Behringer - Hellbabe Wah  [schematic]

A forum devoted to mod, tips and suggestions for upgrading and rehousing your VERY CHEAP commercial stompbox to near boutique excellence.

Behringer - Hellbabe Wah

Postby nsn3 » 25 Feb 2008, 00:25

Hi there

Is there anyway to improve this pedal (swapping components mainly, the enclosure is pretty solid).

Thanks in advance
nsn3
 
Posts: 7
Joined: 18 Dec 2007, 01:54
Has thanked: 0 time
Have thanks: 0 time

Re: Behringer Hellbabe Wah

Postby JiM » 14 Mar 2008, 23:20

Hi,
I've got one of these sub-40€ wah, initially bought with the idea of ripping its guts :twisted: and using only the box (cheaper than an empty wah shell at SmallBear, counting tax & shipping to Europe).
In fact, the wah sounds not so bad to my ears, so it might be worth upgrading ...

The Behringer HellBabe is intended to be a clone of the Dunlop CryBaby From Hell (Dimebag Darrell signature), with 6-position range selector, and 3 small pots for Q, hi-freq range, and gain of the switchable boost. It also has dual output, one of them is labelled "OUT/BYPASS" (more on that later). It's also meant to copy the Dunlop CryBaby Bass, being switchless, with a spring returning the pedal in heel-down position when not in use, then going automatically in bypass after an adjustable time. And finally, it also mimics the Morley ones by having the pot replaced by an opto-electronic circuit. Despite being mostly a plastic box, the steel bottom plate is really heavy and the underside of the rocker pedal is also a metal plate for sturdyness.

I think all these features are not only there to appeal the customer, they also help to keep production costs down. :wink: A couple of photoresistors and LEDs might be cheaper than a decent wah potentiometer and more reliable than a crappy one, saves a heavy-duty switch, and the spring action allows a less-than-perfect hinge fitting. (When removing the spring, i was not able to keep the pedal in a fixed position, even after tightening the axle.) And all the range adjustments makes it a one-size-fits-all product, for guitar or bass or whatever ... suits me well.

First of all, some simple mechanical mods are required for it to be useable. The travel of the pedal is quite short, and the swell is not very progressive in it.
  • Remove the two front (toe) rubber pad under the rocker pedal. Cut about 2mm of rubber with a knife on the non-amorting end. Put them back in place : now the travel is a bit longer. Don't do that to the rear (heel) ones, it might mess with the bypass detection.
  • Open the box by unscrewing the rubber pads and removing the bottom plate. Now look at the rear part : here are the "optical pot" and the optical bypass switch. Both are a red LED and a photoresistor, separated by a piece of crappy cardboard "soldered" to the moving pedal. I mean, "melted plastic". :cry: This is quite fragile, i wish i will not have to hack something sturdier. There are two roughly triangular holes in the cardboard, the big one is for bypass (as soon as you touch the pedal, some light comes through), and the tiny one is the actual wah pot ! You can adjust the wah sweep by bending a bit the LED or the photoresistor leads, and/or by CAREFULLY enlarging a bit the small notch with a sharp scalpel, bearing in mind that it's a matter of quantity of light on the photoresistor. We are talking about a few 0.1mm of cardboard to scrape, not more. After making a mistake (you will) you can use a tiny bit of electrical tape to mask some of the excessive hole. You can then try several shapes, not only triangular : a trumpet-like shape works quite well for me. Now we can use the extra travel obtained by the first mod !
OK, enough for the mechanics, what about electrons ?
  • The power jack is really in a wrong place, i suggest to wire another one in parallel, in a more conveniently located hole, for example on the front side.
  • The "OUT/BYPASS" jack : according to Dimebag (RIP), there is a second INPUT on the left of the CryBaby From Hell to avoid messing with cable under the pedal. On the HellBabe, both leftside jacks are OUTPUTs, and carry exactly the same signal. WTF ? :scratch: Looking at the output PCB, there are pads for a switch or a jumper, allowing to choose the behaviour of the second output. Warning, the silkscreen seems to be wrong, both position are swapped. When in "OUTPUT" mode, the hard-wired default, both outputs are identical ; it might help with tuner hookup or dual/stereo FX chain ... When in "BYPASS" mode, which requires to cut a track on the PCB and wire the jumper, both INPUT and OUT/BYPASS jacks are equivalent : you can use either one as input, and the other as non-true-bypass (possibly tone-sucking, but without wah) output.
I can post blurry guts pictures if you want, and i have RE some bits of the schematic ... not easy with double-sided surface-mount PCB, but i will eventually finish it on a rainy day.

Some suggesions of mods (almost complete schematic required before messing with that) :
  • add a fuzz switch on the boost circuit (may be as simple as a two-diode clipper to ground)
  • adjust frequency response(s) to taste
  • replace low quality components with better ones (will be difficult for SMD parts !)
  • make Boost activation independant of Wah activation
  • scrap all the guts and build a Colorsound FuzzPhase in the box. http://filters.muziq.be/model/colorsound/fuzzphaze
User avatar
JiM
Diode Debunker
 
Posts: 910
Joined: 11 Mar 2008, 23:56
Location: France
Has thanked: 31 times
Have thanks: 37 times

Re: Behringer Hellbabe Wah

Postby nsn3 » 15 Mar 2008, 16:39

I'm willing to choose the last option.

The main problem is the mechanical part, more specificity how to make something to turn the pot.

But yeah, i would like to see some gut shots of your own Hellbabe.

btw, is there anyway to make it true-bypass? I find a bit (a big bit) tone sucking.
nsn3
 
Posts: 7
Joined: 18 Dec 2007, 01:54
Has thanked: 0 time
Have thanks: 0 time

Re: Behringer Hellbabe Wah

Postby JiM » 16 Mar 2008, 02:09

Hi,
Here is a picture of the inside, with one of the PCB lifted to show the "OUT/BYPASS" jumper location. This PCB carries only passive components : jacks and pots. On the other one you can see the inductor and the trimpot setting the bypass delay, between the range selector and the input jack. Excepted the caps everything else is SMD. All the opto components are on the last PCB, the red status LED is in series with the position sensor LED.

My intention was to keep (and maybe improve, once fully RE) the bypass & sensing system.
To modify it for classical mechanics (true-bypass switch and gear-actionned pot), you would rip the rubber battery bed, drill a hole for the bypass switch (easy in plastic) and to fine-tune its height for precise action. The wiring would be the same as your favorite true-bypass, and you would need to change or detach the input jack. Not very difficult so far.
Then you would open another hole for the gear, find a way to attach it to the pedal (it's a metal plate there, you may use rivets or screws to attach the hinge) and find a way to attach the pot and its gear in the right position. One idea is to make a "box in the box" from folded sheet metal, something like this : http://www.diyguitarist.com/DIYStompboxes/ST1590BB.htm
Or just copy the mounting bracket from a classic wah, anf glue it with heavy-duty resin.

For a dual-function pedal, you may use two bypass switches, one in each front corner. i guess the torsion of the pedal would allow to activate one switch at a time, but you'd better check that before dilling anything ...
You do not have the required permissions to view the files attached to this post.
User avatar
JiM
Diode Debunker
 
Posts: 910
Joined: 11 Mar 2008, 23:56
Location: France
Has thanked: 31 times
Have thanks: 37 times

Re: Behringer Hellbabe Wah

Postby nsn3 » 16 Mar 2008, 16:01

I've already been messing with the photoresistors.

The bypass led was somehow twisted, so I pulled it a bit. Now it starts right after moving the pedal.

Today I'll try different positions for the pedal "led" and cut the excess of rubber feet.

I guess I won't make it true-bypass. If I'm going to rip it apart then I'll install some decent wah, something like RMC Wizard.
nsn3
 
Posts: 7
Joined: 18 Dec 2007, 01:54
Has thanked: 0 time
Have thanks: 0 time

Re: Behringer Hellbabe Wah  [schematic]

Postby JiM » 14 Apr 2008, 22:27

I finally found the time to draw the schematic of this thing. Here it is !

Yes, it's quite messy, and there may still be some mistakes, SMD is so small ...
Ideas for improving this pedal, anyone ?

The wah filter looks like a crybaby, but some values differ, and obviously there are more controls. The value of the inductance is unknown (resistance is 6.3 Ohm).
In the bypass section, the JFET switches have about 100 Ohm Ron, it's J112 on the silkscreen but lower quality J113 are populated. The hex inverter is used for LDR sensing, delaying, and as LED driver :shock:

And there is a lonely op-amp (IC2c) waiting to become a Dist+ or a LFO ... :mrgreen:
You do not have the required permissions to view the files attached to this post.
User avatar
JiM
Diode Debunker
 
Posts: 910
Joined: 11 Mar 2008, 23:56
Location: France
Has thanked: 31 times
Have thanks: 37 times

Re: Behringer Hellbabe Wah

Postby KiLoX » 30 Apr 2008, 08:32

READ IF YOU FEEL YOU HAVE A PROBLEM WITH THE SWEEP RANGE OF YOUR HELLBABE.

first sorry for my english

mine has a very little sweep range, so little it just seem the pedal goes on and off, i couldn't play with this. i was quite upset, it was unusable, unless you get veeeeery precise with your feet, which gets boring quickly.

first i removed the two rubber feel at the front of the rocker, so that the pedal bends higher. the sweep goes higher now and the pedal range is improved. i'll add some tape to avoid the noise of the colliding plastic but this is a great improvement to the pedal, and anyone can do it with no warranty problem.

then i opened my hellbabe to check what was inside it. i've found there was a big design problem. the optical sensor just wasn't getting any signal until (more than) halfway through the complete range of the pedal.

there's some small plastic piece inside which hides the red light from the led so that it doesn't reach the optical sensor controlling the sweep frequency. when you press the pedal, a hole in the plastic, shaped as a triangle, allows the red light to progressively reach the sensor.

this triangle isn't just long enough. as i thought my unit was unusable i thought damn let's try it i got nothing to loose.

WARNING !! DOING THE FOLLOWING WILL END YOUR WARRANTY !!

so i cutted the triangle to make it longer. my cut wasn't very clean so i added some opaque scotch tape to adjust my shot. after a few try (take your time and do things progressively) and a special adjustement for my taste (i gave it an exponential curve with some tape), i was thrilled to play my "new" hellbabe.

now the sweep goes on as soon as you put your feet on the pedal. i can make slowly progressive sweeps which were absolutely impossible without this modification.

i'm really happy with this pedal now, it's very versatile and from what i remember from a cry baby i used to own, i now prefer my hellbabe

enjoy


http://reviews.harmony-central.com/revi ... /HB01/10/2


Will this works? :?
KiLoX
 
Posts: 2
Joined: 30 Apr 2008, 08:10
Has thanked: 0 time
Have thanks: 0 time

Re: Behringer Hellbabe Wah

Postby JiM » 30 Apr 2008, 23:27

I did exactly that, see my first (lenghty) post in this topic.
And maybe i got the idea from this guy, i don't remember exactly.
I also needed to tape an over-optimistic cut in the fragile cardboard (not exactly plastic) sliding between LED and LDR, but it works fine now. :blackeye

I highly recommend this mod, but i highly recommend to be VERY careful too ! It's about less than half a milimeter to cut/shave ...
User avatar
JiM
Diode Debunker
 
Posts: 910
Joined: 11 Mar 2008, 23:56
Location: France
Has thanked: 31 times
Have thanks: 37 times

Re: Behringer Hellbabe Wah

Postby KiLoX » 02 May 2008, 00:19

Shit i made a 2mm cut :slap:
KiLoX
 
Posts: 2
Joined: 30 Apr 2008, 08:10
Has thanked: 0 time
Have thanks: 0 time

Re: Behringer Hellbabe Wah

Postby gusg » 09 Jun 2008, 05:21

Hi everyone,

I have a problem that has been driving me mad. I bought my Hell Babe second hand and when I got it and plugged it in it gave me a wicked wah sound combined with my Marshall high gain distortion. I was rocking away until I took my foot off the pedal to bypass the wah all off sudden nothing! Or so I thought. I could hear a very faint very muddy sounding guitar until I put my foot on the pedal again and 'hey presto' the usual sound I get from my amp and the awesome wah were back. Foot off the pedal again and it all disappears to quite muddy playing that you can hardly hear.

Why is this happening? Am i doing something wrong?

Cheers
Gus
gusg
 
Posts: 1
Joined: 09 Jun 2008, 05:16
Has thanked: 0 time
Have thanks: 0 time

Re: Behringer Hellbabe Wah

Postby JiM » 11 Jun 2008, 18:12

The bypass circuit on this wah is tone sucking, but not that much !

As your pb occurs in bypass only, the possible failure points are rather limited. Looking at the schematic i've posted above, the obvious suspect would be T2 or the passive devices directly connected to it (C15 and R35 on the signal path ; D2, C16, R22, up to IC2F on the control path). All other devices (esp. IC1A and B) are involved in the wah sound, which is OK. At least IC2 B and D are fine, as you can switch T1 on and off.

Does the Status (red) led act as expected ?
Do you use the Boost function ?

One quick test could be to jumper T2 drain and source while in bypass, to check if your tone comes back. This can be done directly on T2, or on R35 pins 3 and 4 (i don't remember which is the easier to access). The tricky part is, when the case is open, light hits LDR1 and the effect is active ... :slap:
User avatar
JiM
Diode Debunker
 
Posts: 910
Joined: 11 Mar 2008, 23:56
Location: France
Has thanked: 31 times
Have thanks: 37 times

Re: Behringer Hellbabe Wah

Postby Nikifena » 14 Jun 2008, 21:47

2 pictures from me:
http://www.picvalley.net/u/749/2021798720.JPG
http://www.picvalley.net/u/807/1641549078.JPG

I measure behringer's inductor - 900uH @1khz.
Nikifena
Solder Soldier
 
Posts: 186
Joined: 04 Oct 2007, 07:12
Location: Bulgaria
Has thanked: 4 times
Have thanks: 35 times

Re: Behringer - Hellbabe Wah

Postby demoboi » 07 Dec 2008, 05:18

what is the value for the bypass trimer? Is it 1M?
demoboi
 
Posts: 6
Joined: 07 Dec 2008, 05:00
Has thanked: 0 time
Have thanks: 0 time

Re: Behringer - Hellbabe Wah

Postby Hanglow » 09 Dec 2008, 13:29

You could also just put in a colorsound inductorless wah (also used in zvex wah probe). Low part count and sounds great to my ears at least.
Hanglow
 
Posts: 38
Joined: 30 Dec 2007, 21:25
Has thanked: 0 time
Have thanks: 1 time

Re: Behringer - Hellbabe Wah

Postby chicago_mike » 30 Dec 2008, 19:37

Would vactrols work?
Skyline FX 2013
User avatar
chicago_mike
Tube Twister
 
Posts: 1760
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Have thanks: 302 times

Re: Behringer Hellbabe Wah

Postby russellcframe » 31 Jan 2009, 21:21

gusg wrote:Hi everyone,
I took my foot off the pedal to bypass the wah all off sudden nothing! Or so I thought. I could hear a very faint very muddy sounding guitar until I put my foot on the pedal again and 'hey presto' the usual sound I get from my amp and the awesome wah were back.


I have a very similar problem which I'm hoping to get fixed. I just bought my Hellbabe and was enjoying it for the first 15 minutes or so, then I too had it cut out when it went into bypass. I can also here some crackling noise when it is in bypass.

The problem isn't constant, sometimes bypass works fine. But if I play for 10 minutes its sure to happen.

I took it apart and verified that the led lights were working as expected and not engaging unexpectedly. All looks well. Also, the "active" light is off when the problem is occurring, so I think it is definitely just something within the bypass circuit.

Given that it is intermittent and crackling I suspect something is loose/cracked.

I will try what was suggested above with troubleshooting the bypass circuit if I can figure it out, I'm pretty ignorant about electrical components.

-Russ
russellcframe
 
Posts: 1
Joined: 31 Jan 2009, 21:06
Has thanked: 0 time
Have thanks: 0 time

Re: Behringer - Hellbabe Wah

Postby Ripdivot » 31 Jan 2009, 23:13

Mine also wouldn't work in bypass either. I repaired it a couple years ago or so. The problem was one of the fets (T1,T2) used for switching. I can't remember which one but I replaced it and it fixed the problem and it's been good ever since.
Ripdivot
Resistor Ronker
 
Posts: 318
Joined: 19 Jan 2008, 20:15
Location: Canada
Has thanked: 9 times
Have thanks: 73 times

Re: Behringer - Hellbabe Wah

Postby varimac » 31 Mar 2009, 06:10

nsn3 wrote:Hi there

Is there anyway to improve this pedal (swapping components mainly, the enclosure is pretty solid).

Thanks in advance




I acquired a Hellbabe very cheaply and came to the same conclusion as most others, ie:- too little travel.
After trying the 'rubber stop slicing' and the 'triangle extension', I found a tiny improvement but not enough to call the mod a success IMHO
After a few minutes watching how the pedal operated (with the baseplate removed) it became obvious that the pedal simply could not move any more - it needed to move beyond the limit of travel both forward and backward.
So using my trusty Dremel I sliced off angled strips from the front, back and sides. Take a look at the pics and you'll see what I mean. The Pic with 'Audio Fanzine' in the background is one I Googled of a standard Hellbabe. The othe pic is my modded HellBabe. You can see the much greater angle in the fully back position (this makes the biggest difference) - the angle in the toe-down position is also greater (but not quite so much).
Inside I lengthened the bigger aperture by about 3 - 4mm (so the pedal activates earlier) and lengthened the small triangle slot by a massive 4 - 6mm so the sweep feels about double the previous length.
Put it back together and Wow! Or should I say 'Wah!' Chalk and cheese! No comparison! Much, much more usable. Feels like a good, mid-quality wah now.

I only registered here to share this, so I hope it's of some interest/help to someone :)
You do not have the required permissions to view the files attached to this post.
varimac
 
Posts: 2
Joined: 31 Mar 2009, 04:49
Has thanked: 0 time
Have thanks: 0 time

Re: Behringer - Hellbabe Wah

Postby nooneknows » 01 Apr 2009, 13:02

thank you varimac, very interesting!
nooneknows
Resistor Ronker
 
Posts: 290
Joined: 26 Mar 2008, 22:53
Has thanked: 23 times
Have thanks: 6 times

Re: Behringer - Hellbabe Wah

Postby ckunce » 09 Apr 2009, 19:22

Could someone post pics of the triangle opening after modding?
ckunce
 
Posts: 1
Joined: 09 Apr 2009, 19:17
Has thanked: 0 time
Have thanks: 0 time

Next

Return to Pimp-My-Cheap-Pedal

Who is online

Users browsing this forum: No registered users and 2 guests