Peavey 5150 Serial Number Lookup

May 18, 2006  This Site Might Help You. RE: Given a Serial Number, How can I tell what year my Peavey Wolfgang was made? If I have a Peavey Wolfgang guitar, how can I tell what year it was made? I know Gibson ha.

I just thought I would chime in here. I've bias modded 1 of my 3 5150's. I gigged with the bias modded amp for years. I have to say that IMO it's not worth it. It will sound very slightly thicker, but the resulting loss of low end tightness isn't worth it at all. It also becomes somewhat congested in the midrange. The bias mod is probably the most overhyped mod you'll read about on HCAF IMO (right next to the EMG 18v mod).

Of course you can set it back to a colder setting if you don't like the sound of it with a hotter bias, but I wouldn't even go through the trouble. I just thought I would chime in here. I've bias modded 1 of my 3 5150's. I gigged with the bias modded amp for years. I have to say that IMO it's not worth it. It will sound very slightly thicker, but the resulting loss of low end tightness isn't worth it at all. It also becomes somewhat congested in the midrange.

Dell monitor as 500 manual. The bias mod is probably the most overhyped mod you'll read about on HCAF IMO (right next to the EMG 18v mod). Of course you can set it back to a colder setting if you don't like the sound of it with a hotter bias, but I wouldn't even go through the trouble. I think you're missing the point of the bias mod, at least what I'd consider to be the point anyway. It's not so that you can just bias it warmer, it's so that you can bias it. There's a misconception that the amp, due to not having a bias pot, is 'self biasing' somehow.

People sometimes think that fixed bias means this, that the manufacturer didn't include a bias pot because it's set to bias automatically. (In case you knew this, let me continue anyway for the sake of those who didn't, since many people have this misconception.) Amps like this ship with the bias set one particular way for whatever tubes are put in them stock, and that can vary significantly as it is. It will also vary significantly when you put in new tubes.

A fixed bias amp will usually require adjustment to the bias pot to bias new tubes (even of the same brand/type/production batch) the same as the last set of tubes. You might luck out and the new tubes will bias the same, but you shouldn't count on it because it usually doesn't work out that way. 'Fixed bias' refers to the voltage you set to 'idle' the tubes.

That voltage needs to be adjusted based on how the tubes are biasing, what they're doing (how much current they're drawing at 'idle'). There's an argument that the 5150 was biased cold from the factory, and why bother changing it.

That's understandable, if that's what you like. But not all tubes are going to bias 'as cold' as the stock ones (or the ones you currently have in the amp) leaving the circuit stock without adjustment, and some will bias 'so cold' as to sound thin/scratchy/weak.

I've read plate current draw of some 6L6GC in stock 5150s to be as low as 7mA per tube, and the tubes weren't defective. And even if you like the bias set that way, chances are you wouldn't like it so the tubes draw 30mA each. You have no way of adjusting the bias to be where you want it to be, and it'll be different for each set of tubes (some more than others, and there's almost no telling how far out they can be). So you might not notice a difference in your 5150s because of the tubes you have in them and how they coincidentally bias.

You may not care to ever bias it warmer than average. But there's value to being able to bias the amp, which you'd probably eventually realize after changing tubes enough times and finding a set which (unknown to you) is biasing significantly differently from the last set, which significantly affects the sound of the amp in a way you won't like. I think you're missing the point of the bias mod, at least what I'd consider to be the point anyway. It's not so that you can just bias it warmer, it's so that you can bias it. There's a misconception that the amp, due to not having a bias pot, is 'self biasing' somehow.

People sometimes think that fixed bias means this, that the manufacturer didn't include a bias pot because it's set to bias automatically. (In case you knew this, let me continue anyway for the sake of those who didn't, since many people have this misconception.) Amps like this ship with the bias set one particular way for whatever tubes are put in them stock, and that can vary significantly as it is. It will also vary significantly when you put in new tubes. A fixed bias amp will usually require adjustment to the bias pot to bias new tubes (even of the same brand/type/production batch) the same as the last set of tubes. You might luck out and the new tubes will bias the same, but you shouldn't count on it because it usually doesn't work out that way. 'Fixed bias' refers to the voltage you set to 'idle' the tubes.