Zendrive or Eternity?

[11 Gauge]

I'm about to clone one or the other of these.

I've got friends with both, have spent time with both, love them both.

I just can't decide which to go with - they're both great.

I'd build one of each (plus a Timmy), but I'm up to my elbows in stomps as is.

Has anyone spent considerable time with both? Particularly for gig uses?

I'm leaning towards the Eternity since it's a bit more of a true Tubescreamer than the Zen (no special diodes or chip), but the extra pot (voice control), different diodes (mosfets and schottky), and chip (AD712) don't really make the Zen much different from a Screamer, either.

Thoughts, insights, or otherwise?

[maestrovert]

uh, you could build a dual stomp box with both, right ?


as a friend would say: "too much of a good thing is muchly betterer !"

[Nub]

Originally Posted by 11 Gauge

but the extra pot (voice control), different diodes (mosfets and schottky), and chip (AD712) don't really make the Zen much different from a Screamer, either.

That's kind of like saying that the different engine & suspension in a Porsche 911SC don't really make it much different from a VW Beetle...

[11 Gauge]

Originally Posted by Nub

That's kind of like saying that the different engine & suspension in a Porsche 911SC don't really make it much different from a VW Beetle...

That's a very poor analogy, IMO. Those two vehicles have nothing in common!

A better analogy would be to take a Beetle engine and swap the 32 PICT carb for a 34 PICT, the points and condenser for an electronic module, and the stock exhaust for a Kadron unit...

[11 Gauge]

Originally Posted by maestrovert

you could build a dual stomp box with both

This might be the best way to go.

The only issue is the monstrosity would have SEVEN knobs! I hate lots of knobs...

Of course I could lose the voice knob by simply using a trimpot - once I hit the magic spot, I would leave it there, no doubt. I actually have a pretty good idea what value resistor I'd put in it's place, as well.

And if they make a 500K/100K ganged pot, I could toggle between the drive controls...

And if they make a 50K/5K ganged pot, I could toggle between the tone controls...

AND...with a single switch, I could toggle between the diode sets and coupling cap pair.

I'm sure that the Eternity would sound great with the Zen chip (AD712). I might even converge parts of the two designs.

Thanks, Rob - a very elegant solution (if they make the pots).

[ramseybella]

And where would one find these schematics?

[guit30]

Vince Gill says that the Zendrive is the only pedal that he really is crazy about. I do like the sound of a tubescreamer. I love my Nashville Hot Boost, which also has a 4558 opamp in it.
I would love to try a Zen Drive some time
Jim

[Nub]

Originally Posted by 11 Gauge

That's a very poor analogy, IMO. Those two vehicles have nothing in common!

Maybe I should've waited until after I'd had some more coffee...

Originally Posted by 11 Gauge

A better analogy would be to take a Beetle engine and swap the 32 PICT carb for a 34 PICT, the points and condenser for an electronic module, and the stock exhaust for a Kadron unit...

You're going too far in the opposite direction, I suspect there's more to the differences than that. I can't argue diodes & chips with you, because I'm an electronics doofus, and wouldn't know a schottky from a donut . But I have tried a ton of TS variants, and many of the "Dumble tone" pedals; most of them sounded great, but none of them sounds exactly like the Zendrive. My thinking about clones is this: If they don't sound the same, they're NOT the same, no matter what the builder says. I have to think that if it was just a matter of taking a TS schematic & changing a few minor parts, and given the multitude of TS mods that have been done, the "Zen-cloners" would've gotten it right by now.

[11 Gauge]

Originally Posted by ramseybella

And where would one find these schematics?

Right here:

[11 Gauge]

Originally Posted by Nub

I have to think that if it was just a matter of taking a TS schematic & changing a few minor parts, and given the multitude of TS mods that have been done, the "Zen-cloners" would've gotten it right by now.

It has been done already. That's why I'm about to build one myself.

Ditto for the Eternity.

I just build 'em for personal satisfaction, and to save a bunch of scratch in the process. I imagine that many folks who roll their own do the same thing. That's probably why you can't find one that "gets it right."

For the average guitarist, it probably does seem like there's magic in those boxes. I can understand that.

[maestrovert]

Originally Posted by 11 Gauge

This might be the best way to go.

The only issue is the monstrosity would have SEVEN knobs! I hate lots of knobs...

Of course I could lose the voice knob by simply using a trimpot - once I hit the magic spot, I would leave it there, no doubt. I actually have a pretty good idea what value resistor I'd put in it's place, as well.

And if they make a 500K/100K ganged pot, I could toggle between the drive controls...

And if they make a 50K/5K ganged pot, I could toggle between the tone controls...

AND...with a single switch, I could toggle between the diode sets and coupling cap pair.

I'm sure that the Eternity would sound great with the Zen chip (AD712). I might even converge parts of the two designs.

Thanks, Rob - a very elegant solution (if they make the pots).

this might be a really -no, i mean really- stoopid question, but here goes:
Could you cobble up the pots you'd need, or somehow modify the value(s) of existing pots ?
"Where there's a will, there's a way"

[Nub]

Originally Posted by 11 Gauge

It has been done already. That's why I'm about to build one myself.

Ditto for the Eternity.

I just build 'em for personal satisfaction, and to save a bunch of scratch in the process. I imagine that many folks who roll their own do the same thing. That's probably why you can't find one that "gets it right."

For the average guitarist, it probably does seem like there's magic in those boxes. I can understand that.

Nah, I don't think there's any magic to it. But every time I've heard a Zendrive clone, it just doesn't sound like the real thing (the 'Net is full of those)... That tells me there's something in the Zendrive schematics that are floating around that isn't accurate.

I'll definitely be interested to see how your project turns out, and hear it A/B'd with a Zen.

[11 Gauge]

Originally Posted by maestrovert

this might be a really -no, i mean really- stoopid question, but here goes:
Could you cobble up the pots you'd need, or somehow modify the value(s) of existing pots ?
"Where there's a will, there's a way"

Not stupid at all - I frequently find myself "augmenting" the taper of pots with resistors. But the taper can get all goofed up if you have to do anything extreme. For instance, if you have to cut down a 500K drive pot (like on the Zen) to a 100K (like on the Eternity), that's a five-fold impedance reduction. If it's anything other than a linear taper, then all bets are off.

I'll probably end up grafting together the best parts of each design. Actually, it's looking more and more like it'll be a Zen, since that seems to be all the buzz in response to my query.

[tonfarbe]

I only hope that this thread stays civil
One question: Do you etch your own PCBs or do you build your pedals with perfboards?

As a DIY newbie, I would love to see an illustrated build thread of one of your pedals.

[stax]

Been listening to some of the clips of the Zendrive on youtube and would be interested in building something similar myself.
Love to have a fraction of 11 gauges knowledge but unfortunately need a bit more info than the schematics shown.
Does any one know if there are any layouts or even kits available to get into the ballpark sound wise?
Stax

[11 Gauge]

Originally Posted by tonfarbe

I only hope that this thread stays civil
One question: Do you etch your own PCBs or do you build your pedals with perfboards?

As a DIY newbie, I would love to see an illustrated build thread of one of your pedals.

I hope it stays civil, as well. I'm not trying to irritate those who have a real Zen (or Eternity, Timmy, etc.), and not trying to take anything away from Hermida. I'm more like a guy who builds partscasters when it comes to pedals - I build one for myself, and keep it at that. If I build a ped for a friend, I always alter the circuit (usually for their specific requirements, anyway).

I try to avoid etchant like the plague these days. I've been using certain chemicals for the past 3 decades, and trying to put a halt to it.

Perfboards are wonderful, and for something as simple (circuitwise) as a Zen, they are perfect. Actually, they leave A LOT of room for expansion.

If I ever get together a method that would make sense as an illustrated build, I'll do it. Unfortunately, my method is kinda multithreaded (I have multiple projects going on in my head and the bench at the same time). I don't think it would be very productive!

If you want to etch your own board and drill your own box, go here:

http://revolutiondeux.blogspot.com/2...at-fsborg.html

I suggest trying a General Guitar Gadgets or BYOC build if you're new to all of this. Everything is clearly illustrated.

I'd also suggest researching the history of the Tubescreamer. After doing that, it becomes apparent how many of these boxes are based on it, despite what anyone says. When you put two schematics side-by-side and they look more similar than different, there's no denying it...

[11 Gauge]

Originally Posted by stax

Been listening to some of the clips of the Zendrive on youtube and would be interested in building something similar myself.
Love to have a fraction of 11 gauges knowledge but unfortunately need a bit more info than the schematics shown.
Does any one know if there are any layouts or even kits available to get into the ballpark sound wise?
Stax

You can start with a General Guitar Gadgets or BYOC Tubescreamer kit, and tweak from there. They keep the buffer transistors, so you'll have to move your input and output wires to before/after them (or jumper them), though.

The biggest "challenge" with the Zen and an existing board is the diode array: you have to get a pair of mosfets and 3 schottky's where the TS only has a pair. It's actually not that difficult - just takes a bit of soldering ingenuity and maybe some heat shrink to keep anything from shorting.

And where the "voice" control goes on the Zen, you simply wire up a 10K pot in place of the 4.7K bias resistor in the TS circuit.

Also, the Zen's tone circuit is simpler: it uses a single cap dumped to ground prior to the recovery gain stage. A TS has it tied to the inverted input of this gain stage - you simply leave all of those parts out, and put a jumper where the 1K resistor was!

You might also want to print out as many schematics as you can, starting with the Tubescreamer. A good second one would be the FullDrive II, as it's very similar. From there, you could add the Eternity, Timmy, Zen, Clay Jones, and countless others. You could even combine different parts of them.

Also, GGG and others will typically add boutique mods with their kits. They explain what the mods do, and you can build on them as your knowledge increases.

[Webfoot]

What are the ZD diodes used... BAT41... what are these?

[Nub]

Originally Posted by tonfarbe

I only hope that this thread stays civil

Originally Posted by 11 Gauge

I hope it stays civil, as well. I'm not trying to irritate those who have a real Zen (or Eternity, Timmy, etc.), and not trying to take anything away from Hermida.

I'm guessing these comments were aimed at me...
you did ask for "thoughts, insights, or otherwise" in your op... I was providing the "otherwise."


I'm not irritated at all by your Zen clone project, 11 Gauge; in fact, I sincerely hope it's a success for you. My comments were in regards to your indicating that the Zendrive was not really much different from a Tube Screamer; like I said, I've heard other guys make that statement & their clones don't sound like the Zen. And this being the Internet, statements (and schematics!) are accepted (and repeated) as fact, whether there is definitive, "sound" proof to back them up or not.

Btw, I haven't ever tried an Eternity, so I can't comment on it, but I think the dual pedal idea is a cool one. Best of luck with your project.

[tonfarbe]

Originally Posted by Nub

I'm guessing these comments were aimed at me...

No, not at all.
Maybe you remember my own thread about a pedal clone build (my first ever)
which had to be shut down by the moderators 'cause it ended in ugly arguing

[11 Gauge]

Originally Posted by Nub

I'm guessing these comments were aimed at me...

No - not at all. I was just trying to elaborate on any intentions that I have, which don't include upsetting or irritating boutique pedal builders or customers. I think that the vast majority of boutique'ers do a wonderful job, especially considering that you get most of 'em built by hand, and all wrapped up in a neato little package.

But - I do recall the thread that was shut down. I don't want a repeat of anything like that.

[11 Gauge]

Originally Posted by Webfoot

What are the ZD diodes used... BAT41... what are these?

The Zen uses a pair of 2N7000 mosfets and three BAT41 Schottky diodes for clipping/distortion...

The 2N7000 is used in countless other pedals (OCD is the other hot fave), and is actually a great way to round off the distortion in almost any pedal that uses something "traditional" like 1N4148 silicon diodes.

With a mosfet, there are 3 leads. You tie the G & D together, and this becomes your "cathode" of your "mosfet diode" (equivalent to the side with the stripe), with the S being the "anode".

That BAT41 is a Schottky diode that has a very low forward current that switches it on. It's basically the modern equivalent of a 1N34A germanium diode. My guess is that these were chosen because 1N34A's are a little big for tight circuitboards, and the BAT41 is 30 cents, while a 1N34A is 50 cents. Hermida put an expensive chip in the Zen (~$4), so saving 60 cents per pedal for diodes helps to offset that cost.

Lots and lots of pedal builders are catching on to Schottky diodes. The new Big Muff RI uses the 1N6263.

[Webfoot]

Thanks for the info. Any OCD schematics?

[11 Gauge]

Here's V4:

[Webfoot]

Thanks again.

I built a BYOC TS kit and put in a lot of different LED, diode and cap mod combinations with external switches. It worked out very well. I can actually get an amazing sound at low volume levels... dare I say even dumblesque if desired. But when the palying volume goes up, it falls apart. Not sure if this is the fault of the BYOC/tube screamer (TS) box I built or the amp I modded (15 watt blues jr with Billm mods etc.... trying to be lightweight for a change... down from a 70 lb heavily modded bassman).

So many times you think you have a good sound but in a gigging situation it's not there at all. I suspect these other pedals probably have a more focused sound for standing out. I do have a bb preamp and a timmy. I like the bb preamp voicing a lot. My only wish is that it had less compression. So far it is my number one pedal if I could only take one. It is great for rhythm rock playing and okay for solos (not a lot of note hang time like with a TS style circuit). Timmy is another pedal I have and is good for low level gain and country pickin. Very open sounding but have not found a real use for it yet as I tend to play either really clean or really dirty. Probably best as a 'clean lead - light grit' boost.

Really want to find that one pedal that does it all in range of OD to distortion. For me that would be doing both hard rock rhythms and soloing... by just using the volume knob on a guitar with that one pedal into a clean amp.

This guy has a good sound...

http://www.youtube.com/watch?v=_n-xmn4iboc&feature=user

also has some sound clips with a OCD that sound very close.

[11 Gauge]

Originally Posted by Webfoot

Really want to find that one pedal that does it all in range of OD to distortion. For me that would be doing both hard rock rhythms and soloing... by just using the volume knob on a guitar with that one pedal into a clean amp.

I'll give you some clues.

You probably need a combination LED/1N4148 clip pair. This will give you the right balance of compression and boost. If it gets ratchety sounding, you need to bypass it with an incrementally bigger cap until the icepick goes away. Don't be afraid to go bigger than .001 uF. Most people keep the "bright cap(s)" too small, IMO.

You can do it with diodes in the feedback loop - this will keep from overcompressing/limiting. The key is to put them in the second/recovery gain stage, but you'll probably have to re-voice the entire circuit. You may also need to bias this stage like the OCD does. The cool thing is that you can keep upping the resistor in the loop until you get the right amount of drive.

The other trick to stop the icepick is to keep the drive levels as low as possible in the loops, and drop interstage series resistance as much as possible. Even though the stock TS uses 500K for drive, it usually helps to drop it to 250K or even 100K (like the Eternity), and then recover it on the second stage, with a FB loop resistance of 22K or better.

Part of the reason why the OCD works where others fail (IMO):

- The mosfets. They round over the clipping in ways that other diodes simply can't, and they do it at a higher threshold.

- The TLO82 op amp. It's input impedance is usually higher than other chips, which allows for greater drive levels. It's kinda counterintuitive, since most folks are going to cleaner chips with a greater bandwidth product. Listen to the higher gain clips at the website, and you can hear that this pedal is noisy when you crank it. That's the TL0XX family of chips, for certain!

[guit30]

Hi,
The secret of the zen drive could be in the burr brown ic, this company makes the best a/d converters and a lot of sonic products, never saw a burr brown product used in a pedal
Jim

[Webfoot]

Thanks for the tips... I think I understand most of what you are saying but might get back to you with more questions.

I noticed in your profile you have quite a few teles with different pickups. I am curious about not-tele neck pickups. How do you like using a single coil strat pickup? Is it richer and warmer then the standard neck pickup?

[11 Gauge]

Originally Posted by guit30

Hi,
The secret of the zen drive could be in the burr brown ic, this company makes the best a/d converters and a lot of sonic products, never saw a burr brown product used in a pedal
Jim

Actually, the Zen doesn't use a BB, which is actually owned by TI now...

Most of the "follow the leader" modders are using OPA's in their mods, so I think you'll see less and less of them in the boutique stuff.

The Zen uses an Analog Devices chip.

Granted, if you stuffed your favorite OPA in one and an AD in another, you probably couldn't distinguish between them. But I think that pedal builders kind of like bragging rights for using a different chip. The KoT uses a JRC4580D, which is really a headphone amp chip. The Timmy uses a JRC4559, etc...

There are thousands of op amps that will retrofit into most of these overdrives, and many of them sound good in an OD pedal. You could spend a lifetime simply swapping chips...

[11 Gauge]

Originally Posted by Webfoot

How do you like using a single coil strat pickup? Is it richer and warmer then the standard neck pickup?

It's subjective, more than anything.

The biggest reason is that I'm not a Strat player, but love the neck pickup sound. I can get close with some Tele neck pickups, but no cigar...

The Tele pickup is actually warmer sounding, IMO. The Strat pickup has more attitude, snap, and definition.

I grew up listening to Hendrix, Gilmour, and others. I love that neck pickup tone.

[guit30]

The website says they use a Burr Brown ?
J

[11 Gauge]

Believe me - it's an AD712.

The guy who produced the schematic (Luis Jimenez Lopez, aka "Stratotrasto") has a real passion for getting things accurate.

If you don't believe me, here's what he had to do to satisfy himself with a proper Univibe replica:

http://translate.google.com/translat...ial%26hs%3DrKL

The bottom line is that probably any of the current super low distortion op amps will work sufficiently, and probably plenty of the oldies will, as well. It really becomes a matter of minutiae, and how picky you are about chip tweaking.

I tend to trust my ears when A/B'ing. As long as I've got a good control subject (i.e. a friend's Zen that I promise not to dissect!), I can typically tell when I've got it right.

[guit30]

Not for me, tried one out at Alf's website, too dirty
JIm