Building the tap tempo tremolo

[Taylor]

Regarding your board, we can't really know if you messed it up unless we know what it's doing. If it's working, then it's good.

There's a lot of info on fixing the tick in this thread, if you read over it.

[Ultrakd]

one problem is the multiplier footswitch isnt working. One of its pads good pulled out . Also the volume/gain isnt really working. Im using a pot instead of a trimmer, which hole goes to which lug?

[Taylor]

Looking at the silkscreen side of the board, with the tempo pot at the top...

The upper mult switch pad connects to the little via to the right of the 78L05. The lower pad connects to ground.

Gain knob: The upper pad should go to one outer lug of your pot, and the lowest pad should go to the wiper of your pot. Don't connect anything to the middle trimpot pad.

[Ultrakd]

Looking at the silkscreen side of the board, with the tempo pot at the top...

The upper mult switch pad connects to the little via to the right of the 78L05. The lower pad connects to ground.

Gain knob: The upper pad should go to one outer lug of your pot, and the lowest pad should go to the wiper of your pot. Don't connect anything to the middle trimpot pad.

Ok so the upper multi switch lug goes to that little hole to the right of the 78L05. What are the other 3 little holes on the board for?

[Taylor]

They are vias. They connect the top and bottom copper layers. You don't need to do anything with them. In the case of the multiplier switch we're just using that via because it's an available place to which you can solder, but in normal use you can and should ignore vias.

[Ultrakd]

Ok now nothing is working...I think I might need to get a new board and be more careful with the next one. I think I just messed up to many of the pads. How much is just a board?

[bside2234]

I'm hoping someone can help me.
I am wanting to do the rotary switches for the Waveform and the Multiplier pots. I got the Waveform working properly. I did have to switch the +5v and the ground wires around because it was working backwards. That fixed it.
I'm having problems with the Multiplier rotary. Again, I had to switch the +5v and ground wires to get it to not work backwards. My drawing illustrates this but my board illustration below doesn't.
The issue I'm having is the steps start out slow and progressively increase until I reach position 6. It goes back to the slowest tempo again.
I had a 5k resistor on each end (R1 and R7) and both positions 5 and 6 went back to the slowest setting.
I replaced one 5k with a 10k in R7 and that fixed position 5 but 6 still went back to the slowest.
I then put 10k in all of them and that didn't change anything. Positions 1-5 are ok but 6 goes back to the slowest.
I'm using the 6 position rotary from Smallbear. I triple and quadruple checked my board. I read to "not use the two top positions" and I assumed that meant the top 5k and the first 10k. I also removed the 3k6 resistor going to the Multiplier pot.
Here are the voltages I'm getting in each position which seem like they would be right. There is also the board I'm using. Remember I had to reverse the +5v and ground to get it to not work backwards which the board doesn't reflect.

[.Mike]

I read to "not use the two top positions" and I assumed that meant the top 5k and the first 10k.

I wonder if there is a bit of confusion with this. Like the datasheet says, the top two options are not used, but the resistance still must be there for the voltage divider to work right.

Add up your string of resistors. Does it equal 80K?



Mike

[bside2234]

Oh!!!!! Seven 10k resistors = 70k. I see now. I still need to use 9 resistors but I will be "tapping" into the 6 junction points for the 6 position switch. Correct? So if I tack on an extra 10k and 5k in series on the end, hook the wire up to that and change the resistor on the other end to 5k, I should be in business. I'll try it in the morning. I did get a little confused with that part. I took it as they weren't needed at all. Obviously!

Edit: Technically, I should be able to just put a 15k resistor on the "unused" end which would be a little cleaner. Right? Man, I'm not going to be able to sleep tonight. I've been mulling over this for a few days now.

[.Mike]

Yes, I believe that is how it works.

In theory, you can use 5K (tap1) 10K (tap2) 10k (tap3) 10k (tap4) 10k (tap5) 10k (tap6) 25k.

Mike

[bside2234]

Sweet! That would even be nicer as I can use the existing pads. I'll give it a try. Thanks.

Edit: Tried the 25k and it worked like a charm. Thank you!

[lwatford]

Any ideas for getting rid of a pop which switching it on?

[bside2234]

Mine doesn't pop.

[Johnny B]

Does anyone know where to source nice graphics of the waveshapes of the TTT to use on the pedal decal?

[.Mike]

Does anyone know where to source nice graphics of the waveshapes of the TTT to use on the pedal decal?

Since I plan on etching them into mine when I (finally) build it, I put together a 1200dpi vector PDF to share.

It should preserve the quality no matter how you scale it if you use the Acrobat print scaling.

Taplfo Waveshapes - 1200dpi.pdf

I also have the PSD if anyone wants it.

Mike

[Johnny B]

Does anyone know where to source nice graphics of the waveshapes of the TTT to use on the pedal decal?

Since I plan on etching them into mine when I (finally) build it, I put together a 1200dpi vector PDF to share.

It should preserve the quality no matter how you scale it if you use the Acrobat print scaling.

Taplfo Waveshapes - 1200dpi.pdf

I also have the PSD if anyone wants it.

Mike

Thanks, Mike. The waveforms cut, paste and resize perfectly. Has anyone worked out the angular position of the pot for each of the 8 waveforms? I am using a 16mm Alpha pot with a 300 degree rotational angle.

[Johnny B]

I think I may have answered my own question on the waveform pot angular positions. I have based the calcs on a pot with 300 degree rotation. I used the resistor chain shown on page 8 of the Tapflo datasheet with 7 10k resistors and a 5k on each end. The angles are calculated from the vertical ( 6 o'clock).
Position   Degrees
1   48.75
2   86.25
3   123.75
4   161.25
5   198.75
6   236.25
7   273.75
8   311.25
Can anyone confirm?

[bside2234]

Personally, I think you are making it a lot more work than it needs to be plus if the tolerance of pots (the actual value not what is written on it) comes into play, you will be off.

I would build the pedal, tape a piece of paper to the pedal around the pot, mark all the positions on the paper and either scan it and use that to make the graphic or just eyeball it from there. I think you may find that the switching points aren't exactly even. At least on the first one I built. I just marked each position directly on the enclosure and they are not very even where they switch over. It may just be mine though.

[moose23]

I'm using this Quartz Crystal QM002 http://www.banzaimusic.com/Quartz-Crystal-QM002.html

That's a 2MHz crystal you have there. You need a 20MHz crystal.

Im sure this is a stupid question but with the photocoupler does the long leads go into the holes where the + is or do the short leads?

http://www.silonex.com/datasheets/specs/images/pdf/103708.pdf

The dot indicates the cathode of the LED side of the optocoupler.

Mike

Ah totally messed up on that myself so. Thanks for the quick help. I'll order the right one now, hopefully it'll work perfectly.

and it dig work perfectly, cheers for the help. Lovely sounding pedal and lovely boards to work with.

[Gaetano Capuano]

CRAP where can I purchase an NSL-32