Building the tap tempo tremolo

[Johnny B]

I built the circuit with C9 at 1nF rather than 330pF and had absolutely no problem with ticking.

I was wrong.   I didn't notice the ticking at first, but having played with the tremolo more, I now realise that I have ticking in square wave mode, even with the pedal switched off. I have wired the pedal as per the wiring diagram in the build instructions but would like to do the switching mod described by Taylor on page 3 of the thread.
Unfortunately, the link on page 3 doesn't work and I can only download a low res version of the diagram at http://img820.imageshack.us/img820/6872/taptempotremalternateby.th.jpg
Taylor, could you please repost the link for the hi-res version of the diagram. Many thanks

[Taylor]

Strange, the link is working for me. Are you sure?

http://imageshack.us/f/820/taptempotremalternateby.jpg/

It does open up some pop-ups, so if you have popup blocker on, you may not be able to view it. The next time I'm at my other computer, I will add the alternate wiring to the build document and add it to the musicpcb website.

[Johnny B]

Strange, the link is working for me. Are you sure?

http://imageshack.us/f/820/taptempotremalternateby.jpg/

It does open up some pop-ups, so if you have popup blocker on, you may not be able to view it. The next time I'm at my other computer, I will add the alternate wiring to the build document and add it to the musicpcb website.

I have pop-ups enabled from imageshack.us, but all I get is a grey square. Perhaps once you have updated the build document, you could post the link on this thread. Many thanks for your support, Taylor.

[Johnny B]

Strange, the link is working for me. Are you sure?

http://imageshack.us/f/820/taptempotremalternateby.jpg/

It does open up some pop-ups, so if you have popup blocker on, you may not be able to view it. The next time I'm at my other computer, I will add the alternate wiring to the build document and add it to the musicpcb website.

I have pop-ups enabled from imageshack.us, but all I get is a grey square. Perhaps once you have updated the build document, you could post the link on this thread. Many thanks for your support, Taylor.

Taylor, I managed to download on my home computer so I think the problem must be a block on the office network. It would be nice, however, to have the build document updated.
Many thanks for all your assistance

[teej212]

If I wanted to, could I use this as a CV pedal? would I be able to simply attach a jack to the positive leg of the LED to have a CV output?

[Taylor]

No, because the signal there is a PWM signal, not an analog LFO. The optocoupler filters the signal into an LFO. You'd need to filter the signal either using the filter circuit in the TAPLFO datasheet, or still using the optocoupler but running a DC voltage through it.

[Johnny B]

So I'm reporting back after trying out different photocells and the NSL-32sr3 solved my depth problem completely and didn't add any ticking BUT when the signal flows through it  there is slight buzz/hum that comes in and out with the pulse of the trem. while playing the buzz isn't very noticeable but without playing its very noticeable. any ideas to fix that issue. If I can get that buzz out then it'll be perfect!

Thanks.

I suspect the buzz/hum is just the noise in the system being amplified and switched through the tremolo. Try shorting the input to ground and see if you still have the buzz/hum on the output.

[Johnny B]

I pulled out my oscilloscope and signal generator today to try to solve my ticking problems. I previously rewired the switch as per the diagram on page 3 of this forum and that got rid of the tick when the tremolo is switched off. I also wired my input, output and wire from R10 to switch with screened cable and earthed the screen at one end only.
The scope clearly showed that the click is generated on the negative edge of the output waveform as the tremolo switches off. The front edge rises quite slowly but the back edge falls off sharply. This appears to be in contradiction to the NSL-32 data sheet which shows rise time as 3.5ms and fall time as 500ms. I suppose the tick is generated by the falling edge overshooting at hitting the 0V line. What really had be fooled was that the next door neighbour's electric fence was shorting to earth and generating a click in my amps!
Anyway, I have the external LED pot (25k) set at max resistance (fully anti-clockwise) and my super-bright blue LED is plenty bright enough. I turned down the pot driving the NSL-32 LED anti-clockwise until the click substantially disappeared. This leaves me with unity gain at about half way on the off-board mounted 50k volume pot. I think I sacrifice some depth, particularly at faster speeds, but I'm reasonably happy with the pedal set up now and the ticking, if any, is not noticeable.
Taylor, I must compliment you on a brilliant design. I really can't think of anything else you could want a tremolo to do. I lent mine to a professional muso who works at a local music store last week and he was blown away by it. It A/B ed it against a Voodoo Labs tremolo and said that apart from all the additional features on the TTT, the TTTs tone way far superior - warmer and more transparent. So thanks and well done, Taylor.

[Ultrakd]

which opto is better the NSL-32, the NSL-32R2 or the NSL-32R3?

[pedaljunkie]

Quick question..  Just wondering how (considering ticking issues and what not) to add 2 LEDs that do the exact same thing (for a blinking eyes kind of effect).  Would I solder both LED's in parallel to the 2 pads?  I remember reading  that a few guys were troubleshooting ticking issues and by taking out the LED, I believe, they got rid of it.  I'm hoping this is do-able without causing any extra issues.

Thanks in advance.

[.Mike]

You probably want to connect the LEDs in parallel, just as in the schematic. Each LED and its current limiting resistor (trimpot in this case) should be connected between 5v and the transistor.

The transistor used for the LEDs is to protect the PIC, which can only source 20mA current. It should be able to handle all the LEDs you need. I was concerned about possibly damaging the PIC by pulling too much current when I put together the VCLFO tremolo (which is the basis for the app note schematic for the VCLFO tremolo, the TapLFO, and eventually this great project). I asked for the simplest solution, and that's what I got. An EE friend of mine drew it up on a napkin... heh!

Of course, the more LEDs you have, the more likely you are to have ticking as they turn on and off. Definitely use superbright LEDs.



Mike

[fatecasino]

I fixed everything the pedal is super great! BUT when i put it in the enclosure something went wrong and the pedal started smell really bad!! I found out that the 10 Ohm res. was burnt I replaced it, I replaced the 78L05, the 330 nF, the TL072 but still nothing!!
I don't know where to go next.
The symptoms are:
-The led works perfectly and changes rate as I tap or move the pot knobs
-With polymeter I found out that the ground(-) of the audio out  makes a circuit with the (+) of the audio out. How is this possible?! When I touch the ground(-)  with my finger I don't get any sound from the amp.

Any suggestions? what should I try to replace next?The photocoupler?

[.Mike]

The 10-ohm resistor is optional, and can be replaced with a jumper. If it burnt, though, it's because something pulled way too much current through it. Since it happened when you put it in the enclosure, I would suspect a short, like a wiring error.

If the LED is flashing, it is likely that the regulator is feeding proper power to the Taplfo, which appears to be functioning properly.

Does it pass signal in bypass?

Mike

[fatecasino]

no, absolutely no sound in bypass

[.Mike]

It's sounding more and more like a wiring error on your build.

Assuming you are wiring it for true bypass, not getting signal in bypass is a problem. That should be debugged first, since the pedal is highly unlikely to work if it can't pass signal in bypass.

Mike

[fatecasino]

Hi Mike!
thanks for your help!
Perhaps I didn't explain my situation really well (I just don't like writing long posts in fora)

• I built the pedal
  I put it on a piece of wood for testing
  It played perfectly
  I prepared the enclosure
  I put everything on  place

Then, trying to close the enclosure I squeezed it too much and probably some "naked" parts of the circuit touched each other creating  a circuit.As a result too much current passed through the 10 Ohm res. and burnt it.
Obviously it burnt some other parts too in the audio side of the circuit (the TAPFLO part seems to work fine ))
I changed some parts(10 Ohms, the 78L05, the 330 nF, the TL072 ) with no success. So I am asking which part to replace next (
The symptoms are:

-The led works perfectly and changes rate as I tap or move the pot knobs
-With polymeter I found out that the ground(-) of the audio out  makes a circuit with the (+) of the audio out. How is this possible?! When I touch the ground(-)  with my finger I don't get any sound from the amp.
-I get no sound whatsoever.

Should I change the photocoupler? Is it involved with the audio part of the circuit?
Thanks!

[.Mike]

Obviously it burnt some other parts too in the audio side of the circuit (the TAPFLO part seems to work fine ))

Maybe, maybe not.

Beyond the TL072, there isn't much to the audio path. We're talking 3 capacitors and 5-6 resistors. You could replace the whole thing and it probably wouldn't make a difference, since...

...if your pedal does not pass sound in bypass, it most likely has a wiring error that needs to be corrected.

-With polymeter I found out that the ground(-) of the audio out  makes a circuit with the (+) of the audio out. How is this possible?!

If the signal and ground of your audio out jack are connected, there most likely is a wiring error that needs to be corrected.


If this were my build, I would separate it out. Remove the tremolo circuit from the enclosure. Hook it up via a breadboard to make sure it works. If it doesn't work, debug it before moving to the next step, which would be...

Get the offboard stuff working without the tremolo circuit. Take you enclosure, put in the switch and two jacks. Plug your guitar in. Make sure you get signal passing through, and when you push the switch, the signal stops.

Then put the known working effect in the enclosure with the known working bypass.



Mike

[mpv]

Hi all,

I am planning to build TTT and I am wondering if I could use my own fixed preset(s) (set with trimmers) for tempo, depth and other controls?
I guess that this needs some relays (or analog switching ICs) which are controlled using a switch (probably a stomp switch).

Do you have any idea what will happen when the switch is activated and those preset settings are sent to circuit, are there possibilites that some settings are not sitting in?
And what about noises when switching control pads from one pot set to another?

MPV

[Taylor]

Seems like a fine idea to me.

Do you have any idea what will happen when the switch is activated and those preset settings are sent to circuit, are there possibilites that some settings are not sitting in?

I'm not sure what you mean by this - could you rephrase it?

And what about noises when switching control pads from one pot set to another?

MPV

I wouldn't expect any noise, since the pots are not directly connected to the audio, don't draw much current, and some minor discontinuity in the waveform should not be an issue. I have swept the multiplier while playing quite a bit - no issues there. But if your setup involves switching you will need to look closely at any chance of the pot inputs floating momentarily, and make sure you take that into account when designing your switching. Also, this is probably obvious, but if you have multiple presets active at once, the voltages will add and you'll get a different setting than if either one of them were active alone.

[mpv]

Seems like a fine idea to me.

Do you have any idea what will happen when the switch is activated and those preset settings are sent to circuit, are there possibilites that some settings are not sitting in?

I'm not sure what you mean by this - could you rephrase it?

I mean could there be a situation where some "new" settings will be ignored when switching from one pot set to another?