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Roland VG-99 V-Guitar System => VG-99 General Discussion => Topic started by: amagalma on April 18, 2013, 01:07:20 AM

Title: VG-99 - Custom AMP questions
Post by: amagalma on April 18, 2013, 01:07:20 AM
Hello! :)

I've been reading the manual on Custom Amp settings but I cannot understand what is the difference between "Low" and "Bass", and between "High" and "Treble". Can someone explain to me please? Thanks! :)

Quoting the manual:
"LOW -50–+50 Adjusts the preamp section's low-frequency tone."
"BASS 0–100 Adjusts the tone for the low frequency range."
"HIGH -50–+50 Adjusts the preamp section's high-frequency tone."
"TREBLE 0–100 Adjusts the tone for the high frequency range."
Title: Re: Custom AMP questions
Post by: arkieboy on April 18, 2013, 01:22:09 AM
It's semi-parametric innit!


The LOW and HIGH parameters allow you to customise the type of tone controls on your custom amp - LOW sets the centre frequency the bass control operates on and HIGH the high control.  Then the BASS and TREBLE are just the regular amp controls that control the amount of cut in the frequencies you have selected with the LOW and HIGH.


Remember you also have BOTTOM and EDGE which control the amp's overall responsiveness to bass and treble frequencies, and how these frequencies break up when the amp is pushed.


Steve
Title: Re: Custom AMP questions
Post by: amagalma on April 18, 2013, 01:49:17 AM
Thank you very much arkieboy for your quick response :) but I am afraid this is not the case!

The centre frequencies of the Bass and Treble controls are set by the "Bass Freq" and "Treble Freq" parameters respectively.

Quoting again the manual: (p.143)
"BASS FREQ (Bass Frequency) -50–+50 Adjusts the frequency affected by the BASS parameter."
"TREBLE FREQ (Treble Frequency) -50–+50 Adjusts the frequency affected by the TREBLE parameter."

(https://www.vguitarforums.com/smf/proxy.php?request=http%3A%2F%2Fi412.photobucket.com%2Falbums%2Fpp208%2Felantric%2FVG-99%2FPicture6-1.png&hash=7f6a049dc11ff6091b593a91efae2708d59be3ae)
Title: Re: Custom AMP questions
Post by: arkieboy on April 18, 2013, 07:59:12 AM
... ah, the screen shot is from the mixer equaliser. 


I assumed when you said 'custom amp settings' you meant the custom amp type in the cosm amp modeller, hence mentioning 'bottom' and 'edge'


see page 39




Title: Re: Custom AMP questions
Post by: amagalma on April 18, 2013, 08:29:18 AM
Thank you Steve for trying to help me! :)

I have no idea how and why this pic attachment appeared on my post!  ??? (I am on Windows and this comes from OSX and is out of topic!)

I do refer to the  'custom amp settings' in the custom amp type in the cosm amp modeller! The explanation of the controls are on page 143 of the manual. What I do not understand is what is the difference between LOW vs BASS and what is the diference between HIGH vs TREBLE.
Title: Re: Custom AMP questions
Post by: Elantric on April 18, 2013, 09:14:53 AM
QuoteI have no idea how and why this pic attachment appeared on my post!  ??? (I am on Windows and this comes from OSX and is out of topic!)

It was I who attached pic of an example of a VG-99 Parametric EQ - which is what you were describing here:
QuoteThe centre frequencies of the Bass and Treble controls are set by the "Bass Freq" and "Treble Freq" parameters respectively.

Quoting again the manual: (p.143)
"BASS FREQ (Bass Frequency) -50–+50 Adjusts the frequency affected by the BASS parameter."
"TREBLE FREQ (Treble Frequency) -50–+50 Adjusts the frequency affected by the TREBLE parameter."



QuoteWhat I do not understand is what is the difference between LOW vs BASS and what is the diference between HIGH vs TREBLE.
To understand all EQ controls( and the mysterious "Custom Amp EQ Controls") I find it handy to have a Pink Noise generator and a RTA Real Time Analyzer.

Several RTA's are free or cheap on iPad, and many other versions are available,
 
Feed Pink Noise into an input (like the VG-99 Guitar IN), connect the VG-99 Output to the RTA, and watch what each EQ Control does to the Output Frequency response curve.

Using an Audio Precision AP2700 I made a full set of these graphs for old Line6 Vetta series in 2004, and these looks like this

http://www.vettaville.com/vetta_frequency_plots.htm (http://www.vettaville.com/vetta_frequency_plots.htm)
http://www.vettaville.com/documents/VETTA_CAB_SIMS1.pdf (http://www.vettaville.com/documents/VETTA_CAB_SIMS1.pdf)
Title: Re: Custom AMP questions
Post by: arkieboy on April 18, 2013, 09:29:24 AM
as ever, the thing to do is devise an experiment


try this - select a sound (strat edge 045 seems decent)


change the cab model for 'custom' on screen 1 of the VG


select 'twin' as the model on page 2


go to page three and check everything is at zero,


set bass middle and treble to 50 on page 4 and presence to 0.  gain at 100 so we can listen to the edge and bottom


pick a parameter and vary it.


I chose the treble freq and the treble control.  when the treble freq is low it, the treble control sounds more like a high mid control to me.  (and yes my bad - i mistook 'high' for 'treble'  :-\ , that will teach me to do this at work instead of in my studio)


So what do you think it does?  I'm wondering if it is an overall 'pre-eq' eq meant to model differences in the preamp, the kind you might get by changing electrical components or components aging ..  pink noise analysis would help here as Elantric says


Steve


Title: Re: Custom AMP questions
Post by: amagalma on April 21, 2013, 06:08:15 AM
Thank you both for your responses! :)

I am going to try it with pink noise and Voxengo's SPAN through the USB connection!