#1
so. if overdriving an amp puts out more watts than listed RMS, potentially up to double, how do you control or tell how many watts you output?

does master volume basically = watts?

does guitar volume = watts?

if cranking everything = outputs more watts and overdrives amp then doesnt half master volume = roughly half wattage used? how can you guage if your maxing your amp or not nearly using enough of it?
#2
Master volume is how much power your sending to the OT, it's like a floodgate control, when it's at half, then your using half of your amps power, now, you can boost your amp to make it sound like it's pushing more, but if your amp is rated for 50 watts, then it's only going to push 50 watts, may sound louder, but it's only pushing 50 watts, it can't push any more than that, the fuses will blow, since your amps is directly related to your watts, you use more watts, then you use more amps.

That's how I understand it.
#3
I've seen a lot about this on UG lately.
From what I've got, is that the amps RMS wattage, is rating at the CLEAN power output, once you start to overdrive it, that's when the wattage starts going higher, but I believe you've stated this.

But controlling it? I'm not so sure you can. I'd say... get an attenuator, or just higher wattage speakers if you're worried about damaging anything? I dunno :/
#4
Quote by ethan_hanus
Master volume is how much power your sending to the OT, it's like a floodgate control, when it's at half, then your using half of your amps power, now, you can boost your amp to make it sound like it's pushing more, but if your amp is rated for 50 watts, then it's only going to push 50 watts, may sound louder, but it's only pushing 50 watts, it can't push any more than that, the fuses will blow, since your amps is directly related to your watts, you use more watts, then you use more amps.

That's how I understand it.

The 50W rating is how much the output will produce before clipping. Preamp distortion doesn't really count but if you push the output into clipping it will be higher than 50W. Even given that the highest voltage presented to the OT is the plate voltage, power is proportional to the area under the graph so if you square off the tops you get more area => more power.

Edit. You don't blow the fuses because the maximum current is no higher but the duration of that maximum current is longer because it spends more time at the maximum extremity. ie not more current, but a higher duty cycle.
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Last edited by Cathbard at Aug 12, 2010,
#5
so the volumes control transformers, which regulate power. so master volume directly connects available power?

so this is why lower master/higher channel sounds more distorted? because your pushing more gain into lower watts?

what about guitar volume? that only controls the strength of the input right? and the higher the input the more the amp reacts?
#6
Think of it this way. It's an amplifier. That is to say it takes a signal and increases it's voltage level by a ratio. A larger input signal (controlled by the guitar volume) will therefore be multiplied to a higher output voltage. The Master volume changes the amplification ratio of the power amp.
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Randall RM100 & RM20
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Fender 5F1 Champ clone
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Marshall 1960A
Boss GT-100


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#7
well that is true. i turned my master all the way up, channel down, and it took my distortion pedal WAY WAY WAY better. i can crank more gain out my amp.

before, with higher gain it seemed like the amp would begin clipping, like i was choking it out.

i attribute this to the mater being up and allowing all wattage and headroom for the gain as possible, whereas before i was trying to play hard music through an amp that was only using half or less its available wattage. it is basically the same as using triode mode to paly hard rock. sounds about the same. its like im putting my amp is a straight jacket....turning the master up is the hulk ripping off his clothes
#8
Well a guitar amp is actually two amplifiers -the preamp and the power amp. The first amp is the preamp which amplifies the signal enough for the power amp's needs and then the power amp amplifies it enough for the speaker's needs.
The true meaning of "gain" is the "amplification ratio". The gain knob adjusts the amplification ratio of the preamp and the Master Volume adjusts the ratio of the power amp. If the preamp's gain ratio times the input signal is too high the tops of the signal get chopped off because the amplified voltage would be higher than the voltage supply to the preamp tubes - that's your preamp distortion.
Similarly if the amplification ratio of the power amp times the signal being fed to it by the preamp would result in a higher voltage than it's power supply voltage then the signal is clipped there as well resulting in power amp distortion. The two sections therefore interact.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#9
Quote by Cathbard
Well a guitar amp is actually two amplifiers -the preamp and the power amp. The first amp is the preamp which amplifies the signal enough for the power amp's needs and then the power amp amplifies it enough for the speaker's needs.
The true meaning of "gain" is the "amplification ratio". The gain knob adjusts the amplification ratio of the preamp and the Master Volume adjusts the ratio of the power amp. If the preamp's gain ratio times the input signal is too high the tops of the signal get chopped off because the amplified voltage would be higher than the voltage supply to the preamp tubes - that's your preamp distortion.
Similarly if the amplification ratio of the power amp times the signal being fed to it by the preamp would result in a higher voltage than it's power supply voltage then the signal is clipped there as well resulting in power amp distortion. The two sections therefore interact.

^That.

At full blast an amp can go WAAAY over its RMS (more common, AFAIK, with tube amps, more specifically, tube power amps, than SS). There's some orange 50w head - not sure which one - that I've heard can hit 90w output at full bore.
Current Gear:
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Quote by Anonden
You CAN play anything with anything....but some guitars sound right for some things, and not for others. Single coils sound retarded for metal, though those who are apeshit about harpsichord probably beg to differ.
#10
Quote by oneblackened
^That.

At full blast an amp can go WAAAY over its RMS (more common, AFAIK, with tube amps, more specifically, tube power amps, than SS). There's some orange 50w head - not sure which one - that I've heard can hit 90w output at full bore.


IIRC Ritchie Blackmore's modded Marshall Majors put out around 270w RMS and 470w at full tilt. An old Plexi era 100w Marshall can easily hit 185-200w at full bore. I think an AC30 only puts out about 36w when cranked. Tube amps how I love you.
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Last edited by mmolteratx at Aug 13, 2010,
#11
Quote by mmolteratx
IIRC Ritchie Blackmore's modded Marshall Majors put out around 270w RMS and 470w at full tilt. An old Plexi era 100w Marshall can easily hit 185-200w at full bore. I think an AC30 only puts out about 36w when cranked. Tube amps how I love you.



The funny part is, AC30s are loud enough for stadium shows.
Current Gear:
LTD MH-400 with Gotoh GE1996T (EMG 85/60)
PRS SE Custom 24 (Suhr SSH+/SSV)
Ibanez RG3120 Prestige (Dimarzio Titans)
Squier Vintage Modified 70s Jazz V
Audient iD22 interface
Peavey Revalver 4, UAD Friedman BE100/DS40
Adam S3A monitors
Quote by Anonden
You CAN play anything with anything....but some guitars sound right for some things, and not for others. Single coils sound retarded for metal, though those who are apeshit about harpsichord probably beg to differ.
#12
Quote by oneblackened


The funny part is, AC30s are loud enough for stadium shows.

This gets regurgitated ad neuseum and it makes no sense whatsoever. At the big stadium gigs you have a PA big enough to drain the power plant for a small town. The bigger the gig the smaller the amp you can get away with. Jeff Beck has been seen doing huge gigs with a 5W Fender Champ.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#13
Quote by oneblackened


The funny part is, AC30s are loud enough for stadium shows.

A low wattage tweed combo would be loud enough for stadium shows too if they miced it
#14
Quote by mmolteratx
IIRC Ritchie Blackmore's modded Marshall Majors put out around 270w RMS and 470w at full tilt. An old Plexi era 100w Marshall can easily hit 185-200w at full bore. I think an AC30 only puts out about 36w when cranked. Tube amps how I love you.


Orange has a Bass head rated at 500 watts RMS, and it can go god only knows how high if you cranked it.