Vox AC30/ 6 (TBX). Add an MV ?

[Sea Chief]

Apologies, I'm doing my best to contain my exasperation.

Seachief, do you understand how a potentiometer functions as a volume control? Do you understand that it is a voltage divider? That the guitar signal is a (varying/AC) voltage?
Ignore everything else for now. Can you just answer those three questions please.

A voltage divider? No, I have never heard of these two words in conjunction with each other.

Surely, if this is a fundamental component of understanding any of this, then I might have been told this-? Especially if i say that I'm right back at step 1, trying to understand *how a Volume on a preamp affects the power amp (& why it's located here & not just before the 'exit' to the speakers). I have stated this is where I'm at, countless times now. I just cannot be expected to understand any of the diagrams, see any relevance to any of them, certainly not a step onward & being capable of -comparing- one to another... IF... I say as clearly as I possibly possibly can, that I'm right back *here at step 1. Can I?

Thanks, SC

[Sea Chief]

Apologies, I'm doing my best to contain my exasperation.

Seachief, do you understand how a potentiometer functions as a volume control? Do you understand that it is a voltage divider? That the guitar signal is a (varying/AC) voltage?
Ignore everything else for now. Can you just answer those three questions please.

Again, I have never heard of "the guitar signal is a (varying/AC) voltage".

I was asking about Master Volume, so guitar signal hasn't been in discussion, until you mentioned it. I wasn't expecting guitar signal to be relevant to the volume controls on my amp whatsoever tbh. Guitar signal seems, to be alot of what you're talking of, within explanations I'm hugely confused about: meaning I am -more- confused with it's inclusion wondering why this is suddenly being talked about.

Furthermore "varying/ AC voltage" has never been mentioned on the thread either. Certainly not with "guitar signal is a.." preceeding it.

Thanks, SC

[loudthud]

As to how the MV -only- affects the power amp section in your diagram.. this is WAY in advance of where my understanding is. I haven't on god's earth got a clue as to why or how an MV can affect just the power amp, if it's placed before it (& if that's where your diagram suggests it is placed).

You don't seem to understand signal flow. Do you expect the signal to go backwards through the Master Volume and affect the Preamp ? Do you know what a Voltage Divider is ?

Are you refusing to answer the questions because you don't know the answers ?

Are you one of these AI Robots that just posts stuff to get a reaction from people.

A voltage divider? No, I have never heard of these two words in conjunction with each other.

It has been suggested that Sea Chief has some pathological need to be helped and paid attention to. He pretends not to understand so he can get more attention. This makes him feel whole somehow and the more someone tries to explain something to him, the more he doesn't understand.

Sea Chief, please seek help from medical professionals in your location.

[DrGonz78]

Hi Greg,

Yes, I turn the knob on my hifi & the volume goes up. Or..
Yes, I turn the knob on my guitar valve amp, & the volume goes goes up.

SC

Try answering him with short coherent sentences for the Love of Jeebus. All this blabbering is not helpful.

edit: part of your post that I deleted was the majority of the post. Really only two sentences stand out as a good answer.

[Sea Chief]

Try answering him with short coherent sentences for the Love of Jeebus. All this blabbering is not helpful.

edit: part of your post that I deleted was the majority of the post. Really only two sentences stand out as a good answer.

Ok 2nd post, apologies I missed that yourself wrote the one earlier (which contained 'noise floor': Gonz I've never in my life heard of this term- so I mean how can this 'noise floor' unknown, do anything other than further confuse me?

This is what I'm trying to explain: I appreciate the explanations & replies, but feel -overwhelmed- with a sudden shedload of unknowns like sag, headroom, (squared off) waves, oscilloscopes, terms like noise floor, voltage dividers, Input gain stages, signal chains; then the multiplying by 10 (why 10??), the whole guitar volume thing mystery (100mV if strings hit hard, but a far higher 2v if they're not seemingly being hit at all).. all pretty much in one go.

I'm only trying to understand why a vol is on the preamp, instead of fundamentally on the power amp (before it exits to the spkrs), & what a gain knob is relative to a vol knob. And lastly what an MV is. IE my Gain knob (Randall RD5) sounds like a super-saturated distortion -effect- affair, bearing zero resemblence to my Vol knob on my Ac30 or my Twin Reverb: why is this?

Thanks, SC

[Greg Robinson]

Input gain stages

What the hell do you think the tubes ARE?

signal chains

How the signal flows through the amp. Much like water through a pipe.

then the multiplying by 10 (why 10??)

What do you think amplifiers DO? You do realise they take a signal and amplify it right? 10 was an arbitrary choice, as you have already been told. Each gain stage will amplify by some amount, dependant on the design of the circuit. I chose 10 for my example because it's an easy number.

the whole guitar volume thing mystery (100mV if strings hit hard,

Again, an arbitrary, but not unrealistic number. A guitar will put out some volume. The volume can be represented as a voltage. I chose, for the example, that number to be 100mV.

but a far higher 2v if they're not seemingly being hit at all).

You MUST be taking the piss right? Not once in my diagrams was 2V mentioned. AND btw smartarse, if the strings are not being hit then the level is 0V.

I'm only trying to understand why a vol is on the preamp,

Well we've all done our best to try and explain that to you, but as it turns out, we tried to teach you multiplication tables before you understood the basics of addition like 1+1=2.

what a gain knob is relative to a vol knob.

Gain and volume are different names for the same control. Typically on a non master volume amp, this control is called volume. Often (but not always) on a master volume amp this is relabeled gain for clarity - to avoid having two controls both labelled volume.