EA COMPLETED!!!

[Kaiowas]

Just finished the breadborading of the EA trem, and it sounds NATURAL!!!, very cool sound, but i've got a couple of question:

1) The EH Pulsar can switch from two types of waveform, by slecting from two single earthed caps. Can I do something similar with the EA (I mean, put a switch to select from two caps and get different waveforms)??

2) Generally speaking, how do i transform a sine wave into a square wave??

Thanks!

[ExpAnonColin]

Just finished the breadborading of the EA trem, and it sounds NATURAL!!!, very cool sound, but i've got a couple of question:

1) The EH Pulsar can switch from two types of waveform, by slecting from two single earthed caps. Can I do something similar with the EA (I mean, put a switch to select from two caps and get different waveforms)??

2) Generally speaking, how do i transform a sine wave into a square wave??

Thanks!

1) I'm not familiar with either schematic, however I find that normally putting a cap to ground just shaves off the waveform but is inconsistent with the frequency.

2) You can certainly do it by clipping it.  That's probably the most common way-there are a lot of various ways to do it.  I mean, you could probably try a fuzz face schematic, I think that clips it quite a bit, but there are quite a few schematics out there for square wave converters.  A Schmidt trigger would work well.

-Colin

[vdm]

i think by square wave you mean the output wave from the tremelo not the actual signal waveform. im afraid though that the way the pulsar creates the lfo is different to the EA. the switchable caps in the pulsar are actually smoothing caps, as the lfo in the pulsar is iself a square wave. the two different caps smooth the edges of the wave (more capacitance the smoother the wave), so unless there is a cap i can't see in the EA doing this to the waveform, it could be possible that the lfo in the EA is actually a sine wave oscillator.

if by any chance one of the caps in the EA does smooth the wave, it will be C4,5,6 or 7 (my guess would be C4) though i don't know what effect this will have on the sound, so you may want to wait for more replies, as lowering these values may cause the entire modulator to stop working... no harm in trying i guess, and i don't think you can fry anything in the circuit by lowering those values... i dont think  :wink:

anyway - goodluck on the rest of your build

trent

[Tim Escobedo]

IIRC, the EA has a phase shift oscillator producing pretty much a sine wave. I suspect it might be easier to just redesign the LFO as a two opamp oscillator giving simultaneous triangle/square waves.

[smoguzbenjamin]

You could use a switch and a 555 as an oscillator which if used correctly can produce a pretty fast almost square-wave output. But then you run into the trouble of pots, the depth and rate controls are likely to be different values.

My EA trem has a pretty choppy tremolo when the depth is at max, I used the schematic at runoffgroove though.

[Kaiowas]

Thanks for your replies, i found out (just like smoguzbenjamin said) that it had a pretty choppy sound with the depth pot at its max, so i won't complicate myself.  :wink:

And let me tell you, that pulsing LED mod is SWEEET!!!!   , what a helpfull mod, i'm so happy with it!!

Once again thank you guys!

[smoguzbenjamin]

It's a pretty cool circuit!

[Kaiowas]

I know it was supposed to be over, but, i've found a little problem, when the depth pot (1M Ohm) is earthed (Leg1 = to the 560K resistor, Leg2 = Gate of Q2, Leg3 = Earth) the sign seems to bypassed, but if you remove the earth of the Leg3 the effect works.

What could it be  :? ?

[smoguzbenjamin]

There should be a resistor between the depth pot lug 3 and ground/earth whatever you wanna call it. I used 560 ohms if I remember correctly...