Hetrick "Flip-Flop"

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SleepIsWrong
Posts: 9
Joined: Tue Jun 02, 2020 4:19 am

Hetrick "Flip-Flop"

Post by SleepIsWrong » Sun Jul 12, 2020 1:13 am

I'm having trouble getting the Hetrick "Flip-Flop" module to work. I run a cable from the trigger jack on the main panel to the "T In" port on Flip-Flop. I then wire the "FFT" port to the "start" port on the 8-step sequencer. I wire the "!FFT" port to the "stop" port of the 8-step sequencer. When I press a key on my keyboard the sequencer starts as expected. The next key press stops it. The next key press the sequencer may start but more often than not it begins rapidly oscillating between on and off. If I hook the "FFT" and "!FFT" outputs of the Flip-Flop to the Macauley voltage meter I get similar behavior. A new instance of the Flip-Flop will show +5v at the "FFT" port and 0v at the "!FFT" port upon first keyboard press - press a key and the "FFT" port shows 0v and "!FFT" shows +5v. After that the voltages seem to come on and off seemingly randomly. The LEDs on the Flip-Flop do show the correct state (correct meaning they consistently alternate being on/off).

I've also tested the FFD and !FFD outputs. Feeding the "D In" a +5v signal then triggering, sends +5v out of the FFD ouput. Changing the input at "D In" to -5v the status light correctly goes to the "!FFD" port but the voltage remains at the "FFD" port and flickers on the "!FFD" port.

Maybe I'm misunderstanding how it is supposed to work?

Thanks in advance for any help!

Mike

tgrey
Posts: 9
Joined: Sat Apr 03, 2021 8:39 pm

Re: Hetrick "Flip-Flop"

Post by tgrey » Thu Apr 29, 2021 10:26 pm

I see the same behavior, and it definitely doesn't seem right to me either... tho I'm pretty new to all of this, so maybe someone more experienced knows a reason this is happening?

If I use Andrew Macaulay's "Trigger Sync and Gate Toggle" module, I can get it to work as expected. Since that module only offers a positive output, I also had to add Cherry's "Boolean Logic" model to get the inverse to send to the stop trigger input.

Similarly, just to troubleshoot that the problem doesn't only stem from the "!FFT" output, I tried only using the "FFT" out of Hetrick's module, and using the boolean to flip it for the opposite state as well, but that didn't work either.

Honestly... I've noticed a few similar problems with others of Hetrick's modules, and since this has gone unaddressed for almost a year already, I'm more than a little concerned.

Steve W
Posts: 104
Joined: Thu Jul 16, 2020 5:55 pm

Re: Hetrick "Flip-Flop"

Post by Steve W » Thu Apr 29, 2021 11:35 pm

After noting the same issue using the 8-step sequencer, I used Adroit's CV Watcher which has 5 CV lines to monitor the FFT and !FFT outputs. At first I looked at the trigger coming from VM's panel and just one Hetrick Flip-Flop. Clearly the outputs of the module don't respond to those triggers 100% of the time. Then I connected a second Flip-Flop. For the most part both instances missed responding to the triggers at the same time.

On the Flip-Flop modules, the leds do change according to incoming signals.

The top line is the trigger. The next line is the FFT out of Flip-Flop 1, then the !FFT out, followed by the FFT and !FFT outputs of Flip-Flop 2. Consistently both instances responded (or failed to respond) at the same time. Consistently, the leds indicated that the triggers were received.
Attachments
Flip-Flop Test.png
Flip-Flop Test.png (131.89 KiB) Viewed 142 times

tgrey
Posts: 9
Joined: Sat Apr 03, 2021 8:39 pm

Re: Hetrick "Flip-Flop"

Post by tgrey » Fri Apr 30, 2021 1:51 am

Not only does it not seem to respond to all triggers/gates coming in... but I am also seeing voltage jumps coming out of the Hetrick gate pretty regularly, and I don't see them from the Macauley toggle. Oscilloscopes don't seem fast enough to catch it either, but if you patch it into either Macauley's "Dual Volt Meter" or Monkey Business Audio's "Volt Meter" and you can see sometimes it seems to be jumping between 0 and 5 volts when it should be stable.

I wonder if this is why gating the sequencers seems troublesome, they keep getting re-triggered by the spikes perhaps?

Steve W
Posts: 104
Joined: Thu Jul 16, 2020 5:55 pm

Re: Hetrick "Flip-Flop"

Post by Steve W » Fri Apr 30, 2021 2:29 am

Your observation about instability goes along with what I saw in the CV Watcher when I used a time base of 5 msec. Basically the FFT and !FFT lines show up as almost solid. At first I wasn't sure what to make of that, but after magnifying the almost solid line, I'd say the CV Watcher is showing constant flux.

I have a few screen shots that might help explain what we see with 8-step sequencer start/stop/self-oscillating-run-amok issue.

Flip-Flop Test-002-Composite.png
Flip-Flop Run Amok
Flip-Flop Test-002-Composite.png (217.76 KiB) Viewed 134 times

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