Building the tap tempo tremolo

[Poste]

Taylor thanks for the fast and great reply.

I have more question now,

1)Does your circuit include short circuit protection, if not how could I do this easily/is it really required?

2) How would I wire an LED into that power curcuit to show whether batt or external power is being used?

Thanks
Phil

[Poste]

Sorry for the double post,

This is the film cap I swapped out for a electolytic cap
http://www.taydaelectronics.com/servlet/the-1798/1uF-100V-85C-Radial/Detail

I cant find whether it is polar or not, could someone please tell me.

Thanks
Phil

[Taylor]

It is polar, you can tell because of the stripe which indicates negative. You can still use it, just insert them so the negative points towards the bottom of the board in both cases (the bottom being the edge which reads "tap tempo tremolo".

Yes, the 4001 diode offers protection from a wrong power supply.

Don't know a simple way to do the LED indication for battery/external, maybe somebody else has an idea?

[Taylor]

I am getting ready to build your tremolo project and am trying to figure out which rotary switches to order for the wave form and multiplier knobs. How many poles do I need?

You only need one pole. The pole connects to where the wiper of the pot would normally go for each respective control. You need as many throws as the number of waveforms/multipliers you want. If you want them all, you need 6 throws for the multiplier and 8 for the waveform. This one will work for either, just set the position limiting washer to the proper spot:

http://www.smallbearelec.com/Detail.bok?no=477

How many poles do I need?

I am a respectful person, which is why I managed to avoid a lightbulb joke here.

[bigstomper]

So....the pole on the rotary goes to the wiper position on the board of where the pot was.  Where do the other two holes run to? The end resistors on the rotary?

[Taylor]

They would go to the outer lugs. 5v is the leftmost pad for each pot, ground is the rightmost pad.

[bigstomper]

And just to be clear....the rotary switches are non-shorting?

[Taylor]

Hmm... I don't think it really matters. Shorting means that the pole will connect to both throw 1 and throw 2 while it's in between positions 1 and 2. Since this is a digital input, I don't think you'll hear any discontinuity if you use a non-shorting jack. There is a lowpass filter on each pot which should smooth glitches anyway...

Yeah, I don't think it really matters.

[jonny]

Just got an order with a VTL5C3 and put that in, but still seem to have ticking problems. I got 2 extra NSL-32s but am yet to try them. The VTL5C3 did a little better than my first NSL-32 though. I could almost completely removed ticking but with those settings on the trims there was a massive volume drop(gain trim set to max of course). I have a 50 watt tube amp, and I would have to put volume on 12(max) to match the bypassed volume on 2.

Anyway I'll try the other NSL-32's but I'm really not sure why it's not working for me! 

[Taylor]

What's your wiring look like? I've noticed a lot of people don't use the board-mounted pots, and have long spaghetti wiring - this is likely the cause of ticking problems in those cases. The PCB has 3 separate ground planes to keep ground currents from yanking on the audio, so with every one I've built, using board mounted pots and keeping wire runs short has made ticking not an issue.

Don't know if this applies in your situation, just something I thought worthy of note.

[jonny]

Yeah definitely a possibility, I have quite long wires  just for the pots etc. I'll also be getting a scope soon so can have a look with that soon. Still gonna try the nsl-32s..

[neldom]

I have a quick question that I have not seen yet. Though there are many place to look so I may have just missed it.
Is it possible to add a momentary footswitch for nonlatching action just when you have your foot down? Would just a second 3PDT in parallel work for this?
Thanks.

[Taylor]

You mean a momentary bypass switch that only turns on the trem when you press down?

A second 3pdt in parallel would not work, because although it would "connect the unconnected" when pressed down, it would not disconnect the connected poles. from the main 3PDT.

You could go wild and replace the switching with a logic-driven relay. It's very easy to make a logic bypass circuit that's switchable with a toggle between momentary and latching. But that whole affair would be complex.

The simplest way would be to add a toggle that routes the... uh, I'll just draw it. hang on. 

[Taylor]

I think this'll do what you want:

http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44108&g2_serialNumber=1

Now, the momentary switch in this case is not true bypass. You need to have the trem on, then switch your toggle to momentary mode. Now you will not hear any trem; the input is routed to the output and the PCB. Stepping on the switch disconnects the clean signal from the output and connects the trem signal.

[neldom]

So then my next question in the chain would be... could i use a dpdt switch to combine the switching of the toggle and spdt?
By the way thanks for the incredible work here...

[Taylor]

No, not really. Here's why. When you turn the pedal on, you'll hear tremolo. You need the toggle to put the pedal in momentary mode, and bypass the tremolo until the momentary switch is activated. If you combined the toggle with the momentary, you would have tremolo on all the time when the effect is switched on, regardless of the position of the momentary.

[Moonibopper]

Just built the pedal... everything works great, but I'm having issues with the tap tempo just like user spargo (posted a while back.) Anyone have the same issues? Anything I could do to remedy it?

Sweet, adjusted the pots and set the wave distort knob to middle and it works great now! Except the tap switch seems to be pretty spasmatic?  Like I'll tap it to a tempo and it just kind of randomly seems to pick a tempo...

[JKowalski]

Just built the pedal... everything works great, but I'm having issues with the tap tempo just like user spargo (posted a while back.) Anyone have the same issues? Anything I could do to remedy it?

Sweet, adjusted the pots and set the wave distort knob to middle and it works great now! Except the tap switch seems to be pretty spasmatic?  Like I'll tap it to a tempo and it just kind of randomly seems to pick a tempo...

Could be that your tap switch has pretty bad bounce, perhaps put a decoupling capacitor (10nf?) across the leads of the switch.

[Taylor]

Also, note that the chip listens to pairs of taps. Some people are used to tap tempo where it averages all the recent taps. This one doesn't do that. If you tap three times, then tap twice, the period between your third and fourth taps will be the current tempo, but that's probably not what you were expecting.

I had the same problems when I built the first prototype, and thought something was wrong, but realized I was just tapping wrong.

[Moonibopper]

Thanks for the help. If I were to tap in two different tempos (the 1st with two taps, then the 2nd with two taps - total of 4 taps), how much time needs to pass between the 2nd and 3rd tap so that the pedal doesn't think it's a continuous 4 taps?

Also, note that the chip listens to pairs of taps. Some people are used to tap tempo where it averages all the recent taps. This one doesn't do that. If you tap three times, then tap twice, the period between your third and fourth taps will be the current tempo, but that's probably not what you were expecting.

I had the same problems when I built the first prototype, and thought something was wrong, but realized I was just tapping wrong.