Expressing a tremolo...

[H4T]

I'm curious, if I built something like the EA Tremolo, could I wire up one of the pots to an expression rocker in such a way that I could be playing a solo, then when I need to, I can lean forward on the rocker and get a subtle vibrato effect, without a volume boost? I was thinking I could wire up the "Speed" pot, so its normally not affecting the tone (ie, at 0 position) and when I rock the rocker, the speed increasing, and you can hear the vibrato.

Perhaps I'm too lazy to just learn to vibrato my own damn self, but I thought it would be cool if I could use an expression pedal to cleanly pull of vibratos for me with a tremolo. Would that work as I would hope?

[Somicide]

uhh... tremelo is volume oriented, if i'm correct.  if not, someone can correct me.  vinbrato is pitch change, like bending.  they're unrelated AFAIK.

PnL,

Jeff

[Pushtone]

See the GeoFex page and article "Add an Expression Pedal" under FX Projects - FX Mods

http://www.geofex.com/

Here's a direct link to the article.
http://www.geofex.com/Article_Folders/xprnped.htm


Sounds easy enough.

And check out this $15.00 volume pedal. Yeah it,s plastic... but at that price consider it a wah shell ready to gut.
http://img3.musiciansfriend.com/dbase/pics/products/tn/15/150050.t.jpg
http://www.musiciansfriend.com/srs7/g=guitar/s=effects/search/detail/base_pid/150050/

[Mark Hammer]

Classic analog synths and I suppose even their more modern digital counterparts normally have a control wheel off to the left side of the keyboard.  The control wheel can be used for a bunch of things, but often it is used to control the amount of modulation provided to something by an LFO.  That something could be an oscillator for "warble", a filter, and so on, but it is often a VCA.  The VCA provides volume variations depending on the characteristics of the control voltage it gets.  The LFO is essentially always "on" but the control wheel sets how much of that constant LFO waveform output is fed to the VCA.

This is analogous to adjusting the depth control on the EA tremolo, which also, incidentally, attenuates the output of the EA tremolo's onboard LFO.  So, if you were able to build the EA tremolo into something like a wah shell, with a 1meg pot under foot control, you could do exactly what you describe.

Do note, however, that the *perceived* average volume of tremolo tends to be lower because of the silent periods.  What that means is that as you were to increase the amount of modulation applied to the FET so as to produce more obvious tremolo modulation, the perceived volume would change.  My sense is that in the case of the EA tremolo, the modulation actually *increases* the gain of the bipolar transistor so as to produce tremolo, which may be less of a problem than reducing the gain would be.  That being said, the circuit doesn't seem designed to easily allow a predictable volume level with increased modulation.  There IS a volume control, which helps; I just don't know how much.  Do-able, though.

[Paul Perry (Frostwave)]

The 'speed' pot might not be the way to go, because the oscillator is always on, and even if the speed was near zero, the LFO might be at a value corresponding to a trough in the output, so you will hear nothing.

Better would be a 'pannig' arrangement, where your control pans between the effect output, and the unprocessed signal.
Would it work to just have a pot, one end to the original signal, the other end to the output of the effect, and tap off from the wiper?

Worth a try. What can go wrong? (well, one thing, is if the phase reverses as the signal goes thru the unit... but you have a 50% chance!)

[R.G.]

I copped an idea from Thomas Organ for the modification I made to the EA tremolo. The tremolo is normally stopped, and when a note is hit, it releases the tremolo to run. Because the oscillator gain is low, many cycles of build up are needed for it to come to full depth. So notes start un-tremolo-ed and the trem builds up as you hold them.

Penfold had a tremolo that had speed set up to be proportional to loudness - loud note, fast trem, slowing down as the note fades out.

You can, in general, add either manual or auto expression to either speed or depth. The trick is making it sound interesting as you play.

[Eric H]

The trick is making it sound interesting as you play.

There's always a catch.

-Eric

[Mark Hammer]

The Line 6 Tap Tremolo pedal in their Tonecore series has envelope controlled LFO speed.  Smack a chord and the LFO rate instantly gets faster, slowing down as the note/chord dies out.

[Eric H]

The Line 6 Tap Tremolo pedal in their Tonecore series has envelope controlled LFO speed.  Smack a chord and the LFO rate instantly gets faster, slowing down as the note/chord dies out.

My Roland/Boss  Phase-5 does the same thing. It's one of those features that sounds better on paper --at least for me
The dynamic range is very narrow, and follows the envelope changes too slowly. For me, the effect ends up being too random for standard music, and not random enough for the free-improv stuff that's been my primary focus the last 25 years.

IMHO
-Eric

[slotbot]

ive been tinkering with putting different shaped waves into a 566 VCO. ad the output of the VCO controlling the tremolo. it sounds pretty fun. but i dont i havent boxed one up yet.....