Hermida Audio - Zendrive [ goop-alarm ]  [traced]

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Ripdivot
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Post by Ripdivot »

If you are going to run it at 18 volts you just need to make sure the caps are rated for at least 25 volts (better yet 35 volts) and you shouldn't have a problem. It is always a good idea to use caps with double the voltage rating that you need. I tried mine on 18v but ended up just using 9v.

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Post by timmyo »

Ripdivot wrote:If you are going to run it at 18 volts you just need to make sure the caps are rated for at least 25 volts (better yet 35 volts) and you shouldn't have a problem. It is always a good idea to use caps with double the voltage rating that you need. I tried mine on 18v but ended up just using 9v.
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Gila_Crisis
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Post by Gila_Crisis »

i used an OPA2134 in mine and it works really fine!
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Smrtokvitek
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Post by Smrtokvitek »

Hi I have little question. I would like to make Zendrive 2. It looks like classic zendrive just with the tube added. Does anybody know how to make it ?

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abfackeln
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Post by abfackeln »

Had some time to kill waiting on the AP pcb's to come in, so....
I've been watching this thread for a while and been wanting to build one, so after digging around in the parts bins realized I had everything I needed (except the 470n caps - more on that in a minute).
I used madbeans pcb layout (thanks madbean!), but built it up on the ol' Radio Shack pad-per-hole stuff (I have piles of those things). Got it together pretty quick today, sounds pretty good. Haven't had a chance to dime it yet as it's getting late, so hopefully tomorrow.
Still needs some paint & knobs - not the cleanest of my builds, but proved to be a good project for a rainy day. I dig the "ultra-violet" led's I picked up from PPP. Also note the "clever" use of stacked caps to achieve the 470n's.... :wink:

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Dallas
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Post by Dallas »

Here is a layout with mods for a switch on the board. It uses an on/off/on switch for regular clipping, asy. clipping, or no clipping. Special thanks to Derek's work for a starting point -thanks very much.

The funky lower left corner is because I'm using a small size perf board that does that in the corners.

LED power is on there too - for using true bypass footswitch etc.

It is possible to have LED indicators for the two types of clipping with a 3pdt switch, or even give all three clipping positions a separate indicator including off with a 4pdt switch. If you need help PM me.

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Post by Dallas »

Updated - thanks for input.

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quaternotetriplet
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Post by quaternotetriplet »

Is the hermida distortion the same as the zendrive with a little high gain???

How can i increase the gain of the zendrive??

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Post by Gila_Crisis »

increase the gain pot to 1M or more :P
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Dallas
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Post by Dallas »

Here is my completed pedal via the above schematic. Instead of just "no clipping" in the off position for the on/off/on switch I ended up using 2 red LEDs. Wide open was just too much for my ears volume wise and the 2 LEDs sound superb. I used 4 silicone diode's for one clip and the asymmetrical clipping shown for the other. 2 LEDs are placed in the path of the clip signal permanently. When switch is in the off position the 2 LEDs are active. When the other positions are chosen the LEDs are automatically bypassed by the tighter signals coming from the other clipping options.
Just put the two LED's somewhere on the board in a clipping arrangement. Wire the two switch wires as normal to the switch center and add two wires to the same spots on the switch that go to the LEDs. That's just one way -
It sounds superb.

This box was purchased from pedalpartsplus.com. The graphics are lazer decal stock. The silver part of the decals is just Silver Sharpee colored directly to the box, so that the clear part of the decal centers shows it. It's a really nice shiny silver in person - too easy.

Thanks again for all the input on this thread - much appreciated.

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guiltyspark
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Post by guiltyspark »

Back to the chip, might have to disagree on the AD712 being the stock chip. I just got a 712 and it looks nothing like the stock chip, plus it has a notch at one end. Stock chip looks like a TI or Fairchild product to me.

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Post by quaternotetriplet »

Hi, i wonder which capacitor or resistor should i change?, to remove the nasal sound of the zendrive??

gtrwrks
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Post by gtrwrks »

The R/C and variable R network off the FB loop - as you adjust the Voice, you alter the Gain; more gain, more mids - you could remove the 'Voice' and set the amount of lowend roll of that you wish - Jack Orman's handy calculator can pinpoint the R/C values.

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Post by quaternotetriplet »

I'm sorry I hope i understand. I'm just a Noob on diy pedals.
Any links? :oops:

NoGlory
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Post by NoGlory »

Can someone tell me whether to use Log or Lin pots for de Zendrive. It's confusing cause A and B is different at different places...

I guess Lin for the drive, voice and tone. And Log for the volume?

NoGlory

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Greg
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Post by Greg »

NoGlory wrote:Can someone tell me whether to use Log or Lin pots for de Zendrive. It's confusing cause A and B is different at different places...

I guess Lin for the drive, voice and tone. And Log for the volume?
Yes.. that's right. All Linear except the Volume.

I agree that the A and B designation can be confusing.
culturejam wrote: We are equal opportunity exposure artists.

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Greg
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Post by Greg »

quaternotetriplet wrote:I'm sorry I hope i understand. I'm just a Noob on diy pedals.
Any links? :oops:
To make it a bit easier to understand...
You already have control over the mids with the Zen.
The "Voice" knob affects Bass cut (but also affects Drive when you adjust it). The more Bass you allow into the circuit, the less effective mids you'll hear.
The Tone knob affects Treble. Again the more Treble you allow in, the less mids.

A mid push is in the nature of this type of circuit, but you should be able to get rid of the nasal quality easily.. Of course it can be affected by pickups, etc as well.
If it still has too many mids for your taste I suggest you try the Timmy.
culturejam wrote: We are equal opportunity exposure artists.

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Post by NoGlory »

And the 1N400X diode, does it matter whether it is a 1N4001 or a 1N4007 for example?

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jmorrero
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Post by jmorrero »

NoGlory wrote:Can someone tell me whether to use Log or Lin pots for de Zendrive. It's confusing cause A and B is different at different places...

I guess Lin for the drive, voice and tone. And Log for the volume?

NoGlory
pots are all linear...

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jmorrero
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Post by jmorrero »

guiltyspark wrote:Back to the chip, might have to disagree on the AD712 being the stock chip. I just got a 712 and it looks nothing like the stock chip, plus it has a notch at one end. Stock chip looks like a TI or Fairchild product to me.

Guiltyspark
i agree...

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