I built this for myself, but thought some of you might find it interesting. The only other wah schem I have handy is for the Clyde McCoy, and I'm thinking about adding it on. Come to think of it, I might have a Shinei wah somewhere; I'll check it out. If anybody has any unusual wah schems, pm them to me and I'll add them on.
Thanks to RG for allowing me to use his schem. I like it very much because the names he gave the components are illustrative of their purpose.
(http://aronnelson.com/gallery/albums/TCobrettis-Stuff/Wah_Comparisons.gif)
I added the Shinei.
Anybody know anything about the Roger Mayer wah?
Great list.
That's a good idea. I don't know if would put the Boomerang on that list as it's considerably different than the schematic shown...
Paul, I tried to describe the differences at the bottom. Did I miss anything?
QuotePaul, I tried to describe the differences at the bottom. Did I miss anything?
Well, if you compare schematics, how the inductor is incorporated into the circuit on the Boomerang is much different. It's so different that I do not think you can really put it on the list above because it really needs its own schematic with a description of what each part does.
Paul, looking at this schem I can't see the difference. Can you explain it so I can understand what I am missing? Thanks for the help.
(http://www.montagar.com/~patj/mboomer.gif)
There I go trying to work and surf again. :icon_rolleyes: Sorry about that. One version of the schematic that I drew got me confused. :icon_redface:
It gets confusing when you look at the Vox patent document the way it is drawn and the way the Boomerang schematic is drawn. The main differences that I see in the Boomerang are:
1. 820K (not 620K) feedback resistor on Q2
2. 1uF caps at hot and wiper of 100K pot
3. 1.5M resistor from collector of Q1 to inductor
I think these are then main factors in what makes the Boomerang sound different.
Here is the BG-2 schematic, similar to the BG-1:
(http://www.diyguitarist.com/Images/OrigBG-2schem.jpg)
This is a schematic and PCB that I drew based on my own original Boomerang: http://www.diyguitarist.com/PDF_Files/BoomerangBG2PCB.pdf
This seems like as good of a thread as any to discuss some of my work with the Boomerang, so here goes:
I've always wanted to build a wah and the one I've wanted to tackle is the Maestro Boomerang. Since Paul Marossy had recently shared a confirmed schematic and I had the wah shell from the Phozer 2 development, I decided to finally do so.
I started by using the Radio Shack transformer that RG mentions in his wah tech article. I needed to tweak the component values a bit for a good sound, but I held off sharing my work until I had a proper inductor. Then I finally got a yellow Fasel and over two days I modified the circuit to my liking.
In its stock form, there was some distortion present in the bass section of the sweep as well as an abundance of midrange. I reduced the mids, gain, and bass to my liking, then added an adjustable Q control.
The result is a smoother, fuller sounding wah than my modded Vox V847.
I used a Dunlop Hot Potz II in parallel with a 33k resistor as Paul did to create the 25k pot of the Maestro.
(http://runoffgroove.com/noomerang.png)
Here are two clips of the circuit. There's a little bit of my strumming picked up by the mike, but it doesn't detract too much.
Setup: Tele bridge pup - wah - Ampeg Rocket II (reverb on) close-miked - mixer - sound card.
http://runoffgroove.com/dry-vox-noo.mp3 has the same passage played dry, then through my modded Vox wah, then the Noomerang.
http://runoffgroove.com/noo.mp3 features the Noomerang only.
Cool Mr. Tremblay. The Boomerang is definitely one worth messin' with. The funny thing is that my original has no distortion, but my clones have a little bit. The transistors that you use seem to make a big difference in this circuit. :icon_cool:
It's very interesting to see the "ROG" version of the Boomerang; thanks for posting it.
I'll have to take my extra Boomerang PCB and try these ROG mods! :icon_cool:
within the next month, im going to build one.
i still have the giant shell...so...yeah... :D
very interesting thread!
just wanted to follow the updates.
great job fellas! ;)
Quick question for the ROG team: that 1.5M resistor to ground on the input, why did you add that? I'm just curious...
cool stuff! :icon_biggrin: :icon_cool:
Quote from: Paul Marossy on December 15, 2006, 10:44:06 AM
Quick question for the ROG team: that 1.5M resistor to ground on the input, why did you add that? I'm just curious...
As a better-safe-than-sorry switch pop pulldown.
QuoteAs a better-safe-than-sorry switch pop pulldown
That's what I thought. I haven't had any problems with popping, but it doesn't hurt to add one in...
So, first is that Vox the Clyde McCoy? If so, then the Crybaby is nearly identical?
QuoteSo, first is that Vox the Clyde McCoy? If so, then the Crybaby is nearly identical?
Yes, and yes. :icon_cool:
Interesting. Then I probably WON'T like the McCoy either. I don't like the Crybaby, I thought the Vox would be closer to the whole Voodoo Child sound. Guess not.
QuoteInteresting. Then I probably WON'T like the McCoy either. I don't like the Crybaby, I thought the Vox would be closer to the whole Voodoo Child sound. Guess not.
You have to remember that there are a LOT of factors involved in that sound - not just the wah pedal. Jimi had his stuff tweaked by Roger Mayer, and his amps were modded, and he played an upsidedown Strat a lot of the time, the stars and planets were aligned just right (joke!), among other things... :icon_wink:
I have an upside-down strat (I'm lefty also), and indeed just the strat itself helps with that sound, it just sounded more smooth and natural to me than the Crybaby I fixed and played around with. I don't really want to sound like Jimi, I just want a wah sound like that. I just always thought it was the McCoy circuit that did it.
That Vox was actually the V847, I updated the schem to include the McCoy. I apologize for the confusion.
BTW, my V847 sounds much better than my Crybaby. The differences may be small, but they are significant. I haven't built the Clyde, so I can't comment on it's Hendrixiness. Part of my current theory on the Hendrix wah tone is that since Hendrix ran his wah into his Octavia, which acted like an output buffer, that having a output bufffer on your wah is part of that tone.
Quote from: PenPen on December 15, 2006, 04:06:41 PM
Interesting. Then I probably WON'T like the McCoy either. I don't like the Crybaby, I thought the Vox would be closer to the whole Voodoo Child sound. Guess not.
btw, talking about Hendrix Wah sound...
The BBC Sessions "Burning of the midnight lamp" sound is what i would like to get from my wah.
my definition of Wah sound!
just awesome!
Yeah, that is a classic. I had the old BBC single disc, and just a couple of days ago I got the new 2 disc set but I haven't heard it yet. I hadn't thought about it, but since I posted this schematic I've been doing some serious work on my wah, and this song is a good reference point for me to use for the ideal sound. Another amazing Hendrix wah moment is the talking wah from Still Raining, Still Dreaming off of Electric Ladyland. Genius.
On the table, I see the Crybaby has Cout and Cef at .001u while all the others are .2u or more. I'm not sayng that's wrong, but....... it looks a bit suspicious.
I must say, it's great to see a table like that.. reminds me of literary analysis where one is trying to recreate the "original" Canterbury Tales from the various copies. Guess we'll have a family tree next. :icon_wink:
Paul, you may be right. I based the table on this schem:
(http://www.geocities.com/CollegePark/Library/1355/crybaby.gif)
But after your post I started digging and I found this:
(http://www.geocities.com/CollegePark/Library/1355/crybaby95.gif)
So, I looked at my Crybaby from the late 80s/early 90s (pre-input buffer) and it has .22u caps in it. So, I think I'm gonna change it on the table.
Nice catch!
Every CryBaby/Vox wah pedal that I have seen has 0.22uF caps in it. With 0.001uF caps in those positions, it would sound horrible - probably like a mosquito! :icon_lol:
if you can look past all the bypass circuity and buffers, the Steve Vai Bad Horsie and Mark Tremonti wahs from Morley also use the same classic circuit:
http://morleypedals.com/downloads.html
there are also schematics for an Electroharmonix one and a Dallas Arbiter one, as well as some others with the same type of circuit on http://www.schematicheaven.com/effects.htm
Thanks, Seljer. When I get home from visiting my family for Christmas I'll add those to the chart.
looking at this, i wonder about my bad horsie. i searched for a schem and only found the bad horsie 2. here it is:
http://www.morleypedals.com/vai-2es.pdf (http://www.morleypedals.com/vai-2es.pdf)
now my question is this. i have been wanting to mod the sweep and range of this for a while. so can someone tell me:
1) do you guys know what differences there are component-wise between 1 and 2? is the schematic essentially the same with a few tweaked values?
2) which part of the above schematic would contain the parts i would tweak to increase the wah range and smooth the sweep from toe-down to toe-up? when toe-down (but on), the travel from there to about halfway doesn't do much, then a small space in the middle does a LOT, then the top towards toe down changes in the same fashion as the bottom.
basically it seems like the bulk of the effect is bunched in the middle. any thoughts?
anyone know the huge difference between this schem and the "average" wah schem (besides opto-electric switching)?
heres the first bad horsie - http://morleypedals.com/vai-1es.pdf
C9 would be the capacitor that controls the sweep range
I believe changing the value of R13 to something slightly larger (2k to 3k) would smooth out the transistion from bass->treble. Though to really adjust the sweep you'd have to do something with that moving semi opaque cover they have between the LEDs and LDRs
(the part names are the same on both schematics)
and as far as I can tell, the wah section is identical on both the bad horsie 1 and 2. The 2 only has some power filtering/protection added as well as the contour modecoming after the wah (which is just a fixed position opamp based twin-t type wah after the regular wah circuit)
http://www.geocities.com/j4_student/NewWayWah.gif
some dunlop variants
:icon_cool:
Wow, I have never heard of the Clav Wah. I guess it's designed for Clavinet, which might explain the very high value for the feedback cap.
Thanks Paul!
I added a couple more wahs.
this is an old thread but i like it!
Paul, thanks for publicizing how cool this circuit is. i have a broken boomerang circa 72 at my house. with the elrad inductor but the 25k pot was long gone, replaced by a common 100k. looks like a good bet to get it started and done right. i will post results.
BTW, I despise the dearmond casing, the gear always feels like it has a glitchy 'drag' on it due to the spring at the back of the straight gear. i have owned several of the dearmond vol peds as well, never like them!
Tremblay (heyB!) , i like the clips you posted. the low end emphasis in the sweep is cool , the overall tone of the wah is sweet.
Re: the Philpott '97 crybaby shem. - i think there are two versions of that schem floating around , i could swear i had the same schem printed out 6 yrs ago that had .01 caps where the .001s are in the schem in question.
Re: the morley sweep on the opto circ - has anyone anylized the sweep of those wahs to see how they compare to the crybaby sweep?
On a related note:
I had total success with a new invention using dual LED/LDRs in a small plastic case. the throw was the same length as the straight gear on the crybaby. ( two separate chambers with two 'shutters' moving on a common shaft)
By using two LDRs, the two legs can be tied together to simulate a pot. One closes while the other opens
By altering the shape of the 'shutter', various ramps or tapers can be obtained. all of this tested out beautifully, was able to simulate all kinds of tapers by changing the shape of the shutter triangles ( see diagram).
It worked perfectly in my wah and also in a volume pedal.
if anyone knows of this being done before please let me know
I didn't feel it was worth patenting (if it hasn't been patented already) since the application is fairly limited. As a retrofit for existing wahs or volume pedals it would require a power hookup and add battery drain. I guess a wider application would be audio circuits where custom tapers would be cost prohibitive. very easy to change taper by altering the shutter shape.
The upshot would be that users could easily try different tapers by swapping out different shutter inserts.+ no pot to wear out
(http://img.photobucket.com/albums/v311/joegagan/wah/optopot.jpg)
Quote from: joegagan on February 14, 2007, 12:36:37 PM
BTW, I despise the dearmond casing, the gear always feels like it has a glitchy 'drag' on it due to the spring at the back of the straight gear. i have owned several of the dearmond vol peds as well, never like them!
I'm not a fan of the DeArmond shell either. While the long rack is nice, the lack of adjustable tension makes for an odd feel. Also, the pot mounting is reversed from the Vox/Crybaby shell, so the taper is reversed as well. You could wire the pot for heel-down being the treble position to have the correct taper, but that's pretty counter-intuitive to play. The only decent option is to use a linear pot.
Quote
Tremblay (heyB!) , i like the clips you posted. the low end emphasis in the sweep is cool , the overall tone of the wah is sweet.
Thanks, I'm glad they sound good to you. The overall tone is close to my modded Vox, but with a fuller sound.
QuotePaul, thanks for publicizing how cool this circuit is.
Well, I like it! :icon_wink:
When you guys mention the "DeArmond shell", are you referring to the shell that the Boomerang is in? I much prefer the good old CryBaby type shell. I built one of my Boomerang circuits in one. It's on my pedal board right now as a matter of fact. You can hear it in action on the tunes called "Wholed Me" and "I Let Go" at http://www.myspace.com/j201jams :icon_cool:
Quote from: Paul Marossy on December 14, 2006, 12:34:34 PM
...
1. 820K (not 620K) feedback resistor on Q2
2. 1uF caps at hot and wiper of 100K pot
3. 1.5M resistor from collector of Q1 to inductor
I think these are then main factors in what makes the Boomerang sound different.
...
How much difference do you guys think the 1.5M resistor above the inductor, and the 25k (or simulated 25k..) pot make to the Boomerang vs. Vox/Crybaby?
What about the 820k resistor on Q2?
I'm building a Crybaby, but I think I'll sub some Boomerang values, at minimum the 1uF caps.
What difference does the 25k pot in Boomerangs actually make, vs 100k?
I know it's "more correct" for a Boomer, but what does it DO differently?
Does it mostly change the sweep? - Does it affect the overall tone? - Does it also affect the range?
Does it sweep through less total range, or sweep through the same range faster?
What about the 1.5Meg resistor from Q1 collector to the inductor, etc. It would affect the biasing, and also the Q, Does it also affect the frequency, or tone?
Boomerangs have, nominally, the same inductor, & the same sweep cap as a Crybaby, but a lot more low end gets through.
The MAJOR differences I see are the 25k pot, & the 1.5Meg resistor.. Can anybody offer more insight on the effect of the 1.5Meg resistor?
It LOOKS to me like it would cause less bass to be attenuated by the inductor, but I don't know if it really works like that?
the boomerang is designed around the 25k pot except the stock centralab pots often were 29k average. with a 100k , the biasing is not correct, circuit sounds weak.
2. to make matters worse, the pot is on opposite side of wah , thus needing rev log instead of log, when people put a 100k wah pot, they get it wrong twice. the emphasis is completely off when a log taper is used.
the old trick of putting a 33k across the outer two lugs of a 100k wah pot does not work well, sounds awful compared to the correct pot. not to mention taper is wrong , see # 2.
the 1.5 meg is not critical, in fact, the dearmond 1800, which is an improved clone of the boomerang has a 270k there ( and 100k Rs to Gd at base of each trans.)
the BIG difference is the lack of the 470k mix resistors. the 1.5 meg takes the place of one of them, but there is nothing tying the bias of Q2 to the bias of Q1 the way a crybaby works. this allows better tuning of the first stage in my experience and is part of why the boomers were consistently able (unit to unit) to get such a wide sweep in stock form despite parts tolerances of the parts of the time.
if you have time, my article on boomerangs is here, it has mostly general info but you may enjoy it : ( pinned aritcle at top of my Fb page )
https://www.facebook.com/WahWahByJoeGagan
Thanks Joe. I enjoyed your article.
I was mostly thinking in terms of modding the crybaby circuit to be more boomerang-ish.
I can certainly see how trying to use a log pot would be unsatisfactory when mounted on the other side of the shell, that's all backwards..
- The pot shouldn't affect the bias, it has those DC blocking caps..
The crybaby circuit could use an update with a few more resistors. As it stands, it IS a little tricky to get bias & gain just right, everything is interdependent.
- I just built a wah on a Tonepad crybaby board. I used 2n5088s, didn't measure the hfe, but they are probably pretty high gain.. It turned out super quiet though, very low noise. I measured the voltages & played around with the bias & gain.
I ended up with something Noomerang-ish. - No 820k to the base of Q2 though. - I chose 680k in series with the inductor. (Where the 1.5M goes, or 470k in crybaby..)
- 1uF caps around the wah pot. .047uF input cap, 320R "gain" resistor, (Q1 emitter resistor) kept the .01 sweep cap, & 33k "Q" resistor.
I ended up liking 3.3k for the feedback, or "midrange" resistor. & I liked 47k in parallel with the wah pot.
This was a HUGE improvement for me, over the standard, modern crybaby. Mellower yet clear, lots more bass. & the sweep seems pretty usable.
I haven't played that many wahs though, & never a real boomerang; maybe I don't know what I'm missing.. ;)