpg
Ryan
As for whether the "C" clip is too hairy - that's a matter of taste. I prefer the sound of the original 5150 - and according to the schematics these components are the only differences between the lead channel on the two amps. The clean channel is completely different (and is better on the 5150-II) so you're getting the best of both worlds with the mod. Again, that's as far as my ears are concerned.
I'm pretty sure the Peavey parts sheet calls for 400V capacitors, but I don't recall if the resistor was 1/4 watt or 1/2 watt. I happened to use some big old capacitors because that's what I was able to get from the old dude in town who works on amps. As you can see in the pics there is plenty of room to work on the main board. The preamp tube board is a little tighter, but I was still able to cram a huge capacitor onto it.
I'd also like to mention that the cap & resistor on the main board do not represent a shining moment in my soldering career. I did it quick & dirty just to see if I liked it and figured I'd clean it up later if I kept it that way. As it stands, that was the last time I had the amp apart until today. Since it works and I've gigged with it I see no reason to fuck around with it.
Also, I didn't reduce the resolution on these photos so they are pretty huge.
Main board. Changes circled in yellow. Legs of the original capacitor are circled in red:
http://www.ryanadam.com/5150/IMG_0532.JPG
Main board from further back to get a better idea of where it's located:
http://www.ryanadam.com/5150/IMG_0533.JPG
Pre-amp tube board from above. New cap is circled in yellow:
http://www.ryanadam.com/5150/IMG_0534.JPG
Peavey layout with location of C17 marked:
http://www.ryanadam.com/5150/IMG_0536.JPG
Peavey layout with location of C2 marked:
http://www.ryanadam.com/5150/IMG_0537.JPG
The only other mod I've done to my 5150:
http://www.ryanadam.com/5150/IMG_0540.JPG
Same shot, but with the flash which obscures the fact that the whole panel lights up:
http://www.ryanadam.com/5150/IMG_0539.JPG
If you want to check out some solder work I'm less ashamed of, check out the Metal Panel JMP 50 clone I just put together:
http://www.guitar-hardware.com/ampkit/IMG_0517.jpg
Ryan
Hourglass, thanks for all the pics, and info, for the C2, did you remove the 0.001uF capacitor and then put in a 0.022uF, or did you tie it across the legs also. Is there capacitors that you would recommend before I try this. Thanks for any help
got the resistor tonight, but unfortunately couldn't find the right value of caps...Hopefully Thursday I'll be able to do this if I can find the right values locally. Otherwise, www.mouser.com has everything you need pretty cheap (for others considering this mod).
Remove the old one. The 22n cap shifts the roll off point of that stage to around 72hz.
You can use any good quality cap. Some people prefer Mallory 150s(me) and some people like sprauge orange drops. get a 400v cap or above. I use 630v throughout my amps, but 400v is more than enough for there.
Also, for a person that asked, I'm pretty sure if my math was correct that a 1/4watt would be fine, but I never use less that 1/2 watt in anything I build, even if it's overkill. For the price of a single resistor, just get the 1/2watt and be happy that it won't ever be an issue.
Also, before you remove C17, just add the 470k resistor across the legs. You may like this, and then wouldn't have to worry about removing C17.
Edit- Sorry, I keep thinking of things to say. Just to let you know, adding the 2.2n and 470k in parallel in place of C17 is more of a SLO value. Having a 470pF and 470k in parallel is more of a Marshall value. So try both! You may like one or the other better.
Edit- Sorry, I keep thinking of things to say. Just to let you know, adding the 2.2n and 470k in parallel in place of C17 is more of a SLO value. Having a 470pF and 470k in parallel is more of a Marshall value. So try both! You may like one or the other better.
Remove C2 then put the new cap in its place. Since you can easily pull out the preamp tube board, you can put it through the holes and attach it right to the solder pads. I will advise that you be careful with your iron here. If you overheat the pads they'll lift right off of the board.
For C17 I removed the original cap and replaced it with the 470K resistor and a .0022uF cap.
For C17 I removed the original cap and replaced it with the 470K resistor and a .0022uF cap.
If you just add the 470K with the original C17 cap, what is the difference between this and doing the 470K/.0022uF mod (thus removing the original C17 cap)?
With the .0022, you are going to let more low end into the next stage.
With the original cap, you are letting less low end in to the next stage.
It's all a matter of taste.
Removing C19 might benefit the amp also.
come on isnt easier to get a 5150, i already got a II the only thing worth doing is a bias mod and tube config to taste, voila its awesome, how do u improve a 5150, get another one.
+1
YEAAH, Why you all waste your time with these mods, when you can take some money from the money trees and buy another amp?
Anyway Deviljaw, I opened this thread only for curiosity...it's obvious that if you buy a 5150 you get the 5150 sound, so your post is useless.
YEAAH, Why you all waste your time with these mods, when you can take some money from the money trees and buy another amp?
Anyway Deviljaw, I opened this thread only for curiosity...it's obvious that if you buy a 5150 you get the 5150 sound, so your post is useless.
Nebulous
Daniel
I honestly don't see why more people don't agree with you on this one Marcus. Given that we're a recording forum I'm quite surprised people are liking the second clip. That would be a right pain in the ass to sit in a mix. Yes, yes yes, different amp settings, etc, etc....but why? The first clip sounds really good, has tonns of clarity and enough bass for a metal mix. As it is, it's ready to go.
If it ain't broken....
Because some just might prefer the sound of a 5150 over a 5150II, regardless of what THESE specific clips sound like...The clips aren't really AT ALL about what sits better in the mix because both clips weren't equally tailored to provide that kind of outcome. The clips merely present the difference between the unmodded and modded at the same settings, same mic position, etc. Who's to say that tweaking the settings and mic positions to accentuate the modded amp more favorably would have you thinking clip B was better?
As with anything, if you were in a room with a 5150 and a 5150II, each of us would probably have a preference for one or the other...If someone has a 5150II but prefers the tone of the 5150, then this mod will get them closer for little money and effort (providing they can solder).
