Allen Raw Control in a pedal?

Rick Towne

Praise & Western
Gold Supporting Member
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Has anyone either set up either a remote on and off footswitch for the above? Can it be done with a pot to duplicate the onboard amp control?
 
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jaydub69

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Try posting this in the Amp Technical Info section, you may have a better response.

I'd be interested to hear. It's my understanding that David Allen won't use a cable or such to control the raw pot with a pedal because it is too drastic a change in volume. Potential problems would be likely. I wouldn't mind seeing something with a small ratio, however. You know like a full pedal throw would only move the pot a little bit. I could see some potential for that application.
 
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trisonic

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13,152
As I understand it the "Raw" control gradually takes the tone-stack out of the circuit - I don't know how you can duplicate that.
Jimmy Somma set up my BF Vibro-Champ to have a switchable Tone-Stack. I have no idea just how you can merge the two into a footswitch.

Best, Pete.
 

WesKuhnley

Member
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2,241
The first two posters have this exactly right. "Raw" controls are usually implemented as variable bypass of the tone stack, there is simply no good way to remotely control this feature on your amplifier via a pedal. The affect this control has on the sound is simultaneously the removal of the TMB stack's mid scoop, and an increase in gain in the middle of the gain structure of the amplifier, there isn't a good way to implement this effect into a pedal, that wouldn't otherwise color your tone with another TMB tone-stack.

Several builders implement at TS bypass via footswitch, but this control is on/off only, not variable.

Perhaps one way to do it would be to use an amp with no stack, and build a pedal that implements the topology before the amplifier, without "double-stacking" so-to-speak. Food for thought.
 

jaydub69

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1,364
Still I would think that a cable (mechanical) that's connected to a rocker style pedal like a wah or volume pedal could be constructed to physically move the pot. Seems like lots of work though and I'm pretty happy with keeping mine where it is.
 

Wayne Alexander

Silver Supporting Member
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1,476
Not a pedal, but a footswitch. You can modify an amp to have a preamp boost/tone stack bypass and switch that in and out via a footswitch. There's a footswitch like that on Dumbles and Dumble-inspired amps like the Brown Note D-Lite. You could also install a footswitch to switch an Allen amp's raw control in and out.

But if you mean a separate stompbox pedal that sounds exactly like that, it can't be done.
 

calieng

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719
All the RAW does is add resistance to the ground lead from the MID control. It would be very easy to move this to a volume pedal or just a standard footswitch if you just want the effect full on or off.

Just disconnect the ground wire from your MID pot and connect it to a 1/4" shorting jack. Then connect an on/off footswitch or a volume pedal with a standard guitar cable.

I posted the mod on here a few years ago on a MAz Jr with good results. Now Dr. Z offers it for an extra $150.

Let me know if you need a detailed explanation.
 

WesKuhnley

Member
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2,241
All the RAW does is add resistance to the ground lead from the MID control. It would be very easy to move this to a volume pedal or just a standard footswitch if you just want the effect full on or off.

Just disconnect the ground wire from your MID pot and connect it to a 1/4" shorting jack. Then connect an on/off footswitch or a volume pedal with a standard guitar cable.

I posted the mod on here a few years ago on a MAz Jr with good results. Now Dr. Z offers it for an extra $150.

Let me know if you need a detailed explanation.
This is a really terrible idea. You're just asking for noise issues. It can be done easily and without noise with an opto.
 
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jbever

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I have a Brown Sugar and when I change the RAW setting it requires for me to also change the V and T controls. For me it's not just a one knob change.

For what it's worth.
 

RJLII

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10,368
Carr does something sort of similar in their Viceroy model. They call it a footswitchable fixed boost but its really a partial tone stack bypass. The volume and gain boost comes by virtue of the bypass. There are additional details on their site.

You get some variability of the control using the MID tone knob which I gather functions similar to the Allen RAW control. You can dial up nice thick midrange (too thick for me) to suit your taste. With the MID knob all the way off, or with the footswitch engaged the boost/bypass comes on full bore.

I found the switched function way too abrupt, kind of like a mallet to the forehead. That was with my Burstbucker equipped R8 though. I talked to the folks at Carr about the control and they said it's really best suited to single coil guitars to give a midrange and volume boost during solos. I'm guessing it would be much more usable with a Tele.
 

calieng

Member
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719
This is a really terrible idea. You're just asking for noise issues. It can be done easily and without noise with an opto.
For one thing no it did not add any noise when I tried it. But yes you would want to use a good quality cable just to be sure noise does not increase.

The point I was trying to make is that it is a simple mod. People think the RAW control is some magical circuit. It is not. You are just adding a resistance to the ground lead of the MID control with a pot or disconnecting it all together with a switch. One of the most simple mods other than clipping a Bright cap.

There are lots of amps that do switching the same way with no problems but you can also do it with a relay if you have those skills. You can look around some of the amp building sites like 18watt.com for some other circuit mod ideas. Another one I tried was to change the cathode resistor and cap values for V1 with a footswitch to give a slight boost and more gain. Also did this with a direct connection to a grounding footswitch with no noise issues.
 
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Rick Towne

Praise & Western
Gold Supporting Member
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3,359
Thanks for the comments and observations. It appears to my nontechnical eye that an on-off or raw-in/raw out switch can be set up, I suppose like the early raw controls that were I think either on or off.
 

hasserl

Member
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4,708
Anything is possible, it all depends on how important it is to you and how much you're willing to pay for it. You could rather easily add a Raw control that is activated by a foot switch via a relay. Set the Raw control to where you want it and then switch it On/Off via the foot switch. Not really a big deal at all.

You could also make this variable via a swell pedal if you wanted to, but the circuitry would be quite a bit more involved, and hence, more expensive. For most people the 1st method mentioned would likely be sufficient.
 

Billm

Member
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574
As mentioned above, an opto resistor would be a good, noise-free way to remote a raw control. It still winds up with some cost overhead because you want some regulation in the supply to prevent volume fluctuations and the control line/pedal has to be impervious to noise and hum--you wouldn't want 60Hz modulation of your raw/tone stack setting, or differences in operation or linearity because of the length of the wire.
 

topbrent

Member
Messages
441
You could add a relay to control the switching.

That way you wouldn't have 20 feet of external cable to induce pops, EF noise, capacitance and other problems.
The cable to the footswitch would only control the switching relay, not the amp circuitry.

Look at a Dumble for inspiration. The switchable raw is a simplified version of, and would funtion similar to the PAB function in a ODS.

If you went with the relay system, you could incorporate some of the cool other Dumble tricks also, ie, mid boost.

This would add some cool features to your amp and would give some versatility.

You would feed the relay off the 5v rectifier AC.
 
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jamesdlow

Member
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31
I was looking for information about this and came across this old thread. I realised that the VHT Special 6 Ultra has a Raw control (named boost) which is footswitchable. It uses a ground bypass which is sent out through the footswitch similar to the Fender Reverb footswitch, rather than relay bypass:

https://robrobinette.com/Special6UltraMod.htm
 

Alan Wolf

Silver Supporting Member
Messages
601
After I finished building my Encore, I wrote David about both changing the tremelo speed rangeand adding a foot switch for the raw. He sent me a pdf with diagrams, so it must be a popular request. I drilled an extra hole in the chassis to add an extra RCA out for the raw control, and then built a new foot switch with three lit buttons on it. It’s a great addition to an already stellar amp.
 

easyed

Senior Member
Messages
2,560
The "boost switch" on many of the Dr. Z amps does exactly what you're after. It lifts the tone stack but has a rheostat in the pedal to adjust the amount of lift.
 

otaypanky

Play it like you mean it ~
Platinum Supporting Member
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3,036
I assembled a Chihuahua years ago and David modded it a couple of times over the years. One of those mods was to wire in a footswitch. With the switch disengaged the amp was dialed in with a modest amount of mids. Engaging the switch activated the mid/raw control to where you set the knob. It was an awesome feature and was like having a gain channel or boost. That amp is a little beast : )
 






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