Building the tap tempo tremolo

[jonny]

update, I've fixed bypassed ticking(with taylors alternate bypass switching) but the ticking is still there when turned on, I've upped the cap to about 2.5n but no help. (I also put a 470n over there too which removed most of the ticking but ruined the tone)

[Taylor]

Optocouplers vary from one to the next. Some of them have too fast a turn-on time, so you get ticking. That's why I recommend getting a couple in the PDF. So one solution would just be to get another NSL-32.

Also, there's a huge gap between 2.5n and 470n.  You could up that cap to 15n and probably fix it, without losing remotely the amount of high end you lose with a 470n.

[jonny]

Even with 470n there was still quite a bit of ticking, but yeah I think I'll try a few more photocouplers, would the VTL5C3 be any better? I'll also try another NSL-32...

[jmasciswannabe]

Just wanted to say thanks for the fun project and hard work in putting something together for everyone to have fun with. I am still struggling with click, even after using a .0022, but only in the extreme settings at high volume. May try a VTL5C3 or order another NSL32 and see what happens. regardless, very versatile and good great sounding trem. Here are a couple pics of my build.

[Taylor]

If you're not using the visible LED (it's on the inside), I'd take it out of the board. That might make your tick disappear. Right now you just have it pulling current (which is the source of the tick) but not doing anything useful, unless you have a glowing floor setup happening. 

[Taylor]

Even with 470n there was still quite a bit of ticking, but yeah I think I'll try a few more photocouplers, would the VTL5C3 be any better? I'll also try another NSL-32...

You should try another NSL-32, but have you properly set the trimpots up? If you have ticking with a 470n cap I'm guessing it's the trims that need adjusting.

[jonny]

I've mucked around with the trim pots for an hour or so, basically there are places where the ticking stops but then there's no output. The best position of trims still brings up quite a bit of ticking (square wave mostly). I removed the led and that only very slightly reduced the ticking noise. I don't get what causes the ticking, how does it leak into the audio path? I'll have to wait a few weeks to see of I can change optos

[jcwillow777]

Not sure which link to put this in. I got my boards yesterday and started soldering the parts in that I had on hand. Everything has shipped so I should be well on my way this weekend.

I have a Fulltone Supa-Trem. I really like it but wanted to build yours for the tap tempo feature. I like the Supa-Trem because there is a blinking LED to show me the tempo at all times, even when it isn't on. Is it possible to add one to yours? If so, how and will it cause ticking?

Thanks Taylor. I am really impressed with these board, very professionally done!

I'm looking forward to getting the delay done also!

[azrael]

^Yes, the onboard LED displays the waveforms. Don't wire it to the switch, and just leave it hardwired to board, and you've got your tempo LED.
Wire a different LED to the bypass switch to know when it's on.

This is what I did.

[jcwillow777]

Thankyou!! I can't wait to finsh this baby!

[jcwillow777]

Here you go. I'll also add this to the PDF. Note that my way is a little different from joinpobob's suggestion. His leaves the PWM output of the TAPLFO floating when the circuit is bypassed, and while this seems to work for him, it's suppose to be bad practice to do this. In my diagram, I ground the PWM output in bypass through a 10k resistor instead of just disconnecting it.

I have a question about this. I want to add an LED to the 3PDT so I know when it is on or off. Joinpobob's diagram shows how to put in the LED but not tapping into the 10K resistor on the board. Where would I attach the LED to the 3PDT in this diagram so I could know when the pedal is on or off?

[Taylor]

If you want to do what azrael suggests, then ignore that diagram and just solder the LED straight to the NEG and POS pads, and then do a normal bypass wiring like you would do with any other effect, like so:

http://generalguitargadgets.com/diagrams/switch_lo_3pdt_tb_dcjack.gif?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

However, personally, I would (and do) wire it the way my diagram shows, and I find this preferable to having a separate flashing LED and bypass LED. But that's my preference.

[azrael]

I was looking to make the pedal be able to bypass, but still show me a tapped pattern. It was useful for tapping out a pattern whole it was bypassed. I did not have any problem with ticking. Jw, how would bypass like this increase chances of ticking?


Taylor, have you seen the Catalinbread Stereo Semaphore? It's a new tap tempo tremolo that has many of the same features of this circuit.

[Taylor]

Hadn't seen it, but I knew it was on the way. It's using the same chip.

[azrael]

Ah, okay. Still, nice to be ahead of the curve, Eh? Hehe.

Any ideas
On my other question?

Also, never could get that multiplier step up switch to work...

[Taylor]

It might be ambiguous from my last reply, but I have no connection to those guys.

There's nothing wrong with the way you've done it; if you want to see the speed even in bypass, that's the only way to do it. I prefer a single LED, but as I said it's just a preference. It won't create a problem with ticking.

[jcwillow777]

I have my parts, but I couldn't find a 50K resistor. The closest I could find was 51K - will this be okay? The delay calls for 50K resistor(s) too.

I tried azrael's diagram for wiring it up. I got normal volume in bypass, but the bypass LED didn't light up. The tempo LED did. I have since figured out that the LED was bad. When I kicked the pedal on I got a major drop in volume. I messed with the trim pots but it didn't help. SO, I rewired it like Taylor suggested. Now all I get is loud buzzing.

I did run wires for the switch for the mulitiplyer, but I didn't order enough switches so the wires aren't hooked up to anything. Could that be the problem?

I have since ordered some more from SB. Kudos to SB - their turnaround time is much faster than it used to be! I will hopefully have them Sat.

azrael  I have no idea about the ticking. I was just asking because some others have said they had problems.

Off to Radio Shack, I also forgot to order all the resistors for the delay. I thought I had some on hand.

[Taylor]

I have my parts, but I couldn't find a 50K resistor. The closest I could find was 51K - will this be okay? The delay calls for 50K resistor(s) too.

Yes, 51k is fine. Most people use 5% tolerance resistors, which means that a 50k resistor might actually measure 48k or 52k. In general, you can substitute parts like this within the tolerance of normal parts.

I tried azrael's diagram for wiring it up. I got normal volume in bypass, but the bypass LED didn't light up. The tempo LED did. I have since figured out that the LED was bad. When I kicked the pedal on I got a major drop in volume. I messed with the trim pots but it didn't help. SO, I rewired it like Taylor suggested. Now all I get is loud buzzing.

I did run wires for the switch for the mulitiplyer, but I didn't order enough switches so the wires aren't hooked up to anything. Could that be the problem?

As long as the wires are not touching or shorting against anything, they won't make a difference. If you have loud buzzing, you probably have a bad wire joint within the audio path. Use an audio probe (check the debugging links at the top of this page) to go through your audio path and see where your signal dies.

[Poste]

Hi guys, I am new to this forum so play nice.

I have read this from start to finish and have a few questions.

1) Does the TAPFLO chip come with the board?
How do you wire up a 9V battery and also a power source in the same circuit so only one is in use at a time, Can a LED be incorporated to show what power supply is being used.
2) How do I wire up the Gain knob, just replace the trimpot, there isnt any additional resistors or other parts?
3) If I do not want the tap through multiplier, do I just leave the EXT tabs alone, no bridging needed?
4) How do you guys ground the enclosure?
5) I have ordered some metallic caps in place of the film caps, they are the same ratings, will this be fine?
6) How do I wire up a SPDT momentary switch to be a SPST, I would think you bridge the two tabs on one side to make "one"?

I want to get everything sorted before the parts arrive, hopefully in a week so I can start building this pedal, which is going to be my first, yes I have already been told that its not a beginner pedal but I have done some electronics before and have read heaps over the last week.

Thanks in advance,
Phil

[Taylor]

Welcome to the forum Phil. 

1) Does the TAPFLO chip come with the board?

Yes

How do you wire up a 9V battery and also a power source in the same circuit so only one is in use at a time, Can a LED be incorporated to show what power supply is being used.

http://generalguitargadgets.com/diagrams/switch_lo_dcjack.gif?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

2) How do I wire up the Gain knob, just replace the trimpot, there isnt any additional resistors or other parts?

That's right. Electronically the trimpot acts exactly the same as a regular pot.

3) If I do not want the tap through multiplier, do I just leave the EXT tabs alone, no bridging needed?

Correct, leave them alone.

4) How do you guys ground the enclosure?

If you use metal jacks, connected to all the other grounds, they ground the box.

5) I have ordered some metallic caps in place of the film caps, they are the same ratings, will this be fine?

Should be fine, some musicians get very mystical about cap types, personally I don't much care. Make sure they are non-polar.

6) How do I wire up a SPDT momentary switch to be a SPST, I would think you bridge the two tabs on one side to make "one"?

Just leave one of the throws unconnected. Make sure you connect the pole and one throw, not 2 throws.