YAEWSBM - Yet Another Etherwave Standard Bass Mod

Dewster I tried as you told me, initially by inserting a 15pf capacitor and then going up to 33 up to 100pf all obviously eliminated the bass producing the classic roar near zero bit the unusual thing was that with the increase of the farads the volume increased.  However I noticed that for me it is better to play the theremin as it was before for various reasons (less compressed notes the 5 octaves all ahead of me and the sound a little less muffled) I was probably used to the rougher tone than the modification.
Anyway congratulations for your module has incredible bass!

One thing I would like to do and I don't know if anyone else has succeeded which is to eliminate if at all the roar or chainsaw in the bass and make the sound smoother.

"However I noticed that for me it is better to play the theremin as it was before for various reasons (less compressed notes the 5 octaves all ahead of me and the sound a little less muffled) I was probably used to the rougher tone than the modification." -Gianluca

I don't understand why you are experiencing compression of the notes or octaves with the new modification if you are calibrating pitch correctly. Neither the ESPE01 or Dewster's modifications should compress anything.  They do however extend the octave range of the theremin, but because of this you cannot set the zero-beat the same way as you did before the modification, simply because you cannot fit more octaves into the same physical space (your arm's length).  If you are still tuning to zero-beat with your pitch arm pulled back, then of course you will experience note compression because you are trying to fit the original octave range plus the extra bass octaves into the same physical space.

Try setting the pitch to a low note, not zero, when your arm is pulled back.  If you still find the bass notes compressed, then aim for a higher "zero-beat" note.  If the bass notes are too stretched out then tune your Pitch knob for a lower note.  But never try to calibrate to zero-beat.  You can't do that with either of these modifications. 

Your last post above suggests that you do want smoother sound, but your previous post before that indicates that you had gotten used to the rougher tone and wanted something less muffled.  You are probably on the right track with Dewster's suggestion for finding some compromise between the harsh and muffled tone by using the capacitor if you can find one that gives a good compromise.  I don't necessarily like excessively smooth bass either because it makes it harder to sense pitch. But I think if you keep the modification in place, learn how to tune your theremin correctly so that you don't see compression of the note spacings, and play with the coupling capacitor value to put some harmonics back into the bass you will end up being happier for it.

pitts8rh I know exactly that with the module you get two octaves more and for this the field will have to extend beyond the physical body to have the right spacing even if for now I prefer to have the playing field only ahead of me and not move inside  of it, and as I have already said above there are no improvements by inserting capacitors in order to find a right compromise that may be good for me but I'm experimenting with good results in inserting resistors, I'll make other attempts and then let's see.  Thank you

Finally after many attempts I found the best solution for me, inserting a 20k resistor (actually two 10k in series) the sound is now slightly rougher in the bass and in the whole range I now perceive the notes better at least in my configuration  , an interesting thing while testing the various resistance values is that using a value of 100k achieves deeper bass.  Regards

"Finally after many attempts I found the best solution for me, inserting a 20k resistor (actually two 10k in series) the sound is now slightly rougher in the bass and in the whole range I now perceive the notes better at least in my configuration  , an interesting thing while testing the various resistance values is that using a value of 100k achieves deeper bass." - Gianluca

That's good information, and thank you for doing the testing and reporting the results.  I'd actually like to try adding the resistor mod on my Etherwave too.  I hope this all works out for you!

Yes thank you now I will simply devote myself to the magical sound of the theremin.

Interesting!  Thank you Gianluca!

I wonder if you also tried oldtemecula's suggestion of adding a 47pf or 100pf capacitor across the mixing diode?

Interesting!  Thank you Gianluca!

I wonder if you also tried oldtemecula's suggestion of adding a 47pf or 100pf capacitor across the mixing diode? Dewster 

No I have not tried I'm sorry maybe I'll try later.

I built and installed the yaewsbm, 2.0 in my EW Standard and am very pleased with it. I installed pins on the EW header and a female header on my mod.  I only had to tweak the antenna osc. coil a bit and there were no strange sounds or instability at zero beat!  I will compare the sound to Grillo's from his post after he did a similar mod. I tried to insert images of my mod, but couldn't figure out how to insert an image from my computer.  When I copied the filename and pasted, the image was way too big.