Zonkin' Yellow Screamer Owners

[Robert****]

Let your voice be heard!

I still have my Mark II pedal - I should have kept version 1 I think! Just for historical purposes. The version 2 sounds at least as good.

If you have one, which chips do you use in it? I'm not sure where I put my little chips that came with the pedal. I use the stock one but I wouldn't mind trying that one that Keeley uses.

ZYS FTW!!

[Spudman***]

Version 1 here. Serial number 04 or 05 I think. I haven't used it since getting my M13. I think I'm going to deconstruct my analog pedal board and sell a few things off it, but not the Zonker. I have several chips for it and have only tried 2 of them and I can't tell you which one is in it right now (and to think I used to be a geek about that stuff). I should dig it out and experiment some with it. Always happy with what I get from it for sure.

[sunvalleylaw]

I have a MkII and love it. I have whatever chip in it came with. i liked it so much I never messed with the other chips.

[duhvoodooman***]

Not surprisingly, I have two--the original Mark 1 I built from the old BYOC Overdrive kit, and a Mark II (S/N 029) that I threw in for myself during a run of customer builds. I have a special little adapter board in it that I got from Monte Allums that let's me run two op amps simultaneously, and for clipping, I have the BS170 MOSFET pair on one side and a single BS170 on the other side. This latter is an interesting concept I read about on Jack Orman's site in THIS ARTICLE. To quote Jack directly:

"An alternate method is to use on a single mosfet. With this clipper, the positive voltages are clipped by the gate-source diode and the negative voltages are limited by the body diode. This version gives asymmetrical clipping that tends to emphasis the even harmonics.

If the gate-source threshold is 2v and the body diode is 0.7v then the signal will be able to swing only +2v and -0.7v. Try this setup for a different and unique sound. "

It's a little louder and cleaner than the dual MOSFET clippers, and has a real pleasing character to it. I have that first clipping position set up with sockets so that I can change the clippers as the whim strikes me. Another diode combo I really like is one 1N914 silicon diode on one side and three 914's in series (in the opposite polarity direction, of course) on the other side.

My thanks to all of you who purchased ZYS's over the 4 years I was selling them. In total, I sold about 70 of them before I decided to stop building commercially, by far my most popular pedal. A lot of the credit has to go to Robert and his excellent ZYS demo videos. A major portion of the gear I have was purchased with the proceeds from those pedal sales.

[marnold***]

I've got the Lutheran man's version of the ZYS. Honestly I don't remember what the difference is any more, other than there is no switch to change the order of the effects. I've never taken out the stock chip. IIRC, the other chip I have is the infamous TS808 chip.

[Robert****]

I still have people emailing me about the ZYS. Maybe the original ones will sell on eBay for $600 a piece soon.

[piebaldpython***]

I have the "poor man's ZYS" otherwise known as the OD II. Love that pedal, mine has the MOSFET boost. Per a discussion with DVM, because I also have his Rabid Rodent, I did a mix of the chips.....meaning I have one of each in opposition to each other........and that gives the OD a different flavor.

I have the same version as Marnold (he had a Lutheran decal affixed IIRC) and I think the only other difference he has a difference boost than the MOSFET on mine.

The RR is set-up with it's chips so that the OD II chip set-up would be a replication of what I get out of the RR. Vood suggested a mix and match for the OD II to vary things up.

Perhaps, DVM will chime in to explain about the mix-and-match chip thing. lolol

[marnold***]

I have the same version as Marnold (he had a Lutheran decal affixed IIRC) and I think the only other difference he has a difference boost than the MOSFET on mine.

Yep! Mine has the silicon boost. I do have a MOSFET clipping option on the I found my spare chip and it is the JRC4558D aka the TS808 chip. I opened my pedal up to confirm that it has the Burr Brown OPA2134 chip.

This is one pedal that I would never dream of selling. That and my delay are generally the only two I have in front of my amph. Here's the original thread of the birth of my pedal from way back in July of '09. http://www.thefret.net/showthread.php/11850-Dvm-Od2

[Eric***]

This is one pedal that I would never dream of selling. That and my delay are generally the only two I have in front of my amph. Here's the original thread of the birth of my pedal from way back in July of '09. http://www.thefret.net/showthread.php/11850-Dvm-Od2

That's interesting. I don't think I have anything like that. Even my most faithful guitar would probably be on the market given the right circumstances (moving, etc.), though in all honesty I might just have someone look after it instead of selling it. But for almost everything else, I have no 'sacred' equipment. I kind of like it that way, but it's weird given the culture of musicians and guitarists.

[marnold***]

That's interesting. I don't think I have anything like that. Even my most faithful guitar would probably be on the market given the right circumstances (moving, etc.), though in all honesty I might just have someone look after it instead of selling it. But for almost everything else, I have no 'sacred' equipment. I kind of like it that way, but it's weird given the culture of musicians and guitarists.

I hear you. I have two reasons why I wouldn't dream of getting rid of this. The first is practical. It covers all my overdrive / boost needs perfectly. I've yet to find a pedal with similar versatility.

The second reason is personal. It was made for me by someone I consider a friend. From the internal tweaks to the external graphics, it is something that is uniquely mine.

My only complaint about the pedal is that looking on the inside reminds me of how bad my soldering skills are

[duhvoodooman***]

I have the "poor man's ZYS" otherwise known as the OD II. Love that pedal, mine has the MOSFET boost. Per a discussion with DVM, because I also have his Rabid Rodent, I did a mix of the chips.....meaning I have one of each in opposition to each other........and that gives the OD a different flavor.

I have the same version as Marnold (he had a Lutheran decal affixed IIRC) and I think the only other difference he has a difference boost than the MOSFET on mine.

The RR is set-up with it's chips so that the OD II chip set-up would be a replication of what I get out of the RR. Vood suggested a mix and match for the OD II to vary things up.

Perhaps, DVM will chime in to explain about the mix-and-match chip thing. lolol

"Chips" generally refer to IC's, which would be the op amp in the context of this pedal. I think what you're referring to is the use of two different types of transistors in the ZYS/OD2--the silicon bipolar junction transistors (BJTs) used in the stock OD2 (and the classic TS808 circuit) or the BS170 MOSFETs (which stands for metal oxide semiconductor field-effect transistor) that can be substituted for the BJTs in three places in the circuit. These are the input and output buffers in the overdrive part of the circuit, and the gain stage of the boost circuit. You can also use a pair of MOSFETs in the overdrive clipping section, but they're not functioning as transistors there--you're basically just using the diodes that are part of their internal structure as signal clippers. There's a rundown on the effect of these substitutions in THIS POST in Marnold's thread. My personal preference is to use the MOSFET in the input buffer and for the clipper pair, and stay with the BJT's in the output buffer and the boost stage. But this is highly subjective and "YMMV" applies here, in spades....

[piebaldpython***]

I found a "note" from DVM to me when I asked a question that explains the "chips" I was referring to:

"You can even mix the two types--one 1N914 and one red LED--for a kind of hybrid sound. If you do that, be sure that the flat side of the LED and the black stripe on the 1N914 face in opposite directions. Just be a little careful when removing the diodes from the sockets. The 1N914's in particular are quite fragile--the body is made of glass--so don't grab 'em with a pair of metal pliers! Lifting straight up and pushing straight down works best when removing or installing these."

[aeolian]

I have a version 2. I never took the time to experiment with the different chips to see what difference it makes. It sounds great already.

I use it every week at band practice. This past Sunday we played a half-hour set at an Open Mic and I got some response that the guitar sounded gritty. The only small issue with my ZYS is that the volume control of the overdrive likely has a lot of gain, since I engage the overdrive mid-song a lot I have to tweak it carefully because just turning up a little bit makes the guitar a lot louder than without the overdrive engaged. Sound-wise there can be no complaints.

[duhvoodooman***]

I found a "note" from DVM to me when I asked a question that explains the "chips" I was referring to:

"You can even mix the two types--one 1N914 and one red LED--for a kind of hybrid sound. If you do that, be sure that the flat side of the LED and the black stripe on the 1N914 face in opposite directions. Just be a little careful when removing the diodes from the sockets. The 1N914's in particular are quite fragile--the body is made of glass--so don't grab 'em with a pair of metal pliers! Lifting straight up and pushing straight down works best when removing or installing these."

OK, those would be the clipping diodes. The ZYS Mk II's have compression sockets installed in the clipping diode eyelets for the first clipping position (toggle to the left side), so that you can try diffierent clipping diode combinations and see what you like the best.

....The only small issue with my ZYS is that the volume control of the overdrive likely has a lot of gain, since I engage the overdrive mid-song a lot I have to tweak it carefully because just turning up a little bit makes the guitar a lot louder than without the overdrive engaged. Sound-wise there can be no complaints.

Sounds like you probably have one of the early Mark II's. I found that the volume for the OD side came on too quickly and the boost volume came on too slowly, so I started switching the linear taper pot on the OD side with the audio taper pot for the boost volume in later builds, which seemed to take care of the problem nicely.

[Nelskie]

To be honest, I’m not really sure what version my ZYS pedal is. DVM, perhaps you can provide me with some input on that as I’d be interested to know.

Chip-wise, it’s really a can’t miss endeavor. To my ear, they all sounded good. As I recall, DVM’s personal choice was one of the Texas Instruments chips - largely on the basis of overall responsiveness across all of the different settings. Having used all (3) of the included chips at one time or another, my favorite is still the JRC4558D – i.e. the chip used in the original TS-808’s. Even with all the tonal flexibility the ZYS has on tap, there’s a certain old school ‘feel’ that the JRC chip imparts that’s hard for me to move away from. Having now come across this post, I may again re-explore my options in that dept. – if for nothing more than an enjoyable afternoon of playing and tone-farming.

The reasons I like my pedal are far too many to mention. But one in particular, I think, extends the highest compliment a player can extend. DVM’s ZYS is at the headwaters of not one – but two of my personal ‘go-to’ tones. And when I say that, I don’t mean that I’m emulating a famous player’s tone or sound. These are my tones. As in when I want to put my personal stamp on a piece of music, these are two of the silver bullets in my gun.

Anyways, after five years of regular playing, my ZYS – i.e.“Big Yellah” - - is still going strong. Which is good, cuz’ I have a lot of music left to create. Cheers to the ‘Old Guard’. - - nelskie

[loopyloop]

Hi... I am new here and hope to learn a coupke of things about this pedal. I woukd like to get one, based on reviews, but I'd like to know what the mods are as compared to the original byoc od2 kit?
Is this an ok question to ask?

[marnold***]

Hi... I am new here and hope to learn a coupke of things about this pedal. I woukd like to get one, based on reviews, but I'd like to know what the mods are as compared to the original byoc od2 kit?
Is this an ok question to ask?

Here's all the gory details. http://www.duhvoodooman.com/miscimag...l/zys_mkII.htm

DVM doesn't build them anymore but he has contracted out to someone who will build one for you. His site has the details.

[loopyloop]

Thank you very much indeed... now I have to learn what it all means!

[Monkus]

My ZYS MkII is my Golden Monkey. About three years rocking hard - bandmate swears he hears the freedom of ladies' undies when the stomp happens.