Amp help needed!!!

[loudblackguitars]

Ive got a 6506+ head. Its not nearly as good an amp as the original 5150. It has less gain for sure. So last night I was jamming with a drummer, I usually keep it at 3.5, maybe 4 ( volume that is ). Last night I decided to see how loud i could get it, and past 4 the volume does nothing. Is this normal?

Im using a brand new 4x12 Engl standard cab.

Also, is there a mod that I can have done to spice this amp up?

[Dmoney]

Did turning up the volume do nothing at all, or did it change the tone but not get any louder?


the 6505 and 5150 are pretty much identical I think. same probably goes for the 6505+ and 5150-II

I had a 6505 and I've toured with an older 5150.
the 6505+ sounds different to a 6505, and probably a 5150 too.

I'd say the amp should keep getting louder. I used to play with the gain about 6 or 7 on the dial and the master volume up the same. The EQ isn't very responsive.

Those amps are biased notoriously cold. You could try and get it biased warmer. I think the 6505+ might actually have an adjustable bias. on the 6505/5150, the big mod is the adjustable bias mod. My 6L6's used to idle at 12mA before I did that mod.

I was reading about 5150 mods recently. there are a few. some people say its only really worth getting a bias mod (if you need it) or maybe a transformer upgrade because of the hassle involved with changing the parts that peavey install.

FJA mods website has a list of options, so that might be an idea to help you get an idea of what COULD be done.
http://www.fjamods.com/5150II.html

Transformer and tone stack mods and a bunch of stuff. some ideas i guess.

[Roobubba]

I have a 5150-II (= 6505+). Gain on tap isn't a problem, provided you slam the front end of the amp nice and hard. In fact, now I've playing fat strings with a baritone (albeit with a 'low output' pickup), and boosting through a Bloody Murder (TS type pedal), I can sit quite happily with preamp gain on 3 or 4, and post amp gain on 4, and it's brutally loud. Beyond 4 to 4.5, the volume increase isn't hugely noticeable in a small room, because frankly it's SO DAMNED FRIKKEN LOUD!

Speakers do make a big difference.  I used to run the stock Peavey 5150 cab, but now I've replaced the sheffield speakers with Celestion G12K-100s and EVM-12L black labels in X pattern.

Be sure that you're using the correct output impedance for your cab, too.

How old are the power tubes? What pre-amp tubes have you got in there?

Before thinking about modding your amp, you should double check all the basics! Power amp stage tubes are the first thing to check.

I took my amp to an amp tech after I got it (second hand), I'd recommend you do the same.

FWIW, it's not by any standards a bad amp (unless maybe there's something wrong with yours?).

Hope this helps,
Roo

[loudblackguitars]

When I turned it up id just got messier, not louder. I sometimes run a DOD Yngwie overdrive in front, but its not really necessary. It does have ports to adjust the bias. Tubes are stock...

[Roobubba]

How long have you had it? (or, how old is it?) Power tubes don't last forever, they may need replacing (and it's best to get a tech to do this if you're not sure - they'll hopefully also bias them properly so you don't have to!). This is the same for any valve amp, by the way.

I'd take it to a tech!!

Roo

[Brown tone]

it's completely normal for the amp to reach it's maximal loudness with MV at 3 or 4, I've seen marshall jcm-800 that does it hafway between 2 and 3! The sound gets messier because the poweramp starts to distort.

Peaveys external bias is actually a great idea, but the execution is so bad it renders the implementation useless.  The port for metering actual amount of negative bias is somewhere between pointless and unuseful as different sets of tubes will bias differently with the same amount of negative voltage.

Almost all amp manufacturers ship their amp with cheapo tubes and changing them, whether they are new or not, will most likely improve the sound.