NEW PRODUCT: Taptation Tap Tempo controller

[slacker]

The TapTation gets away with this because it is an unfiltered PWM output which is a square wave that is switching the MOSFET between full on and off with the off resistance limited by the depth pot.

Yeah I realised that you were using a PWM signal after I'd posted, so what I suggested might not work. I've ordered a kit so I'll play around and  see what I can come up with. Worst case scenario you'd just have to include the mosfet and the original transistor and switch between them, be easy enough to use a dual ganged pot to control the depth of both.

[The Tone God]

Worst case scenario you'd just have to include the mosfet and the original transistor and switch between them, be easy enough to use a dual ganged pot to control the depth of both.

Or maybe keep the depth controls separate and you can have two selectable modulation settings.

Andrew

[Brymus]

@ TTG
What benefit might your taptation add to Rick's "Little Angel" chorus ?
If any.   

[Morocotopo]

Great thing!

To make things clear, this is a chip, not a chip in a PCB, right? You have to incorporate it in a build / layout, right?

And it can do this:
- Replace any LFO, and add tap tempo capability with rhythmic division options

Am I right?

[Brymus]

Citing the above post  ^^^^^^^^
I was thinking along the lines of using it to replace the Littel Angel LFO and to get the modulation in time to what was desired.
Thanks for saying it better.

[The Tone God]

To make things clear, this is a chip, not a chip in a PCB, right? You have to incorporate it in a build / layout, right?

And it can do this:
- Replace any LFO, and add tap tempo capability with rhythmic division options

Am I right?

Yes this is a stand alone IC. No PCB. If it gets popular I may make a PCB availible. I will not say it will replace ANY LFO because it depends on the spec of the original LFO. What it does provide is a triangle shaped PWM output that swings about 0.2v to 4.8v @ 5v input power supply and can sink or source about 20mA. An R/C network can smoothen out the PWM to make it analog or you can keep it PWM. The tempo divisions are applied to the PWM output and you can select the duty cycle to be half or full sweep with each tempo pulse.

I was thinking along the lines of using it to replace the Littel Angel LFO and to get the modulation in time to what was desired.

Look at the design with having pin 6 tied there nothing special the digital pot will provide so that part is out. I don't know the spec of the LFO as I haven't built it but it looks like in that design you could use the TapTation to fill that function.

Actually on my delay, based on an earlier version of the TapTation, I set the delay pot for the fastest time and play with the modulation speed which is separate from the delay time. It does make for a decent mock chorus.

Andrew

[Marcvv]

Hi Andrew,

Did you create a layout for the taptation. Perf or vero?

Thanks, Marc

[The Tone God]

Did you create a layout for the taptation. Perf or vero?

I don't normal work with vero and when I work with perf its on the fly. I'm sure others will chip in layouts if TapTation get popular. If it does get even more popular I'll look at making PCB availible.

Andrew

[Marcvv]

Ok, I will make my own then.

Thanks, Marc

[slacker]

I'll be building mine on vero when it arrives, I'll post the layout.

[Marcvv]

Hi,

I created a perf board layout for the taptation. I will post it once I verified it.

Marc

[Marcvv]

Build the taptation with my own perf board layout and I have it almost working.

I have it hooked up to an echobase now. I guess I will have to remove the delay pot from the echobase but have not done that yet.
I also have no momentary switch so it is a bit hard to check if it really works on tapping the tempo. Most of the functions seem to work as intended.
I will work on it again later and try to post the layout.

(I have to find out how to attach that to this post.

Marc

[Marcvv]

Here is the layout I made and for now it works. I hope it is ok if I post it. Let me know if there are any objections.
Still have to check some things.

[Processaurus]

Andrew, I didn't see it in the PDF, and was wondering what the frequency of the PWM from the triangle wave output is?

[The Tone God]

I also have no momentary switch so it is a bit hard to check if it really works on tapping the tempo. Most of the functions seem to work as intended.

You can use a toggle footswitch, like a bypass switch, for the tap tempo by grounding pin 4.

I should also mention that the time pin is set to the fastest tempo when connected to ground and slowest when connect to Vcc. That might seem backwards to some.

Thanks for the layout! I'm sure many will enjoy it.

Andrew, I didn't see it in the PDF, and was wondering what the frequency of the PWM from the triangle wave output is?

I should have put that in. The base frequency is around 310Khz. I'll update the docs with that.

Andrew

[slacker]

Got mine today and immediately threw it on the breadboard and hooked it up to one of my Echo Bases. First impressions of it are very good, hats off to the Tone God for a nicely thought out bit of kit.

The tap tempo works reliably, with no glitches or misread taps, and that's just using a bit of wire tapped to ground.
The modulation is very nice, going from just adding a subtle waver to over the top pitch bending.

For those interested in adding this to the Echo Base I tried hooking up the modulation (pin 7 of the digital pot to the collector of the original transistor) and it works fine. With the depth on minimum the tap tempo seems to work accurately enough, so the small resistance of the transistor doesn't appear to be a problem. That was just listening to the delays whilst watching the tap tempo LED though, I haven't tried tapping in time to a beat and seeing if it stays in sync. In the event that the accuracy is affected it's easy enough to just add a switch to disconnect the modulation completely, so it's not a big deal.

Just need to find a bigger box to fit it all in now. I'm thinking switchable modulation with depth controls for each. A rotary switch to give all the tap divisions. Then bypass, mod on/off and tap tempo stomps.

 

[Marcvv]

I hooked up the taptation to my PT 80 now (used an echobase first) and it works really well!! Very nice control over tap tempo. Modulation works very good. The 100k pot actually gives a longer delay time to the PT80. It is very grainy with the longest delay time, but usable and with the double tempo switch you are back to the original PT 80. Rehoused the PT 80 with the taptation in a new box and it is really worth it. Well done Tonegod!!

I discovered a mistake in my perf board layout. I corrected the mistake and the corrected and verified layout is the on posted now. (a few posts back).

[Marcvv]

I have been playing some more with the taptation and the PT80 and I notice on louder volume that I have a ticking in time with the tap tempo.
I disassembled it as I thought it might have to do with the placement of the taptation pcb and the connections to the PT 80. Ad fas as I can tell placement is not of influence on the ticking.

I found out that if I remove the tempo indication leds that the ticking is gone. I replaced the leds with several others and also with a larger resistor added to the 1k that is on the board. This made no difference. Any ideas how I can get rid of the ticking???

Thanks, Marc

[slacker]

I would try connecting the ground from the Taptation board directly to ground on the DC jack or battery negative and perhaps try a large capacitor between the 5 volts in to the board and ground.
You could also try using "super bright" LEDs that way you can use a really large resistor like 50K to limit the current to something really low.

[Marcvv]

I would try connecting the ground from the Taptation board directly to ground on the DC jack or battery negative and perhaps try a large capacitor between the 5 volts in to the board and ground.
You could also try using "super bright" LEDs that way you can use a really large resistor like 50K to limit the current to something really low.

Hi Ian,

I found one super bright led and that does solve the problem when wired with a large resistor. As I only had one of those I tried the other suggestion and wired the ground of the taptation board directly to ground on the DC jack (I had it wired to the ground of the PT 80 board first). Problem solved!! Not even a large capacitor needed.

Thanks, Marc