Zakk Wylde Overdrive pedal finished !!! Any ideas for mods and more gain ?

[Angelo777]

No, I'm pretty sure your pedal isn't drawing more current than your power supply has available.  It's very unlikely that's the problem, because the ZW product manual states that its current draw is less than 2.2mA.


If your gain is maxed out and you're still thinking to yourself "This isn't enough distortion/this distortion doesn't sizzle and howl like I want it to," then you probably aren't going to get enough distortion out of this circuit.  It has a lot of distortion available, but it's single-stage distortion; it's not a high-gain sound like a Boogie or a Soldano.  The sound you're looking for may require multiple gain stages cascaded into each other - i.e., distorting already distorted sounds.  What I'm saying is that you're probably just looking for a different KIND of distortion rather than the AMOUNT of distortion the ZW can give you.

If, on the other hand, you're thinking "this isn't chunky enough," then you may benefit from trying clipping diodes with a higher forward voltage (something like replacing D3 with an LED) to make it a little cleaner and more dynamic, because chunk and snap won't happen without dynamics.  Think of palm-muted power chords: are you trying to get them to go "chunk chunk chunk chunk" or "bzzh bzzh bzzh bzzh"?  And also keep in mind that good rhythm-guitar chunk isn't necessarily the same tone as good lead-guitar singing sustain.


After a glimpse at your schematic, yes, the ZW is essentially just a Boss Super Overdrive with mostly-true-bypass and tweaked tone control values.  The main difference between the two is that the MXR product has better bypass than the Boss, SMD components that prevent users from modding it (in its commercial form), and it costs more than twice as much as the SD-1 because it's a signature product with a fancy paint job.

On to the nitty gritty.
C12 cuts out some upper treble frequencies in the gain stage before the signal even sees the tone control, particularly at high gain settings.  It has the effect of smoothing out the clipping a little bit and taking some of the edge off.  It does not "scoop mids" in any way whatsoever.  C4 also cuts out treble frequencies and it has a very audible impact on your tone: IMO it cuts highs so much that it's like playing with a pillow in front of your speaker.  You should try the circuit without C4.  Just remove it and don't replace it or jumper it at all.

C6 restricts bass content before the signal reaches the gain stage.  If you change it to a 0.1µF cap it'll fatten the sound up a lot.

Baaron,

That was very interesting thoughts indeed. Thank you also for the mods.
Though all those thoughts i stated .... i did because the video from youtube.com has nothing to do with the distortion i'm getting from the ZW pedal i have built.... mine has at least 3/10 of the distortion i am hearing in the youtube videos.... thats the reason for all those *maybe* thoughts....

Thanks again,
Angelo777

[BAARON]

Do you know if they are playing the pedal through a clean amp in the YouTube video, or are you hearing the pedal And distortion from the amp?

[Angelo777]

Do you know if they are playing the pedal through a clean amp in the YouTube video, or are you hearing the pedal And distortion from the amp?

Baaron,

Listen to yourself mate

http://www.youtube.com/watch?v=cO46SLtj23A

There you go

I am not getting an overdrive like this ..... no bloody way 

[Angelo777]

Baaron,

Also check this dude here --> http://www.youtube.com/watch?v=_M6WV2SlQv4&feature=related

The distortion i'm getting from mine is if HE puts the gain in his video in 3/10 

Any helpfull ideas mate ? Anybody ?

Cheers!
Angelo777

[Angelo777]

I guess there tube amps are helping them get that punch and that extra distortion from ZW-44 ....

Angelo777

[Jurgen]

The ZW OD into a clean channel won't get you much gain. ZW himself uses the OD pedal to push his cranked JCM800 into even more distortion. Using an overdrive pedal into an already distorting tube amp used to be a pretty standard setup for metal players back in the 80's, before 5150s, Rectos and other hyper gain amps hit the market.

[BAARON]

Is it possible that your gain pot is wired wrong (i.e., is it in parallel with R6 instead of in series with it), or perhaps it is not 1 meg?  If one of those were the case, it would certainly make it into a low-gain pedal.

P.S. Listen to some Boss SD-1 Super Overdrive demos too.  Same circuit + marketed to different niches = different demo styles.

[Angelo777]

BAARON wrote:

Is it possible that your gain pot is wired wrong (i.e., is it in parallel with R6 instead of in series with it), or perhaps it is not 1 meg?

Nope. All is good and it is 1M. I also tried putting a second 1M pot in series with the other one just to check if it was possible to give some extra gain but nothing happened...

Jurgen wrote:

The ZW OD into a clean channel won't get you much gain.

By the way, yesterday i went to a friend of mine who owns a musical instruments & accesories store and i put the original ZW OD to hear it . The sound was exactly the same as the one i built and also the gain was also the same... so I suppose that the dude one the video in youtube definatelly uses a tube amp and also he has cranked up the volume of the tube amp which gave him that extra compression and extra boost and gain. So my ZW is working great....

Its time for me to add 3 more gain stages to make it a little more tough  as an overdrive pedal.

Stay tuned for the upcoming mods !!!

Cheers!

[BAARON]

Well at least you know that the schematic and your build were both right!  The pedal just doesn't do what the demos make it out to be.  That's very disappointing when that happens.

[MetalGuy]

Yeah, you see the funny thing is that i heard the pedal from youtube and the sound is completelly different from what i am getting from this pedal... a lot less distortion ... mostly like a signal booster with half of the distortion of the pedal i heard from youtube-proguitar video... Though proguitar.com uses a big amp cracked up the volume so the bigger signal is added in the output pretty easily

I built this pedal some time ago because I wanted to have one pedal of this type by hand . I started it without any big expectations because only by looking at the schematic you can see that it is a lightly modded SD-1.
After I built it I compared it to the original (which I borrowed from a friend) It was obvious that the sound wasn't the same. All the parts I used were per schematic the only difference was I was using regular parts instead of SMD's like the original. I measured many times all the parts values on the original PCB and they seemed to match the schematic. I couldn't find a 120p cap though. At some point I even changed the diodes to the oroginal SMD ones together with the last 3u3 cap but both effects still sounded different. To make the long story short at same setting the original was brighter and seemed to have a little more gain. I noticed that by decreasing the 10n cap I was getting closer but at some point I lost interest. I'm still curious however what could be the reason for the difference between the two except for the obvous fact that the original is SMD based.

[Brymus]

Yeah, you see the funny thing is that i heard the pedal from youtube and the sound is completelly different from what i am getting from this pedal... a lot less distortion ... mostly like a signal booster with half of the distortion of the pedal i heard from youtube-proguitar video... Though proguitar.com uses a big amp cracked up the volume so the bigger signal is added in the output pretty easily

I built this pedal some time ago because I wanted to have one pedal of this type by hand . I started it without any big expectations because only by looking at the schematic you can see that it is a lightly modded SD-1.
After I built it I compared it to the original (which I borrowed from a friend) It was obvious that the sound wasn't the same. All the parts I used were per schematic the only difference was I was using regular parts instead of SMD's like the original. I measured many times all the parts values on the original PCB and they seemed to match the schematic. I couldn't find a 120p cap though. At some point I even changed the diodes to the oroginal SMD ones together with the last 3u3 cap but both effects still sounded different. To make the long story short at same setting the original was brighter and seemed to have a little more gain. I noticed that by decreasing the 10n cap I was getting closer but at some point I lost interest. I'm still curious however what could be the reason for the difference between the two except for the obvous fact that the original is SMD based.

That could well be the difference in IC runs.

[Angelo777]

Hello everyone,

Back with some mods. In the schematic, do the following...

This is not a verified mod yet so please procced as you wish at your own risk! Though theoretically it would work like charm  




Also you could put a lower value in 10nF that MetalGuy suggested... I think that this cap changes the frequency that is being amplified or whatsoever and has an effect in the final gain ( just a thought ... )

Best Regards,
Angelo777

[MetalGuy]

That could well be the difference in IC runs.

Unless there are different types of 33178 the only difference as I already mentioned is that mine is DIP8 package and the original is SMD /as everything else there/.

[fretzburner]

To make a Zakk Wylde OD to GT-OD just add 10k resistor from C7 positive to tone pot connecting R5,C4,neg input of opamp.I tested it and it increase bass,mid,and overall gain/volume. Make a switch and you have ZW-44 and GT-OD in one pedal.