WEM - Project V

[digi2t]

Well, I haven't had time to do the video with the HB guitar, but I did try it. Does sound a bit fatter for sure.

On another issue, I was playing with the resistors around the Edge/Drive switches. What was really bugging me was the significant volume drop when both switches were off. I found that replacing the 150K with a 47K resistor made a nice difference. The volume loss was greatly reduced, while maintaining the Drive or Edge tone changes. Something to ponder.

I had been using 2.2uF tantalum electro caps so far (including for the video), but I received the 2.5uF's axial cans the other day. I threw them in, and they did make a difference. They added a certain crispness to the fuzz, so I may go for these instead.

Would anybody have a particular type of inductor(s) that I should try in this? I mean, just for the hell of it? While it's on the board. A part number would be nice, I'm not that knowledgeable about them, other than wah inductors.

Cheers,
Dino

[digi2t]

I was digging through my stock today, and came across some MPSA18's. I threw them in just for fun. It gives it a more "peel your face off" edge to the fuzz. I like it.

Also, I had a board out a trashed Korg D1200 recorder, and noticed it had two ferrite coils, like this;



So, I took one off, and stuck it between Q1 and Q2, as the schematic. Didn't do anything sound-wise, but looks cool enough though

I'm working on a vero now. I'll post when it's done.

Cheers,
Dino

[digi2t]

Here's a vero;



The vero is unverified for the time being, but as always, if anyone spots an error(s), please let me know. I'll be "fine-toothing" it myself, but I believe it should correct. The more eyes the better. It may appear cut off on the right side, but if you save the image to your computer, and open it in a photo editor, it should appear complete. Let me know if there is a problem.

I decided to go with axial caps for most of them, since I could only find the exact values in axial format. The 320uF, I'm replacing with a 330uF. 320's are real tough to find. It does make for a bigger board, but I'm trying to stay as true as possible here. Especially since these are the values that sound the best on my breadboard. You can go with 2.2uF's, instead of the 2.5's, but I found that it made a difference to my ears. With the 2.5's, I got a tiny bit more of a buzz-saw edge to it.

As for the inductor, you can just jumper here, or use anything that comes in under 10 ohms. The true value of the original is still unknown at this time. Truthfully, I tried several different ones, and it makes no audible difference. A jumper will do, but I'm throwing a TDK EL0606 series inductor here, just for mojo .

The original circuit used seven BC108B's, and one BC186. I tried 2N3904/2N3906, 2N5088/2N5087, as well as BC108(9)/2N2907 combos. All sound nice, but the MPSA18/2N5087 set up is the one I like the best. In any case, there's gobs of gain, and a ton 'o fuzz. Just plain nasty!

One other change I made from the schematic, is the 150K resistor going to the Drive switch. I've reduced this to 47K on the vero. The 150K was just to much of a "muffler" when the Drive and Edge switches were both off. The 47K allows it to maintain a more decent volume level, whereas the 150K really kills the volume.

So, the parts are ordered, and the board is prepped. One last verification of the vero, and it's build time. Stay tuned....

[digi2t]

I found a couple of errors in the vero, so I deleted the one above. He's the updated one;



I've gone over it thoroghly, and it matches up with the schematic. I changed the 150K resistor for a 47K, since I find it much less stiffling with both switches off.

Once again, download it onto your computer, open it with any photo editor / viewer, and you should get the whole picture. For some reason, the right side is getting lopped off here.

Cheers,
Dino

[digi2t]

Alright. Final version of the vero. Found another small error, but this one is verified.



Here are some pics of the build;









As you can see, it's a tight fit. Also, I was digging through some junk boards the other day, when I came across and old radio (maybe tape deck??) board. It had several of these copper coil air inductors. On a lark, I carefully pulled one out, and slipped it onto the board. Instant "WTF" mojo . Other mods, the 150K resistor has been replaced by a 47K, the 4.7ohm resistors are actually parallel 10ohm resistors (5.1ohms) for more weirdness, there is a 220pF silver mica on Q5, and I added a 1.5M resistor to avoid any possible popping from the bypass switch.

Anyhow, I've done the video, demo'ing both single coil, and humbucker guitars. Since there was a previous query on the humbucker issue, I did both. Enjoy.


Link


Once again, many, many, many thanks to Grizzlytone, nightraven, PRR, and Mark Hammer for all the hard work, info, tips, encouragement, and so on. You guys are tops.

Cheers,
Dino

[digi2t]

Hmmm....

I was listening to Eno's "Here come the warm jets" yesterday, and I'm convinced that it's done with this pedal. That doubled high pitched hissy buzz is attainable with this circuit. As a matter of fact, when I initially bread boarded this with the BC108's, I was getting it with it biased a certain way. Actually, I was using "B"'s in the Q1, 3, and 7 spots, and "C"'s in the Q2, 4, 6, and 8 spots. A 2N2907A for the PNP. I wasn't particularly fond of it, so I veered away from it. Listening to Warm Jets, I'm thinking that maybe Eno opened it up, and fiddled with the trimmers, or maybe that was just the stock sound of it?

If I remember correctly, if I biased Q5 on the hot side (3.5 to 3.6 volts, maybe a bit more), I would get that crispy high pitch buzz. It's just that it made the pedal a bit hard to control, since anything over noon on the Attack knob would give you occasional zippering noises out of the blue.

Just an observation.

Cheers,
Dino

[Mbas974]

this is a great project ... but Eno used the kay fuzz

[digi2t]

this is a great project ... but Eno used the kay fuzz

I'm not really one to argue with you. Afterall, the quest for certain tones can be a long, tortuous journey. All information is power.

Thanks for chiming in.

Cheers,
Dino

[nightraven]

this is a great project ... but Eno used the kay fuzz

not quite you're thinking of Daniel Lanois who is one of the big Kay Fuzz fans and also collaborated with Eno quite a bit... if not then please give us more details!

[digi2t]

An interview with Brian Eno, originally published in 1981, then repeated (with a new introduction) in Keyboard Wizards, Winter 1985, conducted by Jim Aikin.
Which may be found here; http://music.hyperreal.org/artists/brian_eno/interviews/keyb81.html

Exerpt;

K.W. - What kind of fuzz box do you have?

B.E. - I have a great one. It's very old. It's called a Project WEM. I've never seen another one. But it's a lovely fuzz box. It's been used by many famous guitar players, because they say it's got a unique sound. People have actually tried to make copies of it. They took down all the components and tried to build another one, but they never really got quite the same thing. I've used it on all my records, actually, from the first record I made. Whenever you hear my particular fuzz guitar sound, that's the fuzz box. Sometimes what sounds like guitar is really synthesizer or vice versa.... Then the less essential things, things that aren't always there: I sometimes use phasers, though I'm pretty uninterested in them. They work with certain types of sounds, but I dislike the regularity of the sweep. I might be more interested in one that switched between different phase angles, for instance, rather than sweeping between them. I use a pitch-to-voltage converter sometimes.

Also, interviews with Brian Eno and Harold Budd from Electronic Soundmaker & Computer Music, October 1984, by Chris Everard
Which may be found here; http://music.hyperreal.org/artists/brian_eno/interviews/escm84.html#instruments

Exerpt;

C.E. - If there had been as many synths around as there are today when you recorded Here Come The Warm Jets and your earlier albums, do you think they would have sounded different?

B.E. - "That's a good question... I wonder... Because, as you probably know there is a vast quantity of synths available now and all other forms of equipment... Well, I'm not all that interested in equipment as you would have probably realised from the scant amount of which I own (laughs). If I find a couple of things I like I am very happy with them, and I'll just work with them.

"For instance, one thing I loved on those early albums is an old guitar which I used to have called a Starway which I bought for nine pounds fifteen shillings in Portsmouth 14 years ago - no, sixteen years ago! Anyway this guitar I had had strings on it when I got it and I never changed them for years, it was a sort of policy never to change them because I used it with an old fuzz box - a Project Wem Fuzz Box... Good Lord we're going back some! Yes (laughs, gesturing with hands to show an invisible box about a foot long and six inches square on the table) It was at least this big! Anyway, to get the best fuzz sound - for me anyway - you need to feed in a sound which contains no or little harmonics, then you get really excellent fuzz sounds, it doesn't sound like fuzz guitar any more, it's like some other new instrument..."

And just for fun, I'll add this exerpt from a Fripp interview. Not because it talks about the WEM (which it doesn't), but purely because I absolutely LOVE the answer to the second question...

Fripp interview from 1974

http://www.elephant-talk.com/wiki/Interview_with_Robert_Fripp_in_Guitar_Player_(1974)

R.F. - ...The best fuzz-box to use is a Burn's Buzz-around which they discontinued making in England about six years ago. I have two of them, but they're not at the moment attached to my pedal board. The more pedals you go through, the longer leads you need, and in turn the less volume you get. You lose gain along the way. To lessen that, the wah-wah and the fuzz are on the knock-off circuit. In other words, when I'm playing, all the time I'm going through the volume, but when I'm using either fuzz or wah-wah, I knock a different pedal which brings in a different circuit for the fuzz and the wah-wah. When I'm not using them I press a button and knock them out of the circuit so that the circuit shortens, and I keep up my gain. I also use a Watkins Kopy Kat echo unit. It's all right, but it's not particularly good. It suffices for what I want, which is not really a lot of echo effects but just a slight edge, because the sound on stage is very dead in a lot of halls I play in. It really doesn't matter what kind of fuzz box you use. It has more to do with the state of mind.

G.P. - But if somebody wanted to obtain the same sound you got, wouldn't it be important to know what type of fuzz you were using?

R.F. - No. I can get that same sound with every kind of fuzz box I've ever used. It's not a question of equipment.

Now THERE'S a killjoy!

[John Lyons]

Nice work Dino!

[digi2t]

Nice work Dino!

Thank you Sir. Came together with some fine help. Quite challenging for a fuzz, but every time I play with it, it brings a smile to my face.

[kaycee]

intrepid work indeed

Smother it in echo and through a cocked wah at volume and I can see it getting some of those filthy Pink Fairies tones. Many thanks for the vero!

[digi2t]

Hi all,

Just an update here. I ordered some 4.7 ohm resistors, to try in place of my parallel 10 ohm resistors (5.1 ohms) that I used. I didn't really think that it would make any difference really, but WRONG, it did.

It sounds a bit buzzier now, like a high-end fizz, which is especially dominant with the EDGE on, and DRIVE off. It really comes through as the note decays, and brings it much closer to the "Warm Jets" tone.

I had some BC109B's, and BC179B's come in, but it sounds so good right now, that I don't want to mess with it anymore. I think the 4.7 ohm resistors were the final piece of the puzzle. The BC109's will have to wait for another project.

Roger, out.
Dino

[LaceSensor]

Another call of verified, I used your v1 layout but made the corrections as per 2.

[LaceSensor]

Another call of verified, I used your v1 layout but made the corrections as per 2.

[digi2t]

Very nice, BRAVO!!

How does it sound? Did you use the 220pF cap?

[LaceSensor]

Very nice, BRAVO!!

How does it sound? Did you use the 220pF cap?

Hi

It sounds very nice
I ran out of MPSA18 so I used 2n5088 and the 2n5087

I didnt use the 220pf cap, didnt even try it, as the harsher sounds are desired as per the original.

[sinner]

Hey LaceSensor is that orange shielded wire? Where did you get it from?

[digi2t]

Very nice, BRAVO!!

How does it sound? Did you use the 220pF cap?

Hi

It sounds very nice
I ran out of MPSA18 so I used 2n5088 and the 2n5087

I didnt use the 220pf cap, didnt even try it, as the harsher sounds are desired as per the original.

Yup, tried the `88 / `87 combo as well, but I found that the MPSA18`s had a certain, je ne sais quoi. I really went back and forth on those, for days, with the MPSA`s winning out. They seemed to retain some of the fizzy buzz on the note decay, while giving me a decent `Muffish`roar as well. I must add, I only use SS amps, so I don`t have any tubes to drive. Makes a huge difference in how I need my pedals to perform.
But, without a doubt, it`s all between ones ears at the end of the day. I just find that with that many trannies, it`s a fun circuit to breadboard, and then mix and match transistors/caps/resistors. Not only is it quite tolerant of different trannies, but it allows you change the nature of the beast to suit ones tastes.

One of the most fun circuits I`ve ever played with. I`ve got a bunch of fuzz pedals, but to date, this one has become somewhat of a permanent fixture between my guitar and amp. My brain just seems to go ``OH WOW```every time I use it