Hi, I have just bought a DR-Q re-issue and when i turn it on I get a huge volume drop, but when i slide to BASS switch on it the level it seems about normal…is this normal….or is it that i just dunno what i’m doing?

Thanks Drew.

drewid - 03 March 2010 05:53 AM

Hi, I have just bought a DR-Q re-issue and when i turn it on I get a huge volume drop, but when i slide to BASS switch on it the level it seems about normal…is this normal….or is it that i just dunno what i’m doing?

Thanks Drew.

I just got a new Nano Doctor Q in the mail today and am experiencing the same problem.  With the toggle switch up (bass mode) it’s not quite unity gain.  With toggle down, huge volume drop - can’t be normal…

I removed the battery and hooked it up to my Pedal Power 2+ (9v, tip negative) same problem. 

I’m plugging guitar, into Doctor Q, into amp - so nothing else in the chain.

Hey guys, I bought my doctor Q a few years ago, and just today I figured out how to fix this. Glad this thread was already up.

Here is how I fixed it, this requires NO soldering or re-building of the circuit board:

!. Unplug your pedal. Open the pedal by removing the four screw in the four corners of the top of the pedal. The black back then slides right off.

2. Turn the unit over and look at the circuit board from the back. Right above the foot-switch (Blue box) there is a hole in the green circuit board, towards the bottom. Look through that hole and you will see a small slot, which is how you adjust this trim pot. I had a small jewelers screw driver that worked, something like a martini-sword might also fit.

About the trim pot: This pot appears to control Envelope feedback. When turned to the left (counter-clockwise), it increases the volume cut, and adds a lot more wah feedback. It sounds insane. Turning it to the right (clockwise) reduces the volume cut!
If you turn the trim pot really far right, you lose the envelope effect, so I recommend turning it a bit at a time and then plug it back in and see how the volume cut is.

I performed this today, and I have never been happier! It doesn’t cut the volume of my amp anymore, and now I can put distortion in front of it and get really awesome sound! WIDDLY WAAAAAH

Cool!

I’ll give it a whirl.

thanks.

V
Just to make sure, the Doctor-Q Re-Issue = Nano Doctor Q… right?

Attached is gut shot of the Doctor Q (nano)

Is that the trim pot in the upper right hand corner?  (slot is kind of arrow shaped)

Click on image to enlrage.

That is indeed the trim pot, thats how they look (the arrow shaped adjustment screw) in the pedals I have taken apart so far.
My Q, which I took apart, is the normal sized wedge box, but internally it looks like the same trim pot. If you take the whole chip out, and look at the other side, it should be labeled “TRIM 100K”. The unit that houses the white adjustment screw looks like a small bead. Mine is white, but the nano soul preacher has a black one.

Let me know your results with this, I am curious.

After about half an hour of adjusting the trim pot i got the sound i was looking for without volume drop - YOU GUYS ARE THE BEST

Thank You

Drew.

This is the first we are hearing about a volume problem on the Dr. Q. We have to look into it.

Thanks Flick:

A couple other similar experiences on TheGearPage:

http://www.thegearpage.net/board/showthread.php?t=684564

PS off topic: you guys are conspicuously absent from this cool site:
http://pedalboardplanner.com/

Flick - When I first got this pedal, I didn’t notice the cut because I thought it was just the filter. I first became wary when I used the Q after a distortion pedal. I liked the sound I was getting, but when I turned the Q off, I was surprised at how much volume was being cut - I had to keep the volume on the distortion cranked to get enough signal through the Q.

That was before I tweaked the trim pot, now it sounds quite nice. I was wondering if you can address the use of these internal trim pots - by which I mean, what was EHX’s logic in making them internal controls? I can only imagine that they are placed internally because:
        A ) They control a minute piece of the effect that would be too sensitive to mess around with as an external control
        B ) It is cheaper to install the small ‘bead’ potentiometer than it is to build a pedal with another proper potentiometer, requiring another hole in the pedal and another knob.

I imagine it is more a combination of these two causes. I am curious as to how much the price would increase for the consumer if these additional knobs were external. Do any of the knobs on the QTron and other more advanced envelope filters mimic the behavior of the Dr. Q internal trim?

Vorvick - I may join the gear page, but please go ahead and link them to this or copy/paste my fix instructions.

Nano Q users - What does your trim pot say next to it? MY nano soul preacher says “TRIM 10K”, but the trim pot on my big Q says “TRIM 100K”. I don’t know what kind of “normal” potentiometer I would need in order to replace these

Hey Eric:

I hope to try the fix tonight - will definately link your solution at the gear page. 

PV

Flick, I have had two Dr-Q’s in as many weeks, both suffered from them same issue, i had returned the first thinking it was faulty, only to receive the second with the same problem at which point I posted this thread, thanks to the advice i got here mt second faulty pedal is now working….......PS I love EHX pedals hence why i keep buying more so I hope this feedback helps!

Cheers,

Drew.

Hey Eric:

The fix worked for me - Thanks!

It may not be voiced the way EHX had in mind, but it’s much more useable from a volume standpoint.

I posted your fix on the gear page:

http://www.thegearpage.net/board/showthread.php?p=7891314#post7891314

Cheers,

V

Click on the photo so it’s full size

The circuit board has a hole in it - look in the upper right corner.  (It’s in about 45 degrees from the screw hole)

Inside the hole you can see the white screw or pot or whatever it’s called, and you can partially see the arrow shaped slot for the screw driver.

If you have a nano dr q, it might be easier to just open it up.

V

I am attaching an image, there is a violet circle around the access to the trim pot.

Which clockwise are you referring to? When you hold the Doctor Q rightside up or upside down?