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#1 amsdenj

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Posted 14 March 2016 - 02:44 PM

Here's a bit more explanation on the Helix amp parameters. I'd like to add this to helix help.com, but don't have a password to make edits. Can someone else make the updates?

 
Master
 
Adjusts the amount of power amp distortion: 0% clean 50% normal, 100% driven. Note that 50% may not be normal as the amps may have been modeled with the Master set too high. Consider using lower values, or the minimum distortion required to fit the song.
 
This parameter is highly interactive with all other power amp parameters—the lower the Master is set, the less effect the other controls will have.
 
Low Master and high Drive gives smother preamp distortion while high Master lower Drive gives more power amp, symmetric and more aggressive distortion. 

 

Sag

Controls power amp sag or compression 0% tight, 50% normal, 100% more touch for dynamic sustain.
 
Lower Sag values offer a "tighter" responsiveness for metal and djent playing; higher values provide more touch dynamics & sustain for blues and classic rock riffs. High Bias (closer to class A) reduces the effect of the Sag control. Sag doesn’t exist in class A amplifiers since the average plate current doesn’t change.
 
Sag is caused by the amplifiers power supply being unable to meet the demand when the map is pushed hard with high Master. When the power sags, the amp output drops and then recovers, creating a unique compression effect with some additional, but temporary distortion when you pick hard. Unlike compressors before the amp, sag compression occurs even when the amp is already very distorted.
 
Large sag gives more compression, better sustain, and can accentuate pick attack. But the amp will appear somewhat less responsive especially at the low end and can get muddy.

 

Hum

Controls how much heater hum interacts with your tone. Tube amplifiers generally used low voltage AC in the tube heaters, and sometimes this could add some hum into the signal. 
 
At higher settings, things get freaky. Higher levels cause some intermodulation distortion as the heater hum mixes with the signal. Generally left at 0 unless you are looking for a specific effect.

Ripple

Controls how much AC ripple in the power supply interacts with your tone. The power supply of a tube amp is filtered with large capacitors. If the amp is driven hard, these capacitors can’t provide sufficient filtering and some AC ripple is introduced into the signal. This is similar to hum but is on the plate of the tube instead of the heater and has a different shape.
 
At higher settings, things get freaky. Also generally left at 0 unless you are looking for a specific effect.

 

Bias

Changes the Bias of the power tubes. Lower values achieve a "colder" Class AB biasing. At maximum, the amp is operating in Class A.
 
Higher or “hot" bias will increase the warmth, reduce headroom, distort earlier or at a lower Master setting, and (in a tube amp) decrease the tube life. Lower or “cold" bias will make the sound less sweet, but will tighten it up and make it more dynamic.

 

Bias X

Determines how the power amp tubes' voicing reacts when pushed hard, controlling how much the bias changes when the amp is driven hard. Bias X is a bit like Sag, except it controls change in a tube’s operating point due to change in the tube bias when the amp is driven hard.
 
Set low for a tighter feel. Set high for more tube compression. This parameter is highly reactive with the Drive and Master settings.

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#2 SymphonicDischord

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Posted 14 March 2016 - 05:30 PM

Thanks for posting this, it definitely shed some light on how to dial in those settings.
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#3 spikey

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Posted 14 March 2016 - 05:59 PM

sticky


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Too much measuring and not enough music-making...    :lol: 

 


#4 kts222555111000

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Posted 15 March 2016 - 02:00 AM

 

Here's a bit more explanation on the Helix amp parameters. I'd like to add this to helix help.com, but don't have a password to make edits. Can someone else make the updates?

 
Master
 
Adjusts the amount of power amp distortion: 0% clean 50% normal, 100% driven. Note that 50% may not be normal as the amps may have been modeled with the Master set too high. Consider using lower values, or the minimum distortion required to fit the song.
 
This parameter is highly interactive with all other power amp parameters—the lower the Master is set, the less effect the other controls will have.
 
Low Master and high Drive gives smother preamp distortion while high Master lower Drive gives more power amp, symmetric and more aggressive distortion. 

 

Sag

Controls power amp sag or compression 0% tight, 50% normal, 100% more touch for dynamic sustain.
 
Lower Sag values offer a "tighter" responsiveness for metal and djent playing; higher values provide more touch dynamics & sustain for blues and classic rock riffs. High Bias (closer to class A) reduces the effect of the Sag control. Sag doesn’t exist in class A amplifiers since the average plate current doesn’t change.
 
Sag is caused by the amplifiers power supply being unable to meet the demand when the map is pushed hard with high Master. When the power sags, the amp output drops and then recovers, creating a unique compression effect with some additional, but temporary distortion when you pick hard. Unlike compressors before the amp, sag compression occurs even when the amp is already very distorted.
 
Large sag gives more compression, better sustain, and can accentuate pick attack. But the amp will appear somewhat less responsive especially at the low end and can get muddy.

 

Hum

Controls how much heater hum interacts with your tone. Tube amplifiers generally used low voltage AC in the tube heaters, and sometimes this could add some hum into the signal. 
 
At higher settings, things get freaky. Higher levels cause some intermodulation distortion as the heater hum mixes with the signal. Generally left at 0 unless you are looking for a specific effect.

Ripple

Controls how much AC ripple in the power supply interacts with your tone. The power supply of a tube amp is filtered with large capacitors. If the amp is driven hard, these capacitors can’t provide sufficient filtering and some AC ripple is introduced into the signal. This is similar to hum but is on the plate of the tube instead of the heater and has a different shape.
 
At higher settings, things get freaky. Also generally left at 0 unless you are looking for a specific effect.

 

Bias

Changes the Bias of the power tubes. Lower values achieve a "colder" Class AB biasing. At maximum, the amp is operating in Class A.
 
Higher or “hot" bias will increase the warmth, reduce headroom, distort earlier or at a lower Master setting, and (in a tube amp) decrease the tube life. Lower or “cold" bias will make the sound less sweet, but will tighten it up and make it more dynamic.

 

Bias X

Determines how the power amp tubes' voicing reacts when pushed hard, controlling how much the bias changes when the amp is driven hard. Bias X is a bit like Sag, except it controls change in a tube’s operating point due to change in the tube bias when the amp is driven hard.
 
Set low for a tighter feel. Set high for more tube compression. This parameter is highly reactive with the Drive and Master settings.

 

 

Thank you for posting this. The information and your time and effort is much appreciated.

As an aside I also want to thank you for your acoustic guitar patch listed elsewhere on this forum. I think you designed it for a real acoustic guitar but I can assure you it works really well and is the basis of all my acoustic patches for my Variax acoustic settings.

Thanks again.


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#5 duncann

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Posted 15 March 2016 - 04:10 AM

Here's a post that Ben Adrian made just recently relating to the tone controls: http://www.thegearpa...5#post-21593186


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#6 amsdenj

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Posted 15 March 2016 - 03:52 PM

Maybe its better to avoid the word normal the context of the Master volume. For those amps that have master volume, assuming Line6 modeled them faithfully, the min, 50% and max values would be whatever they were on the modeled amp.

 

For amps that don't have a master volume, we don't know how Line6 scaled the control they added. For maximum flexibility, I would expect they would have modeled the the amp with the Master control at 50% so that users would have the option of changing the master up or down from the fixed value in the modeled amp. This is similar to what they did for the Middle control added to amps that don't have that control, but rather use a fixed value. 

 

Another possibility might be that the default value for the Master on amps that don't have a Master control would correspond to the design of that amplifier. But these are just guesses.

 

The interesting point however is the ability to control preamp vs power amp distortion and how they are a bit different in terms of harmonics generated and dynamics of compression vs. sag and bias extension.


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#7 spikey

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Posted 15 March 2016 - 05:50 PM

Maybe its better to avoid the word normal the context of the Master volume. For those amps that have master volume, assuming Line6 modeled them faithfully, the min, 50% and max values would be whatever they were on the modeled amp.

 

For amps that don't have a master volume, we don't know how Line6 scaled the control they added. For maximum flexibility, I would expect they would have modeled the the amp with the Master control at 50% so that users would have the option of changing the master up or down from the fixed value in the modeled amp. This is similar to what they did for the Middle control added to amps that don't have that control, but rather use a fixed value. 

 

Another possibility might be that the default value for the Master on amps that don't have a Master control would correspond to the design of that amplifier. But these are just guesses.

 

The interesting point however is the ability to control preamp vs power amp distortion and how they are a bit different in terms of harmonics generated and dynamics of compression vs. sag and bias extension.

Thanks for the info- what sounds good to me is usually my general answer, but it would be nice to know the questions you pose. Im not even sure this hasn't already been answered at some point. Anyone?


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Too much measuring and not enough music-making...    :lol: 

 


#8 BigRalphN

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Posted 16 March 2016 - 05:36 PM

Here's a bit more explanation on the Helix amp parameters. I'd like to add this to helix help.com, but don't have a password to make edits. Can someone else make the updates?

Master

Adjusts the amount of power amp distortion: 0% clean 50% normal, 100% driven. Note that 50% may not be normal as the amps may have been modeled with the Master set too high. Consider using lower values, or the minimum distortion required to fit the song.

This parameter is highly interactive with all other power amp parameters—the lower the Master is set, the less effect the other controls will have.

Low Master and high Drive gives smother preamp distortion while high Master lower Drive gives more power amp, symmetric and more aggressive distortion.

Sag
Controls power amp sag or compression 0% tight, 50% normal, 100% more touch for dynamic sustain.

Lower Sag values offer a "tighter" responsiveness for metal and djent playing; higher values provide more touch dynamics & sustain for blues and classic rock riffs. High Bias (closer to class A) reduces the effect of the Sag control. Sag doesn’t exist in class A amplifiers since the average plate current doesn’t change.

Sag is caused by the amplifiers power supply being unable to meet the demand when the map is pushed hard with high Master. When the power sags, the amp output drops and then recovers, creating a unique compression effect with some additional, but temporary distortion when you pick hard. Unlike compressors before the amp, sag compression occurs even when the amp is already very distorted.

Large sag gives more compression, better sustain, and can accentuate pick attack. But the amp will appear somewhat less responsive especially at the low end and can get muddy.

Hum
Controls how much heater hum interacts with your tone. Tube amplifiers generally used low voltage AC in the tube heaters, and sometimes this could add some hum into the signal.

At higher settings, things get freaky. Higher levels cause some intermodulation distortion as the heater hum mixes with the signal. Generally left at 0 unless you are looking for a specific effect.
Ripple
Controls how much AC ripple in the power supply interacts with your tone. The power supply of a tube amp is filtered with large capacitors. If the amp is driven hard, these capacitors can’t provide sufficient filtering and some AC ripple is introduced into the signal. This is similar to hum but is on the plate of the tube instead of the heater and has a different shape.

At higher settings, things get freaky. Also generally left at 0 unless you are looking for a specific effect.

Bias
Changes the Bias of the power tubes. Lower values achieve a "colder" Class AB biasing. At maximum, the amp is operating in Class A.

Higher or “hot" bias will increase the warmth, reduce headroom, distort earlier or at a lower Master setting, and (in a tube amp) decrease the tube life. Lower or “cold" bias will make the sound less sweet, but will tighten it up and make it more dynamic.

Bias X
Determines how the power amp tubes' voicing reacts when pushed hard, controlling how much the bias changes when the amp is driven hard. Bias X is a bit like Sag, except it controls change in a tube’s operating point due to change in the tube bias when the amp is driven hard.

Set low for a tighter feel. Set high for more tube compression. This parameter is highly reactive with the Drive and Master settings.

I have been reading over this and have some thoughts running through my head. As an old guy that actually remembers when the first Boston album came out I have always been intrigued by the guitar tone. Initially, before he designed all of the Rockmann gear to make gone tones, he used his Gibsob, Stacks of Marshall Amps and some of his home made effects. One of the things I remember from an interview was that he attributed some of the tone to weak tubes and faulty circuits. This was part of the reason he needed to make the gear to create the sound live. Now I may be mixing some fact with urban legend but in any event I was wondering if we might be able to get in the ballpark by experimenting with all of these features and adding effects. Load up a Marshall and go from there. I may start trying, though I seldom get close to artist sounds. It might be a good challenge for people. I do know analog chorus and tape echo are a must.
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#9 glideman

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Posted 16 March 2016 - 08:15 PM

They also used some mid range super boost with graphic EQ's if I'm  not mistaken.  I forget the particular frequencies, but I'm pretty sure I remember a graphic EQ pedal being involved.


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#10 jshimkoski

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Posted 18 March 2016 - 07:20 AM

 

Here's a bit more explanation on the Helix amp parameters. I'd like to add this to helix help.com, but don't have a password to make edits. Can someone else make the updates?

 
Master
 
Adjusts the amount of power amp distortion: 0% clean 50% normal, 100% driven. Note that 50% may not be normal as the amps may have been modeled with the Master set too high. Consider using lower values, or the minimum distortion required to fit the song.
 
This parameter is highly interactive with all other power amp parameters—the lower the Master is set, the less effect the other controls will have.
 
Low Master and high Drive gives smother preamp distortion while high Master lower Drive gives more power amp, symmetric and more aggressive distortion. 

 

Sag

Controls power amp sag or compression 0% tight, 50% normal, 100% more touch for dynamic sustain.
 
Lower Sag values offer a "tighter" responsiveness for metal and djent playing; higher values provide more touch dynamics & sustain for blues and classic rock riffs. High Bias (closer to class A) reduces the effect of the Sag control. Sag doesn’t exist in class A amplifiers since the average plate current doesn’t change.
 
Sag is caused by the amplifiers power supply being unable to meet the demand when the map is pushed hard with high Master. When the power sags, the amp output drops and then recovers, creating a unique compression effect with some additional, but temporary distortion when you pick hard. Unlike compressors before the amp, sag compression occurs even when the amp is already very distorted.
 
Large sag gives more compression, better sustain, and can accentuate pick attack. But the amp will appear somewhat less responsive especially at the low end and can get muddy.

 

Hum

Controls how much heater hum interacts with your tone. Tube amplifiers generally used low voltage AC in the tube heaters, and sometimes this could add some hum into the signal. 
 
At higher settings, things get freaky. Higher levels cause some intermodulation distortion as the heater hum mixes with the signal. Generally left at 0 unless you are looking for a specific effect.

Ripple

Controls how much AC ripple in the power supply interacts with your tone. The power supply of a tube amp is filtered with large capacitors. If the amp is driven hard, these capacitors can’t provide sufficient filtering and some AC ripple is introduced into the signal. This is similar to hum but is on the plate of the tube instead of the heater and has a different shape.
 
At higher settings, things get freaky. Also generally left at 0 unless you are looking for a specific effect.

 

Bias

Changes the Bias of the power tubes. Lower values achieve a "colder" Class AB biasing. At maximum, the amp is operating in Class A.
 
Higher or “hot" bias will increase the warmth, reduce headroom, distort earlier or at a lower Master setting, and (in a tube amp) decrease the tube life. Lower or “cold" bias will make the sound less sweet, but will tighten it up and make it more dynamic.

 

Bias X

Determines how the power amp tubes' voicing reacts when pushed hard, controlling how much the bias changes when the amp is driven hard. Bias X is a bit like Sag, except it controls change in a tube’s operating point due to change in the tube bias when the amp is driven hard.
 
Set low for a tighter feel. Set high for more tube compression. This parameter is highly reactive with the Drive and Master settings.

 

 

 

Thank you amsdenj for providing more in depth information. The amps section of helixhelp.com has been updated with your improvements and added a thank you note as well.

 

In the future, if you (or anyone) has improvements they'd like to see on helixhelp.com feel free to send me a private message.


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#11 jshimkoski

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Posted 18 March 2016 - 07:37 AM

Here's a post that Ben Adrian made just recently relating to the tone controls: http://www.thegearpa...5#post-21593186

 

Thank you for this link. It has been added to helixhelp.com as well.


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