PTAP: PT2399 tap tempo control

[earthtonesaudio]

You can divide the 2399's clock by some ridiculous number like 625,018 to drive a LED in-time with the tempo, but it requires a couple/few ICs and a lot of diodes.  If there's a tempo output from the PTAP, that would be way better... dunno if there is though.

[mjcyates]

I finally had the opportunity to get this wired up. It works like a champ. My end goal is to have two rebotes in one box. One left on all of the time for ambience and the other wired with the PTAP to be used for rhythmic stuff.

[Philbot5000]

I'm a little embarrassed to ask this, because I'm sure the answer is obvious to someone a little more experienced, but I'm putting together a parts list for the PTAP and I'm a little confused.

The diagram above seems really straight forward,  I get it.  However when I look at the schematics (http://thoughtprocessinc.com/files/PTAP%20Schematic%20A2.png), I see a capacitor (C3 = 0.1uF) that doesn't appear in the layout above.  Ugh, anyone care to help out the not as experienced?

Here's my parts list:

R1 = Existing Delay Pot
R2 = 10K
D1 = 1N4752A
U1 = ATtiny45 (from decc)
U2 = 78L05
U3 = MCP41050 (from decc)
C1 = 0.1uF
C2 = 0.33uF
C3 = ?? (schematic lists 0.1uF)

[Auke Haarsma]

In the layout posted you have C1 doing the work of C1 and C3 in the schematic. I don't think you need to add C3 to the layout. It is fine as it is.

[liveloveshare]

What's the best option:  the rate led attached to the delay circuit or the ptap? Anyone done this?

I'm actually kind of interested in this--is there any reasonable way to do this?

[earthtonesaudio]

What's the best option:  the rate led attached to the delay circuit or the ptap? Anyone done this?

I'm actually kind of interested in this--is there any reasonable way to do this?

http://www.aronnelson.com/gallery/main.php/v/cathexis/Veroboard+Layouts/Magnus+Modulus/PT2399+Tempo+Indicator.jpg.html
http://www.diystompboxes.com/smfforum/index.php?topic=50185.0

[ppatchmods]

i bought the ptap2 for my rebote and used it for the rate led. you have to do some simple modification but it works nicely. i couldn't get it to work with water clear led's though, just standard red, green, yellow.

[mjcyates]

Finally finished this project. Two rebote delays in one box. I leave one on all the time with the level at about 10 oclock. I have the second one hooked up with the PTAP  and level at 100%. Works great! Thanks for the PTAP DECC!

[aziltz]

killer bang up job!  I'm gonna have to go bang one out now...

[aziltz]

killer bang up job!  I'm gonna have to go bang one out now...

Actually I have a couple questions.  After reading through the PTAP manual, I'm curious if, it is possible to separate the functions of the Delay Pot, as in, have a Pot for Manual Delay Time and a Pot for the Subdivisions Selection?  I think it would double the functionality of PTAP/2399 Delay if you don't have to change any settings when switching back and forth.

[decc]

Actually I have a couple questions.  After reading through the PTAP manual, I'm curious if, it is possible to separate the functions of the Delay Pot, as in, have a Pot for Manual Delay Time and a Pot for the Subdivisions Selection?  I think it would double the functionality of PTAP/2399 Delay if you don't have to change any settings when switching back and forth.

You can use a standard SPDT toggle to select between two different delay pots, though you will have to manually flip the switch since there aren't any available pins to do this with the microcontroller.

Maybe you might be able to jury rig something with a FET switch and the tempo LED output of the PTAP2? A low level (LED on) on that pin selects the "tap" pot, more than a couple seconds of a continuous high level (LED off) switches back to the "manual" pot?

And I'm glad to hear about the success people are having with their PTAPs!

[aziltz]

Thanks for the quick reply decc,

I'm definitely gonna add this to the to-do list.

[aziltz]

has anyone built this up yet?  I'd love to hear a build report and/or demo!

[mth5044]

Has there been any success with the magnus modulus? I see that it has a 1k and a 4.7k after the time pot.

[bside2234]

i bought the ptap2 for my rebote and used it for the rate led. you have to do some simple modification but it works nicely. i couldn't get it to work with water clear led's though, just standard red, green, yellow.

What kind of modification? I really want to do this to my Magnus and I really want a tempo LED.

[ppatchmods]

i used the ptap2 and the ptap2 pcb. you have to add all the parts as listed but leave off the extra led+resistor, 2nd switch, & 2nd pot. i used the pad led2 on the board. works great

[bside2234]

Thanks! I thought it was going to be more than that!

[bside2234]

I did the PTAP2 on the Magnus. It works ok but I'm not getting a manual mode. The tap mode works fine. There is not any delay effect when I put it in manual though which is kind of cool as it works as a delay bypass. Just wondering what I did wrong in case I want to fix it.
I left off the series/parallel switch, the series/parallel led, and the second Time pot.

[bside2234]

Actually in manual mode there is a little effect. You can really only hear it when I turn the Time pot and the Feedback pot all the way up.
I wonder if I just have a bad pot but it seems to work fine in Tap mode. I'll just change it out anyway. Do you think I need to jumper the series/parallel connection at all? Maybe I'll try that after I change the pot out.

[decc]

You don't need to jumper the serial/parallel switch connection since there is an internal pull-up resistor in the MCU.

This is pretty strange behavior though. I recommend putting a pull-up on the unused pot #2 connection since the internal pull-up is disabled on this pin and floating inputs are to be avoided, though if this fixes things I would be surprised. First step I would take in tracking down the problem would be to disconnect the digital pot from the PT2399 and hook up a multimeter to measure resistance. Turn the delay pot and see that the digital pot tracks it.