Tri-vibe with digital LFO

[Mr_Destruct]

Hey, I'm currently doing a version of the tri-vibe, but I'd like to use a digital LFO, specifically the Electric Druid Tap Tempo LFO using a TS924 (bipolar with +-9V). Currently I'm only using the bessel filters in the circuit suggested in the datasheet (page 5). When the depth is turned all the way down, the output is resting at 2.44V, which needs to be corrected vis á vis the LM13600 LFO input.

Electric druid Tap LFO datasheet: http://electricdruid.net/datasheets/TAPLFO2Datasheet.pdf

ROG tri-vibe: http://www.runoffgroove.com/tri-vibe.html

While it is working, I'm getting a pretty hefty click (in particular square and random) and the depth is quite lacking. I'm sure is down to the difference in offset between the TS924 chip and what the LM13600 expects. To make the LFO play nice with the tri-vibe, I'm assuming it needs to be centered at 4.5V. Is there an easy way to alter the offset and boost the output to make it work with the LM13600?

Also, if needed, how can I filter the edges off the square and random waveforms?

Any help would be much appreciated

[Galego]

From the experiments i made, even filtering still lets some noise through from the PWM. That's why it's much easier to just use Vactrols/led-ldr.

Why not look into led/ldr based vibes? Those would be much easier to implement, just like the tap tempo tremolo.

[Mr_Destruct]

Aah, ok. Cheers for answering! I've looked into LDR-based vibes (Easyvibe, Neovibe etc), but the one's I've found sound too "thick and phasey". I'd like to get something akin to the tri-vibe in "vibe" position, which has more of a pure quality to the pitchshifting (to my ears anyways )... Are there any other vibes you know of that can do this?

I guess there's no way of driving an LDR with the TapLFO into the Tri-vibe either?

[thedefog]

I got a 555 timer to shape an LED lighting and dimming by running the output to a pot controlling the feed to a 100uf cap to ground. The trick with that though is that as it gets faster, the cap may not be able to discharge fast enough to keep it from turning into total crap... Dunno if that helps you but it wouldn't hurt to throw a few different value electrolytic caps to ground from the output of those waveforms mentioned and see what happens.

[Mr_Destruct]

Thanks thedefog, I've already tried different caps to ground etc But because the offset is wrong I have to correct this first. Preferably using a digital buffer/inverter with hardcore filtering and have a pot to alter the offset manually. I'm looking for a way to convert the PWM signal of the Tap LFO to 9v p-p, then attenuate the signal down to 5V again to work with the Tri-vibe LM13600 LFO inputs. I've checked out R.G. Keen's ASMOP3, however I'm unsure wether I can use this while still being able to change the offset +-...

http://www.geofex.com/Article_Folders/ASMOP/asmopphase.gif

[thedefog]

Gotcha. Wish I knew more about how to approach this, my knowledge of digital stuff is pretty limited to some simple Arduino stuff. It seems like there should be an easier way to do this though than ramping up from 5v to 9v, then back down to 5v again for the LM13600.