Something more... a Woody?

[Elijah-Baley]

Hello guys.
Two years to build pedals, and now I have some overdrives, distortions and fuzzes, a phase and a tremolo, I have to complete a delay, a reverb and an autowah, adjusting a pair of chorus, and start some other simple pedals.
Is this the time to build something more.
An acoustic simulator.

I don't want to buy one, but I want to build. I chose a Mark Hammer's Woody.
- There are some versions of this, the first version, it needs two 9v batteries, I don't wanna it.
- Sabrotone has a good layout on veroboard, is the same but adjusted to work with one battery. Verified, but someone have problems with it.
- There is Olver Alex version, slightly modded, and it works with one battery. That's ok, but I don't find a veroboard layout of it.
- And then there is a PCB on TH Custom, it is a bit different, but the schematic is the same of Oliver Alex and seems work fine. But I should to buy it.

A stripboard layouts will be perfect to me, but the sabrotone version doesn't convince me fully.
The TH Custom's PCB is used enough by many diyers, but I don't like too much the idea to buy a board instead to build it by myself as usually I did. Anyway the cost is not so high, but it is a further cost. Especially in this case where the board is not so complex.

What layout I could choose?

Thank you!

[Cozybuilder]

Hi EB-
Why not modify the Sabrotone vero layout to the Oliver Alex version?

[Elijah-Baley]

Is that possible? Actually seems to me a bit different. I also tried to build it by myself, but... Never mind .
I'd need some help even to modify that, and I do not know if it will work or not.
I know, I am complicated.

[Cozybuilder]

First, get the schematic for each. Compare, and find the differences.

Next, label the components on the vero layout, and mark which ones need to be changed.

Now, for simple resistor or cap value changes, thats just a substitution.

For other types of changes, you will have to look at where they go electrically, and find sections of the vero that will allow you to make these changes. You might have to jumper, or perhaps add a row or column to allow these.

I'll help if you want, or there may be someone on the forum who already has a verified layout?

[karbomusic]

Mark Hammer's Woody

No matter how hard I try, the inevitable thought that I can now not unthink has been thought.

[Mark Hammer]

If the mental image lasts any longer than 4hrs, you should call your doctor.

[Elijah-Baley]

 

First, get the schematic for each. Compare, and find the differences.

Next, label the components on the vero layout, and mark which ones need to be changed.

Now, for simple resistor or cap value changes, thats just a substitution.

For other types of changes, you will have to look at where they go electrically, and find sections of the vero that will allow you to make these changes. You might have to jumper, or perhaps add a row or column to allow these.

I'll help if you want, or there may be someone on the forum who already has a verified layout?

This is based on the original schematic:


This is the sabrotone's layout:


This is based on the modified schematic according Olver Alex:


TH Custom's PCB is pretty similar to this with some noise filter caps and some different values.

These three schematics/layouts appear much different between them.

I think there's a lot work here to do.

[bluebunny]

Mark Hammer's Woody

No matter how hard I try, the inevitable thought that I can now not unthink has been thought.

Let me fix that for you.

[Cozybuilder]

Elijah- There are quite a few differences between the Oliver Alex schematic and Harald Sabro's layout. I'm traveling tomorrow, and will be quite busy for the next few days- it will be next weekend before I have much of a chance to do anything with this.

[Elijah-Baley]

Thanks a lot for helping, Cozybuilder!
Meanwhile, I'll try to look them.

[Elijah-Baley]

I have to do place an order in a shop where I found this:
http://www.op-electronics.com/en/other/285-acoustic-simulator-8000285716445.html.
It is the same PCB of TH Custom, included some noise filter, and same price: 6 €. The schematic is the same, just two resistor's values, but I need just the PCB so I don't care.

Should I buy it? It is a further cost, I never bought a PCB, but I admit, I am a bit curious.

[Cozybuilder]

A quick look at this PCB indicates it follows Mark Hammer's schematic. I don't have the time to do a full tracing right now (double sided takes a bit of time), and this site didn't show the component values so can't say for sure, but the connections I checked are the same. For 6 euros, this is something I'd buy.

[Elijah-Baley]

Indeed, the PCB seems to me pretty similar, or maybe identical to TH Custom PCB.
You can find the schematic and the bill of material in the datasheet PDF document in the page I linked. Just for take a look.
I checked every single components, the name R1, R2, C1, C2, etc. are the same. The only exceptions in the two PCBs are two resistors: R1 and R2, TH shows 10k, Op-Electronics shows 12k. And TH has one of the two noise filter cap of 330pf instead 470pF like Op-Electronics, but that is ok.

6 € is a further cost, but I'd like to buy a PCB for once, it is verified (well, TH custom it is, but Op-Electronics should be a real copy of it). Considering I have no many choices... It should be good, in the end.

Thanks!

[Jdansti]

There's nothing wrong with spoiling yourself by purchasing a PCB now and then!

[Elijah-Baley]

Exactly. I was expecting I'd buy a PCB in case like a flanger effect, or complex delay or something. Ok, this acoustic simulator, it's pretty simple, but I didn't found nothing could satisfied me on veroboard layout, so it is kind of similar thing: I didn't find the right layout for me and I buy a PCB. And I can build my effect how I wanted.
I'm also lucky, because I found, coincidently, what I want in a shop I was planning to make my order. I have just to wait a bit to place my next orders.

[KazooMan]

I spent the winter woodworking and haven't made any pedals for a while.  This thread reminded me that I always intended to build a Woody so I finally got around to it.  I used the vero layout posted by Elijah-Baley above and it reminded me that I really don't care for vero.  32 cuts and 15 jumpers for such a small project!  At any rate, that is not the reason for the post.  I thought the Woody should have a wood themed enclosure so I tried something new for me.  I put the pedal in an old aluminum enclosure I had from a prior project for now and then laminated on a piece of birdseye maple veneer (from the woodworking hobby).  I made some quick labels using the reverse printing on transparency stock method and then glued that down with spray adhesive.  The results are shown below.  I will have to put the pedal in a nicer powder coated enclosure and do a bit more work on the labels, but I think the prototype was a success.

[Elijah-Baley]

WOW! Really nice!
So, you used the sabrotone layout? (Where's gain pot?)

[KazooMan]

I put the gain trim pot on the board where it shows on traces K and L.  It connects one end of C10 and the associated diodes to the 150K resistor.  Note that the numbering for these parts is a bit different on the vero layout and the schematic.

Here's the big disclaimer.  I haven't even fired up the pedal yet.  I cut my left little finger on Easter Sunday (seven stitches worth, right on the end of the finger) and haven't picked up a guitar since. 

I will go try out the pedal with a "one finger" playing method that will be somewhat akin to my typing style.  I won't be playing any chords for another week or two.

Note added a bit later:  OK, I tried the pedal.  It works.  No surprise since ALL of my builds work first try

However, I will have some tweaking to do.  I have read Mark Hammer's original description of the pedal and I have confirmed that the trim pot is in the correct location based on his schematic.  However, there is WAY too much top end "sizzle" (as Mark calls it).  Sounds more like a distortion pedal than an acoustic guitar.  I would like to get more of the bass mixed in and calm down the sizzle.  I actually used a twenty turn Bourns trim pot because that was what I had on hand.  I tested it with a meter before I used it to set it at the midpoint, so I know that it is functioning properly.  I can crank it from end to end with little or no change in impact on the high end. 

[Cozybuilder]

K-man- Look at it as a golden opportunity to work on your slide technique.

[Mark Hammer]

Well, I'm honoured that such a fine piece of handiwork bears my name.  On the other hand, if my name is on it, it better sound damn good if you play it for anyone!