5150 modded!

[kaomao]

Ok guys I modded my 5150, now I can set the bias properly.
first impression: the sound is really the same.
all local tech I talked to, told me that it wasn't so true that 5150 with a hotter bias would sound so smoother as others make you believe, there are a lot of things in the amp that make it sound the way it is.
Ok so you're wondering why did I do the mod?
answer: tubes will last longer! I didn't care for a smoother tone, I just wanted to make the amp work good, bias is a must so you can plug every 6l6 not just stock ones.

samples
premod
postmod


Maurizio

 

[Razorjack]

That sounds great, I just wish I had a 5150 to mod!!

 

[Kazrog]

Hmm, I like the pre-mod a little bit better.

 

[kaomao]

Guys, I have to say that hearing the amp live is really the same as before the mod, maybe I changed something (eq/mic pos), but I put a tape on the cab so the position should be really the same as the pre mod.
I can make it sound very similar if I move the mic off centre, tomorrow I'll try to prove that the sound is really the same even with bias set properly.

 

[Andy Sneap]

have you taken the tape off the cab by the way???? It can make a difference believe it or not.

 

[JeffTD]

I have to say I like the pre mod better, as well, but I believe that they sound the same.

That said, I'm getting my 5150 with bias and clarity mods already done, for free! Dumbasses at guitar center don't know what they have!

 

[kaomao]

have you taken the tape off the cab by the way???? It can make a difference believe it or not.

No it was there even before I did the first clip.
Believe me guys, live the amp is the same, maybe that's just me that changed a little bit of eq or mic pos.
Anyway the bias works, it's not a fake trim pot they installed on my amp ahahhaha, tonight clips (if my neighbors won't kill me) and pics of the mod.
All clips I made are with Andy's c4 setting and rolling off frequencies from 60hz and below.

Maurizio

 

[~BURNY~]

Maybe you expected a more noticeable change.
My brother did a bias setting while I was playing on a JCM800 2203. The amp didn't sound drastically different when he moved the pot. The bottom end was a little tighter and the overall sound was a little more compressed (let's say smoother). Nothing spectacular. Just a little more of everything... Of course it was EL34 And I assume that 6L6 tubes are less responsive to bias mod cause they are less responsive to high master volume settings... More "hi-fi"... Ok maybe it's not related at all, I don't know...

 

[kaomao]

Maybe you expected a more noticeable change.
My brother did a bias setting while I was playing on a JCM800 2203. The amp didn't sound drastically different when he moved the pot. The bottom end was a little tighter and the overall sound was a little more compressed (let's say smoother). Nothing spectacular. Just a little more of everything... Of course it was EL34 And I assume that 6L6 tubes are less responsive to bias mod cause they are less responsive to high master volume settings... More "hi-fi"... Ok maybe it's not related at all, I don't know...

Yes I can say that the noticeable change is about the dynamics, a little more dynamic right now compared to the amp pre-modified. If you play hard it sounds a little bit more gainy if you play softer it sounds less gainy, but it's really a little bit not that much. it hasn't the dynamic that you can have with a Marshall SLP, think about AcDc and their tone, that is a dynamic amp.
This is good, but the sound in the end is really the same.
5150 always rules!

Maurizio

 

[kaomao]

I recorded a new sample here you can find it
still here the old premod.

Maurizio

 

[vile_ator]

Thank you for making those clips. Could you tell us what tubes youre using as well? Also I have a 5150 II and it has a Bias adjustment. I have heard its a narrow range adjustment but I can take the bottom end go from being really clean to giving it a bit more bite. What I mean is, as I give it more voltage you can hear the bottom end take on that dirtier Mesa type of bottom. Theres a way to find a nice balance between an accurate low end and one that has more character to it. Its much more hearable than those clips you posted. If I were you I would fuck the proper voltage specs and ture it by ear and then maybe record us some clips.?

Cheers,

Colin

 

[evildonkeymaster]

Hey dudes thought I would jump in. I have a 5150 that a had the bias mod completed on like 6 months back. I am also running tubes from Euro Tubes. Sorry I have no before or "pre" mod clips but I do have two clips I recoded real quick to post here.

One is my Les Paul Custom with a 500T stock in the bridge. 2 guitar tracks one left (Red Channel) one right (Green Channel) recorded with a single SM57, no EQ but I used Andy's C4 settings.

The other is the same set up but my Ibanez RG621 with EMGs, the 85 is at the bridge and this guitar has the 18 volt mod.

Take a listen they are the only two tracks on the page and should be easy to understand which is which.

http://www.audiostreet.net/eyesshuttight

edit: Oh yeah forgive the non shredding slow simple riffs ha ha they are for a slower driving part of a tune.

 

[kaomao]

Thank you for making those clips. Could you tell us what tubes youre using as well?

Stock ones: ruby tubes.
Cool thing peavey has loaded a quartet not well matched, 0.5 volts of difference.
I'll try retubing with a jj matched quartet.

If I were you I would fuck the proper voltage specs and ture it by ear and then maybe record us some clips.?

Cheers,
Colin

The bias is right: 30mA per tube, the range has to be between 30-35, below 30 you get crossover distortion.
running them hotter you can damage your amp
Bob at eurotubes says he runs his tubes really hot at 50mA cause jj's dissipate 30 watt per tube: 30 divided by 500 plate volt = 0.06 or 60 mA (maximum value you could set avoiding to blow out something).
uhm my tech told me isn't really good it's better to stay at 30-35, you're out of crossover distortion here, and everything sounds good.
5150 will sound always the same, with bias you can have more/less tight bottom end more/less nasty fizzyness, but for me the tone is really the same.
sometimes people expets that this monster could sound like a mesa when they got it well biased.
If you want mesa buy mesa, not peavey (not taking about you colin I got what you mean with the bottom end)

Maurizio

 

[evildonkeymaster]

I am running my tubes at about 50mA like Bob (running his JJ's as well) and like the clips I posted above you can hear some really great power to the bottom end (especially on the Les Paul clip). I notice a difference in the amp after it is biased but it still sounds like a 5150 not a Mesa (thank god ha ha).

What I notice in my amp now is it is smoother, more defined power to the bottom end but also more predictable more guitars sound the same through it listen to those clips I posted the Les Paul with a stock 500T sounds a lot like the Ibanez with the Modded EMG85.

 

[Glenn Fricker]

Thanks for the clips, Kaomao!

I like the post mod better, it's got a cleaner top end. Like you mentioned, it's not a huge change in the tone, but it is certainly noticeable.

BTW, if I want that mesa sound, I'll plug in my Recto. Honestly, the 5150 gets a lot more use these days.

Thanks again,
-0z-

 

[KeithRT99]

the post sounds alittle more middy. i like it.

 

[kaomao]

the post sounds alittle more middy. i like it.

As I told here maybe I messed with the mic position when I recorded these clips.
The tone is really the same.
Maybe my tech didn't do a well done mod ahahah
I changed even tubes from ruby to JJ's and these ones doesn't draw that much current as Ruby's.
Maybe it's just me that has a bad quartet, but they really draw less current than ruby. I tested the amp with svetlana, sovtek, ruby tubes and they worked so great while jj's not.
Keep in mind, the bias test points in the triple xxx just measure the voltage and not the plate current as bob at eurotubes says.
So if your tech will do the mod tell him about doing it the proper way.
It's useless if the tech will add test points for measuring the voltage.

Maurizio

 

[KillDivision]

Ok so you're wondering why did I do the mod?
answer: tubes will last longer! I didn't care for a smoother tone, I just wanted to make the amp work good, bias is a must so you can plug every 6l6 not just stock ones.


Maurizio

I tought running the tubes hotter they would last shorter.

 

[kaomao]

I tought running the tubes hotter they would last shorter.

Yep I'm reading what I have written months ago and I can say that I fucked up with notions, well you're right.
If you run them hot they'll last shorter, but only if you run the tubes very hot like bob does. If the're out of cross-over distortion I don't think they will last shorter just because they're a little bit hotter than before.
Anyway biasing is a good thing on 5150 and in every amp, the tubes this way work good and the dynamics are there.

Maurizio