a better explanation of presence controls, the presence control is a reverse operation volume knob for a presence frequency negative feed back loop. its simple, we take a small amount of signal from the output of the output transformer, put it through a circuit to remove bass mids and highs just leaving the presence frequencies that are in the upper mids and lower highs. then feed it back to the cathode of either the phase inverter or some other preamp stage. the presence signal we are feeding back to that stage will be out of phase with the regular signal at that stage and cancel out some of the presence frequencies, this causes lower presence and you get a darker sound. the presence knob is added to the circuit to turn down the presence feed back amount as you turn the knob up so you get less cancellation of presence frequencies and you get a brighter sound.
I got to tell you something I'm seeing this now but it is so true everything you say especially guys like myself who use 200 W Marshall majors you take the two tubes out of the power amp section and honestly it had to be done at an emergency because I blew up tubes there was no difference it never meant to be is actually sounded better but all your information is spot on❤
Great information! I learned a lot from this video. I don't think i have ever heard an explanation of the presence knob before and have always wondered what its function was. Cool stuff explained in a way that most of us can understand. Very helpful!!
You will not die from touching a transformer itself UNLESS you touch the WIRES coming out of it. (Hey, they’re mounted to the chassis, which is grounded. ) Yes, there’s somewhere between 350 and 600 volts running THROUGH it when the amp is powered-up. However, there are CAPACITORS connected to power transformers (and other components) that can hold a charge of hundreds of volts even after the amp is turned off. Again, they are connected to the wires that come out of a transformer, not the transformer casing.
I know I’m late but at the 4:30 mark, about. 50 watt vs 100 amp, a 10 db gain is doubling the loudness, so 8db louder isn’t nothing. That’s the difference between a reasonable listening volume for anyone and the beginning of permanent hearing loss
I think this might be a demo of the USA education system failing - me just being bitchy...... You are right - he refers to a chart that correctly shows us that 3db added is twice the power - i.e. it takes 50 watts to 100 watts to gain 3db. It's on his own charts and he flubbed it. The human ear is - as expected- tuned to hear other humans so it's particularly sensitive to between 200-1000 Hz. However not all frequencies are heard like that and we hear high frequencies easily and low not so much when you relate that volume to watts powering it - that's why the guitar played up at the 12th fret sounds way louder than the bass player - to get that 12th fret 660Hz volume on the bass playing it;'s low E 42 Hz, to sound the same you need 16x more power - so guitar amp 25 watts works like a bass amp 16x25 = 400 watts Now you know why the bass player needs al;l those watts. I could go on - the tone stack works the opposite to how he says - on a Fender if you turn down to zero the treble and bass you get a flat frequency response - plenty of charts and explanations on the web to check that out. And I've only listened to 6 minutes of the 10.
@@jounihaapakoski708110dB is actually 10 times "louder". Our ears perceive 10dB as being twice as loud. But in terms of physics, sound being air molecules vibrating and propagating energy through a medium (in this case, air), those air molecules have ten times more energy with every increase of 10dB. 120dB has a HUNDRED times more kinetic energy of air molecules vs 100dB
Point 1...Tick.....Point 2....Tick.....Point 3.....Tick....Point 4.....Tick......Point 5.....Tick.....Well done! But....you missed the best one.....YOU DON'T NEED TO USE THE STANDBY SWITCH. 😉
It's like...ya know...I just...and then... you can totally jump any amplifier with two channels if you just jump far enough. You know... just have fun with it.
no AMP is flat on ten and baxandall is not a TMB tone stack! #1 all wrong!!! Fender and marshall don't have baxandall EQ, vintage Orange had.... and those were flat with bass and treble on 5! Remove and make a new video please!
As a physics teacher, there are some scientific inaccuracies contained within this video. If you're a newbie learning this stuff for the first time, go elsewhere first
OMFG!!!! Jimi Hendrix was trying to explain the tone stack to all of us in “if 6 was 9” this whole damn time!!! It makes perfect sense!!!
Brendan Fraser remembered his time in the movie Airheads fondly and works at Casino Guitars now...neat.
a better explanation of presence controls,
the presence control is a reverse operation volume knob for a presence frequency negative feed back loop.
its simple, we take a small amount of signal from the output of the output transformer, put it through a circuit to remove bass mids and highs just leaving the presence frequencies that are in the upper mids and lower highs. then feed it back to the cathode of either the phase inverter or some other preamp stage. the presence signal we are feeding back to that stage will be out of phase with the regular signal at that stage and cancel out some of the presence frequencies, this causes lower presence and you get a darker sound. the presence knob is added to the circuit to turn down the presence feed back amount as you turn the knob up so you get less cancellation of presence frequencies and you get a brighter sound.
I got to tell you something I'm seeing this now but it is so true everything you say especially guys like myself who use 200 W Marshall majors you take the two tubes out of the power amp section and honestly it had to be done at an emergency because I blew up tubes there was no difference it never meant to be is actually sounded better but all your information is spot on❤
I really liked this. You guys rule. Dont stop making this type of content!
Who gave a cup of coffee and a mic to a ball bag in a hoodie?
4:52 drinking game take a shot every time he swallows nothing
Great information! I learned a lot from this video. I don't think i have ever heard an explanation of the presence knob before and have always wondered what its function was. Cool stuff explained in a way that most of us can understand. Very helpful!!
Thanks for sharing. Good stuff!!
I actually didn't know most of this. So that was great!
Well that was a useful bit of wisdom. One question, does the point that was made about the Fender EQ also apply to a Vox AC10C1?
Very cool & laid back explanation of tubw amp stuff, thanks for the info y'all
You will not die from touching a transformer itself UNLESS you touch the WIRES coming out of it. (Hey, they’re mounted to the chassis, which is grounded. )
Yes, there’s somewhere between 350 and 600 volts running THROUGH it when the amp is powered-up. However, there are CAPACITORS connected to power transformers (and other components) that can hold a charge of hundreds of volts even after the amp is turned off. Again, they are connected to the wires that come out of a transformer, not the transformer casing.
Nice post! Thanks.
Five things he doesn’t know about valve amps….
@Canadian gear head If there’s one thing I know, … it’s what you just said!
Lol yep!
Here's five things various muppets on UA-cam said that I accepted as fact.
Is it necessary to burn in new guitar amp tubes? if so how? Thanks
Safe to say input 2 is better for bedroom practice?
I know I’m late but at the 4:30 mark, about. 50 watt vs 100 amp, a 10 db gain is doubling the loudness, so 8db louder isn’t nothing. That’s the difference between a reasonable listening volume for anyone and the beginning of permanent hearing loss
I think this might be a demo of the USA education system failing - me just being bitchy...... You are right - he refers to a chart that correctly shows us that 3db added is twice the power - i.e. it takes 50 watts to 100 watts to gain 3db. It's on his own charts and he flubbed it. The human ear is - as expected- tuned to hear other humans so it's particularly sensitive to between 200-1000 Hz. However not all frequencies are heard like that and we hear high frequencies easily and low not so much when you relate that volume to watts powering it - that's why the guitar played up at the 12th fret sounds way louder than the bass player - to get that 12th fret 660Hz volume on the bass playing it;'s low E 42 Hz, to sound the same you need 16x more power - so guitar amp 25 watts works like a bass amp 16x25 = 400 watts Now you know why the bass player needs al;l those watts. I could go on - the tone stack works the opposite to how he says - on a Fender if you turn down to zero the treble and bass you get a flat frequency response - plenty of charts and explanations on the web to check that out. And I've only listened to 6 minutes of the 10.
yeah, the loudness, db. volume part is total bs, but it happens..
@@jounihaapakoski708110dB is actually 10 times "louder". Our ears perceive 10dB as being twice as loud. But in terms of physics, sound being air molecules vibrating and propagating energy through a medium (in this case, air), those air molecules have ten times more energy with every increase of 10dB.
120dB has a HUNDRED times more kinetic energy of air molecules vs 100dB
Thanks!😊
That was just excellent. More please!
4:27 a difference of about 8 decibels.... That's a lot!! That's more than twice as loud
amazing content
1:45 “oh…excuse me”
A lot of guitarists only get to use input 2 on birthdays and anniversaries.
LOL
LMFAO Ryan!
Dude this is valuable info thank you so much!!
And now I am educated🔥
Point 1...Tick.....Point 2....Tick.....Point 3.....Tick....Point 4.....Tick......Point 5.....Tick.....Well done!
But....you missed the best one.....YOU DON'T NEED TO USE THE STANDBY SWITCH. 😉
Great video. Well done.
It's like...ya know...I just...and then... you can totally jump any amplifier with two channels if you just jump far enough. You know... just have fun with it.
Great video.
After 40 years someone finally explains this amp stuff to me?! Crazy
Anybody else looking at "Shooter McGavin" from Happy Gilmore ?
Good info!
2nd time watching
Dime out your amp. That's all you need to know.
Theres a lot wrong here. A lot. Hes pretending he knows.
I know it sizzles
I usually really enjoy this channel but as an engineer I can tell you that almost every bit technical information in this video is wrong...
Agree.
no AMP is flat on ten and baxandall is not a TMB tone stack! #1 all wrong!!! Fender and marshall don't have baxandall EQ, vintage Orange had.... and those were flat with bass and treble on 5! Remove and make a new video please!
As a physics teacher, there are some scientific inaccuracies contained within this video. If you're a newbie learning this stuff for the first time, go elsewhere first
at least get sober before trying to discuss something crucial😊