Master volume design for amps- how does it effect tone?

[JohnnyGuitar]

I know that using a master volume (or gain+volume knobs) allows you to back down the gain, raise the volume and get cleaner tone... as far as I know, thanks to driving the tubes less...

Does using such a design has a negative side? How does it effect tone?
I read an article about Van Halen, and they talked about him getting his early tone from using amps with a non master volume design (his PLexi of course)... why is it so important? or is it important at all?

 

[JB_From_Hell]

Re: Master volume design for amps- how does it effect tone?

With a master-volume amp, you're not gonna get your power tubes working as hard.

 

[Rushfan2112]

Re: Master volume design for amps- how does it effect tone?

I have a question similar to this. If you keep the master wide open, and use the volume to control your gain, will this be the same as a NMV amp? Any tonal differences?

 

[drew_half_empty]

Re: Master volume design for amps- how does it effect tone?

how come no one has come out with a no load pot for the master volume

wouldn't this be the best of both worlds?

 

[Simon_F]

Re: Master volume design for amps- how does it effect tone?

I know that using a master volume (or gain+volume knobs) allows you to back down the gain, raise the volume and get cleaner tone... as far as I know, thanks to driving the tubes less...

Does using such a design has a negative side? How does it effect tone?
I read an article about Van Halen, and they talked about him getting his early tone from using amps with a non master volume design (his PLexi of course)... why is it so important? or is it important at all?

The purpose of the original "master volume" amps (as Marshall called them) was kind of the opposite of what you describe. Originally, tube amps just had a volume control. The more you turned it up, the louder it got. If you turned it up really loud the power tubes would distort, producing classic power stage distortion. If you kept the volume knob lower it sounded clean.

The new feature of "master volume" amps was actually not the master volume but the "pre-amp volume" (gain control) that allowed you to overdrive the pre-amp tubes with the master volume set low. This allowed you to achieve distortion at low volumes, but it's a different kind of distortion. If you set the pre-amp volume high and the master volume low you are pushing the pre-amp tubes. If you set the master volume high you are pushing the power tubes.

I'm going to leave the discussion of EVH's gear to those who know what they're talking about.

 

[JohnnyGuitar]

Re: Master volume design for amps- how does it effect tone?

The purpose of the original "master volume" amps (as Marshall called them) was kind of the opposite of what you describe. Originally, tube amps just had a volume control. The more you turned it up, the louder it got. If you turned it up really loud the power tubes would distort, producing classic power stage distortion. If you kept the volume knob lower it sounded clean.

The new feature of "master volume" amps was actually not the master volume but the "pre-amp volume" (gain control) that allowed you to overdrive the pre-amp tubes with the master volume set low. This allowed you to achieve distortion at low volumes, but it's a different kind of distortion. If you set the pre-amp volume high and the master volume low you are pushing the pre-amp tubes. If you set the master volume high you are pushing the power tubes.

I'm going to leave the discussion of EVH's gear to those who know what they're talking about.

I know... it's pretty much the same thing- more volume to your power amp and less to your pre-amp yileds cleaner tone... the opposite causes distortion... Peavey got it right by giving you seperate volume knobs for the pre and power amps...
My question was (still w/o an answer)- how does it change the tone of your amp besides giving yuo better control of the drive? I'm starting to think it was mentioned regarding EVH's tone only to show he didn't use a really high gain amp...
One more thing I thinking about now- do higer output power amp tube+lower output pre amp tube (when it's relative to other combinations)= cleaner tone?

 

[Gearjoneser]

Re: Master volume design for amps- how does it effect tone?

I think there's a certain amount of 'non mastervolume snobbiness' when talking about this issue, mostly because it's players regurgitating info they read.
There's two schools of thought....the blues guys who only want to hear power stage overdrive, and modern rockers who's style needs a lot of preamp gain. Some call it 'buzzy' and some call it highgain that suits a style of music.

That said, I subscribe to both camps because I play both blues and technical rock. When I plug in a strat or tele, I'd prefer to use my non master Gibson Goldtone, a blackface, a tweed, or something like that. If I need gain, I'm not afraid of falling into the 'buzzy' territory. Gain is just another group of colors. And a master volume is definitely needed to get that type of sound.

I never understood why anybody would be on one side or the other. It's just tone.

 

[shredaholic]

Re: Master volume design for amps- how does it effect tone?

I have a question similar to this. If you keep the master wide open, and use the volume to control your gain, will this be the same as a NMV amp?

Yes.

I have an MV fitted in my Plexi, and when I boost the preamp gain in it I use the MV to stop the preamp overloading the phase inverter. When I turn the extra gain stages off, I keep the master wide open and it sounds totally stock.

 

[CapoFirstFret]

Re: Master volume design for amps- how does it effect tone?

how come no one has come out with a no load pot for the master volume

wouldn't this be the best of both worlds?

There is a company that integrated that idea into their circuit, but I can't recall which company it was.

I'll try to research it and figure it out.

 

[OlinMusic]

Re: Master volume design for amps- how does it effect tone?

I always noticed a difference in tone (and possibly circuit, no?) to Early MV's vs NMVs. NMVs always seem to open up more, though you need a hot plate.

The Bogner Ecstasy Classic and some similar amps, have defeatable MV's. This feature is interesting. I perceive a slight difference.

Mixing MV amps like Soldanos with NMV amps like Marshalls gets you the most amazing tone on earth. I have experienced something similar myself, but seeing ****ey Betts, Warren Haynes, and EVH do it, really floored me.

 

[Vasshu the humanoid typhoon]

Re: Master volume design for amps- how does it effect tone?

Hiwatt has always made some very good sounding MV amps, I have little worries about any "lack" of tone
My AC-15 clone is non MV...well another sound.

 

[devastone]

Re: Master volume design for amps- how does it effect tone?

I always noticed a difference in tone (and possibly circuit, no?) to Early MV's vs NMVs. NMVs always seem to open up more, though you need a hot plate.

The preamps are different, the MV models cascade more stages into each other in the preamp while the NMV have the high and low channels more in parallel.

MV and non-MV JMP preamp schematics, notice that the inputs on the NMV each feed one side of the first preamp tube, hence they are in parallel, but if you use the "high" input on the MV it cascades through both sides of the first preamp tube hence adding another gain stage.

 

[MattPete]

Re: Master volume design for amps- how does it effect tone?

Wasn't the first MV, except for the MV, otherwise identical to the NMV? I think this was only a short run, and after that they made several changes to the preamp stage of the MV amps.

 

[devastone]

Re: Master volume design for amps- how does it effect tone?

I could be wrong, but to my knowledge the JMPs in the schematic I linked above were the first Marshall MVs.