ROG Thor Bright switch.

Started by polifemo, October 22, 2007, 05:13:48 AM

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polifemo

I find the ROG Thor to be a wonderful pedal!
Right I'm using it with a detuned (to "B") Strat when doing TOOL/King´s X type of stuff.
The "pure" distortion and clear low end of the pedal makes it perfect for higher gain rhythm work.

The added brightness - when engaging the bright switch - however, has always been a bit "over the top", but yesterday I added a 220k resistor in series with the 470pF bright cap.

Sounds fantastic!!!!!!
Can't think of a better pedal for what I'm using it for  :icon_cool:
ROG rocks!

stm

#1
Hi polifemo,

It happens that as you turn down gain, the treble boost produced by the bright cap is higher and higher.  For instance, with the gain pot at noon you have around 20 dB (10x) of relative high frequency boost!  The series resistor you added is limiting maximum boost to around 11 dB (3.5x) in this condition.

On the other hand, as you turn up gain, the effect of the bright cap is less and less prominent being nil at max gain. This happens either with or without the resistor you added.

I've been puzzled that no one has mentioned such a simple and elegant solution to the bright switch in amps, particularly when intending to play at low OD levels.  Just consider you could put a 3-position center-off switch, where middle position is Bright Off, one side goes straight to the cap for Normal Bright, and the other side of the switch goes to the cap with your limiting resistor in series for a Moderate Bright option.

Glad to hear you are enjoying Thor!

P.D.  By the way, I'd like to ask for some feedback on how you are using Thor.
a) Which is your typical Gain pot setting ? (assuming you are using a log or audio pot)
b) Do you use the Bottom switch on or off?
c) Are you using it with a SS or valve amp?
d) Is your amp set clean, near break up, or already distorting?

EDIT:  Corrected the maximum boost value with the 220k resistor from 15dB to 11dB.

polifemo

#2
Quote from: stm on October 22, 2007, 10:58:43 AM
Hi polifemo,
Glad to hear you are enjoying Thor!

P.D.  By the way, I'd like to ask for some feedback on how you are using Thor.
a) Which is your typical Gain pot setting ? (assuming you are using a log or audio pot)
b) Do you use the Bottom switch on or off?
c) Are you using it with a SS or valve amp?
d) Is your amp set clean, near break up, or already distorting?


The guitar I´m using has low output PU´s and I usually end up with the gain at about 1 o´clock .
For this setting I use the bottom switch "on", but when/if I go for higher gain settings I turn the bottom switch "off".
My amps are all tube amps.
I run my amp clean.

The Thor is also great for an agressive "Texas tone" using the neck PU of a Strat. My gain setting for this would be at about 11 o´clock.

So all n´all I would say that no matter what guitar I´m using (Les Paul style or Strat style) my gain settings range from 11 o´clock to 3 o´clock.
As I wrote earlier the bottom switch is "on" up to about 1 o´clock - 2 o´clock, and "off" when going higher. (Especially if using max gain!)
The bright witch can be "on" or "off" at all settings depending on what type of sound I´m after.

stm

Thanks for the feedback.  Seems like your unit has plenty of gain.

May I ask which JFETs you used for the first and second stages?

polifemo

Quote from: stm on October 22, 2007, 11:22:28 AM
Thanks for the feedback.  Seems like your unit has plenty of gain.

May I ask which JFETs you used for the first and second stages?

Right now I don´t know  :icon_redface: (The pedal isn´t new - I´ve had it for a while - but I´ll find out  ;)

What I can tell you about is the first mod I tried in order to attenuate the treble produced by the bright switch:

I soldered another 470pF cap in parallel with the bright switch cap in order to include some mids into the bright caps signal.
The result was pleasing as well, but the pedal became a bit "grittier/meatier" sounding.

Nothing wrong with that, but I preferred the sound produced with the 220k in series  8)

/Peter


ps I did not come up with any of these ideas by myself  ::) I´m lucky enough to have really talented friends helping me out  :icon_biggrin: ds

primalphunk

I'm not sure where to add the resistor in series to reduce the level of brightness. Does it go from Q2 to the 470p cap or from the bright switch to the other leg of the bright cap?

B Tremblay

Quote from: primalphunk on April 09, 2012, 06:45:54 PM
I'm not sure where to add the resistor in series to reduce the level of brightness. Does it go from Q2 to the 470p cap or from the bright switch to the other leg of the bright cap?

The resistor should be placed between the 1n / Gain Lug 3 junction and the 470p cap.
B Tremblay
runoffgroove.com

StereoKills

Fantastic! I use my Thor at relatively low gain settings and always though the bright/bottom were a bit much. I've gotta try this.

I like the bass that the Bottom adds in, but it seems the sound gets more.....compressed? Any thoughts on reducing that?
"Sometimes it takes a thousand notes to make one sound"