Really starting to dislike my 5150. Help :(

[Lord Toneking]

So i borrowed a stock 6505 from another forum member. Well I really had fun using that amp so I went out and bought a sig 5150. It needed screen resistors and some tubes so I went ahead and did a bias mod while I was at it. It now has a totally different feel than the 6505 had and Im thinking that I like the stock 'crossover' distortion better than mine with the bias mod

Can I just bias it very cold and get that sound back, or do I have to remove the mod?

 

[Vrad]

So i borrowed a stock 6505 from another forum member. Well I really had fun using that amp so I went out and bought a sig 5150. It needed screen resistors and some tubes so I went ahead and did a bias mod while I was at it. It now has a totally different feel than the 6505 had and Im thinking that I like the stock 'crossover' distortion better than mine with the bias mod

Can I just bias it very cold and get that sound back, or do I have to remove the mod?

Yes you should be able to bias it cold. The Bias mod just gives you a bigger sweep.
However, I'm not sure what values your particular bias mod is done, so it's hard to say exactly. I'm working under the assumption that you just followed the conventional bias mod.

 

[Lord Toneking]

So i borrowed a stock 6505 from another forum member. Well I really had fun using that amp so I went out and bought a sig 5150. It needed screen resistors and some tubes so I went ahead and did a bias mod while I was at it. It now has a totally different feel than the 6505 had and Im thinking that I like the stock 'crossover' distortion better than mine with the bias mod

Can I just bias it very cold and get that sound back, or do I have to remove the mod?

Yes you should be able to bias it cold. The Bias mod just gives you a bigger sweep.
However, I'm not sure what values your particular bias mod is done, so it's hard to say exactly. I'm working under the assumption that you just followed the conventional bias mod.

Yeah, just the conventional bias mod

What would I set bias at?

 

[Vrad]

So i borrowed a stock 6505 from another forum member. Well I really had fun using that amp so I went out and bought a sig 5150. It needed screen resistors and some tubes so I went ahead and did a bias mod while I was at it. It now has a totally different feel than the 6505 had and Im thinking that I like the stock 'crossover' distortion better than mine with the bias mod

Can I just bias it very cold and get that sound back, or do I have to remove the mod?

Yes you should be able to bias it cold. The Bias mod just gives you a bigger sweep.
However, I'm not sure what values your particular bias mod is done, so it's hard to say exactly. I'm working under the assumption that you just followed the conventional bias mod.

Yeah, just the conventional bias mod

What would I set bias at?

On my 6505+ it was absurd... Like 17mA I think

 

[Skrapmetal]

Could it be the new tubes that you aren't liking? Bias mod doesn't really do that much beyond push the tubes to their full potential (and the pot can be dialed right back down if you don't like them hot).

 

[fluff191]

Could it be the new tubes that you aren't liking? Bias mod doesn't really do that much beyond push the tubes to their full potential (and the pot can be dialed right back down if you don't like them hot).

+1

If you have new tubes, you need to break those puppies in.

 

[Greazygeo]

Just lower the bias to whatever it was stock. Running the bias hotter is ok if the amp is not played loud. Played loud it will get too fuzzy and mushy.

 

[Lord Toneking]

Just lower the bias to whatever it was stock. Running the bias hotter is ok if the amp is not played loud. Played loud it will get too fuzzy and mushy.

We play very loud actually. So youre saying if i bias it cold it will sound better louder eh?

 

[155]

17 ma sounds about right or less stock, mine sounds best around 30-32 though

 

[D-Rock]

Are you boosting that bitch?

 

[Greazygeo]

Just lower the bias to whatever it was stock. Running the bias hotter is ok if the amp is not played loud. Played loud it will get too fuzzy and mushy.

We play very loud actually. So youre saying if i bias it cold it will sound better louder eh?

Yes.

 

[Anonymous]

eager to hear replies as i have a bone stock 5150 ver 1 being mailed to me very soon.


i'm just going to play it for a while and get used to it, then go from there...but one thing i would like to know ahead of time, will it need the bias mod to run EL34's? if so, then i'll keep it stock with 6L6's until i get a feel for what i want out of it.

i won't be boosting mine.

 

[BeZo]

All the bias mod does it replace a resistor with a potentiometer that varies the resistance at the point of the bias resistor. This allows you to adjust the bias for new tubes without having to take the bias resistor out and solder in the proper resistor. This does not mean you can just tweak it to wherever you like. There is still an equation to figure out the proper bias of a specific set of tubes, like the ones you have. Since every tube is different, and putting different pairs in will get you different results, new tubes have to be biased to their specific needs. If you bias them too hot, they will sound great, but they will not last long. If you bias them too cold, your amp can sound weak and fizzy, but the tubes will last because they aren't getting used to their full extent.

Since every tube is different, you can't really set the bias adjustment to someone else's specs. You have to bias the amp to whatever tubes YOU have in the amp. That's what setting the bias is.

That said, I would take it to have it biased, or get the math and read the voltage to bias it yourself. It will sound better when you do.

 

[glpg80]

bias is not going to make THAT much a difference people. Crossover distortion is only a fraction of the benefits or negatives here.

Tell us what preamp tubes are loaded in it.

what are you slamming the front end with? 5150's and weak pickups are not going to cut it for the heavier tones, you need a boost or a seriously heavy pick attack.

5150's need to be opened up - they are not bedroom amplifiers. they bring the brutal at band volumes, for bedroom playing there are much better amplifiers out there that exist.

what speakers are you using? what do you have in the effects loop?

 

[tonechasers]

tubes makes all the diff in the world. what tubes did you get and what are the grade of them? the sigs blow the plus etc. away a way more aggressive bad ass tone. I dissagree with volume I say they start sounding awesome on 2 and get better from there. I never needed a boost with mine turned the gain down to 4 or 5 and that was plenty. bass on 4 or 5 mids highs and presence 6, res 4 or 5. fuck I miss that amp.

 

[Lord Toneking]

Are you boosting that bitch?

I do have a maxon od808 on my board but I really dont like it boosted tbh, moreso the 'feel' I get with it boosted

 

[Lord Toneking]

bias is not going to make THAT much a difference people. Crossover distortion is only a fraction of the benefits or negatives here.

Tell us what preamp tubes are loaded in it.

what are you slamming the front end with? 5150's and weak pickups are not going to cut it for the heavier tones, you need a boost or a seriously heavy pick attack.

5150's need to be opened up - they are not bedroom amplifiers. they bring the brutal at band volumes, for bedroom playing there are much better amplifiers out there that exist.

what speakers are you using? what do you have in the effects loop?

I just got all new tubes from Valvequeen. Theyre Rubys...both power and pres with a jj mixed in there. I tried a mixture of some tung sols, sovtek, jj, eh, and chinese pres...idk what the deal is

As far as cabs I have two splawn cabs. A 4x12 with small blocks and a 2x12 with a governor and a manowar

Only thing I run in the loop is a line 6 DL4

Oh...and I play two ebmm Axis guitars. One is stock and the other has a D sonic in the bridge and a Fred in the neck

Dont get me wrong, the amp sounds pretty good, it just is missing something. It tires my ears out very quickly

 

[glpg80]

no offense but i have never been a fan of ruby pre's.

V1 = JJ ECC83 (not S)
V2 = TAD 12AX7
V5 = TAD 12AX7
V4 = Phase Inverter
V3 = Effects loop 12AU7

or:

V1 = Tung-sol/9th Gen Chinese
V2 = JJECC83
V5 = JJECC83
V4 = TAD 12AX7 Phase Inverter
V3 = Effects loop 12AU7

I would try these. Tried and true tube combinations. Get a flashlight and look at the PCB board to locate which socket is which, they are not in order from left to right.

If that does not work then maybe you just dont like them? I always loved my 5150 at the core, but knew it could be better. there are more options available on the table but the prices are not going to get any cheaper.

 

[Greazygeo]

bias is not going to make THAT much a difference people. Crossover distortion is only a fraction of the benefits or negatives here.

Tell us what preamp tubes are loaded in it.

what are you slamming the front end with? 5150's and weak pickups are not going to cut it for the heavier tones, you need a boost or a seriously heavy pick attack.

5150's need to be opened up - they are not bedroom amplifiers. they bring the brutal at band volumes, for bedroom playing there are much better amplifiers out there that exist.

what speakers are you using? what do you have in the effects loop?

I just got all new tubes from Valvequeen. Theyre Rubys...both power and pres with a jj mixed in there. I tried a mixture of some tung sols, sovtek, jj, eh, and chinese pres...idk what the deal is

As far as cabs I have two splawn cabs. A 4x12 with small blocks and a 2x12 with a governor and a manowar

Only thing I run in the loop is a line 6 DL4

Oh...and I play two ebmm Axis guitars. One is stock and the other has a D sonic in the bridge and a Fred in the neck

Dont get me wrong, the amp sounds pretty good, it just is missing something. It tires my ears out very quickly

Bias it back down, use the "normal" gain input and turn it up.

The Ruby's are just Chinese, the pre's are good for gain and low noise.

 

[fek]

I like Ruby pre's. I have been picking up a few ARS because they are cheaper and identical from what I can tell. Chinese too I believe. Either way, sound good to me.

I use a RM100 these days and love being able to bias at will. I keep the 34's in there at 30 but have experimented hotter and colder. 30 seems to be where it's at for me.