#1
Hi guys, I have been playing through a Blackstar HT5 for a while now (my first tube amp) and loved it. I felt I needed more clean headroom and overall volume for playing with others though. I've since gotten a Carvin V3-Micro and Blackstar HT-20

Both of those are quite a bit higher power than my HT5 so I can't really crank it like I'm accustomed to while playing in the house.

I've been looking for a primer on what Gain, Volume & Master do exactly -- and how they relate to one another. I can definitely hear that increasing gain changes the distorted sound of the amp, but it also changes the volume. The volume of the lead channel obviously changes the volume of sound, but not quite in the same way as the master volume.

From what I can tell, gain determines how much distortion there is (not sure of how that happens technically). The volume seems to mainly affect the preamp circuit. And the master volume affects the power circuit.

But what are the relationships between them? It seems like increasing the master volume with moderate gain & volume give me a more "organic" sound. It almost feels like the most ideal sound (for me anyway) would be a dimed master with moderate volume and gain to taste.

I assume the type of tubes would make quite a bit of difference. The Blackstar is running 2xECC83 on the preamp side, and 2xEL34 on the power section. Are ECC83s happy being pushed? Or should that primarily be done with the EL34s? Not knowing this kind of information is what's bugging me...

I did try and search for this over the last couple days, but no joy. Any help in understanding the functions and relationships between these three would be helpful and most appreciated.
Richard

I tried setting my password to "penis". It said my password wasn't long enough.

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#2
"Gain" in the sense of audio refers to signal strength. That has nothing to do with how loud it is, but instead how strong the signal is running through your electronics. Components in an audio circuit will "clip" (aka overdrive or distort) when the signal passing through them become too strong (i.e. the gain is increased past a certain point.) Tubes sound great when they clip, which is why they are used in amps.

"Volume" is simply how loud your amp is perceived by you. There are tons of factors that go into perceived volume, such as speakers, cab construction, where you are in relation to the speaker, room acoustics, etc. But for all intents and purposes, volume just means how loud something is.

"Master Volume" on a guitar amp is actually a second gain knob. The knob usually labeled "gain" controls the strength of the signal hitting the preamp of your amp. This overdriven signal is then passed to the master volume, which controls how strong that signal is when it gets passed on the the power amps section. As the gain increases in the power amp, so will volume to an extent. However, turning the master volume all the way up will overdrive your output tubes too (since it's really controlling the gain of the signal getting passed to them.) Like you said, this sounds more "organic" in a lot of cases.

In conclusion, you really just need to find what works for you. Cranked amps have a good reputation - you get the overdrive from the preamp mixed in with power tube distortion to create a good "classic" sound. However, the only way to get that is to turn up your master volume, which means that you can't truly achieve those tones at low volumes. Also, speakers sound different once they start getting worked hard, so there's that to take into consideration too. Just play around with different settings and don't be afraid to crank it.

Hope that makes some sense
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#4
gain (as it's labelled on a guitar amp) generally affects how much preamp tube distortion you have (or on a blackstar, diode clipping LOLOLOLOL). the channel volume is basically just a volume control which will affect loudness. ditto the master, though it may be in a different part of the circuit so there may be some differences in tone- high master with lower channel volume may sound different to higher channel and lower master volume.

at higher levels the master volume will probably start to distort the power amp tubes, too.
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#5
Gain is a signal level control before a circuit that will distort the signal. The more distorted a signal becomes the less of a volume increase you get as you increase the signal level before the distorting circuit. Even though "gain" only means signal level change, the association of putting the gain control in front of a distortion cicuit makes "gain" synonomous with distortion.

Volume is a signal level control in a location of the circuit that changes volume, while not having much affect on the distortion. If you have two channels you will sometimes have a volume control for each channel that allows you to balance the volume when switching between the two. In addition you might have a master volume that allows you to control the overall volume for each channel.

The volume control also allows you to boost the volume going into the power tubes and does affect power tube distortion. Whereas gain affects preamp distortion.
#6
Okay, so if I were to set gain relatively high and the master volume relatively high, adjusting the volume of that channel shouldn't have any affect on the overall tone?

In effect I could crank the gain and master volume, but keep things civil by adjusting the volume of the channel.
Richard

I tried setting my password to "penis". It said my password wasn't long enough.

PRSi:
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H&K TubeMeister
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#7
Pretty much. As I explained in my post setting the channel volume is for setting the volume difference when switching between channels.
#8
i'd have thought they'd all interact.

if you're bleeding a ton of signal off to ground (which is what pretty much any pot on an amp is doing when turned low), it's going to affect things.

you're not gonna be able to get, for example, power tube distortion by setting the master volume high but the channel volume low. it doesn't work like that.
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Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#9
Yeah there is going to be some interaction. I'm pretty sure you have to determine that on an amp to amp basis.
#10
yep, sure.
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#11
Yeah, for sure I'm not expecting to dime the gain & master volume, then put the channel volume super low and expect a full saturated sound.

But the main thing I'm getting out of this is that the master volume is what's really pushing the power section, not the channel volume. This is the opposite of what I thought. So even on my clean channel, that volume is only affecting the output of the channel -- not really affecting the tone by way of power "gain"...
Richard

I tried setting my password to "penis". It said my password wasn't long enough.

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*SE Soapbar II
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#12
nah they're both affecting the volume. you probably aren't pushing the power section unless both are pretty high.
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Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#13
Quote by Dave_Mc
nah they're both affecting the volume. you probably aren't pushing the power section unless both are pretty high.

Hmmm...

(It does sound best with all 3 pushed relatively high.)
Richard

I tried setting my password to "penis". It said my password wasn't long enough.

PRSi:
*ME Quatro
*CE-22
*SE Soapbar II
H&K TubeMeister
TC Electronic Nova System

PBT Native
#14
Tubes amplifying is analog amplification at it's best.

The guitar produces an analog signal (imagine an xy-axis) and the gain increases the amplitude of this signal. If you increase the strength of this signal high enough the pre-amp tube will give a distorted sound because the pre-amp tube is overdriven.

The master volume works in the power amp circuit that alters the 'overal' produced sound level.

The channel volume works between the pre-amp and power amp circuit (after pre-amp and before power amp).
It increases or decreases the amplitude of the signal coming from the pre-amp (which might be distorted because of the gain earlier in the circuit) before it goes out to the power section.

Like somebody said, the channel volumes are there to level out the differences of the signal strength (amplitude) between channels before it goes to the power section.
A selected channel with high gain (increased amplitude) would sound louder then the other channel with low gain if there wouldn't be a channel volume.
But the channel volume doesn't alter the tone before it goes to the power amp. If you want to overdrive the power tubes as well, then the channel volume must be raised as well, so it will affect tone only when the power tubes are overdriven.
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Last edited by xgunterx at Aug 4, 2011,
#15
All of those three controls are gain, they just operate in different parts of the circuit. Gain is literally the amplification factor, ie. Vout/Vin.
Your "gain" control is early in the signal path (near the start of the preamp) so turning it up overdrives the preamp. It does that by amplifying the signal which is why it also increases the volume.
The others are later in the chain and therefore only affect things further down the line.
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Last edited by Cathbard at Aug 4, 2011,
#16
It depends on the amp.

Gain controls usually sit between gain stages and control how much signal passes from one to the next. This limits how hard the following gain stages (IE Triodes of the tubes) can be pushed, and thus limits the amount of distortion/clipping you get from each stage.

Channel Volume can be thought of like a control on a mixing desk for the volume of each input. If each channel has a channel volume, you can match them by adjusting how much signal comes through from each, by increasing or decreasing the volume. These will come after all of the preamp circuitry for that channel, depending on how much of each channel is independent from the others (IE if there is a shared tonestack between 2 channels, the volume controls will come before that)

Master Volume limits the amount of signal that passes from Pre to Power amp. They come after the Channel volumes and act like a volume control on a mixing desk for adjusting the final output. Basically this is what you need to crank to get Power Tube distortion, but you need to run the preamp pretty hot to achieve that too. These are after everything else in terms of volume control and sit after the phase inverter and before the power tubes (or just before the power tubes if there is only one)

Volume on an amp without a Master Volume control (IE Marshall Plexis) is essentially all three of those rolled into one. It sits in exactly the same place as a gain control, but since there is no Master Volume limiting the amount of signal hitting the poweramp after the preamp, this control will also act as the Master Volume. You need to crank it to get distortion, and as a result, as the amp gets dirtier, it gets louder, as a result of more signal hitting the power tubes.
#17
Quote by Cathbard
All of those three controls are gain, they just operate in different parts of the circuit. Gain is literally the amplification factor, ie. Vout/Vin.
Your "gain" control is early in the signal path (near the start of the preamp) so turning it up overdrives the preamp. It does that by amplifying the signal which is why it also increases the volume.
The others are later in the chain and therefore only affect things further down the line.


yeah
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?