New "Cool" ZYS Clipping Mode

[duhvoodooman***]

My souped up modification of the BYOC TS-808 clone pedal, which I call the "Zonkin' Yellow Screamer" (ZYS) has three switchable clipping modes. On the pedal, they're labeled Hot, Normal and Cool. The Normal mode uses the same basic silicon diode clipping as the original Tube Screamer, albeit set up asymetrically for a bit more smoothness. The Hot mode uses a pair of yellow LED's that give a louder, sharper overdrive that is often described as "Marshall-like" in its character. For the Cool mode, I've used a 3x3 array of 1N34A germanium diodes, which give a smoother, quite "bluesy" signal clip. While the tone is quite nice, the drawback to this mode is a significant loss in volume vs. the "dry" signal, due to the low voltage threshold of this diode type.

Through my reading on a number of different effects-related websites, I came across many references to other means of inducing signal clipping beyond simple diode arrays. One that caught my attention was MOSFET-based clipping (metal oxide semiconductor field effects transistor). MOSFET clipping is reputed to give a smoother overdrive tone than silicon diodes, similar to the germanium tone, but with more volume and fullness. The use of MOSFETs for clipping has become quite popular in high-end overdrive and distortion pedals--the Fulltone OCD and Fulldrive 2 pedals maybe the most familiar examples.

Anyway, since the parts involved were cheap--a couple of IRF520 MOSFET's at about a buck each, and a couple of 25 cent 1N34A germanium diodes--I decided to give it a try. I bought the MOSFETs from Small Bear Electronics, and soldered them and the 1N34A diodes (which I had a few of on hand) together on a small piece of perfboard. Then I just opened up my ZYS, removed the old 3x3 germanium clipping section, and wired in the new MOSFET array. While not as neat and well laid out as it would be if I'd built the pedal this way originally, it fits in the enclosure nicely and, most importantly, works perfectly.

The MOSFET clipping array does indeed give a very nice overdriven tone, and I can understand why they are popular in boutique pedals. While not quite as "soft" in character as the germanium array I used previously, it is very noticeably smoother and warmer sounding than the stock silicon diode clipping. It seems to have a somewhat fuller sound, too, which I would guess has something to do with harmonics. I'd say that this clipping mode comes as close to the tone of an overdriven tube amp as any pedal I've played personally. And the volume is essentially identical to the stock TS clipping, so no volume loss anymore when I switch to the Cool setting!

I'll try to get a clip posted in the next couple of days so that those interested can hear the difference for themselves....

[Tone2TheBone]

What would be the cost for this modification on existing ZYS pedals Voo?

[duhvoodooman***]

The parts are cheap, but the "price driver" is the time it takes, which is a couple of hours in all between disassembly, fabbing the new clipping array, and reassembly. I'd say $25 plus shipping.

Just like getting your car fixed--it's the LABOR that kills ya!

[Tone2TheBone]

The parts are cheap, but the "price driver" is the time it takes, which is a couple of hours in all between disassembly, fabbing the new clipping array, and reassembly. I'd say $25 plus shipping.

Just like getting your car fixed--it's the LABOR that kills ya!

Understandable. The only thing that I'd be concerned about too is having USPS deliver the package back and forth. Oh but you already know my reservations about that!

[duhvoodooman***]

Understandable. The only thing that I'd be concerned about too is having USPS deliver the package back and forth. Oh but you already know my reservations about that!

One word (learned the hard way): INSURANCE.

[Mark]

Hey DVH what are the possibilities of a layout drawing and parts purchase. I build and refurb amps so Im not a stranger to an iron. Id just need parts and a diagram to find my way as to what needs a burnin.

[WackyT]

Is this mod going to become stock in future versions of the "Zonkin' Yellow Screamer"?

[duhvoodooman***]

Is this mod going to become stock in future versions of the "Zonkin' Yellow Screamer"?

I'm definitely leaning that way!

[duhvoodooman***]

Hey DVH what are the possibilities of a layout drawing and parts purchase. I build and refurb amps so Im not a stranger to an iron. Id just need parts and a diagram to find my way as to what needs a burnin.

I'll e-mail a couple diagrams to you. Mark. As far as the parts go, here are links:

IRF520 MOSFET

1N34A Germanium Diode

You'll need two of each.

BTW, who's "DVH"?

-- DVM

[Mark]

DaVanHalen, DaVoodooHead DafreakinMarkforgothowtotypemynamecorrectly OR how bout BRAI FART ....there did it again Brain Fart LOL

Oh and thank you DBH: :

[duhvoodooman***]

Oh and thank you DBH

DBH....hmm, lemme think....Duh Butt Head??

[Robert****]

Sounds interesting. Man, this beast of a pedal already has a million options. You're just gonna keep adding more features just so we have to get them and use this pedal to ruin or weekends by flipping knobs for hours, aren't ya? :

[duhvoodooman***]

Sounds interesting. Man, this beast of a pedal already has a million options. You're just gonna keep adding more features just so we have to get them and use this pedal to ruin or weekends by flipping knobs for hours, aren't ya?

This wouldn't be an additional feature, but rather a substitution for the existing 3x3 germanium diode clipping array that's used for the "Cool" clip mode setting. Tonally, it's not quite as "soft" as the germaniums, but it doesn't have the volume loss problem, and it sure sounds warm and S-M-O-O-O-O-T-H! I really like it. I'll do my best to get a clip posted this weekend....