PT-80 tap tempo, what am I missing here?

[Chico]

I read a couple of posts lately about the desire to add a tap tempo to the PT-80.

I have one and think it is a fine pedal, but the posts got me thinking.
The data sheet shows a control voltage input.  It has been said before (check previous posts) that one could simply use a PIC to measure tap time, convert to control voltage, voila
... I know, not that easy, but...
Isn't all this putting the cart before the horse?

The PT-80 has a max delay time of 342ms.

If you wanted to tap something conventional, like quarter notes and get quarter notes out, and If I did the math right, you need 250 ms delay at 240 bpm, 500ms delay at 120 bpm, 1 sec delay at 60 bpm.

It does not look like the PT-80 gives enough delay time to use with a tap tempo control that would operate in what I understand to be the conventional approach, that is, tap in quarter notes and get quarter notes out.

I know other rhythmic patterns are cool, e.g., dotted eighth, but I think a common application of tap tempo would be to set the delay to quarter notes.

You could tap in quarter notes and get the delay to snap to the closest 8th, 16th etc.   That would at least put the delay in synchronization, I guess.

Anyone else reach this same conclusion?

Tom

[R.G.]

Delays, in common with flangers, choruses and phasers, all use an LFO to change the amount of delay. The tap tempo feature is intended to change the rate of the LFO, not the amount of delay.

A phaser, for instance, may only have microseconds to milliseconds of delay. However, a phaser LFO sweeps the phaser from once in a few seconds to several times per second. Tap tempo sets the sweep rate, not the phase delay.

[Paul Perry (Frostwave)]

That's a very subtle point, RG! but, I still think that when 'tap tempo' is used in the context of echo, it means the length of the echo, or at least a simple multiple of it. I had a 'tap tempo' input to a MIDI interface, that allowed you to set playback tempo on the midi file, by tapping in the 1/4 note speed (useful for composing to movies).

[Chico]

Paul:

I think of tap tempo (at least in the delay sense) along the lines you describe.  Like on my Line6 and Lexicon units, I can tap in a quarter note, and voila, my delay repeats on the quarter note (or what ever other musical interval is programmed.)

I bring this up because I was thinking about tackling this project (adding a tap tempo to my PT-80), and when I started thinking about what I wanted out of a tap tempo feature versus what the PT-80 can deliver, I decided to leave the circuit as is.   The PT-80 has such a cool vibe, and holds its own without the tap control.

It seams to me that to really get a lot of milage out of tap tempo on a delay, you really need at least 800ms-1 second of delay minimum.

Just thought I would throw the subject out for discussion.

RG:  I do get your point about tap tempo on lfos for chorus, phaser, etc., but I thought on the PT-80, which uses the Princeton PT2399, the delay time was controlled by a VCO, not an LFO.  So to change the delay time, you need to change dc value of the control voltage at the VCO input.  As such, I envisioned tapping quater notes, which time duration is computed and used to derive an appropriate control voltage to change the delay time to correspond to the tempo.

Best regards

Tom

[ExpAnonColin]

You could always just line up a few and even underclock them, if you want. 2 @ 500ms wouldn't sound that bad.

-Colin