Morley Power Wah Boost Voodoo Thread

PolkaHero · #1 09-29-2007, 04:55 PM

Just picked up one of these monsters and want to learn more about it. I've learned how the photoresistor functions based on the flap that moves up and down inside the pedal. I searched some old threads and some guys on here mention of lining the base of the pedal with tinfoil and changing the position of the photoresistor to allow more light to reach the component. Does doing this broaden the range of the sweep of the wah (i.e., more highs)? I've attached a pic of the innards showing what appears to be 2 photoresistors under the paper/duct tape canopy. Are both of these functional? If not, which one would I move so it picks up more light from the bulb?

Concerning the boost control: It sounds like this thing actually adds a little distortion to the sound. Is it supposed to do this? The gain that is available with it engaged is completely ridiculous!!! Is there anyway to "tame" the massive volume gain that occurs when you put the pedal in it toe down position? It almost tears your head off!

Well, that's all I have for now. I may have more questions when the experts start chiming in. Long live Cliff Burton!

Niff · #2 09-29-2007, 08:32 PM

i dunno the physics behind the boost exactly.. but it's key to that screaming sound, whether you have the distortion before or after. it just adds harmonics, or something.

and the only thing i've found to tame the insane brightness (not volume) of having it toe-down is to have the tone on whatever distortion i'm using turned down, and to crank the bass up and cut the treble a bit on my bass.

JanusZarate · #3 09-29-2007, 08:39 PM

Boost = harmonics/distortion? You betcha! The current reissue does that too when you crank the Boost knob. It's more "reasonable" in terms of volume, though.

And yeah, if you're aiming for that Cliff-Burton sound, keep in mind that his normal tone was never "bright". If it were, his Power Wah solos would be ear-piercing, almost deafening!

PolkaHero · #4 09-29-2007, 09:37 PM

Quote:

Originally Posted by MysticBoo

And yeah, if you're aiming for that Cliff-Burton sound, keep in mind that his normal tone was never "bright". If it were, his Power Wah solos would be ear-piercing, almost deafening!

I don't know, his full-range sweeps seem to get into higher harmonics than my pedal is capable of right now. The overall volume, though, doesn't vary as much as my pedal is doing right now. Would compression help in that regard?

JanusZarate · #5 09-29-2007, 10:16 PM

I should probably clarify - all of the basses he used have pretty bright/progressive tones AFAIK (Ric, Alembic, etc.), but at the amp (a Mesa/Boogie 400 or 400+, I think), the tone is warmer. So yeah, what's driving the PWB is definitely a hot output, but some of that screaming treble is "toned down" at the amp. Some of that harmonic richness is also due to the amp, since it's being pushed harder by the output of the PWB. And as you already noticed, the Boost knob of the PWB adds some of its own, too.

As for volume... compression would certainly help to curb the boosting. Just place it after the PWB.

Niff · #6 09-29-2007, 10:24 PM

it doesn't really boost volume, though. the frequencies just get more and more audible and ear-bleeding.

JanusZarate · #7 09-29-2007, 10:31 PM

That'll be curbed, too, since it's still boosting at the top end (rather than across all the frequencies). Technically, it's still volume boosting, in an odd way.

Niff · #8 09-30-2007, 01:11 AM

true. but to be pedantic, isn't it cutting the low frequencies and boosting the high frequencies by what it cut from the lows? haha.

also contemplating selling my PWB.. argh. after i went through all the trouble of modding it to work on european/oceania voltage. kinda need money. but i have a feeling if i sold it i'd really regret it.

PolkaHero · #9 09-30-2007, 10:42 AM

Okay, thanks for the responses guys! Somebody still hasn't answered my one question about the photoresistors. It looks like there are 2 of them underneath the paper/tape canopy (see my pic in the opening thread). Is this so, or is it really just one of them? I don't want to move anymore components than I have to!

Also, do you know if there's a higher-intensity light bulb that is available? Seems like that would be another way to increase the high harmonics at the top of the sweep.

JanusZarate · #10 09-30-2007, 01:59 PM

I'm sure you could replace the bulb, but you'd have to find one of similar specs. People have a difficult-enough time trying to find the exact replacement for the one that's in there!

As for the photoresistors... the PWB is also a volume pedal, IIRC. One photoresistor is for the volume mode. The other is used for both normal wah and Boost modes. Only one is working at any given time.

I'd just leave them both in - removing one won't do you any favors. And I'm not sure which one's which, anyway.

PolkaHero · #11 09-30-2007, 08:23 PM

Any idea if Cliff had his Morley on the whole time during Pulling Teeth? If so, did he have the pedal mainly in the heel down position most of the time? If I put the pedal in the middle position, it give the bass a really midrangy sound that is very unlike his tone at any point during the solo. There's points during the solo where I believe he has the pedal at some point between heel-down and toe-down but I can't seem to replicate that tone. I should note that I'm using the Big Muff model from my Line 6 BassPodXT rather than the actual pedal as I think the response is a lot better with the Line 6.

Niff · #12 09-30-2007, 08:38 PM

i'm a bit confused as to how he did that myself. there's a point near the heel-down position you can feel where it's super-bassy, then one tiny angle where it starts shifting up a lot. i think it's in the manual (which can be found online). but i keep the pedal sitting right where it "jumps out" of the low frequencies.

jacobmyers · #13 09-30-2007, 09:39 PM

Quote:

Originally Posted by MysticBoo

I'm sure you could replace the bulb, but you'd have to find one of similar specs. People have a difficult-enough time trying to find the exact replacement for the one that's in there!

The bulb in PolkaHero's picture looks like a GE 387. The 387 is used - for the same purpose - in my Morley PWF. They're more commonly found as low-voltage cabin lighting in airplanes.

There were (when I bought my incandescent replacements five years ago) "drop-in" LED replacements for this bulb. They are, if I remember correctly, slightly brighter than the incandescent version. I don't know if those are still in production but I imagine that they are.

The bulbs are readily available from various online merchants for less than a (US) dollar each.

PolkaHero · #14 10-01-2007, 09:18 PM

Tried running my Line 6 compressions after the Morley today with my Big Muff in front of the Morley. Unfortunately, the compressors in the Line 6 don't allow for ratio changes so the response wasn't what I was looking for. I guess I'll have to trade my Big Muff for a compressor pedal and just use the Line 6 distortion (which I prefer to the Big Muff anyway).

I can definitely see using the Boost function with a clean sound. I didn't notice the distortion I was hearing the other day when I was using it. Really cool, useful pedal!

Galdal · #15 10-18-2007, 03:27 PM

hi, I cannot answer your question, but want to learn more myself. i try 3 diffrent muffs, 1 first editon from sovtek(made of melted tanks), and this one is a lot more like cliffs sound when I have it after the pwb, the other sovtek, a lighter version I have to place before the pwb and the same with a regular silver muff NY. they don`t scream if I don`t have them before the pwb and press the treddle all the way down.

something else is that in the manual it is written that in wolume mode there should be no sound with toe up and heel down, mine have regual volume but pressing a bit the sound dissapers and the volume effect starts.. Is yours like that?

did Cliff have the muff before or after the pwb?

niftydog · #16 10-18-2007, 04:34 PM

Quote:

Originally Posted by PolkaHero

...some guys on here mention of lining the base of the pedal with tinfoil and changing the position of the photoresistor to allow more light to reach the component. Does doing this broaden the range of the sweep of the wah (i.e., more highs)?

That would have been me! To broaden the sweep you need to arrange the flap and the photoresistor such that it remains in complete darkness at one end of the sweep, and is directly pointing at the bulb at the other end of the sweep. You'll find these wahs changes personality depending on which way the wind is blowing on any given day, so don't expect it to be rock steady.

The idea behind the tin foil was to reflect some of the "lost" light back towards the photoresistor. My PWO has so much top end that it hurts, and the bottom end of the sweep cannot be reproduced by my bass amp because it's so low! So, yes, you can increase the sweep and you should be able to get SCREAMING high end out of it.

As for replacing the bulb - I don't think it's necessary if you tweak the mechanics. Like I said, the top end of my wah shatters ear drums and that's with the standard bulb and photoresistor installed. But, it can be done if you wish. HOWEVER... brighter bulbs draw more current and more current causes more ripple in the power supply which might cause hum. I've struggled with hum in my wah and it's stock standard!

Quote:

Originally Posted by PolkaHero

2 photoresistors ...Are both of these functional?

Like Boo said, probably one for the wah and one for the volume. The schematics are available from the Morley website - look for the "Tel Ray" schematics page.

PolkaHero · #17 10-18-2007, 05:06 PM

Quote:

Originally Posted by niftydog

That would have been me! To broaden the sweep you need to arrange the flap and the photoresistor such that it remains in complete darkness at one end of the sweep, and is directly pointing at the bulb at the other end of the sweep. You'll find these wahs changes personality depending on which way the wind is blowing on any given day, so don't expect it to be rock steady.

The idea behind the tin foil was to reflect some of the "lost" light back towards the photoresistor. My PWO has so much top end that it hurts, and the bottom end of the sweep cannot be reproduced by my bass amp because it's so low! So, yes, you can increase the sweep and you should be able to get SCREAMING high end out of it.

As for replacing the bulb - I don't think it's necessary if you tweak the mechanics. Like I said, the top end of my wah shatters ear drums and that's with the standard bulb and photoresistor installed. But, it can be done if you wish. HOWEVER... brighter bulbs draw more current and more current causes more ripple in the power supply which might cause hum. I've struggled with hum in my wah and it's stock standard!

Like Boo said, probably one for the wah and one for the volume. The schematics are available from the Morley website - look for the "Tel Ray" schematics page.

Dude, where were you when I asked these questions 2 weeks ago?! Just kidding. Anyway, I lined some aluminum foil in the base as well as moved both of the photoresistors so they are closer to the light bulb. It did seem to give the wah a more aggressive nature (not that it didn't have it before!). I have a Boss compressor that I just won on Ebay coming to tame the massive volume increase that comes with the wah in the toe down position. This thing would literally take heads off if I used it without a compressor/limiter!.

Galdal, In volume mode there should be absolutely no sound with the pedal in the heel-down position. You might have to adjust the flap inside so it completely covers the 2 photoresistors underneath the paper/tape shroud when the pedal is in the heel-down position.

Nifty,

I did download the schematics from Morley, but I have no clue how to read these things. I just ended up moving both resistors.
These pedals rock, they just don't make them like this anymore!

niftydog · #18 10-18-2007, 10:51 PM

Oh yeah, you reminded me. The first thing I did when I got mine was install a volume knob on the output! Mine isn't supposed to boost, but it sure does!

I would normally wade into most threads about Morleys so don't know why I missed your quesitions. Me and Boo are Tel Ray Tragics!

JanusZarate · #19 10-18-2007, 11:03 PM

Quote:

Originally Posted by niftydog

I would normally wade into most threads about Morleys so don't know why I missed your quesitions. Me and Boo are Tel Ray Tragics!

I'm more of a modern Morley guy, but I've have my fair share of exposure to the classics.

I don't think I'm a tragedy by any means though...

...hey, do you hear that? That siren-like call of a Morley Power Wah Boost...

...NO, NIFTY! DON'T LET IT LURE YOU IN!

Galdal · #20 01-14-2008, 11:16 AM

Quote:

Originally Posted by PolkaHero

Dude, where were you when I asked these questions 2 weeks ago?! Just kidding. Anyway, I lined some aluminum foil in the base as well as moved both of the photoresistors so they are closer to the light bulb. It did seem to give the wah a more aggressive nature (not that it didn't have it before!). I have a Boss compressor that I just won on Ebay coming to tame the massive volume increase that comes with the wah in the toe down position. This thing would literally take heads off if I used it without a compressor/limiter!.

Galdal, In volume mode there should be absolutely no sound with the pedal in the heel-down position. You might have to adjust the flap inside so it completely covers the 2 photoresistors underneath the paper/tape shroud when the pedal is in the heel-down position.

Nifty,

I did download the schematics from Morley, but I have no clue how to read these things. I just ended up moving both resistors.
These pedals rock, they just don't make them like this anymore!

Thanks for the info Polkahero!